diff options
Diffstat (limited to 'drivers/gpu/drm/drm_panel.c')
| -rw-r--r-- | drivers/gpu/drm/drm_panel.c | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c new file mode 100644 index 0000000000..e814020bbc --- /dev/null +++ b/drivers/gpu/drm/drm_panel.c @@ -0,0 +1,551 @@ +/* + * Copyright (C) 2013, NVIDIA Corporation. All rights reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sub license, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * 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); + +/** + * DOC: drm panel + * + * The DRM panel helpers allow drivers to register panel objects with a + * central registry and provide functions to retrieve those panels in display + * drivers. + * + * For easy integration into drivers using the &drm_bridge infrastructure please + * take look at drm_panel_bridge_add() and devm_drm_panel_bridge_add(). + */ + +/** + * 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 + * + * Initialize the panel structure for subsequent registration with + * drm_panel_add(). + */ +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; +} +EXPORT_SYMBOL(drm_panel_init); + +/** + * drm_panel_add - add a panel to the global registry + * @panel: panel to add + * + * Add a panel to the global registry so that it can be looked up by display + * drivers. + */ +void drm_panel_add(struct drm_panel *panel) +{ + mutex_lock(&panel_lock); + list_add_tail(&panel->list, &panel_list); + mutex_unlock(&panel_lock); +} +EXPORT_SYMBOL(drm_panel_add); + +/** + * drm_panel_remove - remove a panel from the global registry + * @panel: DRM panel + * + * Removes a panel from the global registry. + */ +void drm_panel_remove(struct drm_panel *panel) +{ + mutex_lock(&panel_lock); + list_del_init(&panel->list); + mutex_unlock(&panel_lock); +} +EXPORT_SYMBOL(drm_panel_remove); + +/** + * drm_panel_prepare - power on a panel + * @panel: DRM panel + * + * 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. + * + * Return: 0 on success or a negative error code on failure. + */ +int drm_panel_prepare(struct drm_panel *panel) +{ + struct drm_panel_follower *follower; + int ret; + + if (!panel) + return -EINVAL; + + if (panel->prepared) { + dev_warn(panel->dev, "Skipping prepare of already prepared panel\n"); + return 0; + } + + mutex_lock(&panel->follower_lock); + + if (panel->funcs && panel->funcs->prepare) { + ret = panel->funcs->prepare(panel); + if (ret < 0) + goto exit; + } + panel->prepared = true; + + 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); + +/** + * drm_panel_unprepare - power off a panel + * @panel: DRM panel + * + * 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_unprepare(struct drm_panel *panel) +{ + struct drm_panel_follower *follower; + int ret; + + if (!panel) + return -EINVAL; + + if (!panel->prepared) { + dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n"); + 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) + goto exit; + } + panel->prepared = false; + + ret = 0; +exit: + mutex_unlock(&panel->follower_lock); + + return ret; +} +EXPORT_SYMBOL(drm_panel_unprepare); + +/** + * drm_panel_enable - enable a panel + * @panel: DRM panel + * + * 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->enabled) { + dev_warn(panel->dev, "Skipping enable of already enabled panel\n"); + return 0; + } + + if (panel->funcs && panel->funcs->enable) { + ret = panel->funcs->enable(panel); + if (ret < 0) + return ret; + } + panel->enabled = true; + + 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 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_disable(struct drm_panel *panel) +{ + int ret; + + if (!panel) + return -EINVAL; + + if (!panel->enabled) { + dev_warn(panel->dev, "Skipping disable of already disabled panel\n"); + return 0; + } + + 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) { + ret = panel->funcs->disable(panel); + if (ret < 0) + return ret; + } + panel->enabled = false; + + return 0; +} +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 +/** + * of_drm_find_panel - look up a panel using a device tree node + * @np: device tree node of the panel + * + * Searches the set of registered panels for one that matches the given device + * tree node. If a matching panel is found, return a pointer to it. + * + * Return: A pointer to the panel registered for the specified device tree + * node or an ERR_PTR() if no panel matching the device tree node can be found. + * + * Possible error codes returned by this function: + * + * - EPROBE_DEFER: the panel device has not been probed yet, and the caller + * should retry later + * - ENODEV: the device is not available (status != "okay" or "ok") + */ +struct drm_panel *of_drm_find_panel(const struct device_node *np) +{ + struct drm_panel *panel; + + if (!of_device_is_available(np)) + return ERR_PTR(-ENODEV); + + mutex_lock(&panel_lock); + + list_for_each_entry(panel, &panel_list, list) { + if (panel->dev->of_node == np) { + mutex_unlock(&panel_lock); + return panel; + } + } + + mutex_unlock(&panel_lock); + 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 + +/** + * 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 + * @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"); |