[PATCH/RFC 3/3] drm: Split drm_modeset_helper_vtables.h
Thomas Zimmermann
tzimmermann at suse.de
Thu Sep 28 13:59:01 UTC 2023
Hi Geert
Am 28.09.23 um 14:16 schrieb Geert Uytterhoeven:
> <drm/drm_modeset_helper_vtables.h> is the second largest header file in
> the DRM subsystem, and declares helpers vtables for various DRM
> components. Several vtables contain methods with the same name, and all
> but one vtable do not fit on the screen, making it hard to navigate to
> the actual method one is interested in.
>
> Make it easier for the casual reviewer to keep track by splitting
> <drm/drm_modeset_helper_vtables.h> in multiple header files, one per DRM
> component.
I never liked this header either, but do we need new header files? Each
struct could be appended to the end of the regular header: struct
drm_plane_helper_funcs to drm_plane.h, drm_connector_helper_func to
drm_connector.h and so on.
Best regards
Thomas
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
> ---
> RFC, a future patch could replace inclusion of
> <drm/drm_modeset_helper_vtables.h> by inclusion of one or more of the
> new files, and reduce compilation time.
> ---
> include/drm/drm_connector_helper_vtable.h | 364 +++++
> include/drm/drm_crtc_helper_vtable.h | 483 ++++++
> include/drm/drm_encoder_helper_vtable.h | 381 +++++
> include/drm/drm_mode_config_helper_vtable.h | 97 ++
> include/drm/drm_modeset_helper_vtables.h | 1466 +------------------
> include/drm/drm_plane_helper_vtable.h | 297 ++++
> 6 files changed, 1627 insertions(+), 1461 deletions(-)
> create mode 100644 include/drm/drm_connector_helper_vtable.h
> create mode 100644 include/drm/drm_crtc_helper_vtable.h
> create mode 100644 include/drm/drm_encoder_helper_vtable.h
> create mode 100644 include/drm/drm_mode_config_helper_vtable.h
> create mode 100644 include/drm/drm_plane_helper_vtable.h
>
> diff --git a/include/drm/drm_connector_helper_vtable.h b/include/drm/drm_connector_helper_vtable.h
> new file mode 100644
> index 0000000000000000..92db9784e4e37e02
> --- /dev/null
> +++ b/include/drm/drm_connector_helper_vtable.h
> @@ -0,0 +1,364 @@
> +/*
> + * Copyright © 2006 Keith Packard
> + * Copyright © 2007-2008 Dave Airlie
> + * Copyright © 2007-2008 Intel Corporation
> + * Jesse Barnes <jesse.barnes at intel.com>
> + * Copyright © 2011-2013 Intel Corporation
> + * Copyright © 2015 Intel Corporation
> + * Daniel Vetter <daniel.vetter at ffwll.ch>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef __DRM_CONNECTOR_HELPER_VTABLE_H__
> +#define __DRM_CONNECTOR_HELPER_VTABLE_H__
> +
> +struct drm_writeback_connector;
> +struct drm_writeback_job;
> +
> +/**
> + * struct drm_connector_helper_funcs - helper operations for connectors
> + *
> + * These functions are used by the atomic and legacy modeset helpers and by the
> + * probe helpers.
> + */
> +struct drm_connector_helper_funcs {
> + /**
> + * @get_modes:
> + *
> + * This function should fill in all modes currently valid for the sink
> + * into the &drm_connector.probed_modes list. It should also update the
> + * EDID property by calling drm_connector_update_edid_property().
> + *
> + * The usual way to implement this is to cache the EDID retrieved in the
> + * probe callback somewhere in the driver-private connector structure.
> + * In this function drivers then parse the modes in the EDID and add
> + * them by calling drm_add_edid_modes(). But connectors that drive a
> + * fixed panel can also manually add specific modes using
> + * drm_mode_probed_add(). Drivers which manually add modes should also
> + * make sure that the &drm_connector.display_info,
> + * &drm_connector.width_mm and &drm_connector.height_mm fields are
> + * filled in.
> + *
> + * Note that the caller function will automatically add standard VESA
> + * DMT modes up to 1024x768 if the .get_modes() helper operation returns
> + * no mode and if the connector status is connector_status_connected or
> + * connector_status_unknown. There is no need to call
> + * drm_add_modes_noedid() manually in that case.
> + *
> + * Virtual drivers that just want some standard VESA mode with a given
> + * resolution can call drm_add_modes_noedid(), and mark the preferred
> + * one using drm_set_preferred_mode().
> + *
> + * This function is only called after the @detect hook has indicated
> + * that a sink is connected and when the EDID isn't overridden through
> + * sysfs or the kernel commandline.
> + *
> + * This callback is used by the probe helpers in e.g.
> + * drm_helper_probe_single_connector_modes().
> + *
> + * To avoid races with concurrent connector state updates, the helper
> + * libraries always call this with the &drm_mode_config.connection_mutex
> + * held. Because of this it's safe to inspect &drm_connector->state.
> + *
> + * RETURNS:
> + *
> + * The number of modes added by calling drm_mode_probed_add().
> + */
> + int (*get_modes)(struct drm_connector *connector);
> +
> + /**
> + * @detect_ctx:
> + *
> + * Check to see if anything is attached to the connector. The parameter
> + * force is set to false whilst polling, true when checking the
> + * connector due to a user request. force can be used by the driver to
> + * avoid expensive, destructive operations during automated probing.
> + *
> + * This callback is optional, if not implemented the connector will be
> + * considered as always being attached.
> + *
> + * This is the atomic version of &drm_connector_funcs.detect.
> + *
> + * To avoid races against concurrent connector state updates, the
> + * helper libraries always call this with ctx set to a valid context,
> + * and &drm_mode_config.connection_mutex will always be locked with
> + * the ctx parameter set to this ctx. This allows taking additional
> + * locks as required.
> + *
> + * RETURNS:
> + *
> + * &drm_connector_status indicating the connector's status,
> + * or the error code returned by drm_modeset_lock(), -EDEADLK.
> + */
> + int (*detect_ctx)(struct drm_connector *connector,
> + struct drm_modeset_acquire_ctx *ctx,
> + bool force);
> +
> + /**
> + * @mode_valid:
> + *
> + * Callback to validate a mode for a connector, irrespective of the
> + * specific display configuration.
> + *
> + * This callback is used by the probe helpers to filter the mode list
> + * (which is usually derived from the EDID data block from the sink).
> + * See e.g. drm_helper_probe_single_connector_modes().
> + *
> + * This function is optional.
> + *
> + * NOTE:
> + *
> + * This only filters the mode list supplied to userspace in the
> + * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid,
> + * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid,
> + * which are also called by the atomic helpers from
> + * drm_atomic_helper_check_modeset(). This allows userspace to force and
> + * ignore sink constraint (like the pixel clock limits in the screen's
> + * EDID), which is useful for e.g. testing, or working around a broken
> + * EDID. Any source hardware constraint (which always need to be
> + * enforced) therefore should be checked in one of the above callbacks,
> + * and not this one here.
> + *
> + * To avoid races with concurrent connector state updates, the helper
> + * libraries always call this with the &drm_mode_config.connection_mutex
> + * held. Because of this it's safe to inspect &drm_connector->state.
> + *
> + * RETURNS:
> + *
> + * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum
> + * drm_mode_status.
> + */
> + enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
> + struct drm_display_mode *mode);
> +
> + /**
> + * @mode_valid_ctx:
> + *
> + * Callback to validate a mode for a connector, irrespective of the
> + * specific display configuration.
> + *
> + * This callback is used by the probe helpers to filter the mode list
> + * (which is usually derived from the EDID data block from the sink).
> + * See e.g. drm_helper_probe_single_connector_modes().
> + *
> + * This function is optional, and is the atomic version of
> + * &drm_connector_helper_funcs.mode_valid.
> + *
> + * To allow for accessing the atomic state of modesetting objects, the
> + * helper libraries always call this with ctx set to a valid context,
> + * and &drm_mode_config.connection_mutex will always be locked with
> + * the ctx parameter set to @ctx. This allows for taking additional
> + * locks as required.
> + *
> + * Even though additional locks may be acquired, this callback is
> + * still expected not to take any constraints into account which would
> + * be influenced by the currently set display state - such constraints
> + * should be handled in the driver's atomic check. For example, if a
> + * connector shares display bandwidth with other connectors then it
> + * would be ok to validate the minimum bandwidth requirement of a mode
> + * against the maximum possible bandwidth of the connector. But it
> + * wouldn't be ok to take the current bandwidth usage of other
> + * connectors into account, as this would change depending on the
> + * display state.
> + *
> + * Returns:
> + * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote
> + * the &enum drm_mode_status value to @status, or a negative error
> + * code otherwise.
> + *
> + */
> + int (*mode_valid_ctx)(struct drm_connector *connector,
> + struct drm_display_mode *mode,
> + struct drm_modeset_acquire_ctx *ctx,
> + enum drm_mode_status *status);
> +
> + /**
> + * @best_encoder:
> + *
> + * This function should select the best encoder for the given connector.
> + *
> + * This function is used by both the atomic helpers (in the
> + * drm_atomic_helper_check_modeset() function) and in the legacy CRTC
> + * helpers.
> + *
> + * NOTE:
> + *
> + * In atomic drivers this function is called in the check phase of an
> + * atomic update. The driver is not allowed to change or inspect
> + * anything outside of arguments passed-in. Atomic drivers which need to
> + * inspect dynamic configuration state should instead use
> + * @atomic_best_encoder.
> + *
> + * You can leave this function to NULL if the connector is only
> + * attached to a single encoder. In this case, the core will call
> + * drm_connector_get_single_encoder() for you.
> + *
> + * RETURNS:
> + *
> + * Encoder that should be used for the given connector and connector
> + * state, or NULL if no suitable encoder exists. Note that the helpers
> + * will ensure that encoders aren't used twice, drivers should not check
> + * for this.
> + */
> + struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
> +
> + /**
> + * @atomic_best_encoder:
> + *
> + * This is the atomic version of @best_encoder for atomic drivers which
> + * need to select the best encoder depending upon the desired
> + * configuration and can't select it statically.
> + *
> + * This function is used by drm_atomic_helper_check_modeset().
> + * If it is not implemented, the core will fallback to @best_encoder
> + * (or drm_connector_get_single_encoder() if @best_encoder is NULL).
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of an atomic update. The
> + * driver is not allowed to change anything outside of the
> + * &drm_atomic_state update tracking structure passed in.
> + *
> + * RETURNS:
> + *
> + * Encoder that should be used for the given connector and connector
> + * state, or NULL if no suitable encoder exists. Note that the helpers
> + * will ensure that encoders aren't used twice, drivers should not check
> + * for this.
> + */
> + struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_check:
> + *
> + * This hook is used to validate connector state. This function is
> + * called from &drm_atomic_helper_check_modeset, and is called when
> + * a connector property is set, or a modeset on the crtc is forced.
> + *
> + * Because &drm_atomic_helper_check_modeset may be called multiple times,
> + * this function should handle being called multiple times as well.
> + *
> + * This function is also allowed to inspect any other object's state and
> + * can add more state objects to the atomic commit if needed. Care must
> + * be taken though to ensure that state check and compute functions for
> + * these added states are all called, and derived state in other objects
> + * all updated. Again the recommendation is to just call check helpers
> + * until a maximal configuration is reached.
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of an atomic update. The
> + * driver is not allowed to change anything outside of the free-standing
> + * state objects passed-in or assembled in the overall &drm_atomic_state
> + * update tracking structure.
> + *
> + * RETURNS:
> + *
> + * 0 on success, -EINVAL if the state or the transition can't be
> + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> + * attempt to obtain another state object ran into a &drm_modeset_lock
> + * deadlock.
> + */
> + int (*atomic_check)(struct drm_connector *connector,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_commit:
> + *
> + * This hook is to be used by drivers implementing writeback connectors
> + * that need a point when to commit the writeback job to the hardware.
> + * The writeback_job to commit is available in the new connector state,
> + * in &drm_connector_state.writeback_job.
> + *
> + * This hook is optional.
> + *
> + * This callback is used by the atomic modeset helpers.
> + */
> + void (*atomic_commit)(struct drm_connector *connector,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @prepare_writeback_job:
> + *
> + * As writeback jobs contain a framebuffer, drivers may need to
> + * prepare and clean them up the same way they can prepare and
> + * clean up framebuffers for planes. This optional connector operation
> + * is used to support the preparation of writeback jobs. The job
> + * prepare operation is called from drm_atomic_helper_prepare_planes()
> + * for struct &drm_writeback_connector connectors only.
> + *
> + * This operation is optional.
> + *
> + * This callback is used by the atomic modeset helpers.
> + */
> + int (*prepare_writeback_job)(struct drm_writeback_connector *connector,
> + struct drm_writeback_job *job);
> + /**
> + * @cleanup_writeback_job:
> + *
> + * This optional connector operation is used to support the
> + * cleanup of writeback jobs. The job cleanup operation is called
> + * from the existing drm_writeback_cleanup_job() function, invoked
> + * both when destroying the job as part of an aborted commit, or when
> + * the job completes.
> + *
> + * This operation is optional.
> + *
> + * This callback is used by the atomic modeset helpers.
> + */
> + void (*cleanup_writeback_job)(struct drm_writeback_connector *connector,
> + struct drm_writeback_job *job);
> +
> + /**
> + * @enable_hpd:
> + *
> + * Enable hot-plug detection for the connector.
> + *
> + * This operation is optional.
> + *
> + * This callback is used by the drm_kms_helper_poll_enable() helpers.
> + */
> + void (*enable_hpd)(struct drm_connector *connector);
> +
> + /**
> + * @disable_hpd:
> + *
> + * Disable hot-plug detection for the connector.
> + *
> + * This operation is optional.
> + *
> + * This callback is used by the drm_kms_helper_poll_disable() helpers.
> + */
> + void (*disable_hpd)(struct drm_connector *connector);
> +};
> +
> +/**
> + * drm_connector_helper_add - sets the helper vtable for a connector
> + * @connector: DRM connector
> + * @funcs: helper vtable to set for @connector
> + */
> +static inline void drm_connector_helper_add(struct drm_connector *connector,
> + const struct drm_connector_helper_funcs *funcs)
> +{
> + connector->helper_private = funcs;
> +}
> +
> +#endif /* __DRM_CONNECTOR_HELPER_VTABLE_H__ */
> diff --git a/include/drm/drm_crtc_helper_vtable.h b/include/drm/drm_crtc_helper_vtable.h
> new file mode 100644
> index 0000000000000000..6dc5d4d7af494a1b
> --- /dev/null
> +++ b/include/drm/drm_crtc_helper_vtable.h
> @@ -0,0 +1,483 @@
> +/*
> + * Copyright © 2006 Keith Packard
> + * Copyright © 2007-2008 Dave Airlie
> + * Copyright © 2007-2008 Intel Corporation
> + * Jesse Barnes <jesse.barnes at intel.com>
> + * Copyright © 2011-2013 Intel Corporation
> + * Copyright © 2015 Intel Corporation
> + * Daniel Vetter <daniel.vetter at ffwll.ch>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef __DRM_CRTC_HELPER_VTABLE_H__
> +#define __DRM_CRTC_HELPER_VTABLE_H__
> +
> +enum mode_set_atomic {
> + LEAVE_ATOMIC_MODE_SET,
> + ENTER_ATOMIC_MODE_SET,
> +};
> +
> +/**
> + * struct drm_crtc_helper_funcs - helper operations for CRTCs
> + *
> + * These hooks are used by the legacy CRTC helpers and the new atomic
> + * modesetting helpers.
> + */
> +struct drm_crtc_helper_funcs {
> + /**
> + * @dpms:
> + *
> + * Callback to control power levels on the CRTC. If the mode passed in
> + * is unsupported, the provider must use the next lowest power level.
> + * This is used by the legacy CRTC helpers to implement DPMS
> + * functionality in drm_helper_connector_dpms().
> + *
> + * This callback is also used to disable a CRTC by calling it with
> + * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
> + *
> + * This callback is used by the legacy CRTC helpers. Atomic helpers
> + * also support using this hook for enabling and disabling a CRTC to
> + * facilitate transitions to atomic, but it is deprecated. Instead
> + * @atomic_enable and @atomic_disable should be used.
> + */
> + void (*dpms)(struct drm_crtc *crtc, int mode);
> +
> + /**
> + * @prepare:
> + *
> + * This callback should prepare the CRTC for a subsequent modeset, which
> + * in practice means the driver should disable the CRTC if it is
> + * running. Most drivers ended up implementing this by calling their
> + * @dpms hook with DRM_MODE_DPMS_OFF.
> + *
> + * This callback is used by the legacy CRTC helpers. Atomic helpers
> + * also support using this hook for disabling a CRTC to facilitate
> + * transitions to atomic, but it is deprecated. Instead @atomic_disable
> + * should be used.
> + */
> + void (*prepare)(struct drm_crtc *crtc);
> +
> + /**
> + * @commit:
> + *
> + * This callback should commit the new mode on the CRTC after a modeset,
> + * which in practice means the driver should enable the CRTC. Most
> + * drivers ended up implementing this by calling their @dpms hook with
> + * DRM_MODE_DPMS_ON.
> + *
> + * This callback is used by the legacy CRTC helpers. Atomic helpers
> + * also support using this hook for enabling a CRTC to facilitate
> + * transitions to atomic, but it is deprecated. Instead @atomic_enable
> + * should be used.
> + */
> + void (*commit)(struct drm_crtc *crtc);
> +
> + /**
> + * @mode_valid:
> + *
> + * This callback is used to check if a specific mode is valid in this
> + * crtc. This should be implemented if the crtc has some sort of
> + * restriction in the modes it can display. For example, a given crtc
> + * may be responsible to set a clock value. If the clock can not
> + * produce all the values for the available modes then this callback
> + * can be used to restrict the number of modes to only the ones that
> + * can be displayed.
> + *
> + * This hook is used by the probe helpers to filter the mode list in
> + * drm_helper_probe_single_connector_modes(), and it is used by the
> + * atomic helpers to validate modes supplied by userspace in
> + * drm_atomic_helper_check_modeset().
> + *
> + * This function is optional.
> + *
> + * NOTE:
> + *
> + * Since this function is both called from the check phase of an atomic
> + * commit, and the mode validation in the probe paths it is not allowed
> + * to look at anything else but the passed-in mode, and validate it
> + * against configuration-invariant hardware constraints. Any further
> + * limits which depend upon the configuration can only be checked in
> + * @mode_fixup or @atomic_check.
> + *
> + * RETURNS:
> + *
> + * drm_mode_status Enum
> + */
> + enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
> + const struct drm_display_mode *mode);
> +
> + /**
> + * @mode_fixup:
> + *
> + * This callback is used to validate a mode. The parameter mode is the
> + * display mode that userspace requested, adjusted_mode is the mode the
> + * encoders need to be fed with. Note that this is the inverse semantics
> + * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
> + * vfunc. If the CRTC cannot support the requested conversion from mode
> + * to adjusted_mode it should reject the modeset. See also
> + * &drm_crtc_state.adjusted_mode for more details.
> + *
> + * This function is used by both legacy CRTC helpers and atomic helpers.
> + * With atomic helpers it is optional.
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of atomic modesets, which
> + * can be aborted for any reason (including on userspace's request to
> + * just check whether a configuration would be possible). Atomic drivers
> + * MUST NOT touch any persistent state (hardware or software) or data
> + * structures except the passed in adjusted_mode parameter.
> + *
> + * This is in contrast to the legacy CRTC helpers where this was
> + * allowed.
> + *
> + * Atomic drivers which need to inspect and adjust more state should
> + * instead use the @atomic_check callback, but note that they're not
> + * perfectly equivalent: @mode_valid is called from
> + * drm_atomic_helper_check_modeset(), but @atomic_check is called from
> + * drm_atomic_helper_check_planes(), because originally it was meant for
> + * plane update checks only.
> + *
> + * Also beware that userspace can request its own custom modes, neither
> + * core nor helpers filter modes to the list of probe modes reported by
> + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> + * that modes are filtered consistently put any CRTC constraints and
> + * limits checks into @mode_valid.
> + *
> + * RETURNS:
> + *
> + * True if an acceptable configuration is possible, false if the modeset
> + * operation should be rejected.
> + */
> + bool (*mode_fixup)(struct drm_crtc *crtc,
> + const struct drm_display_mode *mode,
> + struct drm_display_mode *adjusted_mode);
> +
> + /**
> + * @mode_set:
> + *
> + * This callback is used by the legacy CRTC helpers to set a new mode,
> + * position and framebuffer. Since it ties the primary plane to every
> + * mode change it is incompatible with universal plane support. And
> + * since it can't update other planes it's incompatible with atomic
> + * modeset support.
> + *
> + * This callback is only used by CRTC helpers and deprecated.
> + *
> + * RETURNS:
> + *
> + * 0 on success or a negative error code on failure.
> + */
> + int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
> + struct drm_display_mode *adjusted_mode, int x, int y,
> + struct drm_framebuffer *old_fb);
> +
> + /**
> + * @mode_set_nofb:
> + *
> + * This callback is used to update the display mode of a CRTC without
> + * changing anything of the primary plane configuration. This fits the
> + * requirement of atomic and hence is used by the atomic helpers.
> + *
> + * Note that the display pipe is completely off when this function is
> + * called. Atomic drivers which need hardware to be running before they
> + * program the new display mode (e.g. because they implement runtime PM)
> + * should not use this hook. This is because the helper library calls
> + * this hook only once per mode change and not every time the display
> + * pipeline is suspended using either DPMS or the new "ACTIVE" property.
> + * Which means register values set in this callback might get reset when
> + * the CRTC is suspended, but not restored. Such drivers should instead
> + * move all their CRTC setup into the @atomic_enable callback.
> + *
> + * This callback is optional.
> + */
> + void (*mode_set_nofb)(struct drm_crtc *crtc);
> +
> + /**
> + * @mode_set_base:
> + *
> + * This callback is used by the legacy CRTC helpers to set a new
> + * framebuffer and scanout position. It is optional and used as an
> + * optimized fast-path instead of a full mode set operation with all the
> + * resulting flickering. If it is not present
> + * drm_crtc_helper_set_config() will fall back to a full modeset, using
> + * the @mode_set callback. Since it can't update other planes it's
> + * incompatible with atomic modeset support.
> + *
> + * This callback is only used by the CRTC helpers and deprecated.
> + *
> + * RETURNS:
> + *
> + * 0 on success or a negative error code on failure.
> + */
> + int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
> + struct drm_framebuffer *old_fb);
> +
> + /**
> + * @mode_set_base_atomic:
> + *
> + * This callback is used by the fbdev helpers to set a new framebuffer
> + * and scanout without sleeping, i.e. from an atomic calling context. It
> + * is only used to implement kgdb support.
> + *
> + * This callback is optional and only needed for kgdb support in the fbdev
> + * helpers.
> + *
> + * RETURNS:
> + *
> + * 0 on success or a negative error code on failure.
> + */
> + int (*mode_set_base_atomic)(struct drm_crtc *crtc,
> + struct drm_framebuffer *fb, int x, int y,
> + enum mode_set_atomic);
> +
> + /**
> + * @disable:
> + *
> + * This callback should be used to disable the CRTC. With the atomic
> + * drivers it is called after all encoders connected to this CRTC have
> + * been shut off already using their own
> + * &drm_encoder_helper_funcs.disable hook. If that sequence is too
> + * simple drivers can just add their own hooks and call it from this
> + * CRTC callback here by looping over all encoders connected to it using
> + * for_each_encoder_on_crtc().
> + *
> + * This hook is used both by legacy CRTC helpers and atomic helpers.
> + * Atomic drivers don't need to implement it if there's no need to
> + * disable anything at the CRTC level. To ensure that runtime PM
> + * handling (using either DPMS or the new "ACTIVE" property) works
> + * @disable must be the inverse of @atomic_enable for atomic drivers.
> + * Atomic drivers should consider to use @atomic_disable instead of
> + * this one.
> + *
> + * NOTE:
> + *
> + * With legacy CRTC helpers there's a big semantic difference between
> + * @disable and other hooks (like @prepare or @dpms) used to shut down a
> + * CRTC: @disable is only called when also logically disabling the
> + * display pipeline and needs to release any resources acquired in
> + * @mode_set (like shared PLLs, or again release pinned framebuffers).
> + *
> + * Therefore @disable must be the inverse of @mode_set plus @commit for
> + * drivers still using legacy CRTC helpers, which is different from the
> + * rules under atomic.
> + */
> + void (*disable)(struct drm_crtc *crtc);
> +
> + /**
> + * @atomic_check:
> + *
> + * Drivers should check plane-update related CRTC constraints in this
> + * hook. They can also check mode related limitations but need to be
> + * aware of the calling order, since this hook is used by
> + * drm_atomic_helper_check_planes() whereas the preparations needed to
> + * check output routing and the display mode is done in
> + * drm_atomic_helper_check_modeset(). Therefore drivers that want to
> + * check output routing and display mode constraints in this callback
> + * must ensure that drm_atomic_helper_check_modeset() has been called
> + * beforehand. This is calling order used by the default helper
> + * implementation in drm_atomic_helper_check().
> + *
> + * When using drm_atomic_helper_check_planes() this hook is called
> + * after the &drm_plane_helper_funcs.atomic_check hook for planes, which
> + * allows drivers to assign shared resources requested by planes in this
> + * callback here. For more complicated dependencies the driver can call
> + * the provided check helpers multiple times until the computed state
> + * has a final configuration and everything has been checked.
> + *
> + * This function is also allowed to inspect any other object's state and
> + * can add more state objects to the atomic commit if needed. Care must
> + * be taken though to ensure that state check and compute functions for
> + * these added states are all called, and derived state in other objects
> + * all updated. Again the recommendation is to just call check helpers
> + * until a maximal configuration is reached.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional.
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of an atomic update. The
> + * driver is not allowed to change anything outside of the free-standing
> + * state object passed-in.
> + *
> + * Also beware that userspace can request its own custom modes, neither
> + * core nor helpers filter modes to the list of probe modes reported by
> + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> + * that modes are filtered consistently put any CRTC constraints and
> + * limits checks into @mode_valid.
> + *
> + * RETURNS:
> + *
> + * 0 on success, -EINVAL if the state or the transition can't be
> + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> + * attempt to obtain another state object ran into a &drm_modeset_lock
> + * deadlock.
> + */
> + int (*atomic_check)(struct drm_crtc *crtc,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_begin:
> + *
> + * Drivers should prepare for an atomic update of multiple planes on
> + * a CRTC in this hook. Depending upon hardware this might be vblank
> + * evasion, blocking updates by setting bits or doing preparatory work
> + * for e.g. manual update display.
> + *
> + * This hook is called before any plane commit functions are called.
> + *
> + * Note that the power state of the display pipe when this function is
> + * called depends upon the exact helpers and calling sequence the driver
> + * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> + * the tradeoffs and variants of plane commit helpers.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional.
> + */
> + void (*atomic_begin)(struct drm_crtc *crtc,
> + struct drm_atomic_state *state);
> + /**
> + * @atomic_flush:
> + *
> + * Drivers should finalize an atomic update of multiple planes on
> + * a CRTC in this hook. Depending upon hardware this might include
> + * checking that vblank evasion was successful, unblocking updates by
> + * setting bits or setting the GO bit to flush out all updates.
> + *
> + * Simple hardware or hardware with special requirements can commit and
> + * flush out all updates for all planes from this hook and forgo all the
> + * other commit hooks for plane updates.
> + *
> + * This hook is called after any plane commit functions are called.
> + *
> + * Note that the power state of the display pipe when this function is
> + * called depends upon the exact helpers and calling sequence the driver
> + * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> + * the tradeoffs and variants of plane commit helpers.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional.
> + */
> + void (*atomic_flush)(struct drm_crtc *crtc,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_enable:
> + *
> + * This callback should be used to enable the CRTC. With the atomic
> + * drivers it is called before all encoders connected to this CRTC are
> + * enabled through the encoder's own &drm_encoder_helper_funcs.enable
> + * hook. If that sequence is too simple drivers can just add their own
> + * hooks and call it from this CRTC callback here by looping over all
> + * encoders connected to it using for_each_encoder_on_crtc().
> + *
> + * This hook is used only by atomic helpers, for symmetry with
> + * @atomic_disable. Atomic drivers don't need to implement it if there's
> + * no need to enable anything at the CRTC level. To ensure that runtime
> + * PM handling (using either DPMS or the new "ACTIVE" property) works
> + * @atomic_enable must be the inverse of @atomic_disable for atomic
> + * drivers.
> + *
> + * This function is optional.
> + */
> + void (*atomic_enable)(struct drm_crtc *crtc,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_disable:
> + *
> + * This callback should be used to disable the CRTC. With the atomic
> + * drivers it is called after all encoders connected to this CRTC have
> + * been shut off already using their own
> + * &drm_encoder_helper_funcs.disable hook. If that sequence is too
> + * simple drivers can just add their own hooks and call it from this
> + * CRTC callback here by looping over all encoders connected to it using
> + * for_each_encoder_on_crtc().
> + *
> + * This hook is used only by atomic helpers. Atomic drivers don't
> + * need to implement it if there's no need to disable anything at the
> + * CRTC level.
> + *
> + * This function is optional.
> + */
> + void (*atomic_disable)(struct drm_crtc *crtc,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @get_scanout_position:
> + *
> + * Called by vblank timestamping code.
> + *
> + * Returns the current display scanout position from a CRTC and an
> + * optional accurate ktime_get() timestamp of when the position was
> + * measured. Note that this is a helper callback which is only used
> + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp()
> + * for the @drm_crtc_funcs.get_vblank_timestamp callback.
> + *
> + * Parameters:
> + *
> + * crtc:
> + * The CRTC.
> + * in_vblank_irq:
> + * True when called from drm_crtc_handle_vblank(). Some drivers
> + * need to apply some workarounds for gpu-specific vblank irq
> + * quirks if the flag is set.
> + * vpos:
> + * Target location for current vertical scanout position.
> + * hpos:
> + * Target location for current horizontal scanout position.
> + * stime:
> + * Target location for timestamp taken immediately before
> + * scanout position query. Can be NULL to skip timestamp.
> + * etime:
> + * Target location for timestamp taken immediately after
> + * scanout position query. Can be NULL to skip timestamp.
> + * mode:
> + * Current display timings.
> + *
> + * Returns vpos as a positive number while in active scanout area.
> + * Returns vpos as a negative number inside vblank, counting the number
> + * of scanlines to go until end of vblank, e.g., -1 means "one scanline
> + * until start of active scanout / end of vblank."
> + *
> + * Returns:
> + *
> + * True on success, false if a reliable scanout position counter could
> + * not be read out.
> + */
> + bool (*get_scanout_position)(struct drm_crtc *crtc,
> + bool in_vblank_irq, int *vpos, int *hpos,
> + ktime_t *stime, ktime_t *etime,
> + const struct drm_display_mode *mode);
> +};
> +
> +/**
> + * drm_crtc_helper_add - sets the helper vtable for a crtc
> + * @crtc: DRM CRTC
> + * @funcs: helper vtable to set for @crtc
> + */
> +static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
> + const struct drm_crtc_helper_funcs *funcs)
> +{
> + crtc->helper_private = funcs;
> +}
> +
> +#endif /* __DRM_CRTC_HELPER_VTABLE_H__ */
> diff --git a/include/drm/drm_encoder_helper_vtable.h b/include/drm/drm_encoder_helper_vtable.h
> new file mode 100644
> index 0000000000000000..434de1ebb829f3ed
> --- /dev/null
> +++ b/include/drm/drm_encoder_helper_vtable.h
> @@ -0,0 +1,381 @@
> +/*
> + * Copyright © 2006 Keith Packard
> + * Copyright © 2007-2008 Dave Airlie
> + * Copyright © 2007-2008 Intel Corporation
> + * Jesse Barnes <jesse.barnes at intel.com>
> + * Copyright © 2011-2013 Intel Corporation
> + * Copyright © 2015 Intel Corporation
> + * Daniel Vetter <daniel.vetter at ffwll.ch>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef __DRM_ENCODER_HELPER_VTABLE_H__
> +#define __DRM_ENCODER_HELPER_VTABLE_H__
> +
> +/**
> + * struct drm_encoder_helper_funcs - helper operations for encoders
> + *
> + * These hooks are used by the legacy CRTC helpers and the new atomic
> + * modesetting helpers.
> + */
> +struct drm_encoder_helper_funcs {
> + /**
> + * @dpms:
> + *
> + * Callback to control power levels on the encoder. If the mode passed in
> + * is unsupported, the provider must use the next lowest power level.
> + * This is used by the legacy encoder helpers to implement DPMS
> + * functionality in drm_helper_connector_dpms().
> + *
> + * This callback is also used to disable an encoder by calling it with
> + * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
> + *
> + * This callback is used by the legacy CRTC helpers. Atomic helpers
> + * also support using this hook for enabling and disabling an encoder to
> + * facilitate transitions to atomic, but it is deprecated. Instead
> + * @enable and @disable should be used.
> + */
> + void (*dpms)(struct drm_encoder *encoder, int mode);
> +
> + /**
> + * @mode_valid:
> + *
> + * This callback is used to check if a specific mode is valid in this
> + * encoder. This should be implemented if the encoder has some sort
> + * of restriction in the modes it can display. For example, a given
> + * encoder may be responsible to set a clock value. If the clock can
> + * not produce all the values for the available modes then this callback
> + * can be used to restrict the number of modes to only the ones that
> + * can be displayed.
> + *
> + * This hook is used by the probe helpers to filter the mode list in
> + * drm_helper_probe_single_connector_modes(), and it is used by the
> + * atomic helpers to validate modes supplied by userspace in
> + * drm_atomic_helper_check_modeset().
> + *
> + * This function is optional.
> + *
> + * NOTE:
> + *
> + * Since this function is both called from the check phase of an atomic
> + * commit, and the mode validation in the probe paths it is not allowed
> + * to look at anything else but the passed-in mode, and validate it
> + * against configuration-invariant hardware constraints. Any further
> + * limits which depend upon the configuration can only be checked in
> + * @mode_fixup or @atomic_check.
> + *
> + * RETURNS:
> + *
> + * drm_mode_status Enum
> + */
> + enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
> + const struct drm_display_mode *mode);
> +
> + /**
> + * @mode_fixup:
> + *
> + * This callback is used to validate and adjust a mode. The parameter
> + * mode is the display mode that should be fed to the next element in
> + * the display chain, either the final &drm_connector or a &drm_bridge.
> + * The parameter adjusted_mode is the input mode the encoder requires. It
> + * can be modified by this callback and does not need to match mode. See
> + * also &drm_crtc_state.adjusted_mode for more details.
> + *
> + * This function is used by both legacy CRTC helpers and atomic helpers.
> + * This hook is optional.
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of atomic modesets, which
> + * can be aborted for any reason (including on userspace's request to
> + * just check whether a configuration would be possible). Atomic drivers
> + * MUST NOT touch any persistent state (hardware or software) or data
> + * structures except the passed in adjusted_mode parameter.
> + *
> + * This is in contrast to the legacy CRTC helpers where this was
> + * allowed.
> + *
> + * Atomic drivers which need to inspect and adjust more state should
> + * instead use the @atomic_check callback. If @atomic_check is used,
> + * this hook isn't called since @atomic_check allows a strict superset
> + * of the functionality of @mode_fixup.
> + *
> + * Also beware that userspace can request its own custom modes, neither
> + * core nor helpers filter modes to the list of probe modes reported by
> + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> + * that modes are filtered consistently put any encoder constraints and
> + * limits checks into @mode_valid.
> + *
> + * RETURNS:
> + *
> + * True if an acceptable configuration is possible, false if the modeset
> + * operation should be rejected.
> + */
> + bool (*mode_fixup)(struct drm_encoder *encoder,
> + const struct drm_display_mode *mode,
> + struct drm_display_mode *adjusted_mode);
> +
> + /**
> + * @prepare:
> + *
> + * This callback should prepare the encoder for a subsequent modeset,
> + * which in practice means the driver should disable the encoder if it
> + * is running. Most drivers ended up implementing this by calling their
> + * @dpms hook with DRM_MODE_DPMS_OFF.
> + *
> + * This callback is used by the legacy CRTC helpers. Atomic helpers
> + * also support using this hook for disabling an encoder to facilitate
> + * transitions to atomic, but it is deprecated. Instead @disable should
> + * be used.
> + */
> + void (*prepare)(struct drm_encoder *encoder);
> +
> + /**
> + * @commit:
> + *
> + * This callback should commit the new mode on the encoder after a modeset,
> + * which in practice means the driver should enable the encoder. Most
> + * drivers ended up implementing this by calling their @dpms hook with
> + * DRM_MODE_DPMS_ON.
> + *
> + * This callback is used by the legacy CRTC helpers. Atomic helpers
> + * also support using this hook for enabling an encoder to facilitate
> + * transitions to atomic, but it is deprecated. Instead @enable should
> + * be used.
> + */
> + void (*commit)(struct drm_encoder *encoder);
> +
> + /**
> + * @mode_set:
> + *
> + * This callback is used to update the display mode of an encoder.
> + *
> + * Note that the display pipe is completely off when this function is
> + * called. Drivers which need hardware to be running before they program
> + * the new display mode (because they implement runtime PM) should not
> + * use this hook, because the helper library calls it only once and not
> + * every time the display pipeline is suspend using either DPMS or the
> + * new "ACTIVE" property. Such drivers should instead move all their
> + * encoder setup into the @enable callback.
> + *
> + * This callback is used both by the legacy CRTC helpers and the atomic
> + * modeset helpers. It is optional in the atomic helpers.
> + *
> + * NOTE:
> + *
> + * If the driver uses the atomic modeset helpers and needs to inspect
> + * the connector state or connector display info during mode setting,
> + * @atomic_mode_set can be used instead.
> + */
> + void (*mode_set)(struct drm_encoder *encoder,
> + struct drm_display_mode *mode,
> + struct drm_display_mode *adjusted_mode);
> +
> + /**
> + * @atomic_mode_set:
> + *
> + * This callback is used to update the display mode of an encoder.
> + *
> + * Note that the display pipe is completely off when this function is
> + * called. Drivers which need hardware to be running before they program
> + * the new display mode (because they implement runtime PM) should not
> + * use this hook, because the helper library calls it only once and not
> + * every time the display pipeline is suspended using either DPMS or the
> + * new "ACTIVE" property. Such drivers should instead move all their
> + * encoder setup into the @enable callback.
> + *
> + * This callback is used by the atomic modeset helpers in place of the
> + * @mode_set callback, if set by the driver. It is optional and should
> + * be used instead of @mode_set if the driver needs to inspect the
> + * connector state or display info, since there is no direct way to
> + * go from the encoder to the current connector.
> + */
> + void (*atomic_mode_set)(struct drm_encoder *encoder,
> + struct drm_crtc_state *crtc_state,
> + struct drm_connector_state *conn_state);
> +
> + /**
> + * @detect:
> + *
> + * This callback can be used by drivers who want to do detection on the
> + * encoder object instead of in connector functions.
> + *
> + * It is not used by any helper and therefore has purely driver-specific
> + * semantics. New drivers shouldn't use this and instead just implement
> + * their own private callbacks.
> + *
> + * FIXME:
> + *
> + * This should just be converted into a pile of driver vfuncs.
> + * Currently radeon, amdgpu and nouveau are using it.
> + */
> + enum drm_connector_status (*detect)(struct drm_encoder *encoder,
> + struct drm_connector *connector);
> +
> + /**
> + * @atomic_disable:
> + *
> + * This callback should be used to disable the encoder. With the atomic
> + * drivers it is called before this encoder's CRTC has been shut off
> + * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that
> + * sequence is too simple drivers can just add their own driver private
> + * encoder hooks and call them from CRTC's callback by looping over all
> + * encoders connected to it using for_each_encoder_on_crtc().
> + *
> + * This callback is a variant of @disable that provides the atomic state
> + * to the driver. If @atomic_disable is implemented, @disable is not
> + * called by the helpers.
> + *
> + * This hook is only used by atomic helpers. Atomic drivers don't need
> + * to implement it if there's no need to disable anything at the encoder
> + * level. To ensure that runtime PM handling (using either DPMS or the
> + * new "ACTIVE" property) works @atomic_disable must be the inverse of
> + * @atomic_enable.
> + */
> + void (*atomic_disable)(struct drm_encoder *encoder,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_enable:
> + *
> + * This callback should be used to enable the encoder. It is called
> + * after this encoder's CRTC has been enabled using their own
> + * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is
> + * too simple drivers can just add their own driver private encoder
> + * hooks and call them from CRTC's callback by looping over all encoders
> + * connected to it using for_each_encoder_on_crtc().
> + *
> + * This callback is a variant of @enable that provides the atomic state
> + * to the driver. If @atomic_enable is implemented, @enable is not
> + * called by the helpers.
> + *
> + * This hook is only used by atomic helpers, it is the opposite of
> + * @atomic_disable. Atomic drivers don't need to implement it if there's
> + * no need to enable anything at the encoder level. To ensure that
> + * runtime PM handling works @atomic_enable must be the inverse of
> + * @atomic_disable.
> + */
> + void (*atomic_enable)(struct drm_encoder *encoder,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @disable:
> + *
> + * This callback should be used to disable the encoder. With the atomic
> + * drivers it is called before this encoder's CRTC has been shut off
> + * using their own &drm_crtc_helper_funcs.disable hook. If that
> + * sequence is too simple drivers can just add their own driver private
> + * encoder hooks and call them from CRTC's callback by looping over all
> + * encoders connected to it using for_each_encoder_on_crtc().
> + *
> + * This hook is used both by legacy CRTC helpers and atomic helpers.
> + * Atomic drivers don't need to implement it if there's no need to
> + * disable anything at the encoder level. To ensure that runtime PM
> + * handling (using either DPMS or the new "ACTIVE" property) works
> + * @disable must be the inverse of @enable for atomic drivers.
> + *
> + * For atomic drivers also consider @atomic_disable and save yourself
> + * from having to read the NOTE below!
> + *
> + * NOTE:
> + *
> + * With legacy CRTC helpers there's a big semantic difference between
> + * @disable and other hooks (like @prepare or @dpms) used to shut down a
> + * encoder: @disable is only called when also logically disabling the
> + * display pipeline and needs to release any resources acquired in
> + * @mode_set (like shared PLLs, or again release pinned framebuffers).
> + *
> + * Therefore @disable must be the inverse of @mode_set plus @commit for
> + * drivers still using legacy CRTC helpers, which is different from the
> + * rules under atomic.
> + */
> + void (*disable)(struct drm_encoder *encoder);
> +
> + /**
> + * @enable:
> + *
> + * This callback should be used to enable the encoder. With the atomic
> + * drivers it is called after this encoder's CRTC has been enabled using
> + * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
> + * too simple drivers can just add their own driver private encoder
> + * hooks and call them from CRTC's callback by looping over all encoders
> + * connected to it using for_each_encoder_on_crtc().
> + *
> + * This hook is only used by atomic helpers, it is the opposite of
> + * @disable. Atomic drivers don't need to implement it if there's no
> + * need to enable anything at the encoder level. To ensure that
> + * runtime PM handling (using either DPMS or the new "ACTIVE" property)
> + * works @enable must be the inverse of @disable for atomic drivers.
> + */
> + void (*enable)(struct drm_encoder *encoder);
> +
> + /**
> + * @atomic_check:
> + *
> + * This callback is used to validate encoder state for atomic drivers.
> + * Since the encoder is the object connecting the CRTC and connector it
> + * gets passed both states, to be able to validate interactions and
> + * update the CRTC to match what the encoder needs for the requested
> + * connector.
> + *
> + * Since this provides a strict superset of the functionality of
> + * @mode_fixup (the requested and adjusted modes are both available
> + * through the passed in &struct drm_crtc_state) @mode_fixup is not
> + * called when @atomic_check is implemented.
> + *
> + * This function is used by the atomic helpers, but it is optional.
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of an atomic update. The
> + * driver is not allowed to change anything outside of the free-standing
> + * state objects passed-in or assembled in the overall &drm_atomic_state
> + * update tracking structure.
> + *
> + * Also beware that userspace can request its own custom modes, neither
> + * core nor helpers filter modes to the list of probe modes reported by
> + * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> + * that modes are filtered consistently put any encoder constraints and
> + * limits checks into @mode_valid.
> + *
> + * RETURNS:
> + *
> + * 0 on success, -EINVAL if the state or the transition can't be
> + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> + * attempt to obtain another state object ran into a &drm_modeset_lock
> + * deadlock.
> + */
> + int (*atomic_check)(struct drm_encoder *encoder,
> + struct drm_crtc_state *crtc_state,
> + struct drm_connector_state *conn_state);
> +};
> +
> +/**
> + * drm_encoder_helper_add - sets the helper vtable for an encoder
> + * @encoder: DRM encoder
> + * @funcs: helper vtable to set for @encoder
> + */
> +static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
> + const struct drm_encoder_helper_funcs *funcs)
> +{
> + encoder->helper_private = funcs;
> +}
> +
> +#endif /* __DRM_ENCODER_HELPER_VTABLE_H__ */
> diff --git a/include/drm/drm_mode_config_helper_vtable.h b/include/drm/drm_mode_config_helper_vtable.h
> new file mode 100644
> index 0000000000000000..a56e3490e27411de
> --- /dev/null
> +++ b/include/drm/drm_mode_config_helper_vtable.h
> @@ -0,0 +1,97 @@
> +/*
> + * Copyright © 2006 Keith Packard
> + * Copyright © 2007-2008 Dave Airlie
> + * Copyright © 2007-2008 Intel Corporation
> + * Jesse Barnes <jesse.barnes at intel.com>
> + * Copyright © 2011-2013 Intel Corporation
> + * Copyright © 2015 Intel Corporation
> + * Daniel Vetter <daniel.vetter at ffwll.ch>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef __DRM_MODE_CONFIG_HELPER_VTABLE_H__
> +#define __DRM_MODE_CONFIG_HELPER_VTABLE_H__
> +
> +/**
> + * struct drm_mode_config_helper_funcs - global modeset helper operations
> + *
> + * These helper functions are used by the atomic helpers.
> + */
> +struct drm_mode_config_helper_funcs {
> + /**
> + * @atomic_commit_tail:
> + *
> + * This hook is used by the default atomic_commit() hook implemented in
> + * drm_atomic_helper_commit() together with the nonblocking commit
> + * helpers (see drm_atomic_helper_setup_commit() for a starting point)
> + * to implement blocking and nonblocking commits easily. It is not used
> + * by the atomic helpers
> + *
> + * This function is called when the new atomic state has already been
> + * swapped into the various state pointers. The passed in state
> + * therefore contains copies of the old/previous state. This hook should
> + * commit the new state into hardware. Note that the helpers have
> + * already waited for preceding atomic commits and fences, but drivers
> + * can add more waiting calls at the start of their implementation, e.g.
> + * to wait for driver-internal request for implicit syncing, before
> + * starting to commit the update to the hardware.
> + *
> + * After the atomic update is committed to the hardware this hook needs
> + * to call drm_atomic_helper_commit_hw_done(). Then wait for the update
> + * to be executed by the hardware, for example using
> + * drm_atomic_helper_wait_for_vblanks() or
> + * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
> + * framebuffers using drm_atomic_helper_cleanup_planes().
> + *
> + * When disabling a CRTC this hook _must_ stall for the commit to
> + * complete. Vblank waits don't work on disabled CRTC, hence the core
> + * can't take care of this. And it also can't rely on the vblank event,
> + * since that can be signalled already when the screen shows black,
> + * which can happen much earlier than the last hardware access needed to
> + * shut off the display pipeline completely.
> + *
> + * This hook is optional, the default implementation is
> + * drm_atomic_helper_commit_tail().
> + */
> + void (*atomic_commit_tail)(struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_commit_setup:
> + *
> + * This hook is used by the default atomic_commit() hook implemented in
> + * drm_atomic_helper_commit() together with the nonblocking helpers (see
> + * drm_atomic_helper_setup_commit()) to extend the DRM commit setup. It
> + * is not used by the atomic helpers.
> + *
> + * This function is called at the end of
> + * drm_atomic_helper_setup_commit(), so once the commit has been
> + * properly setup across the generic DRM object states. It allows
> + * drivers to do some additional commit tracking that isn't related to a
> + * CRTC, plane or connector, tracked in a &drm_private_obj structure.
> + *
> + * Note that the documentation of &drm_private_obj has more details on
> + * how one should implement this.
> + *
> + * This hook is optional.
> + */
> + int (*atomic_commit_setup)(struct drm_atomic_state *state);
> +};
> +
> +#endif /* __DRM_MODE_CONFIG_HELPER_VTABLE_H__ */
> diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
> index 91860372be6c064e..a9fb43b07b60872d 100644
> --- a/include/drm/drm_modeset_helper_vtables.h
> +++ b/include/drm/drm_modeset_helper_vtables.h
> @@ -48,1466 +48,10 @@
> * To make this clear all the helper vtables are pulled together in this location here.
> */
>
> -struct drm_writeback_connector;
> -struct drm_writeback_job;
> -
> -enum mode_set_atomic {
> - LEAVE_ATOMIC_MODE_SET,
> - ENTER_ATOMIC_MODE_SET,
> -};
> -
> -/**
> - * struct drm_crtc_helper_funcs - helper operations for CRTCs
> - *
> - * These hooks are used by the legacy CRTC helpers and the new atomic
> - * modesetting helpers.
> - */
> -struct drm_crtc_helper_funcs {
> - /**
> - * @dpms:
> - *
> - * Callback to control power levels on the CRTC. If the mode passed in
> - * is unsupported, the provider must use the next lowest power level.
> - * This is used by the legacy CRTC helpers to implement DPMS
> - * functionality in drm_helper_connector_dpms().
> - *
> - * This callback is also used to disable a CRTC by calling it with
> - * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
> - *
> - * This callback is used by the legacy CRTC helpers. Atomic helpers
> - * also support using this hook for enabling and disabling a CRTC to
> - * facilitate transitions to atomic, but it is deprecated. Instead
> - * @atomic_enable and @atomic_disable should be used.
> - */
> - void (*dpms)(struct drm_crtc *crtc, int mode);
> -
> - /**
> - * @prepare:
> - *
> - * This callback should prepare the CRTC for a subsequent modeset, which
> - * in practice means the driver should disable the CRTC if it is
> - * running. Most drivers ended up implementing this by calling their
> - * @dpms hook with DRM_MODE_DPMS_OFF.
> - *
> - * This callback is used by the legacy CRTC helpers. Atomic helpers
> - * also support using this hook for disabling a CRTC to facilitate
> - * transitions to atomic, but it is deprecated. Instead @atomic_disable
> - * should be used.
> - */
> - void (*prepare)(struct drm_crtc *crtc);
> -
> - /**
> - * @commit:
> - *
> - * This callback should commit the new mode on the CRTC after a modeset,
> - * which in practice means the driver should enable the CRTC. Most
> - * drivers ended up implementing this by calling their @dpms hook with
> - * DRM_MODE_DPMS_ON.
> - *
> - * This callback is used by the legacy CRTC helpers. Atomic helpers
> - * also support using this hook for enabling a CRTC to facilitate
> - * transitions to atomic, but it is deprecated. Instead @atomic_enable
> - * should be used.
> - */
> - void (*commit)(struct drm_crtc *crtc);
> -
> - /**
> - * @mode_valid:
> - *
> - * This callback is used to check if a specific mode is valid in this
> - * crtc. This should be implemented if the crtc has some sort of
> - * restriction in the modes it can display. For example, a given crtc
> - * may be responsible to set a clock value. If the clock can not
> - * produce all the values for the available modes then this callback
> - * can be used to restrict the number of modes to only the ones that
> - * can be displayed.
> - *
> - * This hook is used by the probe helpers to filter the mode list in
> - * drm_helper_probe_single_connector_modes(), and it is used by the
> - * atomic helpers to validate modes supplied by userspace in
> - * drm_atomic_helper_check_modeset().
> - *
> - * This function is optional.
> - *
> - * NOTE:
> - *
> - * Since this function is both called from the check phase of an atomic
> - * commit, and the mode validation in the probe paths it is not allowed
> - * to look at anything else but the passed-in mode, and validate it
> - * against configuration-invariant hardware constraints. Any further
> - * limits which depend upon the configuration can only be checked in
> - * @mode_fixup or @atomic_check.
> - *
> - * RETURNS:
> - *
> - * drm_mode_status Enum
> - */
> - enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
> - const struct drm_display_mode *mode);
> -
> - /**
> - * @mode_fixup:
> - *
> - * This callback is used to validate a mode. The parameter mode is the
> - * display mode that userspace requested, adjusted_mode is the mode the
> - * encoders need to be fed with. Note that this is the inverse semantics
> - * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
> - * vfunc. If the CRTC cannot support the requested conversion from mode
> - * to adjusted_mode it should reject the modeset. See also
> - * &drm_crtc_state.adjusted_mode for more details.
> - *
> - * This function is used by both legacy CRTC helpers and atomic helpers.
> - * With atomic helpers it is optional.
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of atomic modesets, which
> - * can be aborted for any reason (including on userspace's request to
> - * just check whether a configuration would be possible). Atomic drivers
> - * MUST NOT touch any persistent state (hardware or software) or data
> - * structures except the passed in adjusted_mode parameter.
> - *
> - * This is in contrast to the legacy CRTC helpers where this was
> - * allowed.
> - *
> - * Atomic drivers which need to inspect and adjust more state should
> - * instead use the @atomic_check callback, but note that they're not
> - * perfectly equivalent: @mode_valid is called from
> - * drm_atomic_helper_check_modeset(), but @atomic_check is called from
> - * drm_atomic_helper_check_planes(), because originally it was meant for
> - * plane update checks only.
> - *
> - * Also beware that userspace can request its own custom modes, neither
> - * core nor helpers filter modes to the list of probe modes reported by
> - * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> - * that modes are filtered consistently put any CRTC constraints and
> - * limits checks into @mode_valid.
> - *
> - * RETURNS:
> - *
> - * True if an acceptable configuration is possible, false if the modeset
> - * operation should be rejected.
> - */
> - bool (*mode_fixup)(struct drm_crtc *crtc,
> - const struct drm_display_mode *mode,
> - struct drm_display_mode *adjusted_mode);
> -
> - /**
> - * @mode_set:
> - *
> - * This callback is used by the legacy CRTC helpers to set a new mode,
> - * position and framebuffer. Since it ties the primary plane to every
> - * mode change it is incompatible with universal plane support. And
> - * since it can't update other planes it's incompatible with atomic
> - * modeset support.
> - *
> - * This callback is only used by CRTC helpers and deprecated.
> - *
> - * RETURNS:
> - *
> - * 0 on success or a negative error code on failure.
> - */
> - int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
> - struct drm_display_mode *adjusted_mode, int x, int y,
> - struct drm_framebuffer *old_fb);
> -
> - /**
> - * @mode_set_nofb:
> - *
> - * This callback is used to update the display mode of a CRTC without
> - * changing anything of the primary plane configuration. This fits the
> - * requirement of atomic and hence is used by the atomic helpers.
> - *
> - * Note that the display pipe is completely off when this function is
> - * called. Atomic drivers which need hardware to be running before they
> - * program the new display mode (e.g. because they implement runtime PM)
> - * should not use this hook. This is because the helper library calls
> - * this hook only once per mode change and not every time the display
> - * pipeline is suspended using either DPMS or the new "ACTIVE" property.
> - * Which means register values set in this callback might get reset when
> - * the CRTC is suspended, but not restored. Such drivers should instead
> - * move all their CRTC setup into the @atomic_enable callback.
> - *
> - * This callback is optional.
> - */
> - void (*mode_set_nofb)(struct drm_crtc *crtc);
> -
> - /**
> - * @mode_set_base:
> - *
> - * This callback is used by the legacy CRTC helpers to set a new
> - * framebuffer and scanout position. It is optional and used as an
> - * optimized fast-path instead of a full mode set operation with all the
> - * resulting flickering. If it is not present
> - * drm_crtc_helper_set_config() will fall back to a full modeset, using
> - * the @mode_set callback. Since it can't update other planes it's
> - * incompatible with atomic modeset support.
> - *
> - * This callback is only used by the CRTC helpers and deprecated.
> - *
> - * RETURNS:
> - *
> - * 0 on success or a negative error code on failure.
> - */
> - int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
> - struct drm_framebuffer *old_fb);
> -
> - /**
> - * @mode_set_base_atomic:
> - *
> - * This callback is used by the fbdev helpers to set a new framebuffer
> - * and scanout without sleeping, i.e. from an atomic calling context. It
> - * is only used to implement kgdb support.
> - *
> - * This callback is optional and only needed for kgdb support in the fbdev
> - * helpers.
> - *
> - * RETURNS:
> - *
> - * 0 on success or a negative error code on failure.
> - */
> - int (*mode_set_base_atomic)(struct drm_crtc *crtc,
> - struct drm_framebuffer *fb, int x, int y,
> - enum mode_set_atomic);
> -
> - /**
> - * @disable:
> - *
> - * This callback should be used to disable the CRTC. With the atomic
> - * drivers it is called after all encoders connected to this CRTC have
> - * been shut off already using their own
> - * &drm_encoder_helper_funcs.disable hook. If that sequence is too
> - * simple drivers can just add their own hooks and call it from this
> - * CRTC callback here by looping over all encoders connected to it using
> - * for_each_encoder_on_crtc().
> - *
> - * This hook is used both by legacy CRTC helpers and atomic helpers.
> - * Atomic drivers don't need to implement it if there's no need to
> - * disable anything at the CRTC level. To ensure that runtime PM
> - * handling (using either DPMS or the new "ACTIVE" property) works
> - * @disable must be the inverse of @atomic_enable for atomic drivers.
> - * Atomic drivers should consider to use @atomic_disable instead of
> - * this one.
> - *
> - * NOTE:
> - *
> - * With legacy CRTC helpers there's a big semantic difference between
> - * @disable and other hooks (like @prepare or @dpms) used to shut down a
> - * CRTC: @disable is only called when also logically disabling the
> - * display pipeline and needs to release any resources acquired in
> - * @mode_set (like shared PLLs, or again release pinned framebuffers).
> - *
> - * Therefore @disable must be the inverse of @mode_set plus @commit for
> - * drivers still using legacy CRTC helpers, which is different from the
> - * rules under atomic.
> - */
> - void (*disable)(struct drm_crtc *crtc);
> -
> - /**
> - * @atomic_check:
> - *
> - * Drivers should check plane-update related CRTC constraints in this
> - * hook. They can also check mode related limitations but need to be
> - * aware of the calling order, since this hook is used by
> - * drm_atomic_helper_check_planes() whereas the preparations needed to
> - * check output routing and the display mode is done in
> - * drm_atomic_helper_check_modeset(). Therefore drivers that want to
> - * check output routing and display mode constraints in this callback
> - * must ensure that drm_atomic_helper_check_modeset() has been called
> - * beforehand. This is calling order used by the default helper
> - * implementation in drm_atomic_helper_check().
> - *
> - * When using drm_atomic_helper_check_planes() this hook is called
> - * after the &drm_plane_helper_funcs.atomic_check hook for planes, which
> - * allows drivers to assign shared resources requested by planes in this
> - * callback here. For more complicated dependencies the driver can call
> - * the provided check helpers multiple times until the computed state
> - * has a final configuration and everything has been checked.
> - *
> - * This function is also allowed to inspect any other object's state and
> - * can add more state objects to the atomic commit if needed. Care must
> - * be taken though to ensure that state check and compute functions for
> - * these added states are all called, and derived state in other objects
> - * all updated. Again the recommendation is to just call check helpers
> - * until a maximal configuration is reached.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional.
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of an atomic update. The
> - * driver is not allowed to change anything outside of the free-standing
> - * state object passed-in.
> - *
> - * Also beware that userspace can request its own custom modes, neither
> - * core nor helpers filter modes to the list of probe modes reported by
> - * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> - * that modes are filtered consistently put any CRTC constraints and
> - * limits checks into @mode_valid.
> - *
> - * RETURNS:
> - *
> - * 0 on success, -EINVAL if the state or the transition can't be
> - * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> - * attempt to obtain another state object ran into a &drm_modeset_lock
> - * deadlock.
> - */
> - int (*atomic_check)(struct drm_crtc *crtc,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_begin:
> - *
> - * Drivers should prepare for an atomic update of multiple planes on
> - * a CRTC in this hook. Depending upon hardware this might be vblank
> - * evasion, blocking updates by setting bits or doing preparatory work
> - * for e.g. manual update display.
> - *
> - * This hook is called before any plane commit functions are called.
> - *
> - * Note that the power state of the display pipe when this function is
> - * called depends upon the exact helpers and calling sequence the driver
> - * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> - * the tradeoffs and variants of plane commit helpers.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional.
> - */
> - void (*atomic_begin)(struct drm_crtc *crtc,
> - struct drm_atomic_state *state);
> - /**
> - * @atomic_flush:
> - *
> - * Drivers should finalize an atomic update of multiple planes on
> - * a CRTC in this hook. Depending upon hardware this might include
> - * checking that vblank evasion was successful, unblocking updates by
> - * setting bits or setting the GO bit to flush out all updates.
> - *
> - * Simple hardware or hardware with special requirements can commit and
> - * flush out all updates for all planes from this hook and forgo all the
> - * other commit hooks for plane updates.
> - *
> - * This hook is called after any plane commit functions are called.
> - *
> - * Note that the power state of the display pipe when this function is
> - * called depends upon the exact helpers and calling sequence the driver
> - * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> - * the tradeoffs and variants of plane commit helpers.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional.
> - */
> - void (*atomic_flush)(struct drm_crtc *crtc,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_enable:
> - *
> - * This callback should be used to enable the CRTC. With the atomic
> - * drivers it is called before all encoders connected to this CRTC are
> - * enabled through the encoder's own &drm_encoder_helper_funcs.enable
> - * hook. If that sequence is too simple drivers can just add their own
> - * hooks and call it from this CRTC callback here by looping over all
> - * encoders connected to it using for_each_encoder_on_crtc().
> - *
> - * This hook is used only by atomic helpers, for symmetry with
> - * @atomic_disable. Atomic drivers don't need to implement it if there's
> - * no need to enable anything at the CRTC level. To ensure that runtime
> - * PM handling (using either DPMS or the new "ACTIVE" property) works
> - * @atomic_enable must be the inverse of @atomic_disable for atomic
> - * drivers.
> - *
> - * This function is optional.
> - */
> - void (*atomic_enable)(struct drm_crtc *crtc,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_disable:
> - *
> - * This callback should be used to disable the CRTC. With the atomic
> - * drivers it is called after all encoders connected to this CRTC have
> - * been shut off already using their own
> - * &drm_encoder_helper_funcs.disable hook. If that sequence is too
> - * simple drivers can just add their own hooks and call it from this
> - * CRTC callback here by looping over all encoders connected to it using
> - * for_each_encoder_on_crtc().
> - *
> - * This hook is used only by atomic helpers. Atomic drivers don't
> - * need to implement it if there's no need to disable anything at the
> - * CRTC level.
> - *
> - * This function is optional.
> - */
> - void (*atomic_disable)(struct drm_crtc *crtc,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @get_scanout_position:
> - *
> - * Called by vblank timestamping code.
> - *
> - * Returns the current display scanout position from a CRTC and an
> - * optional accurate ktime_get() timestamp of when the position was
> - * measured. Note that this is a helper callback which is only used
> - * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp()
> - * for the @drm_crtc_funcs.get_vblank_timestamp callback.
> - *
> - * Parameters:
> - *
> - * crtc:
> - * The CRTC.
> - * in_vblank_irq:
> - * True when called from drm_crtc_handle_vblank(). Some drivers
> - * need to apply some workarounds for gpu-specific vblank irq
> - * quirks if the flag is set.
> - * vpos:
> - * Target location for current vertical scanout position.
> - * hpos:
> - * Target location for current horizontal scanout position.
> - * stime:
> - * Target location for timestamp taken immediately before
> - * scanout position query. Can be NULL to skip timestamp.
> - * etime:
> - * Target location for timestamp taken immediately after
> - * scanout position query. Can be NULL to skip timestamp.
> - * mode:
> - * Current display timings.
> - *
> - * Returns vpos as a positive number while in active scanout area.
> - * Returns vpos as a negative number inside vblank, counting the number
> - * of scanlines to go until end of vblank, e.g., -1 means "one scanline
> - * until start of active scanout / end of vblank."
> - *
> - * Returns:
> - *
> - * True on success, false if a reliable scanout position counter could
> - * not be read out.
> - */
> - bool (*get_scanout_position)(struct drm_crtc *crtc,
> - bool in_vblank_irq, int *vpos, int *hpos,
> - ktime_t *stime, ktime_t *etime,
> - const struct drm_display_mode *mode);
> -};
> -
> -/**
> - * drm_crtc_helper_add - sets the helper vtable for a crtc
> - * @crtc: DRM CRTC
> - * @funcs: helper vtable to set for @crtc
> - */
> -static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
> - const struct drm_crtc_helper_funcs *funcs)
> -{
> - crtc->helper_private = funcs;
> -}
> -
> -/**
> - * struct drm_encoder_helper_funcs - helper operations for encoders
> - *
> - * These hooks are used by the legacy CRTC helpers and the new atomic
> - * modesetting helpers.
> - */
> -struct drm_encoder_helper_funcs {
> - /**
> - * @dpms:
> - *
> - * Callback to control power levels on the encoder. If the mode passed in
> - * is unsupported, the provider must use the next lowest power level.
> - * This is used by the legacy encoder helpers to implement DPMS
> - * functionality in drm_helper_connector_dpms().
> - *
> - * This callback is also used to disable an encoder by calling it with
> - * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
> - *
> - * This callback is used by the legacy CRTC helpers. Atomic helpers
> - * also support using this hook for enabling and disabling an encoder to
> - * facilitate transitions to atomic, but it is deprecated. Instead
> - * @enable and @disable should be used.
> - */
> - void (*dpms)(struct drm_encoder *encoder, int mode);
> -
> - /**
> - * @mode_valid:
> - *
> - * This callback is used to check if a specific mode is valid in this
> - * encoder. This should be implemented if the encoder has some sort
> - * of restriction in the modes it can display. For example, a given
> - * encoder may be responsible to set a clock value. If the clock can
> - * not produce all the values for the available modes then this callback
> - * can be used to restrict the number of modes to only the ones that
> - * can be displayed.
> - *
> - * This hook is used by the probe helpers to filter the mode list in
> - * drm_helper_probe_single_connector_modes(), and it is used by the
> - * atomic helpers to validate modes supplied by userspace in
> - * drm_atomic_helper_check_modeset().
> - *
> - * This function is optional.
> - *
> - * NOTE:
> - *
> - * Since this function is both called from the check phase of an atomic
> - * commit, and the mode validation in the probe paths it is not allowed
> - * to look at anything else but the passed-in mode, and validate it
> - * against configuration-invariant hardware constraints. Any further
> - * limits which depend upon the configuration can only be checked in
> - * @mode_fixup or @atomic_check.
> - *
> - * RETURNS:
> - *
> - * drm_mode_status Enum
> - */
> - enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
> - const struct drm_display_mode *mode);
> -
> - /**
> - * @mode_fixup:
> - *
> - * This callback is used to validate and adjust a mode. The parameter
> - * mode is the display mode that should be fed to the next element in
> - * the display chain, either the final &drm_connector or a &drm_bridge.
> - * The parameter adjusted_mode is the input mode the encoder requires. It
> - * can be modified by this callback and does not need to match mode. See
> - * also &drm_crtc_state.adjusted_mode for more details.
> - *
> - * This function is used by both legacy CRTC helpers and atomic helpers.
> - * This hook is optional.
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of atomic modesets, which
> - * can be aborted for any reason (including on userspace's request to
> - * just check whether a configuration would be possible). Atomic drivers
> - * MUST NOT touch any persistent state (hardware or software) or data
> - * structures except the passed in adjusted_mode parameter.
> - *
> - * This is in contrast to the legacy CRTC helpers where this was
> - * allowed.
> - *
> - * Atomic drivers which need to inspect and adjust more state should
> - * instead use the @atomic_check callback. If @atomic_check is used,
> - * this hook isn't called since @atomic_check allows a strict superset
> - * of the functionality of @mode_fixup.
> - *
> - * Also beware that userspace can request its own custom modes, neither
> - * core nor helpers filter modes to the list of probe modes reported by
> - * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> - * that modes are filtered consistently put any encoder constraints and
> - * limits checks into @mode_valid.
> - *
> - * RETURNS:
> - *
> - * True if an acceptable configuration is possible, false if the modeset
> - * operation should be rejected.
> - */
> - bool (*mode_fixup)(struct drm_encoder *encoder,
> - const struct drm_display_mode *mode,
> - struct drm_display_mode *adjusted_mode);
> -
> - /**
> - * @prepare:
> - *
> - * This callback should prepare the encoder for a subsequent modeset,
> - * which in practice means the driver should disable the encoder if it
> - * is running. Most drivers ended up implementing this by calling their
> - * @dpms hook with DRM_MODE_DPMS_OFF.
> - *
> - * This callback is used by the legacy CRTC helpers. Atomic helpers
> - * also support using this hook for disabling an encoder to facilitate
> - * transitions to atomic, but it is deprecated. Instead @disable should
> - * be used.
> - */
> - void (*prepare)(struct drm_encoder *encoder);
> -
> - /**
> - * @commit:
> - *
> - * This callback should commit the new mode on the encoder after a modeset,
> - * which in practice means the driver should enable the encoder. Most
> - * drivers ended up implementing this by calling their @dpms hook with
> - * DRM_MODE_DPMS_ON.
> - *
> - * This callback is used by the legacy CRTC helpers. Atomic helpers
> - * also support using this hook for enabling an encoder to facilitate
> - * transitions to atomic, but it is deprecated. Instead @enable should
> - * be used.
> - */
> - void (*commit)(struct drm_encoder *encoder);
> -
> - /**
> - * @mode_set:
> - *
> - * This callback is used to update the display mode of an encoder.
> - *
> - * Note that the display pipe is completely off when this function is
> - * called. Drivers which need hardware to be running before they program
> - * the new display mode (because they implement runtime PM) should not
> - * use this hook, because the helper library calls it only once and not
> - * every time the display pipeline is suspend using either DPMS or the
> - * new "ACTIVE" property. Such drivers should instead move all their
> - * encoder setup into the @enable callback.
> - *
> - * This callback is used both by the legacy CRTC helpers and the atomic
> - * modeset helpers. It is optional in the atomic helpers.
> - *
> - * NOTE:
> - *
> - * If the driver uses the atomic modeset helpers and needs to inspect
> - * the connector state or connector display info during mode setting,
> - * @atomic_mode_set can be used instead.
> - */
> - void (*mode_set)(struct drm_encoder *encoder,
> - struct drm_display_mode *mode,
> - struct drm_display_mode *adjusted_mode);
> -
> - /**
> - * @atomic_mode_set:
> - *
> - * This callback is used to update the display mode of an encoder.
> - *
> - * Note that the display pipe is completely off when this function is
> - * called. Drivers which need hardware to be running before they program
> - * the new display mode (because they implement runtime PM) should not
> - * use this hook, because the helper library calls it only once and not
> - * every time the display pipeline is suspended using either DPMS or the
> - * new "ACTIVE" property. Such drivers should instead move all their
> - * encoder setup into the @enable callback.
> - *
> - * This callback is used by the atomic modeset helpers in place of the
> - * @mode_set callback, if set by the driver. It is optional and should
> - * be used instead of @mode_set if the driver needs to inspect the
> - * connector state or display info, since there is no direct way to
> - * go from the encoder to the current connector.
> - */
> - void (*atomic_mode_set)(struct drm_encoder *encoder,
> - struct drm_crtc_state *crtc_state,
> - struct drm_connector_state *conn_state);
> -
> - /**
> - * @detect:
> - *
> - * This callback can be used by drivers who want to do detection on the
> - * encoder object instead of in connector functions.
> - *
> - * It is not used by any helper and therefore has purely driver-specific
> - * semantics. New drivers shouldn't use this and instead just implement
> - * their own private callbacks.
> - *
> - * FIXME:
> - *
> - * This should just be converted into a pile of driver vfuncs.
> - * Currently radeon, amdgpu and nouveau are using it.
> - */
> - enum drm_connector_status (*detect)(struct drm_encoder *encoder,
> - struct drm_connector *connector);
> -
> - /**
> - * @atomic_disable:
> - *
> - * This callback should be used to disable the encoder. With the atomic
> - * drivers it is called before this encoder's CRTC has been shut off
> - * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that
> - * sequence is too simple drivers can just add their own driver private
> - * encoder hooks and call them from CRTC's callback by looping over all
> - * encoders connected to it using for_each_encoder_on_crtc().
> - *
> - * This callback is a variant of @disable that provides the atomic state
> - * to the driver. If @atomic_disable is implemented, @disable is not
> - * called by the helpers.
> - *
> - * This hook is only used by atomic helpers. Atomic drivers don't need
> - * to implement it if there's no need to disable anything at the encoder
> - * level. To ensure that runtime PM handling (using either DPMS or the
> - * new "ACTIVE" property) works @atomic_disable must be the inverse of
> - * @atomic_enable.
> - */
> - void (*atomic_disable)(struct drm_encoder *encoder,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_enable:
> - *
> - * This callback should be used to enable the encoder. It is called
> - * after this encoder's CRTC has been enabled using their own
> - * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is
> - * too simple drivers can just add their own driver private encoder
> - * hooks and call them from CRTC's callback by looping over all encoders
> - * connected to it using for_each_encoder_on_crtc().
> - *
> - * This callback is a variant of @enable that provides the atomic state
> - * to the driver. If @atomic_enable is implemented, @enable is not
> - * called by the helpers.
> - *
> - * This hook is only used by atomic helpers, it is the opposite of
> - * @atomic_disable. Atomic drivers don't need to implement it if there's
> - * no need to enable anything at the encoder level. To ensure that
> - * runtime PM handling works @atomic_enable must be the inverse of
> - * @atomic_disable.
> - */
> - void (*atomic_enable)(struct drm_encoder *encoder,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @disable:
> - *
> - * This callback should be used to disable the encoder. With the atomic
> - * drivers it is called before this encoder's CRTC has been shut off
> - * using their own &drm_crtc_helper_funcs.disable hook. If that
> - * sequence is too simple drivers can just add their own driver private
> - * encoder hooks and call them from CRTC's callback by looping over all
> - * encoders connected to it using for_each_encoder_on_crtc().
> - *
> - * This hook is used both by legacy CRTC helpers and atomic helpers.
> - * Atomic drivers don't need to implement it if there's no need to
> - * disable anything at the encoder level. To ensure that runtime PM
> - * handling (using either DPMS or the new "ACTIVE" property) works
> - * @disable must be the inverse of @enable for atomic drivers.
> - *
> - * For atomic drivers also consider @atomic_disable and save yourself
> - * from having to read the NOTE below!
> - *
> - * NOTE:
> - *
> - * With legacy CRTC helpers there's a big semantic difference between
> - * @disable and other hooks (like @prepare or @dpms) used to shut down a
> - * encoder: @disable is only called when also logically disabling the
> - * display pipeline and needs to release any resources acquired in
> - * @mode_set (like shared PLLs, or again release pinned framebuffers).
> - *
> - * Therefore @disable must be the inverse of @mode_set plus @commit for
> - * drivers still using legacy CRTC helpers, which is different from the
> - * rules under atomic.
> - */
> - void (*disable)(struct drm_encoder *encoder);
> -
> - /**
> - * @enable:
> - *
> - * This callback should be used to enable the encoder. With the atomic
> - * drivers it is called after this encoder's CRTC has been enabled using
> - * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
> - * too simple drivers can just add their own driver private encoder
> - * hooks and call them from CRTC's callback by looping over all encoders
> - * connected to it using for_each_encoder_on_crtc().
> - *
> - * This hook is only used by atomic helpers, it is the opposite of
> - * @disable. Atomic drivers don't need to implement it if there's no
> - * need to enable anything at the encoder level. To ensure that
> - * runtime PM handling (using either DPMS or the new "ACTIVE" property)
> - * works @enable must be the inverse of @disable for atomic drivers.
> - */
> - void (*enable)(struct drm_encoder *encoder);
> -
> - /**
> - * @atomic_check:
> - *
> - * This callback is used to validate encoder state for atomic drivers.
> - * Since the encoder is the object connecting the CRTC and connector it
> - * gets passed both states, to be able to validate interactions and
> - * update the CRTC to match what the encoder needs for the requested
> - * connector.
> - *
> - * Since this provides a strict superset of the functionality of
> - * @mode_fixup (the requested and adjusted modes are both available
> - * through the passed in &struct drm_crtc_state) @mode_fixup is not
> - * called when @atomic_check is implemented.
> - *
> - * This function is used by the atomic helpers, but it is optional.
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of an atomic update. The
> - * driver is not allowed to change anything outside of the free-standing
> - * state objects passed-in or assembled in the overall &drm_atomic_state
> - * update tracking structure.
> - *
> - * Also beware that userspace can request its own custom modes, neither
> - * core nor helpers filter modes to the list of probe modes reported by
> - * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
> - * that modes are filtered consistently put any encoder constraints and
> - * limits checks into @mode_valid.
> - *
> - * RETURNS:
> - *
> - * 0 on success, -EINVAL if the state or the transition can't be
> - * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> - * attempt to obtain another state object ran into a &drm_modeset_lock
> - * deadlock.
> - */
> - int (*atomic_check)(struct drm_encoder *encoder,
> - struct drm_crtc_state *crtc_state,
> - struct drm_connector_state *conn_state);
> -};
> -
> -/**
> - * drm_encoder_helper_add - sets the helper vtable for an encoder
> - * @encoder: DRM encoder
> - * @funcs: helper vtable to set for @encoder
> - */
> -static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
> - const struct drm_encoder_helper_funcs *funcs)
> -{
> - encoder->helper_private = funcs;
> -}
> -
> -/**
> - * struct drm_connector_helper_funcs - helper operations for connectors
> - *
> - * These functions are used by the atomic and legacy modeset helpers and by the
> - * probe helpers.
> - */
> -struct drm_connector_helper_funcs {
> - /**
> - * @get_modes:
> - *
> - * This function should fill in all modes currently valid for the sink
> - * into the &drm_connector.probed_modes list. It should also update the
> - * EDID property by calling drm_connector_update_edid_property().
> - *
> - * The usual way to implement this is to cache the EDID retrieved in the
> - * probe callback somewhere in the driver-private connector structure.
> - * In this function drivers then parse the modes in the EDID and add
> - * them by calling drm_add_edid_modes(). But connectors that drive a
> - * fixed panel can also manually add specific modes using
> - * drm_mode_probed_add(). Drivers which manually add modes should also
> - * make sure that the &drm_connector.display_info,
> - * &drm_connector.width_mm and &drm_connector.height_mm fields are
> - * filled in.
> - *
> - * Note that the caller function will automatically add standard VESA
> - * DMT modes up to 1024x768 if the .get_modes() helper operation returns
> - * no mode and if the connector status is connector_status_connected or
> - * connector_status_unknown. There is no need to call
> - * drm_add_modes_noedid() manually in that case.
> - *
> - * Virtual drivers that just want some standard VESA mode with a given
> - * resolution can call drm_add_modes_noedid(), and mark the preferred
> - * one using drm_set_preferred_mode().
> - *
> - * This function is only called after the @detect hook has indicated
> - * that a sink is connected and when the EDID isn't overridden through
> - * sysfs or the kernel commandline.
> - *
> - * This callback is used by the probe helpers in e.g.
> - * drm_helper_probe_single_connector_modes().
> - *
> - * To avoid races with concurrent connector state updates, the helper
> - * libraries always call this with the &drm_mode_config.connection_mutex
> - * held. Because of this it's safe to inspect &drm_connector->state.
> - *
> - * RETURNS:
> - *
> - * The number of modes added by calling drm_mode_probed_add().
> - */
> - int (*get_modes)(struct drm_connector *connector);
> -
> - /**
> - * @detect_ctx:
> - *
> - * Check to see if anything is attached to the connector. The parameter
> - * force is set to false whilst polling, true when checking the
> - * connector due to a user request. force can be used by the driver to
> - * avoid expensive, destructive operations during automated probing.
> - *
> - * This callback is optional, if not implemented the connector will be
> - * considered as always being attached.
> - *
> - * This is the atomic version of &drm_connector_funcs.detect.
> - *
> - * To avoid races against concurrent connector state updates, the
> - * helper libraries always call this with ctx set to a valid context,
> - * and &drm_mode_config.connection_mutex will always be locked with
> - * the ctx parameter set to this ctx. This allows taking additional
> - * locks as required.
> - *
> - * RETURNS:
> - *
> - * &drm_connector_status indicating the connector's status,
> - * or the error code returned by drm_modeset_lock(), -EDEADLK.
> - */
> - int (*detect_ctx)(struct drm_connector *connector,
> - struct drm_modeset_acquire_ctx *ctx,
> - bool force);
> -
> - /**
> - * @mode_valid:
> - *
> - * Callback to validate a mode for a connector, irrespective of the
> - * specific display configuration.
> - *
> - * This callback is used by the probe helpers to filter the mode list
> - * (which is usually derived from the EDID data block from the sink).
> - * See e.g. drm_helper_probe_single_connector_modes().
> - *
> - * This function is optional.
> - *
> - * NOTE:
> - *
> - * This only filters the mode list supplied to userspace in the
> - * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid,
> - * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid,
> - * which are also called by the atomic helpers from
> - * drm_atomic_helper_check_modeset(). This allows userspace to force and
> - * ignore sink constraint (like the pixel clock limits in the screen's
> - * EDID), which is useful for e.g. testing, or working around a broken
> - * EDID. Any source hardware constraint (which always need to be
> - * enforced) therefore should be checked in one of the above callbacks,
> - * and not this one here.
> - *
> - * To avoid races with concurrent connector state updates, the helper
> - * libraries always call this with the &drm_mode_config.connection_mutex
> - * held. Because of this it's safe to inspect &drm_connector->state.
> - *
> - * RETURNS:
> - *
> - * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum
> - * drm_mode_status.
> - */
> - enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
> - struct drm_display_mode *mode);
> -
> - /**
> - * @mode_valid_ctx:
> - *
> - * Callback to validate a mode for a connector, irrespective of the
> - * specific display configuration.
> - *
> - * This callback is used by the probe helpers to filter the mode list
> - * (which is usually derived from the EDID data block from the sink).
> - * See e.g. drm_helper_probe_single_connector_modes().
> - *
> - * This function is optional, and is the atomic version of
> - * &drm_connector_helper_funcs.mode_valid.
> - *
> - * To allow for accessing the atomic state of modesetting objects, the
> - * helper libraries always call this with ctx set to a valid context,
> - * and &drm_mode_config.connection_mutex will always be locked with
> - * the ctx parameter set to @ctx. This allows for taking additional
> - * locks as required.
> - *
> - * Even though additional locks may be acquired, this callback is
> - * still expected not to take any constraints into account which would
> - * be influenced by the currently set display state - such constraints
> - * should be handled in the driver's atomic check. For example, if a
> - * connector shares display bandwidth with other connectors then it
> - * would be ok to validate the minimum bandwidth requirement of a mode
> - * against the maximum possible bandwidth of the connector. But it
> - * wouldn't be ok to take the current bandwidth usage of other
> - * connectors into account, as this would change depending on the
> - * display state.
> - *
> - * Returns:
> - * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote
> - * the &enum drm_mode_status value to @status, or a negative error
> - * code otherwise.
> - *
> - */
> - int (*mode_valid_ctx)(struct drm_connector *connector,
> - struct drm_display_mode *mode,
> - struct drm_modeset_acquire_ctx *ctx,
> - enum drm_mode_status *status);
> -
> - /**
> - * @best_encoder:
> - *
> - * This function should select the best encoder for the given connector.
> - *
> - * This function is used by both the atomic helpers (in the
> - * drm_atomic_helper_check_modeset() function) and in the legacy CRTC
> - * helpers.
> - *
> - * NOTE:
> - *
> - * In atomic drivers this function is called in the check phase of an
> - * atomic update. The driver is not allowed to change or inspect
> - * anything outside of arguments passed-in. Atomic drivers which need to
> - * inspect dynamic configuration state should instead use
> - * @atomic_best_encoder.
> - *
> - * You can leave this function to NULL if the connector is only
> - * attached to a single encoder. In this case, the core will call
> - * drm_connector_get_single_encoder() for you.
> - *
> - * RETURNS:
> - *
> - * Encoder that should be used for the given connector and connector
> - * state, or NULL if no suitable encoder exists. Note that the helpers
> - * will ensure that encoders aren't used twice, drivers should not check
> - * for this.
> - */
> - struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
> -
> - /**
> - * @atomic_best_encoder:
> - *
> - * This is the atomic version of @best_encoder for atomic drivers which
> - * need to select the best encoder depending upon the desired
> - * configuration and can't select it statically.
> - *
> - * This function is used by drm_atomic_helper_check_modeset().
> - * If it is not implemented, the core will fallback to @best_encoder
> - * (or drm_connector_get_single_encoder() if @best_encoder is NULL).
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of an atomic update. The
> - * driver is not allowed to change anything outside of the
> - * &drm_atomic_state update tracking structure passed in.
> - *
> - * RETURNS:
> - *
> - * Encoder that should be used for the given connector and connector
> - * state, or NULL if no suitable encoder exists. Note that the helpers
> - * will ensure that encoders aren't used twice, drivers should not check
> - * for this.
> - */
> - struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_check:
> - *
> - * This hook is used to validate connector state. This function is
> - * called from &drm_atomic_helper_check_modeset, and is called when
> - * a connector property is set, or a modeset on the crtc is forced.
> - *
> - * Because &drm_atomic_helper_check_modeset may be called multiple times,
> - * this function should handle being called multiple times as well.
> - *
> - * This function is also allowed to inspect any other object's state and
> - * can add more state objects to the atomic commit if needed. Care must
> - * be taken though to ensure that state check and compute functions for
> - * these added states are all called, and derived state in other objects
> - * all updated. Again the recommendation is to just call check helpers
> - * until a maximal configuration is reached.
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of an atomic update. The
> - * driver is not allowed to change anything outside of the free-standing
> - * state objects passed-in or assembled in the overall &drm_atomic_state
> - * update tracking structure.
> - *
> - * RETURNS:
> - *
> - * 0 on success, -EINVAL if the state or the transition can't be
> - * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> - * attempt to obtain another state object ran into a &drm_modeset_lock
> - * deadlock.
> - */
> - int (*atomic_check)(struct drm_connector *connector,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_commit:
> - *
> - * This hook is to be used by drivers implementing writeback connectors
> - * that need a point when to commit the writeback job to the hardware.
> - * The writeback_job to commit is available in the new connector state,
> - * in &drm_connector_state.writeback_job.
> - *
> - * This hook is optional.
> - *
> - * This callback is used by the atomic modeset helpers.
> - */
> - void (*atomic_commit)(struct drm_connector *connector,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @prepare_writeback_job:
> - *
> - * As writeback jobs contain a framebuffer, drivers may need to
> - * prepare and clean them up the same way they can prepare and
> - * clean up framebuffers for planes. This optional connector operation
> - * is used to support the preparation of writeback jobs. The job
> - * prepare operation is called from drm_atomic_helper_prepare_planes()
> - * for struct &drm_writeback_connector connectors only.
> - *
> - * This operation is optional.
> - *
> - * This callback is used by the atomic modeset helpers.
> - */
> - int (*prepare_writeback_job)(struct drm_writeback_connector *connector,
> - struct drm_writeback_job *job);
> - /**
> - * @cleanup_writeback_job:
> - *
> - * This optional connector operation is used to support the
> - * cleanup of writeback jobs. The job cleanup operation is called
> - * from the existing drm_writeback_cleanup_job() function, invoked
> - * both when destroying the job as part of an aborted commit, or when
> - * the job completes.
> - *
> - * This operation is optional.
> - *
> - * This callback is used by the atomic modeset helpers.
> - */
> - void (*cleanup_writeback_job)(struct drm_writeback_connector *connector,
> - struct drm_writeback_job *job);
> -
> - /**
> - * @enable_hpd:
> - *
> - * Enable hot-plug detection for the connector.
> - *
> - * This operation is optional.
> - *
> - * This callback is used by the drm_kms_helper_poll_enable() helpers.
> - */
> - void (*enable_hpd)(struct drm_connector *connector);
> -
> - /**
> - * @disable_hpd:
> - *
> - * Disable hot-plug detection for the connector.
> - *
> - * This operation is optional.
> - *
> - * This callback is used by the drm_kms_helper_poll_disable() helpers.
> - */
> - void (*disable_hpd)(struct drm_connector *connector);
> -};
> -
> -/**
> - * drm_connector_helper_add - sets the helper vtable for a connector
> - * @connector: DRM connector
> - * @funcs: helper vtable to set for @connector
> - */
> -static inline void drm_connector_helper_add(struct drm_connector *connector,
> - const struct drm_connector_helper_funcs *funcs)
> -{
> - connector->helper_private = funcs;
> -}
> -
> -/**
> - * struct drm_plane_helper_funcs - helper operations for planes
> - *
> - * These functions are used by the atomic helpers.
> - */
> -struct drm_plane_helper_funcs {
> - /**
> - * @prepare_fb:
> - *
> - * This hook is to prepare a framebuffer for scanout by e.g. pinning
> - * its backing storage or relocating it into a contiguous block of
> - * VRAM. Other possible preparatory work includes flushing caches.
> - *
> - * This function must not block for outstanding rendering, since it is
> - * called in the context of the atomic IOCTL even for async commits to
> - * be able to return any errors to userspace. Instead the recommended
> - * way is to fill out the &drm_plane_state.fence of the passed-in
> - * &drm_plane_state. If the driver doesn't support native fences then
> - * equivalent functionality should be implemented through private
> - * members in the plane structure.
> - *
> - * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook
> - * set drm_gem_plane_helper_prepare_fb() is called automatically to
> - * implement this. Other drivers which need additional plane processing
> - * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb
> - * hook.
> - *
> - * The resources acquired in @prepare_fb persist after the end of
> - * the atomic commit. Resources that can be release at the commit's end
> - * should be acquired in @begin_fb_access and released in @end_fb_access.
> - * For example, a GEM buffer's pin operation belongs into @prepare_fb to
> - * keep the buffer pinned after the commit. But a vmap operation for
> - * shadow-plane helpers belongs into @begin_fb_access, so that atomic
> - * helpers remove the mapping at the end of the commit.
> - *
> - * The helpers will call @cleanup_fb with matching arguments for every
> - * successful call to this hook.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional. See @begin_fb_access for preparing per-commit resources.
> - *
> - * RETURNS:
> - *
> - * 0 on success or one of the following negative error codes allowed by
> - * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
> - * this callback is the only one which can fail an atomic commit,
> - * everything else must complete successfully.
> - */
> - int (*prepare_fb)(struct drm_plane *plane,
> - struct drm_plane_state *new_state);
> - /**
> - * @cleanup_fb:
> - *
> - * This hook is called to clean up any resources allocated for the given
> - * framebuffer and plane configuration in @prepare_fb.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional.
> - */
> - void (*cleanup_fb)(struct drm_plane *plane,
> - struct drm_plane_state *old_state);
> -
> - /**
> - * @begin_fb_access:
> - *
> - * This hook prepares the plane for access during an atomic commit.
> - * In contrast to @prepare_fb, resources acquired in @begin_fb_access,
> - * are released at the end of the atomic commit in @end_fb_access.
> - *
> - * For example, with shadow-plane helpers, the GEM buffer's vmap
> - * operation belongs into @begin_fb_access, so that the buffer's
> - * memory will be unmapped at the end of the commit in @end_fb_access.
> - * But a GEM buffer's pin operation belongs into @prepare_fb
> - * to keep the buffer pinned after the commit.
> - *
> - * The callback is used by the atomic modeset helpers, but it is optional.
> - * See @end_fb_cleanup for undoing the effects of @begin_fb_access and
> - * @prepare_fb for acquiring resources until the next pageflip.
> - *
> - * Returns:
> - * 0 on success, or a negative errno code otherwise.
> - */
> - int (*begin_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);
> -
> - /**
> - * @end_fb_access:
> - *
> - * This hook cleans up resources allocated by @begin_fb_access. It it called
> - * at the end of a commit for the new plane state.
> - */
> - void (*end_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);
> -
> - /**
> - * @atomic_check:
> - *
> - * Drivers should check plane specific constraints in this hook.
> - *
> - * When using drm_atomic_helper_check_planes() plane's @atomic_check
> - * hooks are called before the ones for CRTCs, which allows drivers to
> - * request shared resources that the CRTC controls here. For more
> - * complicated dependencies the driver can call the provided check helpers
> - * multiple times until the computed state has a final configuration and
> - * everything has been checked.
> - *
> - * This function is also allowed to inspect any other object's state and
> - * can add more state objects to the atomic commit if needed. Care must
> - * be taken though to ensure that state check and compute functions for
> - * these added states are all called, and derived state in other objects
> - * all updated. Again the recommendation is to just call check helpers
> - * until a maximal configuration is reached.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional.
> - *
> - * NOTE:
> - *
> - * This function is called in the check phase of an atomic update. The
> - * driver is not allowed to change anything outside of the
> - * &drm_atomic_state update tracking structure.
> - *
> - * RETURNS:
> - *
> - * 0 on success, -EINVAL if the state or the transition can't be
> - * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> - * attempt to obtain another state object ran into a &drm_modeset_lock
> - * deadlock.
> - */
> - int (*atomic_check)(struct drm_plane *plane,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_update:
> - *
> - * Drivers should use this function to update the plane state. This
> - * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
> - * drm_crtc_helper_funcs.atomic_flush callbacks.
> - *
> - * Note that the power state of the display pipe when this function is
> - * called depends upon the exact helpers and calling sequence the driver
> - * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> - * the tradeoffs and variants of plane commit helpers.
> - *
> - * This callback is used by the atomic modeset helpers, but it is optional.
> - */
> - void (*atomic_update)(struct drm_plane *plane,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_enable:
> - *
> - * Drivers should use this function to unconditionally enable a plane.
> - * This hook is called in-between the &drm_crtc_helper_funcs.atomic_begin
> - * and drm_crtc_helper_funcs.atomic_flush callbacks. It is called after
> - * @atomic_update, which will be called for all enabled planes. Drivers
> - * that use @atomic_enable should set up a plane in @atomic_update and
> - * afterwards enable the plane in @atomic_enable. If a plane needs to be
> - * enabled before installing the scanout buffer, drivers can still do
> - * so in @atomic_update.
> - *
> - * Note that the power state of the display pipe when this function is
> - * called depends upon the exact helpers and calling sequence the driver
> - * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> - * the tradeoffs and variants of plane commit helpers.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional. If implemented, @atomic_enable should be the inverse of
> - * @atomic_disable. Drivers that don't want to use either can still
> - * implement the complete plane update in @atomic_update.
> - */
> - void (*atomic_enable)(struct drm_plane *plane,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_disable:
> - *
> - * Drivers should use this function to unconditionally disable a plane.
> - * This hook is called in-between the
> - * &drm_crtc_helper_funcs.atomic_begin and
> - * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
> - * @atomic_update, which will be called for disabling planes, too, if
> - * the @atomic_disable hook isn't implemented.
> - *
> - * This hook is also useful to disable planes in preparation of a modeset,
> - * by calling drm_atomic_helper_disable_planes_on_crtc() from the
> - * &drm_crtc_helper_funcs.disable hook.
> - *
> - * Note that the power state of the display pipe when this function is
> - * called depends upon the exact helpers and calling sequence the driver
> - * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> - * the tradeoffs and variants of plane commit helpers.
> - *
> - * This callback is used by the atomic modeset helpers, but it is
> - * optional. It's intended to reverse the effects of @atomic_enable.
> - */
> - void (*atomic_disable)(struct drm_plane *plane,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_async_check:
> - *
> - * Drivers should set this function pointer to check if the plane's
> - * atomic state can be updated in a async fashion. Here async means
> - * "not vblank synchronized".
> - *
> - * This hook is called by drm_atomic_async_check() to establish if a
> - * given update can be committed asynchronously, that is, if it can
> - * jump ahead of the state currently queued for update.
> - *
> - * RETURNS:
> - *
> - * Return 0 on success and any error returned indicates that the update
> - * can not be applied in asynchronous manner.
> - */
> - int (*atomic_async_check)(struct drm_plane *plane,
> - struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_async_update:
> - *
> - * Drivers should set this function pointer to perform asynchronous
> - * updates of planes, that is, jump ahead of the currently queued
> - * state and update the plane. Here async means "not vblank
> - * synchronized".
> - *
> - * This hook is called by drm_atomic_helper_async_commit().
> - *
> - * An async update will happen on legacy cursor updates. An async
> - * update won't happen if there is an outstanding commit modifying
> - * the same plane.
> - *
> - * When doing async_update drivers shouldn't replace the
> - * &drm_plane_state but update the current one with the new plane
> - * configurations in the new plane_state.
> - *
> - * Drivers should also swap the framebuffers between current plane
> - * state (&drm_plane.state) and new_state.
> - * This is required since cleanup for async commits is performed on
> - * the new state, rather than old state like for traditional commits.
> - * Since we want to give up the reference on the current (old) fb
> - * instead of our brand new one, swap them in the driver during the
> - * async commit.
> - *
> - * FIXME:
> - * - It only works for single plane updates
> - * - Async Pageflips are not supported yet
> - * - Some hw might still scan out the old buffer until the next
> - * vblank, however we let go of the fb references as soon as
> - * we run this hook. For now drivers must implement their own workers
> - * for deferring if needed, until a common solution is created.
> - */
> - void (*atomic_async_update)(struct drm_plane *plane,
> - struct drm_atomic_state *state);
> -};
> -
> -/**
> - * drm_plane_helper_add - sets the helper vtable for a plane
> - * @plane: DRM plane
> - * @funcs: helper vtable to set for @plane
> - */
> -static inline void drm_plane_helper_add(struct drm_plane *plane,
> - const struct drm_plane_helper_funcs *funcs)
> -{
> - plane->helper_private = funcs;
> -}
> -
> -/**
> - * struct drm_mode_config_helper_funcs - global modeset helper operations
> - *
> - * These helper functions are used by the atomic helpers.
> - */
> -struct drm_mode_config_helper_funcs {
> - /**
> - * @atomic_commit_tail:
> - *
> - * This hook is used by the default atomic_commit() hook implemented in
> - * drm_atomic_helper_commit() together with the nonblocking commit
> - * helpers (see drm_atomic_helper_setup_commit() for a starting point)
> - * to implement blocking and nonblocking commits easily. It is not used
> - * by the atomic helpers
> - *
> - * This function is called when the new atomic state has already been
> - * swapped into the various state pointers. The passed in state
> - * therefore contains copies of the old/previous state. This hook should
> - * commit the new state into hardware. Note that the helpers have
> - * already waited for preceding atomic commits and fences, but drivers
> - * can add more waiting calls at the start of their implementation, e.g.
> - * to wait for driver-internal request for implicit syncing, before
> - * starting to commit the update to the hardware.
> - *
> - * After the atomic update is committed to the hardware this hook needs
> - * to call drm_atomic_helper_commit_hw_done(). Then wait for the update
> - * to be executed by the hardware, for example using
> - * drm_atomic_helper_wait_for_vblanks() or
> - * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
> - * framebuffers using drm_atomic_helper_cleanup_planes().
> - *
> - * When disabling a CRTC this hook _must_ stall for the commit to
> - * complete. Vblank waits don't work on disabled CRTC, hence the core
> - * can't take care of this. And it also can't rely on the vblank event,
> - * since that can be signalled already when the screen shows black,
> - * which can happen much earlier than the last hardware access needed to
> - * shut off the display pipeline completely.
> - *
> - * This hook is optional, the default implementation is
> - * drm_atomic_helper_commit_tail().
> - */
> - void (*atomic_commit_tail)(struct drm_atomic_state *state);
> -
> - /**
> - * @atomic_commit_setup:
> - *
> - * This hook is used by the default atomic_commit() hook implemented in
> - * drm_atomic_helper_commit() together with the nonblocking helpers (see
> - * drm_atomic_helper_setup_commit()) to extend the DRM commit setup. It
> - * is not used by the atomic helpers.
> - *
> - * This function is called at the end of
> - * drm_atomic_helper_setup_commit(), so once the commit has been
> - * properly setup across the generic DRM object states. It allows
> - * drivers to do some additional commit tracking that isn't related to a
> - * CRTC, plane or connector, tracked in a &drm_private_obj structure.
> - *
> - * Note that the documentation of &drm_private_obj has more details on
> - * how one should implement this.
> - *
> - * This hook is optional.
> - */
> - int (*atomic_commit_setup)(struct drm_atomic_state *state);
> -};
> +#include <drm/drm_crtc_helper_vtable.h>
> +#include <drm/drm_encoder_helper_vtable.h>
> +#include <drm/drm_connector_helper_vtable.h>
> +#include <drm/drm_plane_helper_vtable.h>
> +#include <drm/drm_mode_config_helper_vtable.h>
>
> #endif
> diff --git a/include/drm/drm_plane_helper_vtable.h b/include/drm/drm_plane_helper_vtable.h
> new file mode 100644
> index 0000000000000000..e735aa9733869383
> --- /dev/null
> +++ b/include/drm/drm_plane_helper_vtable.h
> @@ -0,0 +1,297 @@
> +/*
> + * Copyright © 2006 Keith Packard
> + * Copyright © 2007-2008 Dave Airlie
> + * Copyright © 2007-2008 Intel Corporation
> + * Jesse Barnes <jesse.barnes at intel.com>
> + * Copyright © 2011-2013 Intel Corporation
> + * Copyright © 2015 Intel Corporation
> + * Daniel Vetter <daniel.vetter at ffwll.ch>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + */
> +
> +#ifndef __DRM_PLANE_HELPER_VTABLE_H__
> +#define __DRM_PLANE_HELPER_VTABLE_H__
> +
> +/**
> + * struct drm_plane_helper_funcs - helper operations for planes
> + *
> + * These functions are used by the atomic helpers.
> + */
> +struct drm_plane_helper_funcs {
> + /**
> + * @prepare_fb:
> + *
> + * This hook is to prepare a framebuffer for scanout by e.g. pinning
> + * its backing storage or relocating it into a contiguous block of
> + * VRAM. Other possible preparatory work includes flushing caches.
> + *
> + * This function must not block for outstanding rendering, since it is
> + * called in the context of the atomic IOCTL even for async commits to
> + * be able to return any errors to userspace. Instead the recommended
> + * way is to fill out the &drm_plane_state.fence of the passed-in
> + * &drm_plane_state. If the driver doesn't support native fences then
> + * equivalent functionality should be implemented through private
> + * members in the plane structure.
> + *
> + * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook
> + * set drm_gem_plane_helper_prepare_fb() is called automatically to
> + * implement this. Other drivers which need additional plane processing
> + * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb
> + * hook.
> + *
> + * The resources acquired in @prepare_fb persist after the end of
> + * the atomic commit. Resources that can be release at the commit's end
> + * should be acquired in @begin_fb_access and released in @end_fb_access.
> + * For example, a GEM buffer's pin operation belongs into @prepare_fb to
> + * keep the buffer pinned after the commit. But a vmap operation for
> + * shadow-plane helpers belongs into @begin_fb_access, so that atomic
> + * helpers remove the mapping at the end of the commit.
> + *
> + * The helpers will call @cleanup_fb with matching arguments for every
> + * successful call to this hook.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional. See @begin_fb_access for preparing per-commit resources.
> + *
> + * RETURNS:
> + *
> + * 0 on success or one of the following negative error codes allowed by
> + * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
> + * this callback is the only one which can fail an atomic commit,
> + * everything else must complete successfully.
> + */
> + int (*prepare_fb)(struct drm_plane *plane,
> + struct drm_plane_state *new_state);
> + /**
> + * @cleanup_fb:
> + *
> + * This hook is called to clean up any resources allocated for the given
> + * framebuffer and plane configuration in @prepare_fb.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional.
> + */
> + void (*cleanup_fb)(struct drm_plane *plane,
> + struct drm_plane_state *old_state);
> +
> + /**
> + * @begin_fb_access:
> + *
> + * This hook prepares the plane for access during an atomic commit.
> + * In contrast to @prepare_fb, resources acquired in @begin_fb_access,
> + * are released at the end of the atomic commit in @end_fb_access.
> + *
> + * For example, with shadow-plane helpers, the GEM buffer's vmap
> + * operation belongs into @begin_fb_access, so that the buffer's
> + * memory will be unmapped at the end of the commit in @end_fb_access.
> + * But a GEM buffer's pin operation belongs into @prepare_fb
> + * to keep the buffer pinned after the commit.
> + *
> + * The callback is used by the atomic modeset helpers, but it is optional.
> + * See @end_fb_cleanup for undoing the effects of @begin_fb_access and
> + * @prepare_fb for acquiring resources until the next pageflip.
> + *
> + * Returns:
> + * 0 on success, or a negative errno code otherwise.
> + */
> + int (*begin_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);
> +
> + /**
> + * @end_fb_access:
> + *
> + * This hook cleans up resources allocated by @begin_fb_access. It it called
> + * at the end of a commit for the new plane state.
> + */
> + void (*end_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);
> +
> + /**
> + * @atomic_check:
> + *
> + * Drivers should check plane specific constraints in this hook.
> + *
> + * When using drm_atomic_helper_check_planes() plane's @atomic_check
> + * hooks are called before the ones for CRTCs, which allows drivers to
> + * request shared resources that the CRTC controls here. For more
> + * complicated dependencies the driver can call the provided check helpers
> + * multiple times until the computed state has a final configuration and
> + * everything has been checked.
> + *
> + * This function is also allowed to inspect any other object's state and
> + * can add more state objects to the atomic commit if needed. Care must
> + * be taken though to ensure that state check and compute functions for
> + * these added states are all called, and derived state in other objects
> + * all updated. Again the recommendation is to just call check helpers
> + * until a maximal configuration is reached.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional.
> + *
> + * NOTE:
> + *
> + * This function is called in the check phase of an atomic update. The
> + * driver is not allowed to change anything outside of the
> + * &drm_atomic_state update tracking structure.
> + *
> + * RETURNS:
> + *
> + * 0 on success, -EINVAL if the state or the transition can't be
> + * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
> + * attempt to obtain another state object ran into a &drm_modeset_lock
> + * deadlock.
> + */
> + int (*atomic_check)(struct drm_plane *plane,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_update:
> + *
> + * Drivers should use this function to update the plane state. This
> + * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
> + * drm_crtc_helper_funcs.atomic_flush callbacks.
> + *
> + * Note that the power state of the display pipe when this function is
> + * called depends upon the exact helpers and calling sequence the driver
> + * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> + * the tradeoffs and variants of plane commit helpers.
> + *
> + * This callback is used by the atomic modeset helpers, but it is optional.
> + */
> + void (*atomic_update)(struct drm_plane *plane,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_enable:
> + *
> + * Drivers should use this function to unconditionally enable a plane.
> + * This hook is called in-between the &drm_crtc_helper_funcs.atomic_begin
> + * and drm_crtc_helper_funcs.atomic_flush callbacks. It is called after
> + * @atomic_update, which will be called for all enabled planes. Drivers
> + * that use @atomic_enable should set up a plane in @atomic_update and
> + * afterwards enable the plane in @atomic_enable. If a plane needs to be
> + * enabled before installing the scanout buffer, drivers can still do
> + * so in @atomic_update.
> + *
> + * Note that the power state of the display pipe when this function is
> + * called depends upon the exact helpers and calling sequence the driver
> + * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> + * the tradeoffs and variants of plane commit helpers.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional. If implemented, @atomic_enable should be the inverse of
> + * @atomic_disable. Drivers that don't want to use either can still
> + * implement the complete plane update in @atomic_update.
> + */
> + void (*atomic_enable)(struct drm_plane *plane,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_disable:
> + *
> + * Drivers should use this function to unconditionally disable a plane.
> + * This hook is called in-between the
> + * &drm_crtc_helper_funcs.atomic_begin and
> + * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
> + * @atomic_update, which will be called for disabling planes, too, if
> + * the @atomic_disable hook isn't implemented.
> + *
> + * This hook is also useful to disable planes in preparation of a modeset,
> + * by calling drm_atomic_helper_disable_planes_on_crtc() from the
> + * &drm_crtc_helper_funcs.disable hook.
> + *
> + * Note that the power state of the display pipe when this function is
> + * called depends upon the exact helpers and calling sequence the driver
> + * has picked. See drm_atomic_helper_commit_planes() for a discussion of
> + * the tradeoffs and variants of plane commit helpers.
> + *
> + * This callback is used by the atomic modeset helpers, but it is
> + * optional. It's intended to reverse the effects of @atomic_enable.
> + */
> + void (*atomic_disable)(struct drm_plane *plane,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_async_check:
> + *
> + * Drivers should set this function pointer to check if the plane's
> + * atomic state can be updated in a async fashion. Here async means
> + * "not vblank synchronized".
> + *
> + * This hook is called by drm_atomic_async_check() to establish if a
> + * given update can be committed asynchronously, that is, if it can
> + * jump ahead of the state currently queued for update.
> + *
> + * RETURNS:
> + *
> + * Return 0 on success and any error returned indicates that the update
> + * can not be applied in asynchronous manner.
> + */
> + int (*atomic_async_check)(struct drm_plane *plane,
> + struct drm_atomic_state *state);
> +
> + /**
> + * @atomic_async_update:
> + *
> + * Drivers should set this function pointer to perform asynchronous
> + * updates of planes, that is, jump ahead of the currently queued
> + * state and update the plane. Here async means "not vblank
> + * synchronized".
> + *
> + * This hook is called by drm_atomic_helper_async_commit().
> + *
> + * An async update will happen on legacy cursor updates. An async
> + * update won't happen if there is an outstanding commit modifying
> + * the same plane.
> + *
> + * When doing async_update drivers shouldn't replace the
> + * &drm_plane_state but update the current one with the new plane
> + * configurations in the new plane_state.
> + *
> + * Drivers should also swap the framebuffers between current plane
> + * state (&drm_plane.state) and new_state.
> + * This is required since cleanup for async commits is performed on
> + * the new state, rather than old state like for traditional commits.
> + * Since we want to give up the reference on the current (old) fb
> + * instead of our brand new one, swap them in the driver during the
> + * async commit.
> + *
> + * FIXME:
> + * - It only works for single plane updates
> + * - Async Pageflips are not supported yet
> + * - Some hw might still scan out the old buffer until the next
> + * vblank, however we let go of the fb references as soon as
> + * we run this hook. For now drivers must implement their own workers
> + * for deferring if needed, until a common solution is created.
> + */
> + void (*atomic_async_update)(struct drm_plane *plane,
> + struct drm_atomic_state *state);
> +};
> +
> +/**
> + * drm_plane_helper_add - sets the helper vtable for a plane
> + * @plane: DRM plane
> + * @funcs: helper vtable to set for @plane
> + */
> +static inline void drm_plane_helper_add(struct drm_plane *plane,
> + const struct drm_plane_helper_funcs *funcs)
> +{
> + plane->helper_private = funcs;
> +}
> +
> +#endif /* __DRM_PLANE_HELPER_VTABLE_H__ */
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature.asc
Type: application/pgp-signature
Size: 840 bytes
Desc: OpenPGP digital signature
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20230928/fd481920/attachment-0001.sig>
More information about the dri-devel
mailing list