diff options
| -rw-r--r-- | Documentation/gpu/drm-kms.rst | 8 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_crtc.c | 21 | ||||
| -rw-r--r-- | include/drm/drm_crtc.h | 25 |
3 files changed, 47 insertions, 7 deletions
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst index 0c9abdc0ee31..4d4068855ec4 100644 --- a/Documentation/gpu/drm-kms.rst +++ b/Documentation/gpu/drm-kms.rst @@ -48,11 +48,17 @@ CRTC Abstraction ================ .. kernel-doc:: drivers/gpu/drm/drm_crtc.c - :export: + :doc: overview + +CRTC Functions Reference +-------------------------------- .. kernel-doc:: include/drm/drm_crtc.h :internal: +.. kernel-doc:: drivers/gpu/drm/drm_crtc.c + :export: + Frame Buffer Abstraction ======================== diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index cea7a7efa43c..5b522092d4bb 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -47,6 +47,27 @@ #include "drm_internal.h" /** + * DOC: overview + * + * A CRTC represents the overall display pipeline. It receives pixel data from + * &drm_plane and blends them together. The &drm_display_mode is also attached + * to the CRTC, specifying display timings. On the output side the data is fed + * to one or more &drm_encoder, which are then each connected to one + * &drm_connector. + * + * To create a CRTC, a KMS drivers allocates and zeroes an instances of + * &struct drm_crtc (possibly as part of a larger structure) and registers it + * with a call to drm_crtc_init_with_planes(). + * + * The CRTC is also the entry point for legacy modeset operations, see + * &drm_crtc_funcs.set_config, legacy plane operations, see + * &drm_crtc_funcs.page_flip and &drm_crtc_funcs.cursor_set2, and other legacy + * operations like &drm_crtc_funcs.gamma_set. For atomic drivers all these + * features are controlled through &drm_property and + * &drm_mode_config_funcs.atomic_check and &drm_mode_config_funcs.atomic_check. + */ + +/** * drm_crtc_from_index - find the registered CRTC at an index * @dev: DRM device * @idx: index of registered CRTC to find for diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 10661e156d89..2404b23cddb4 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -641,7 +641,7 @@ struct drm_crtc { * * This provides a read lock for the overall crtc state (mode, dpms * state, ...) and a write lock for everything which can be update - * without a full modeset (fb, cursor data, crtc properties ...). Full + * without a full modeset (fb, cursor data, crtc properties ...). A full * modeset also need to grab &drm_mode_config.connection_mutex. */ struct drm_modeset_lock mutex; @@ -774,10 +774,8 @@ struct drm_crtc { * @connectors: array of connectors to drive with this CRTC if possible * @num_connectors: size of @connectors array * - * Represents a single crtc the connectors that it drives with what mode - * and from which framebuffer it scans out from. - * - * This is used to set modes. + * This represents a modeset configuration for the legacy SETCRTC ioctl and is + * also used internally. Atomic drivers instead use &drm_atomic_state. */ struct drm_mode_set { struct drm_framebuffer *fb; @@ -834,7 +832,15 @@ int drm_crtc_force_disable_all(struct drm_device *dev); int drm_mode_set_config_internal(struct drm_mode_set *set); struct drm_crtc *drm_crtc_from_index(struct drm_device *dev, int idx); -/* Helpers */ +/** + * drm_crtc_find - look up a CRTC object from its ID + * @dev: DRM device + * @id: &drm_mode_object ID + * + * This can be used to look up a CRTC from its userspace ID. Only used by + * drivers for legacy IOCTLs and interface, nowadays extensions to the KMS + * userspace interface should be done using &drm_property. + */ static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev, uint32_t id) { @@ -843,6 +849,13 @@ static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev, return mo ? obj_to_crtc(mo) : NULL; } +/** + * drm_for_each_crtc - iterate over all CRTCs + * @crtc: a &struct drm_crtc as the loop cursor + * @dev: the &struct drm_device + * + * Iterate over all CRTCs of @dev. + */ #define drm_for_each_crtc(crtc, dev) \ list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head) |