From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

commit 1b27fbdde1df172dba604855c45078d741f8c858 upstream.

Add functions to the atomic core to retrieve the old and new connectors
associated with an encoder in a drm_atomic_state. This is useful for
encoders and bridges that need to access the connector, for instance for
the drm_display_info.

The CRTC associated with the encoder can also be retrieved through the
connector state, and from it, the old and new CRTC states.

Changed in v4:
- Added to the set
Changed in v5:
- Fix up docbook (Daniel & Laurent)
Changed in v6:
- Updated commit subject (Sam)

Link to v4: https://patchwork.freedesktop.org/patch/msgid/20190508160920.144739-3-sean@poorly.run
Link to v5: https://patchwork.freedesktop.org/patch/msgid/20190611160844.257498-3-sean@poorly.run

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sam Ravnborg <sam@ravnborg.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

[seanpaul removed WARNs from helpers and added docs to explain why
returning NULL might be valid]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611205147.181298-1-sean@poorly.run
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
drivers/gpu/drm/drm_atomic.c | 113 +++++++++++++++++++++++++++++++++++
include/drm/drm_atomic.h | 7 +++
include/drm/drm_connector.h | 9 +++
3 files changed, 129 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 1a4b44923aec..d36742761ada 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1252,6 +1252,119 @@ drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
}
EXPORT_SYMBOL(drm_atomic_get_private_obj_state);

+/**
+ * drm_atomic_get_old_private_obj_state
+ * @state: global atomic state object
+ * @obj: private_obj to grab
+ *
+ * This function returns the old private object state for the given private_obj,
+ * or NULL if the private_obj is not part of the global atomic state.
+ */
+struct drm_private_state *
+drm_atomic_get_old_private_obj_state(struct drm_atomic_state *state,
+ struct drm_private_obj *obj)
+{
+ int i;
+
+ for (i = 0; i < state->num_private_objs; i++)
+ if (obj == state->private_objs[i].ptr)
+ return state->private_objs[i].old_state;
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_atomic_get_old_private_obj_state);
+
+/**
+ * drm_atomic_get_new_private_obj_state
+ * @state: global atomic state object
+ * @obj: private_obj to grab
+ *
+ * This function returns the new private object state for the given private_obj,
+ * or NULL if the private_obj is not part of the global atomic state.
+ */
+struct drm_private_state *
+drm_atomic_get_new_private_obj_state(struct drm_atomic_state *state,
+ struct drm_private_obj *obj)
+{
+ int i;
+
+ for (i = 0; i < state->num_private_objs; i++)
+ if (obj == state->private_objs[i].ptr)
+ return state->private_objs[i].new_state;
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_atomic_get_new_private_obj_state);
+
+/**
+ * drm_atomic_get_old_connector_for_encoder - Get old connector for an encoder
+ * @state: Atomic state
+ * @encoder: The encoder to fetch the connector state for
+ *
+ * This function finds and returns the connector that was connected to @encoder
+ * as specified by the @state.
+ *
+ * If there is no connector in @state which previously had @encoder connected to
+ * it, this function will return NULL. While this may seem like an invalid use
+ * case, it is sometimes useful to differentiate commits which had no prior
+ * connectors attached to @encoder vs ones that did (and to inspect their
+ * state). This is especially true in enable hooks because the pipeline has
+ * changed.
+ *
+ * Returns: The old connector connected to @encoder, or NULL if the encoder is
+ * not connected.
+ */
+struct drm_connector *
+drm_atomic_get_old_connector_for_encoder(struct drm_atomic_state *state,
+ struct drm_encoder *encoder)
+{
+ struct drm_connector_state *conn_state;
+ struct drm_connector *connector;
+ unsigned int i;
+
+ for_each_old_connector_in_state(state, connector, conn_state, i) {
+ if (conn_state->best_encoder == encoder)
+ return connector;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_atomic_get_old_connector_for_encoder);
+
+/**
+ * drm_atomic_get_new_connector_for_encoder - Get new connector for an encoder
+ * @state: Atomic state
+ * @encoder: The encoder to fetch the connector state for
+ *
+ * This function finds and returns the connector that will be connected to
+ * @encoder as specified by the @state.
+ *
+ * If there is no connector in @state which will have @encoder connected to it,
+ * this function will return NULL. While this may seem like an invalid use case,
+ * it is sometimes useful to differentiate commits which have no connectors
+ * attached to @encoder vs ones that do (and to inspect their state). This is
+ * especially true in disable hooks because the pipeline will change.
+ *
+ * Returns: The new connector connected to @encoder, or NULL if the encoder is
+ * not connected.
+ */
+struct drm_connector *
+drm_atomic_get_new_connector_for_encoder(struct drm_atomic_state *state,
+ struct drm_encoder *encoder)
+{
+ struct drm_connector_state *conn_state;
+ struct drm_connector *connector;
+ unsigned int i;
+
+ for_each_new_connector_in_state(state, connector, conn_state, i) {
+ if (conn_state->best_encoder == encoder)
+ return connector;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(drm_atomic_get_new_connector_for_encoder);
+
/**
* drm_atomic_get_connector_state - get connector state
* @state: global atomic state object
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 1e713154f00e..c0b48e25a620 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -403,6 +403,13 @@ struct drm_private_state * __must_check
drm_atomic_get_private_obj_state(struct drm_atomic_state *state,
struct drm_private_obj *obj);

+struct drm_connector *
+drm_atomic_get_old_connector_for_encoder(struct drm_atomic_state *state,
+ struct drm_encoder *encoder);
+struct drm_connector *
+drm_atomic_get_new_connector_for_encoder(struct drm_atomic_state *state,
+ struct drm_encoder *encoder);
+
/**
* drm_atomic_get_existing_crtc_state - get crtc state, if it exists
* @state: global atomic state object
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 97ea41dc678f..6f0a05b6581d 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -397,6 +397,15 @@ struct drm_connector_state {
* Used by the atomic helpers to select the encoder, through the
* &drm_connector_helper_funcs.atomic_best_encoder or
* &drm_connector_helper_funcs.best_encoder callbacks.
+ *
+ * This is also used in the atomic helpers to map encoders to their
+ * current and previous connectors, see
+ * &drm_atomic_get_old_connector_for_encoder() and
+ * &drm_atomic_get_new_connector_for_encoder().
+ *
+ * NOTE: Atomic drivers must fill this out (either themselves or through
+ * helpers), for otherwise the GETCONNECTOR and GETENCODER IOCTLs will
+ * not return correct data to userspace.
*/
struct drm_encoder *best_encoder;

--
2.17.1