diff options
Diffstat (limited to 'include/drm/drm_panel.h')
| -rw-r--r-- | include/drm/drm_panel.h | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index c2ab77add67c..29e3daf1b25d 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -30,8 +30,42 @@ struct drm_connector; struct drm_device; struct drm_panel; +/** + * struct drm_panel_funcs - perform operations on a given panel + * @disable: disable panel (turn off back light, etc.) + * @unprepare: turn off panel + * @prepare: turn on panel and perform set up + * @enable: enable panel (turn on back light, etc.) + * @get_modes: add modes to the connector that the panel is attached to and + * return the number of modes added + * + * The .prepare() function is typically called before the display controller + * starts to transmit video data. Panel drivers can use this to turn the panel + * on and wait for it to become ready. If additional configuration is required + * (via a control bus such as I2C, SPI or DSI for example) this is a good time + * to do that. + * + * After the display controller has started transmitting video data, it's safe + * to call the .enable() function. This will typically enable the backlight to + * make the image on screen visible. Some panels require a certain amount of + * time or frames before the image is displayed. This function is responsible + * for taking this into account before enabling the backlight to avoid visual + * glitches. + * + * Before stopping video transmission from the display controller it can be + * necessary to turn off the panel to avoid visual glitches. This is done in + * the .disable() function. Analogously to .enable() this typically involves + * turning off the backlight and waiting for some time to make sure no image + * is visible on the panel. It is then safe for the display controller to + * cease transmission of video data. + * + * To save power when no video data is transmitted, a driver can power down + * the panel. This is the job of the .unprepare() function. + */ struct drm_panel_funcs { int (*disable)(struct drm_panel *panel); + int (*unprepare)(struct drm_panel *panel); + int (*prepare)(struct drm_panel *panel); int (*enable)(struct drm_panel *panel); int (*get_modes)(struct drm_panel *panel); }; @@ -46,6 +80,14 @@ struct drm_panel { struct list_head list; }; +static inline int drm_panel_unprepare(struct drm_panel *panel) +{ + if (panel && panel->funcs && panel->funcs->unprepare) + return panel->funcs->unprepare(panel); + + return panel ? -ENOSYS : -EINVAL; +} + static inline int drm_panel_disable(struct drm_panel *panel) { if (panel && panel->funcs && panel->funcs->disable) @@ -54,6 +96,14 @@ static inline int drm_panel_disable(struct drm_panel *panel) return panel ? -ENOSYS : -EINVAL; } +static inline int drm_panel_prepare(struct drm_panel *panel) +{ + if (panel && panel->funcs && panel->funcs->prepare) + return panel->funcs->prepare(panel); + + return panel ? -ENOSYS : -EINVAL; +} + static inline int drm_panel_enable(struct drm_panel *panel) { if (panel && panel->funcs && panel->funcs->enable) |