diff options
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 173 | ||||
| -rw-r--r-- | include/drm/drm_panel.h | 82 |
2 files changed, 251 insertions, 4 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 4e1c4e42575b..e814020bbcd3 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -58,6 +58,8 @@ void drm_panel_init(struct drm_panel *panel, struct device *dev, const struct drm_panel_funcs *funcs, int connector_type) { INIT_LIST_HEAD(&panel->list); + INIT_LIST_HEAD(&panel->followers); + mutex_init(&panel->follower_lock); panel->dev = dev; panel->funcs = funcs; panel->connector_type = connector_type; @@ -105,6 +107,7 @@ EXPORT_SYMBOL(drm_panel_remove); */ int drm_panel_prepare(struct drm_panel *panel) { + struct drm_panel_follower *follower; int ret; if (!panel) @@ -115,14 +118,27 @@ int drm_panel_prepare(struct drm_panel *panel) return 0; } + mutex_lock(&panel->follower_lock); + if (panel->funcs && panel->funcs->prepare) { ret = panel->funcs->prepare(panel); if (ret < 0) - return ret; + goto exit; } panel->prepared = true; - return 0; + list_for_each_entry(follower, &panel->followers, list) { + ret = follower->funcs->panel_prepared(follower); + if (ret < 0) + dev_info(panel->dev, "%ps failed: %d\n", + follower->funcs->panel_prepared, ret); + } + + ret = 0; +exit: + mutex_unlock(&panel->follower_lock); + + return ret; } EXPORT_SYMBOL(drm_panel_prepare); @@ -139,6 +155,7 @@ EXPORT_SYMBOL(drm_panel_prepare); */ int drm_panel_unprepare(struct drm_panel *panel) { + struct drm_panel_follower *follower; int ret; if (!panel) @@ -149,14 +166,27 @@ int drm_panel_unprepare(struct drm_panel *panel) return 0; } + mutex_lock(&panel->follower_lock); + + list_for_each_entry(follower, &panel->followers, list) { + ret = follower->funcs->panel_unpreparing(follower); + if (ret < 0) + dev_info(panel->dev, "%ps failed: %d\n", + follower->funcs->panel_unpreparing, ret); + } + if (panel->funcs && panel->funcs->unprepare) { ret = panel->funcs->unprepare(panel); if (ret < 0) - return ret; + goto exit; } panel->prepared = false; - return 0; + ret = 0; +exit: + mutex_unlock(&panel->follower_lock); + + return ret; } EXPORT_SYMBOL(drm_panel_unprepare); @@ -342,6 +372,141 @@ int of_drm_get_panel_orientation(const struct device_node *np, EXPORT_SYMBOL(of_drm_get_panel_orientation); #endif +/** + * drm_is_panel_follower() - Check if the device is a panel follower + * @dev: The 'struct device' to check + * + * This checks to see if a device needs to be power sequenced together with + * a panel using the panel follower API. + * At the moment panels can only be followed on device tree enabled systems. + * The "panel" property of the follower points to the panel to be followed. + * + * Return: true if we should be power sequenced with a panel; false otherwise. + */ +bool drm_is_panel_follower(struct device *dev) +{ + /* + * The "panel" property is actually a phandle, but for simplicity we + * don't bother trying to parse it here. We just need to know if the + * property is there. + */ + return of_property_read_bool(dev->of_node, "panel"); +} +EXPORT_SYMBOL(drm_is_panel_follower); + +/** + * drm_panel_add_follower() - Register something to follow panel state. + * @follower_dev: The 'struct device' for the follower. + * @follower: The panel follower descriptor for the follower. + * + * A panel follower is called right after preparing the panel and right before + * unpreparing the panel. It's primary intention is to power on an associated + * touchscreen, though it could be used for any similar devices. Multiple + * devices are allowed the follow the same panel. + * + * If a follower is added to a panel that's already been turned on, the + * follower's prepare callback is called right away. + * + * At the moment panels can only be followed on device tree enabled systems. + * The "panel" property of the follower points to the panel to be followed. + * + * Return: 0 or an error code. Note that -ENODEV means that we detected that + * follower_dev is not actually following a panel. The caller may + * choose to ignore this return value if following a panel is optional. + */ +int drm_panel_add_follower(struct device *follower_dev, + struct drm_panel_follower *follower) +{ + struct device_node *panel_np; + struct drm_panel *panel; + int ret; + + panel_np = of_parse_phandle(follower_dev->of_node, "panel", 0); + if (!panel_np) + return -ENODEV; + + panel = of_drm_find_panel(panel_np); + of_node_put(panel_np); + if (IS_ERR(panel)) + return PTR_ERR(panel); + + get_device(panel->dev); + follower->panel = panel; + + mutex_lock(&panel->follower_lock); + + list_add_tail(&follower->list, &panel->followers); + if (panel->prepared) { + ret = follower->funcs->panel_prepared(follower); + if (ret < 0) + dev_info(panel->dev, "%ps failed: %d\n", + follower->funcs->panel_prepared, ret); + } + + mutex_unlock(&panel->follower_lock); + + return 0; +} +EXPORT_SYMBOL(drm_panel_add_follower); + +/** + * drm_panel_remove_follower() - Reverse drm_panel_add_follower(). + * @follower: The panel follower descriptor for the follower. + * + * Undo drm_panel_add_follower(). This includes calling the follower's + * unprepare function if we're removed from a panel that's currently prepared. + * + * Return: 0 or an error code. + */ +void drm_panel_remove_follower(struct drm_panel_follower *follower) +{ + struct drm_panel *panel = follower->panel; + int ret; + + mutex_lock(&panel->follower_lock); + + if (panel->prepared) { + ret = follower->funcs->panel_unpreparing(follower); + if (ret < 0) + dev_info(panel->dev, "%ps failed: %d\n", + follower->funcs->panel_unpreparing, ret); + } + list_del_init(&follower->list); + + mutex_unlock(&panel->follower_lock); + + put_device(panel->dev); +} +EXPORT_SYMBOL(drm_panel_remove_follower); + +static void drm_panel_remove_follower_void(void *follower) +{ + drm_panel_remove_follower(follower); +} + +/** + * devm_drm_panel_add_follower() - devm version of drm_panel_add_follower() + * @follower_dev: The 'struct device' for the follower. + * @follower: The panel follower descriptor for the follower. + * + * Handles calling drm_panel_remove_follower() using devm on the follower_dev. + * + * Return: 0 or an error code. + */ +int devm_drm_panel_add_follower(struct device *follower_dev, + struct drm_panel_follower *follower) +{ + int ret; + + ret = drm_panel_add_follower(follower_dev, follower); + if (ret) + return ret; + + return devm_add_action_or_reset(follower_dev, + drm_panel_remove_follower_void, follower); +} +EXPORT_SYMBOL(devm_drm_panel_add_follower); + #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE) /** * drm_panel_of_backlight - use backlight device node for backlight diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index c6cf75909389..d6c73f79c131 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -27,12 +27,14 @@ #include <linux/err.h> #include <linux/errno.h> #include <linux/list.h> +#include <linux/mutex.h> struct backlight_device; struct dentry; struct device_node; struct drm_connector; struct drm_device; +struct drm_panel_follower; struct drm_panel; struct display_timing; @@ -144,6 +146,45 @@ struct drm_panel_funcs { void (*debugfs_init)(struct drm_panel *panel, struct dentry *root); }; +struct drm_panel_follower_funcs { + /** + * @panel_prepared: + * + * Called after the panel has been powered on. + */ + int (*panel_prepared)(struct drm_panel_follower *follower); + + /** + * @panel_unpreparing: + * + * Called before the panel is powered off. + */ + int (*panel_unpreparing)(struct drm_panel_follower *follower); +}; + +struct drm_panel_follower { + /** + * @funcs: + * + * Dependent device callbacks; should be initted by the caller. + */ + const struct drm_panel_follower_funcs *funcs; + + /** + * @list + * + * Used for linking into panel's list; set by drm_panel_add_follower(). + */ + struct list_head list; + + /** + * @panel + * + * The panel we're dependent on; set by drm_panel_add_follower(). + */ + struct drm_panel *panel; +}; + /** * struct drm_panel - DRM panel object */ @@ -190,6 +231,20 @@ struct drm_panel { struct list_head list; /** + * @followers: + * + * A list of struct drm_panel_follower dependent on this panel. + */ + struct list_head followers; + + /** + * @followers_lock: + * + * Lock for followers list. + */ + struct mutex follower_lock; + + /** * @prepare_prev_first: * * The previous controller should be prepared first, before the prepare @@ -246,6 +301,33 @@ static inline int of_drm_get_panel_orientation(const struct device_node *np, } #endif +#if defined(CONFIG_DRM_PANEL) +bool drm_is_panel_follower(struct device *dev); +int drm_panel_add_follower(struct device *follower_dev, + struct drm_panel_follower *follower); +void drm_panel_remove_follower(struct drm_panel_follower *follower); +int devm_drm_panel_add_follower(struct device *follower_dev, + struct drm_panel_follower *follower); +#else +static inline bool drm_is_panel_follower(struct device *dev) +{ + return false; +} + +static inline int drm_panel_add_follower(struct device *follower_dev, + struct drm_panel_follower *follower) +{ + return -ENODEV; +} + +static inline void drm_panel_remove_follower(struct drm_panel_follower *follower) { } +static inline int devm_drm_panel_add_follower(struct device *follower_dev, + struct drm_panel_follower *follower) +{ + return -ENODEV; +} +#endif + #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \ (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE))) int drm_panel_of_backlight(struct drm_panel *panel); |