Den 21.11.2022 11.45, skrev Thomas Zimmermann:
> Introduce struct drm_mipi_dbi_plane_state that contains state related to
> MIPI DBI. It currently only inherits from struct drm_shadow_plane_state,
> so that MIPI DBI drivers can use the vmap'ed GEM-buffer memory. Implement
> state helpers, the {begin,end}_fb_access helpers and wire up everything.
>
> With this commit, MIPI DBI drivers can access the GEM object's memory
> that is provided by shadow-plane state. The actual changes to drivers
> are implemented separately. The new struct drm_mipi_dbi_plane was added
> to avoid exposing struct drm_shadow_plane_state directly. The latter is
> a detail of the actual implementation and having it in the MIPI driver
> interface seems unintuitive.
I don't understand this reasoning. The update functions still uses
drm_shadow_plane_state in order to access ->data[0]. If you want to
avoid exposing it, can't you add an accessor function for ->data[0]
instead? That would actually be useful to me at least since when I first
read the shadow plane code I didn't understand what data really was
referring to. fb_map would have been more clear to me.
Noralf.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
> drivers/gpu/drm/drm_mipi_dbi.c | 113 +++++++++++++++++++++++++++++++++
> drivers/gpu/drm/tiny/ili9225.c | 5 ++
> drivers/gpu/drm/tiny/st7586.c | 5 ++
> include/drm/drm_mipi_dbi.h | 30 ++++++++-
> 4 files changed, 152 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c
> index 40e59a3a6481e..3030344d25b48 100644
> --- a/drivers/gpu/drm/drm_mipi_dbi.c
> +++ b/drivers/gpu/drm/drm_mipi_dbi.c
> @@ -436,6 +436,119 @@ void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe)
> }
> EXPORT_SYMBOL(mipi_dbi_pipe_disable);
>
> +/**
> + * mipi_dbi_pipe_begin_fb_access - MIPI DBI pipe begin-access helper
> + * @pipe: Display pipe
> + * @plane_state: Plane state
> + *
> + * This function implements struct &drm_simple_display_funcs.begin_fb_access.
> + *
> + * See drm_gem_begin_shadow_fb_access() for details and mipi_dbi_pipe_cleanup_fb()
> + * for cleanup.
> + *
> + * Returns:
> + * 0 on success, or a negative errno code otherwise.
> + */
> +int mipi_dbi_pipe_begin_fb_access(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state)
> +{
> + return drm_gem_begin_shadow_fb_access(&pipe->plane, plane_state);
> +}
> +EXPORT_SYMBOL(mipi_dbi_pipe_begin_fb_access);
> +
> +/**
> + * mipi_dbi_pipe_end_fb_access - MIPI DBI pipe end-access helper
> + * @pipe: Display pipe
> + * @plane_state: Plane state
> + *
> + * This function implements struct &drm_simple_display_funcs.end_fb_access.
> + *
> + * See mipi_dbi_pipe_begin_fb_access().
> + */
> +void mipi_dbi_pipe_end_fb_access(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state)
> +{
> + drm_gem_end_shadow_fb_access(&pipe->plane, plane_state);
> +}
> +EXPORT_SYMBOL(mipi_dbi_pipe_end_fb_access);
> +
> +/**
> + * mipi_dbi_pipe_reset_plane - MIPI DBI plane-reset helper
> + * @pipe: Display pipe
> + *
> + * This function implements struct &drm_simple_display_funcs.reset_plane
> + * for MIPI DBI planes.
> + */
> +void mipi_dbi_pipe_reset_plane(struct drm_simple_display_pipe *pipe)
> +{
> + struct drm_plane *plane = &pipe->plane;
> + struct mipi_dbi_plane_state *mipi_dbi_plane_state;
> +
> + if (plane->state) {
> + mipi_dbi_pipe_destroy_plane_state(pipe, plane->state);
> + plane->state = NULL; /* must be set to NULL here */
> + }
> +
> + mipi_dbi_plane_state = kzalloc(sizeof(*mipi_dbi_plane_state), GFP_KERNEL);
> + if (!mipi_dbi_plane_state)
> + return;
> + __drm_gem_reset_shadow_plane(plane, &mipi_dbi_plane_state->shadow_plane_state);
> +}
> +EXPORT_SYMBOL(mipi_dbi_pipe_reset_plane);
> +
> +/**
> + * mipi_dbi_pipe_duplicate_plane_state - duplicates MIPI DBI plane state
> + * @pipe: Display pipe
> + *
> + * This function implements struct &drm_simple_display_funcs.duplicate_plane_state
> + * for MIPI DBI planes.
> + *
> + * See drm_gem_duplicate_shadow_plane_state() for additional details.
> + *
> + * Returns:
> + * A pointer to a new plane state on success, or NULL otherwise.
> + */
> +struct drm_plane_state *mipi_dbi_pipe_duplicate_plane_state(struct drm_simple_display_pipe *pipe)
> +{
> + struct drm_plane *plane = &pipe->plane;
> + struct drm_plane_state *plane_state = plane->state;
> + struct mipi_dbi_plane_state *new_mipi_dbi_plane_state;
> + struct drm_shadow_plane_state *new_shadow_plane_state;
> +
> + if (!plane_state)
> + return NULL;
> +
> + new_mipi_dbi_plane_state = kzalloc(sizeof(*new_mipi_dbi_plane_state), GFP_KERNEL);
> + if (!new_mipi_dbi_plane_state)
> + return NULL;
> + new_shadow_plane_state = &new_mipi_dbi_plane_state->shadow_plane_state;
> +
> + __drm_gem_duplicate_shadow_plane_state(plane, new_shadow_plane_state);
> +
> + return &new_shadow_plane_state->base;
> +}
> +EXPORT_SYMBOL(mipi_dbi_pipe_duplicate_plane_state);
> +
> +/**
> + * mipi_dbi_pipe_destroy_plane_state - cleans up MIPI DBI plane state
> + * @pipe: Display pipe
> + * @plane_state: Plane state
> + *
> + * This function implements struct drm_simple_display_funcs.destroy_plane_state
> + * for MIPI DBI planes.
> + *
> + * See drm_gem_destroy_shadow_plane_state() for additional details.
> + */
> +void mipi_dbi_pipe_destroy_plane_state(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state)
> +{
> + struct mipi_dbi_plane_state *mipi_dbi_plane_state = to_mipi_dbi_plane_state(plane_state);
> +
> + __drm_gem_destroy_shadow_plane_state(&mipi_dbi_plane_state->shadow_plane_state);
> + kfree(mipi_dbi_plane_state);
> +}
> +EXPORT_SYMBOL(mipi_dbi_pipe_destroy_plane_state);
> +
> static int mipi_dbi_connector_get_modes(struct drm_connector *connector)
> {
> struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(connector->dev);
> diff --git a/drivers/gpu/drm/tiny/ili9225.c b/drivers/gpu/drm/tiny/ili9225.c
> index 0115c4090f9e7..9e55ce28b4552 100644
> --- a/drivers/gpu/drm/tiny/ili9225.c
> +++ b/drivers/gpu/drm/tiny/ili9225.c
> @@ -349,6 +349,11 @@ static const struct drm_simple_display_pipe_funcs ili9225_pipe_funcs = {
> .enable = ili9225_pipe_enable,
> .disable = ili9225_pipe_disable,
> .update = ili9225_pipe_update,
> + .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
> + .end_fb_access = mipi_dbi_pipe_end_fb_access,
> + .reset_plane = mipi_dbi_pipe_reset_plane,
> + .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
> + .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
> };
>
> static const struct drm_display_mode ili9225_mode = {
> diff --git a/drivers/gpu/drm/tiny/st7586.c b/drivers/gpu/drm/tiny/st7586.c
> index e773b1f2fd5f3..76b13cefc904f 100644
> --- a/drivers/gpu/drm/tiny/st7586.c
> +++ b/drivers/gpu/drm/tiny/st7586.c
> @@ -277,6 +277,11 @@ static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
> .enable = st7586_pipe_enable,
> .disable = st7586_pipe_disable,
> .update = st7586_pipe_update,
> + .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
> + .end_fb_access = mipi_dbi_pipe_end_fb_access,
> + .reset_plane = mipi_dbi_pipe_reset_plane,
> + .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
> + .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
> };
>
> static const struct drm_display_mode st7586_mode = {
> diff --git a/include/drm/drm_mipi_dbi.h b/include/drm/drm_mipi_dbi.h
> index 36ac8495566b0..0213d4aae0326 100644
> --- a/include/drm/drm_mipi_dbi.h
> +++ b/include/drm/drm_mipi_dbi.h
> @@ -10,6 +10,7 @@
>
> #include <linux/mutex.h>
> #include <drm/drm_device.h>
> +#include <drm/drm_gem_atomic_helper.h>
> #include <drm/drm_simple_kms_helper.h>
>
> struct drm_rect;
> @@ -18,6 +19,19 @@ struct iosys_map;
> struct regulator;
> struct spi_device;
>
> +/**
> + * struct mipi_dbi_plane_state - MIPI DBI plane state
> + */
> +struct mipi_dbi_plane_state {
> + struct drm_shadow_plane_state shadow_plane_state;
> +};
> +
> +static inline struct mipi_dbi_plane_state *
> +to_mipi_dbi_plane_state(struct drm_plane_state *plane_state)
> +{
> + return container_of(plane_state, struct mipi_dbi_plane_state, shadow_plane_state.base);
> +}
> +
> /**
> * struct mipi_dbi - MIPI DBI interface
> */
> @@ -164,6 +178,15 @@ void mipi_dbi_enable_flush(struct mipi_dbi_dev *dbidev,
> struct drm_crtc_state *crtc_state,
> struct drm_plane_state *plan_state);
> void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe);
> +int mipi_dbi_pipe_begin_fb_access(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state);
> +void mipi_dbi_pipe_end_fb_access(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state);
> +void mipi_dbi_pipe_reset_plane(struct drm_simple_display_pipe *pipe);
> +struct drm_plane_state *mipi_dbi_pipe_duplicate_plane_state(struct drm_simple_display_pipe *pipe);
> +void mipi_dbi_pipe_destroy_plane_state(struct drm_simple_display_pipe *pipe,
> + struct drm_plane_state *plane_state);
> +
> void mipi_dbi_hw_reset(struct mipi_dbi *dbi);
> bool mipi_dbi_display_is_on(struct mipi_dbi *dbi);
> int mipi_dbi_poweron_reset(struct mipi_dbi_dev *dbidev);
> @@ -223,6 +246,11 @@ static inline void mipi_dbi_debugfs_init(struct drm_minor *minor) {}
> .mode_valid = mipi_dbi_pipe_mode_valid, \
> .enable = (enable_), \
> .disable = mipi_dbi_pipe_disable, \
> - .update = mipi_dbi_pipe_update
> + .update = mipi_dbi_pipe_update, \
> + .begin_fb_access = mipi_dbi_pipe_begin_fb_access, \
> + .end_fb_access = mipi_dbi_pipe_end_fb_access, \
> + .reset_plane = mipi_dbi_pipe_reset_plane, \
> + .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state, \
> + .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state
>
> #endif /* __LINUX_MIPI_DBI_H */
