/*
* 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.
*/
#ifndef __DRM_PANEL_H__
#define __DRM_PANEL_H__
#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;
enum drm_panel_orientation;
/**
* struct drm_panel_funcs - perform operations on a given panel
*
* 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.
*
* Backlight can be handled automatically if configured using
* drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
* does not need to implement the functionality to enable/disable backlight.
*/
struct drm_panel_funcs {
/**
* @prepare:
*
* Turn on panel and perform set up.
*
* This function is optional.
*/
int (*prepare)(struct drm_panel *panel);
/**
* @enable:
*
* Enable panel (turn on back light, etc.).
*
* This function is optional.
*/
int (*enable)(struct drm_panel *panel);
/**
* @disable:
*
* Disable panel (turn off back light, etc.).
*
* This function is optional.
*/
int (*disable)(struct drm_panel *panel);
/**
* @unprepare:
*
* Turn off panel.
*
* This function is optional.
*/
int (*unprepare)(struct drm_panel *panel);
/**
* @get_modes:
*
* Add modes to the connector that the panel is attached to
* and returns the number of modes added.
*
* This function is mandatory.
*/
int (*get_modes)(struct drm_panel *panel,
struct drm_connector *connector);
/**
* @get_orientation:
*
* Return the panel orientation set by device tree or EDID.
*
* This function is optional.
*/
enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);
/**
* @get_timings:
*
* Copy display timings into the provided array and return
* the number of display timings available.
*
* This function is optional.
*/
int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
struct display_timing *timings);
/**
* @debugfs_init:
*
* Allows panels to create panels-specific debugfs files.
*/
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
*/
struct drm_panel {
/**
* @dev:
*
* Parent device of the 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() or
* drm_panel_dp_aux_backlight() and drivers shall not assign it.
*/
struct backlight_device *backlight;
/**
* @funcs:
*
* Operations that can be performed on the panel.
*/
const struct drm_panel_funcs *funcs;
/**
* @connector_type:
*
* Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
* initialise the drm_connector corresponding to the panel with the
* correct connector type.
*/
int connector_type;
/**
* @list:
*
* Panel entry in registry.
*/
struct list_head list;
/**
* @followers:
*
* A list of struct drm_panel_follower dependent on this panel.
*/
struct list_head followers;
/**
* @follower_lock:
*
* Lock for followers list.
*/
struct mutex follower_lock;
/**
* @prepare_prev_first:
*
* The previous controller should be prepared first, before the prepare
* for the panel is called. This is largely required for DSI panels
* where the DSI host controller should be initialised to LP-11 before
* the panel is powered up.
*/
bool prepare_prev_first;
/**
* @prepared:
*
* If true then the panel has been prepared.
*/
bool prepared;
/**
* @enabled:
*
* If true then the panel has been enabled.
*/
bool enabled;
};
void drm_panel_init(struct drm_panel *panel, struct device *dev,
const struct drm_panel_funcs *funcs,
int connector_type);
void drm_panel_add(struct drm_panel *panel);
void drm_panel_remove(struct drm_panel *panel);
int drm_panel_prepare(struct drm_panel *panel);
int drm_panel_unprepare(struct drm_panel *panel);
int drm_panel_enable(struct drm_panel *panel);
int drm_panel_disable(struct drm_panel *panel);
int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
struct drm_panel *of_drm_find_panel(const struct device_node *np);
int of_drm_get_panel_orientation(const struct device_node *np,
enum drm_panel_orientation *orientation);
#else
static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
{
return ERR_PTR(-ENODEV);
}
static inline int of_drm_get_panel_orientation(const struct device_node *np,
enum drm_panel_orientation *orientation)
{
return -ENODEV;
}
#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);
#else
static inline int drm_panel_of_backlight(struct drm_panel *panel)
{
return 0;
}
#endif
#endif
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