diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panel.c')
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 230 |
1 files changed, 200 insertions, 30 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index dbd5b873e8f2..f634371c717a 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); @@ -44,13 +46,21 @@ static LIST_HEAD(panel_list); /** * drm_panel_init - initialize a panel * @panel: DRM panel + * @dev: parent device of the panel + * @funcs: panel operations + * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to + * the panel interface * - * Sets up internal fields of the panel so that it can subsequently be added - * to the registry. + * Initialize the panel structure for subsequent registration with + * drm_panel_add(). */ -void drm_panel_init(struct drm_panel *panel) +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); + panel->dev = dev; + panel->funcs = funcs; + panel->connector_type = connector_type; } EXPORT_SYMBOL(drm_panel_init); @@ -60,16 +70,12 @@ EXPORT_SYMBOL(drm_panel_init); * * Add a panel to the global registry so that it can be looked up by display * drivers. - * - * Return: 0 on success or a negative error code on failure. */ -int drm_panel_add(struct drm_panel *panel) +void drm_panel_add(struct drm_panel *panel) { mutex_lock(&panel_lock); list_add_tail(&panel->list, &panel_list); mutex_unlock(&panel_lock); - - return 0; } EXPORT_SYMBOL(drm_panel_add); @@ -88,52 +94,134 @@ void drm_panel_remove(struct drm_panel *panel) EXPORT_SYMBOL(drm_panel_remove); /** - * drm_panel_attach - attach a panel to a connector + * drm_panel_prepare - power on a panel * @panel: DRM panel - * @connector: DRM connector * - * After obtaining a pointer to a DRM panel a display driver calls this - * function to attach a panel to a connector. + * Calling this function will enable power and deassert any reset signals to + * the panel. After this has completed it is possible to communicate with any + * integrated circuitry via a command bus. * - * An error is returned if the panel is already attached to another connector. + * Return: 0 on success or a negative error code on failure. + */ +int drm_panel_prepare(struct drm_panel *panel) +{ + if (!panel) + return -EINVAL; + + if (panel->funcs && panel->funcs->prepare) + return panel->funcs->prepare(panel); + + return 0; +} +EXPORT_SYMBOL(drm_panel_prepare); + +/** + * drm_panel_unprepare - power off a panel + * @panel: DRM panel * - * When unloading, the driver should detach from the panel by calling - * drm_panel_detach(). + * Calling this function will completely power off a panel (assert the panel's + * reset, turn off power supplies, ...). After this function has completed, it + * is usually no longer possible to communicate with the panel until another + * call to drm_panel_prepare(). * * Return: 0 on success or a negative error code on failure. */ -int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) +int drm_panel_unprepare(struct drm_panel *panel) { - if (panel->connector) - return -EBUSY; + if (!panel) + return -EINVAL; - panel->connector = connector; - panel->drm = connector->dev; + if (panel->funcs && panel->funcs->unprepare) + return panel->funcs->unprepare(panel); return 0; } -EXPORT_SYMBOL(drm_panel_attach); +EXPORT_SYMBOL(drm_panel_unprepare); /** - * drm_panel_detach - detach a panel from a connector + * drm_panel_enable - enable a panel * @panel: DRM panel * - * Detaches a panel from the connector it is attached to. If a panel is not - * attached to any connector this is effectively a no-op. + * Calling this function will cause the panel display drivers to be turned on + * and the backlight to be enabled. Content will be visible on screen after + * this call completes. + * + * Return: 0 on success or a negative error code on failure. + */ +int drm_panel_enable(struct drm_panel *panel) +{ + int ret; + + if (!panel) + return -EINVAL; + + 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; +} +EXPORT_SYMBOL(drm_panel_enable); + +/** + * drm_panel_disable - disable a panel + * @panel: DRM panel * - * This function should not be called by the panel device itself. It - * is only for the drm device that called drm_panel_attach(). + * This will typically turn off the panel's backlight or disable the display + * drivers. For smart panels it should still be possible to communicate with + * the integrated circuitry via any command bus after this call. * * Return: 0 on success or a negative error code on failure. */ -int drm_panel_detach(struct drm_panel *panel) +int drm_panel_disable(struct drm_panel *panel) { - panel->connector = NULL; - panel->drm = NULL; + 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); return 0; } -EXPORT_SYMBOL(drm_panel_detach); +EXPORT_SYMBOL(drm_panel_disable); + +/** + * drm_panel_get_modes - probe the available display modes of a panel + * @panel: DRM panel + * @connector: DRM connector + * + * The modes probed from the panel are automatically added to the connector + * that the panel is attached to. + * + * Return: The number of modes available from the panel on success or a + * negative error code on failure. + */ +int drm_panel_get_modes(struct drm_panel *panel, + struct drm_connector *connector) +{ + if (!panel) + return -EINVAL; + + if (panel->funcs && panel->funcs->get_modes) + return panel->funcs->get_modes(panel, connector); + + return -EOPNOTSUPP; +} +EXPORT_SYMBOL(drm_panel_get_modes); #ifdef CONFIG_OF /** @@ -172,6 +260,88 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np) return ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL(of_drm_find_panel); + +/** + * of_drm_get_panel_orientation - look up the orientation of the panel through + * the "rotation" binding from a device tree node + * @np: device tree node of the panel + * @orientation: orientation enum to be filled in + * + * Looks up the rotation of a panel in the device tree. The orientation of the + * panel is expressed as a property name "rotation" in the device tree. The + * rotation in the device tree is counter clockwise. + * + * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the + * rotation property doesn't exist. Return a negative error code on failure. + */ +int of_drm_get_panel_orientation(const struct device_node *np, + enum drm_panel_orientation *orientation) +{ + int rotation, ret; + + ret = of_property_read_u32(np, "rotation", &rotation); + if (ret == -EINVAL) { + /* Don't return an error if there's no rotation property. */ + *orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN; + return 0; + } + + if (ret < 0) + return ret; + + if (rotation == 0) + *orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL; + else if (rotation == 90) + *orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP; + else if (rotation == 180) + *orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP; + else if (rotation == 270) + *orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP; + else + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL(of_drm_get_panel_orientation); +#endif + +#if IS_REACHABLE(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>"); |