diff options
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 62 | ||||
| -rw-r--r-- | include/drm/drm_panel.h | 25 |
2 files changed, 85 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 4ab7229fb22b..a5e4084eb0e3 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -21,11 +21,13 @@ * DEALINGS IN THE SOFTWARE. */ +#include <linux/backlight.h> #include <linux/err.h> #include <linux/module.h> #include <drm/drm_crtc.h> #include <drm/drm_panel.h> +#include <drm/drm_print.h> static DEFINE_MUTEX(panel_lock); static LIST_HEAD(panel_list); @@ -196,11 +198,21 @@ EXPORT_SYMBOL(drm_panel_unprepare); */ int drm_panel_enable(struct drm_panel *panel) { + int ret; + if (!panel) return -EINVAL; - if (panel->funcs && panel->funcs->enable) - return panel->funcs->enable(panel); + if (panel->funcs && panel->funcs->enable) { + ret = panel->funcs->enable(panel); + if (ret < 0) + return ret; + } + + ret = backlight_enable(panel->backlight); + if (ret < 0) + DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n", + ret); return 0; } @@ -218,9 +230,16 @@ EXPORT_SYMBOL(drm_panel_enable); */ int drm_panel_disable(struct drm_panel *panel) { + int ret; + if (!panel) return -EINVAL; + ret = backlight_disable(panel->backlight); + if (ret < 0) + DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n", + ret); + if (panel->funcs && panel->funcs->disable) return panel->funcs->disable(panel); @@ -289,6 +308,45 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np) EXPORT_SYMBOL(of_drm_find_panel); #endif +#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE +/** + * drm_panel_of_backlight - use backlight device node for backlight + * @panel: DRM panel + * + * Use this function to enable backlight handling if your panel + * uses device tree and has a backlight phandle. + * + * When the panel is enabled backlight will be enabled after a + * successful call to &drm_panel_funcs.enable() + * + * When the panel is disabled backlight will be disabled before the + * call to &drm_panel_funcs.disable(). + * + * A typical implementation for a panel driver supporting device tree + * will call this function at probe time. Backlight will then be handled + * transparently without requiring any intervention from the driver. + * drm_panel_of_backlight() must be called after the call to drm_panel_init(). + * + * Return: 0 on success or a negative error code on failure. + */ +int drm_panel_of_backlight(struct drm_panel *panel) +{ + struct backlight_device *backlight; + + if (!panel || !panel->dev) + return -EINVAL; + + backlight = devm_of_find_backlight(panel->dev); + + if (IS_ERR(backlight)) + return PTR_ERR(backlight); + + panel->backlight = backlight; + return 0; +} +EXPORT_SYMBOL(drm_panel_of_backlight); +#endif + MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>"); MODULE_DESCRIPTION("DRM panel infrastructure"); MODULE_LICENSE("GPL and additional rights"); diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 2bd1d806dbeb..54b5576ce0a9 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -28,6 +28,7 @@ #include <linux/errno.h> #include <linux/list.h> +struct backlight_device; struct device_node; struct drm_connector; struct drm_device; @@ -59,6 +60,10 @@ struct display_timing; * * To save power when no video data is transmitted, a driver can power down * the panel. This is the job of the .unprepare() function. + * + * Backlight can be handled automatically if configured using + * drm_panel_of_backlight(). Then the driver does not need to implement the + * functionality to enable/disable backlight. */ struct drm_panel_funcs { /** @@ -145,6 +150,17 @@ struct drm_panel { struct device *dev; /** + * @backlight: + * + * Backlight device, used to turn on backlight after the call + * to enable(), and to turn off backlight before the call to + * disable(). + * backlight is set by drm_panel_of_backlight() and drivers + * shall not assign it. + */ + struct backlight_device *backlight; + + /** * @funcs: * * Operations that can be performed on the panel. @@ -195,4 +211,13 @@ static inline struct drm_panel *of_drm_find_panel(const struct device_node *np) } #endif +#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) +int drm_panel_of_backlight(struct drm_panel *panel); +#else +static inline int drm_panel_of_backlight(struct drm_panel *panel) +{ + return 0; +} +#endif + #endif |