[PATCH v2 12/21] drm/bridge: Add a drm_bridge_state object
Boris Brezillon
boris.brezillon at collabora.com
Mon Aug 26 15:26:40 UTC 2019
One of the last remaining objects to not have its atomic state.
This is being motivated by our attempt to support runtime bus-format
negotiation between elements of the bridge chain.
This patch just paves the road for such a feature by adding a new
drm_bridge_state object inheriting from drm_private_obj so we can
re-use some of the existing state initialization/tracking logic.
Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
---
Changes in v2:
* Use drm_for_each_bridge_in_chain()
* Rename helpers to be more consistent with the rest of the DRM API
* Improve/fix the doc
---
drivers/gpu/drm/drm_atomic.c | 39 +++++++
drivers/gpu/drm/drm_atomic_helper.c | 20 ++++
drivers/gpu/drm/drm_bridge.c | 168 +++++++++++++++++++++++++++-
include/drm/drm_atomic.h | 3 +
include/drm/drm_bridge.h | 118 +++++++++++++++++++
5 files changed, 343 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 419381abbdd1..6c249ce39380 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -30,6 +30,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_bridge.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
@@ -1010,6 +1011,44 @@ static void drm_atomic_connector_print_state(struct drm_printer *p,
connector->funcs->atomic_print_state(p, state);
}
+/**
+ * drm_atomic_add_encoder_bridges - add bridges attached to an encoder
+ * @state: atomic state
+ * @encoder: DRM encoder
+ *
+ * This function adds all bridges attached to @encoder. This is needed to add
+ * bridge states to @state and make them available when
+ * &bridge_funcs.atomic_{check,pre_enable,enable,disable_post_disable}() are
+ * called
+ *
+ * Returns:
+ * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
+ * then the w/w mutex code has detected a deadlock and the entire atomic
+ * sequence must be restarted. All other errors are fatal.
+ */
+int
+drm_atomic_add_encoder_bridges(struct drm_atomic_state *state,
+ struct drm_encoder *encoder)
+{
+ struct drm_bridge_state *bridge_state;
+ struct drm_bridge *bridge;
+
+ if (!encoder)
+ return 0;
+
+ DRM_DEBUG_ATOMIC("Adding all bridges for [encoder:%d:%s] to %p\n",
+ encoder->base.id, encoder->name, state);
+
+ drm_for_each_bridge_in_chain(encoder, bridge) {
+ bridge_state = drm_atomic_get_bridge_state(state, bridge);
+ if (IS_ERR(bridge_state))
+ return PTR_ERR(bridge_state);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(drm_atomic_add_encoder_bridges);
+
/**
* drm_atomic_add_affected_connectors - add connectors for crtc
* @state: atomic state
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index cccd9e3531c1..b3f59e757b30 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -736,6 +736,26 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
return ret;
}
+ /*
+ * Iterate over all connectors again, and add all affected bridges to
+ * the state.
+ */
+ for_each_oldnew_connector_in_state(state, connector,
+ old_connector_state,
+ new_connector_state, i) {
+ struct drm_encoder *encoder;
+
+ encoder = old_connector_state->best_encoder;
+ ret = drm_atomic_add_encoder_bridges(state, encoder);
+ if (ret)
+ return ret;
+
+ encoder = new_connector_state->best_encoder;
+ ret = drm_atomic_add_encoder_bridges(state, encoder);
+ if (ret)
+ return ret;
+ }
+
ret = mode_valid(state);
if (ret)
return ret;
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 695ad67d33a5..6c2d7691455b 100644
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -25,6 +25,7 @@
#include <linux/module.h>
#include <linux/mutex.h>
+#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_encoder.h>
@@ -89,6 +90,38 @@ void drm_bridge_remove(struct drm_bridge *bridge)
}
EXPORT_SYMBOL(drm_bridge_remove);
+static struct drm_private_state *
+drm_bridge_atomic_duplicate_priv_state(struct drm_private_obj *obj)
+{
+ struct drm_bridge *bridge = drm_priv_to_bridge(obj);
+ struct drm_bridge_state *state;
+
+ if (bridge->funcs->atomic_duplicate_state)
+ state = bridge->funcs->atomic_duplicate_state(bridge);
+ else
+ state = drm_atomic_helper_bridge_duplicate_state(bridge);
+
+ return &state->base;
+}
+
+static void
+drm_bridge_atomic_destroy_priv_state(struct drm_private_obj *obj,
+ struct drm_private_state *s)
+{
+ struct drm_bridge_state *state = drm_priv_to_bridge_state(s);
+ struct drm_bridge *bridge = drm_priv_to_bridge(obj);
+
+ if (bridge->funcs->atomic_destroy_state)
+ bridge->funcs->atomic_destroy_state(bridge, state);
+ else
+ drm_atomic_helper_bridge_destroy_state(bridge, state);
+}
+
+static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = {
+ .atomic_duplicate_state = drm_bridge_atomic_duplicate_priv_state,
+ .atomic_destroy_state = drm_bridge_atomic_destroy_priv_state,
+};
+
/**
* drm_bridge_attach - attach the bridge to an encoder's chain
*
@@ -114,6 +147,7 @@ EXPORT_SYMBOL(drm_bridge_remove);
int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
struct drm_bridge *previous)
{
+ struct drm_bridge_state *state;
LIST_HEAD(tmp_list);
int ret;
@@ -132,13 +166,24 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
if (bridge->funcs->attach) {
ret = bridge->funcs->attach(bridge);
- if (ret < 0) {
- bridge->dev = NULL;
- bridge->encoder = NULL;
- return ret;
- }
+ if (ret < 0)
+ goto err_reset_bridge;
}
+ if (bridge->funcs->atomic_reset)
+ state = bridge->funcs->atomic_reset(bridge);
+ else
+ state = drm_atomic_helper_bridge_reset(bridge);
+
+ if (IS_ERR(state)) {
+ ret = PTR_ERR(state);
+ goto err_detach_bridge;
+ }
+
+ drm_atomic_private_obj_init(bridge->dev, &bridge->base,
+ &state->base,
+ &drm_bridge_priv_state_funcs);
+
if (bridge == &encoder->bridge)
list_splice(&tmp_list, &encoder->bridge_chain);
else if (!previous)
@@ -147,6 +192,15 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
list_splice(&tmp_list, &previous->chain_node);
return 0;
+
+err_detach_bridge:
+ if (bridge->funcs->detach)
+ bridge->funcs->detach(bridge);
+
+err_reset_bridge:
+ bridge->dev = NULL;
+ bridge->encoder = NULL;
+ return ret;
}
EXPORT_SYMBOL(drm_bridge_attach);
@@ -158,6 +212,8 @@ void drm_bridge_detach(struct drm_bridge *bridge)
if (WARN_ON(!bridge->dev))
return;
+ drm_atomic_private_obj_fini(&bridge->base);
+
if (bridge->funcs->detach)
bridge->funcs->detach(bridge);
@@ -492,6 +548,108 @@ void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
}
EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
+/**
+ * drm_atomic_helper_bridge_destroy_state() - Default destroy state helper
+ * @bridge: the bridge this state refers to
+ * @state: state object to destroy
+ *
+ * Just a simple kfree() for now.
+ */
+void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
+
+/**
+ * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
+ * default
+ * @bridge: the bridge this state is refers to
+ * @state: bridge state to initialize
+ *
+ * For now it's just a memset(0) plus a state->bridge assignment. Might
+ * be extended in the future.
+ */
+void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
+ struct drm_bridge_state *state)
+{
+ memset(state, 0, sizeof(*state));
+ state->bridge = bridge;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
+
+/**
+ * drm_atomic_helper_bridge_reset() - default &drm_plane_funcs.reset hook for
+ * bridges
+ * @bridge: the bridge to reset state on
+ *
+ * Resets the atomic state for @bridge by freeing the state pointer (which
+ * might be NULL, e.g. at driver load time) and allocating a new empty state
+ * object.
+ *
+ * RETURNS:
+ * A valid drm_bridge_state object in case of success, an ERR_PTR()
+ * giving the reaon of the failure otherwise.
+ */
+struct drm_bridge_state *
+drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
+{
+ struct drm_bridge_state *bridge_state;
+
+ bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
+ if (!bridge_state)
+ return ERR_PTR(-ENOMEM);
+
+ __drm_atomic_helper_bridge_reset(bridge, bridge_state);
+ return bridge_state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);
+
+/**
+ * __drm_atomic_helper_bridge_duplicate_state() - Copy the content of the
+ * current bridge state into a
+ * new one
+ * @bridge: bridge element the old and new states are referring to
+ * @new: new bridge state to copy to
+ *
+ * Should be used by custom &drm_bridge_funcs.atomic_duplicate() implementation
+ * to copy the previous state into the new object.
+ */
+void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *new)
+{
+ __drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
+ &new->base);
+ new->bridge = bridge;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
+
+/**
+ * drm_atomic_helper_duplicate_bridge_state() - Default duplicate state helper
+ * @bridge: bridge containing the state to duplicate
+ *
+ * Default implementation of &drm_bridge_funcs.atomic_duplicate().
+ *
+ * RETURNS:
+ * a valid state object or NULL if the allocation fails.
+ */
+struct drm_bridge_state *
+drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
+{
+ struct drm_bridge_state *new;
+
+ if (WARN_ON(!bridge->base.state))
+ return NULL;
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (new)
+ __drm_atomic_helper_bridge_duplicate_state(bridge, new);
+
+ return new;
+}
+EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
+
#ifdef CONFIG_OF
/**
* of_drm_find_bridge - find the bridge corresponding to the device node in
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 927e1205d7aa..1c0a08217712 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -660,6 +660,9 @@ __drm_atomic_get_current_plane_state(struct drm_atomic_state *state,
return plane->state;
}
+int __must_check
+drm_atomic_add_encoder_bridges(struct drm_atomic_state *state,
+ struct drm_encoder *encoder);
int __must_check
drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
struct drm_crtc *crtc);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index cf05b30f2967..11b20e2a9fc6 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -25,6 +25,7 @@
#include <linux/list.h>
#include <linux/ctype.h>
+#include <drm/drm_atomic.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_modes.h>
@@ -32,6 +33,23 @@ struct drm_bridge;
struct drm_bridge_timings;
struct drm_panel;
+/**
+ * struct drm_bridge_state - Atomic bridge state object
+ * @base: inherit from &drm_private_state
+ * @bridge: the bridge this state refers to
+ */
+struct drm_bridge_state {
+ struct drm_private_state base;
+
+ struct drm_bridge *bridge;
+};
+
+static inline struct drm_bridge_state *
+drm_priv_to_bridge_state(struct drm_private_state *priv)
+{
+ return container_of(priv, struct drm_bridge_state, base);
+}
+
/**
* struct drm_bridge_funcs - drm_bridge control functions
*/
@@ -337,6 +355,48 @@ struct drm_bridge_funcs {
*/
void (*atomic_post_disable)(struct drm_bridge *bridge,
struct drm_atomic_state *state);
+
+ /**
+ * @atomic_duplicate_state:
+ *
+ * Duplicate the current bridge state object (which is guaranteed to be
+ * non-NULL).
+ *
+ * The atomic_duplicate_state() is optional, the core falls back on
+ * &drm_atomic_helper_bridge_duplicate_state() when not implemented.
+ *
+ * RETURNS:
+ * A valid drm_bridge_state object or NULL if the allocation fails.
+ */
+ struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
+
+ /**
+ * @atomic_destroy_state:
+ *
+ * Destroy a bridge state object previously allocated by
+ * &drm_bridge_funcs.atomic_duplicate_state().
+ *
+ * The atomic_destroy_state hook is optional, the coref falls back on
+ * &drm_atomic_helper_bridge_destroy_state() when not implemented.
+ */
+ void (*atomic_destroy_state)(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+
+ /**
+ * @atomic_reset:
+ *
+ * Reset the bridge to a predefined state (or retrieve its current
+ * state) and return a &drm_bridge_state object matching this state.
+ * This function is called at attach time.
+ *
+ * The atomic_reset hook is optional, the core falls back on
+ * &drm_atomic_helper_bridge_reset() when not implemented.
+ *
+ * RETURNS:
+ * A valid drm_bridge_state object in case of success, an ERR_PTR()
+ * giving the reaon of the failure otherwise.
+ */
+ struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
};
/**
@@ -379,6 +439,8 @@ struct drm_bridge_timings {
* struct drm_bridge - central DRM bridge control structure
*/
struct drm_bridge {
+ /** @base: inherit from &drm_private_object */
+ struct drm_private_obj base;
/** @dev: DRM device this bridge belongs to */
struct drm_device *dev;
/** @encoder: encoder to which this bridge is connected */
@@ -403,6 +465,12 @@ struct drm_bridge {
void *driver_private;
};
+static inline struct drm_bridge *
+drm_priv_to_bridge(struct drm_private_obj *priv)
+{
+ return container_of(priv, struct drm_bridge, base);
+}
+
void drm_bridge_add(struct drm_bridge *bridge);
void drm_bridge_remove(struct drm_bridge *bridge);
struct drm_bridge *of_drm_find_bridge(struct device_node *np);
@@ -445,6 +513,56 @@ void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
struct drm_atomic_state *state);
+void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+struct drm_bridge_state *
+drm_atomic_helper_bridge_reset(struct drm_bridge *bridge);
+void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *state);
+void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
+ struct drm_bridge_state *new);
+struct drm_bridge_state *
+drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge);
+
+static inline struct drm_bridge_state *
+drm_atomic_get_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge)
+{
+ struct drm_private_state *obj_state;
+
+ obj_state = drm_atomic_get_private_obj_state(state, &bridge->base);
+ if (!obj_state)
+ return NULL;
+
+ return drm_priv_to_bridge_state(obj_state);
+}
+
+static inline struct drm_bridge_state *
+drm_atomic_get_old_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge)
+{
+ struct drm_private_state *obj_state;
+
+ obj_state = drm_atomic_get_old_private_obj_state(state, &bridge->base);
+ if (!obj_state)
+ return NULL;
+
+ return drm_priv_to_bridge_state(obj_state);
+}
+
+static inline struct drm_bridge_state *
+drm_atomic_get_new_bridge_state(struct drm_atomic_state *state,
+ struct drm_bridge *bridge)
+{
+ struct drm_private_state *obj_state;
+
+ obj_state = drm_atomic_get_new_private_obj_state(state, &bridge->base);
+ if (!obj_state)
+ return NULL;
+
+ return drm_priv_to_bridge_state(obj_state);
+}
+
#ifdef CONFIG_DRM_PANEL_BRIDGE
struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
u32 connector_type);
--
2.21.0
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