[RFC v2 3/8] drm: Add helper for simple kms drivers
Daniel Vetter
daniel at ffwll.ch
Mon May 2 20:20:10 UTC 2016
On Mon, May 02, 2016 at 05:55:15PM +0200, Noralf Trønnes wrote:
>
> Den 13.04.2016 13:05, skrev Daniel Vetter:
> >On Fri, Apr 08, 2016 at 07:05:05PM +0200, Noralf Trønnes wrote:
> >>Provides helper functions for drivers that have a simple display
> >>pipeline. Plane, crtc and encoder are collapsed into one entity.
> >>
> >>Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
>
> [...]
>
> >>+static void drm_simple_kms_encoder_disable(struct drm_encoder *encoder)
> >>+{
> >>+}
> >>+
> >>+static void drm_simple_kms_encoder_enable(struct drm_encoder *encoder)
> >>+{
> >>+}
> >>+
> >>+static int drm_simple_kms_encoder_atomic_check(struct drm_encoder *encoder,
> >>+ struct drm_crtc_state *crtc_state,
> >>+ struct drm_connector_state *conn_state)
> >>+{
> >>+ return 0;
> >>+}
> >Above dummy functions shouldn't be necessary.
>
> I could remove .atomic_check, but not .disable and .enable which gave me
> NULL pointer errors. I need .enable or .commit, and .disable or .dpms.
>
> Gist:
>
> void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
> struct drm_atomic_state
> *old_state)
> {
> for_each_connector_in_state(old_state, connector, old_conn_state, i)
> {
> const struct drm_encoder_helper_funcs *funcs;
>
> funcs = encoder->helper_private;
>
> if (funcs->enable)
> funcs->enable(encoder);
> else
> funcs->commit(encoder);
>
> static void
> disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
> {
> for_each_connector_in_state(old_state, connector, old_conn_state, i)
> {
> const struct drm_encoder_helper_funcs *funcs;
>
> funcs = encoder->helper_private;
>
> if (connector->state->crtc && funcs->prepare)
> funcs->prepare(encoder);
> else if (funcs->disable)
> funcs->disable(encoder);
> else
> funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
Hm right. I'm voting that we make them all optional, there's been an
effort all over the place to not force drivers to type in silly dummy
funcs.
> >>+
> >>+static const struct drm_encoder_helper_funcs drm_simple_kms_encoder_helper_funcs = {
> >>+ .disable = drm_simple_kms_encoder_disable,
> >>+ .enable = drm_simple_kms_encoder_enable,
> >>+ .atomic_check = drm_simple_kms_encoder_atomic_check,
> >>+};
> >>+
> >>+static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
> >>+ .destroy = drm_encoder_cleanup,
> >>+};
> >>+
> >>+static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc)
> >>+{
> >>+ struct drm_simple_display_pipe *pipe;
> >>+
> >>+ pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
> >>+ if (!pipe->funcs || !pipe->funcs->enable)
> >>+ return;
> >>+
> >>+ pipe->funcs->enable(pipe, crtc->state);
> >>+}
> >>+
> >>+static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc)
> >>+{
> >>+ struct drm_simple_display_pipe *pipe;
> >>+
> >>+ pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
> >>+ if (!pipe->funcs || !pipe->funcs->disable)
> >>+ return;
> >>+
> >>+ pipe->funcs->disable(pipe);
> >>+}
> >>+
> >>+static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
> >>+ .disable = drm_simple_kms_crtc_disable,
> >>+ .enable = drm_simple_kms_crtc_enable,
> >>+};
> >>+
> >>+static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
> >>+ .reset = drm_atomic_helper_crtc_reset,
> >>+ .destroy = drm_crtc_cleanup,
> >>+ .set_config = drm_atomic_helper_set_config,
> >>+ .page_flip = drm_atomic_helper_page_flip,
> >>+ .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
> >>+ .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
> >>+};
> >>+
> >>+static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
> >>+ struct drm_plane_state *old_state)
> >>+{
> >>+ struct drm_simple_display_pipe *pipe;
> >>+
> >>+ pipe = container_of(plane, struct drm_simple_display_pipe, plane);
> >>+ if (!pipe->funcs || !pipe->funcs->plane_update)
> >>+ return;
> >>+
> >>+ pipe->funcs->plane_update(pipe, old_state);
> >>+}
> >>+
> >>+static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
> >>+ .atomic_update = drm_simple_kms_plane_atomic_update,
> >>+};
> >>+
> >>+static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
> >>+ .update_plane = drm_atomic_helper_update_plane,
> >>+ .disable_plane = drm_atomic_helper_disable_plane,
> >>+ .destroy = drm_plane_cleanup,
> >>+ .reset = drm_atomic_helper_plane_reset,
> >>+ .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
> >>+ .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
> >>+};
> >>+
> >>+/**
> >>+ * drm_simple_display_pipe_init - Initialize a simple display pipe
> >>+ * @dev: DRM device
> >>+ * @pipe: simple display pipe object to initialize
> >>+ * @funcs: callbacks for the display pipe
> >>+ * @formats: array of supported formats (%DRM_FORMAT_*)
> >>+ * @format_count: number of elements in @formats
> >>+ * @connector: connector to attach and register
> >>+ *
> >>+ * Sets up a display pipe which consist of a really simple plane-crtc-encoder
> >>+ * pipe coupled with the provided connector.
> >>+ *
> >>+ * Returns:
> >>+ * Zero on success, error code on failure.
> >>+ */
> >>+int drm_simple_display_pipe_init(struct drm_device *dev,
> >>+ struct drm_simple_display_pipe *pipe,
> >>+ struct drm_simple_display_pipe_funcs *funcs,
> >>+ const uint32_t *formats, unsigned int format_count,
> >>+ struct drm_connector *connector)
> >>+{
> >>+ struct drm_encoder *encoder = &pipe->encoder;
> >>+ struct drm_plane *plane = &pipe->plane;
> >>+ struct drm_crtc *crtc = &pipe->crtc;
> >>+ int ret;
> >>+
> >>+ pipe->funcs = funcs;
> >>+
> >>+ drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
> >>+ ret = drm_universal_plane_init(dev, plane, 0, &drm_simple_kms_plane_funcs,
> >>+ formats, format_count,
> >>+ DRM_PLANE_TYPE_PRIMARY, NULL);
> >>+ if (ret)
> >>+ return ret;
> >>+
> >>+ drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
> >>+ ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
> >>+ &drm_simple_kms_crtc_funcs, NULL);
> >>+ if (ret)
> >>+ return ret;
> >>+
> >>+ encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
> >>+ drm_encoder_helper_add(encoder, &drm_simple_kms_encoder_helper_funcs);
> >>+ ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
> >>+ DRM_MODE_ENCODER_NONE, NULL);
> >>+ if (ret)
> >>+ return ret;
> >>+
> >>+ ret = drm_mode_connector_attach_encoder(connector, encoder);
> >>+ if (ret)
> >>+ return ret;
> >>+
> >>+ return drm_connector_register(connector);
> >>+}
> >>+EXPORT_SYMBOL(drm_simple_display_pipe_init);
> >>+
> >>+MODULE_LICENSE("GPL");
> >>diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
> >>new file mode 100644
> >>index 0000000..0f7461b
> >>--- /dev/null
> >>+++ b/include/drm/drm_simple_kms_helper.h
> >>@@ -0,0 +1,44 @@
> >>+/*
> >>+ * Copyright (C) 2016 Noralf Trønnes
> >>+ *
> >>+ * This program is free software; you can redistribute it and/or modify
> >>+ * it under the terms of the GNU General Public License as published by
> >>+ * the Free Software Foundation; either version 2 of the License, or
> >>+ * (at your option) any later version.
> >>+ */
> >>+
> >>+#ifndef __LINUX_DRM_SIMPLE_KMS_HELPER_H
> >>+#define __LINUX_DRM_SIMPLE_KMS_HELPER_H
> >>+
> >>+struct drm_simple_display_pipe;
> >>+
> >>+struct drm_simple_display_pipe_funcs {
> >>+ void (*enable)(struct drm_simple_display_pipe *pipe,
> >>+ struct drm_crtc_state *crtc_state);
> >>+ void (*disable)(struct drm_simple_display_pipe *pipe);
> >>+ void (*plane_update)(struct drm_simple_display_pipe *pipe,
> >>+ struct drm_plane_state *plane_state);
> >On 2nd thought maybe we want an atomic_check in here too, with same
> >parameters *pipe, *crtc_state and *plane_state (so that it's useful for
> >both plane-only updates and modeset changes).
>
> I could do this for the plane:
>
> struct drm_simple_display_pipe_funcs {
> void (*plane_check)(struct drm_simple_display_pipe *pipe,
> struct drm_plane_state *plane_state);
> }
>
> static void drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
> struct drm_plane_state *state)
> {
> struct drm_simple_display_pipe *pipe;
>
> pipe = container_of(plane, struct drm_simple_display_pipe, plane);
> if (!pipe->funcs || !pipe->funcs->plane_check)
> return;
>
> pipe->funcs->plane_check(pipe, state);
> }
>
> static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs
> = {
> .atomic_check = drm_simple_kms_plane_atomic_check,
> };
>
> But how should I do crtc_state ?
Atomic core guarantees that if you have a plane state, then the crtc state
for that plane is always hanging around. You should be able to get at it
(but only for atomic_check functions, there's a different way in the
commit hooks) using:
drm_atomic_get_existing_plane_state(plane_state->state,
plane_state->crtc);
Yes I know I should get around to documeting all the structures we have
... Unfortunately it's a bit a mess and I'd like to clean up the code
organization first a bit.
Cheers, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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