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/*
* 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/errno.h>
#include <linux/list.h>
struct device_node;
struct drm_connector;
struct drm_device;
struct drm_panel;
struct display_timing;
/**
* struct drm_panel_funcs - perform operations on a given panel
* @disable: disable panel (turn off back light, etc.)
* @unprepare: turn off panel
* @prepare: turn on panel and perform set up
* @enable: enable panel (turn on back light, etc.)
* @get_modes: add modes to the connector that the panel is attached to and
* return the number of modes added
* @get_timings: copy display timings into the provided array and return
* the number of display timings available
*
* 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.
*/
struct drm_panel_funcs {
int (*disable)(struct drm_panel *panel);
int (*unprepare)(struct drm_panel *panel);
int (*prepare)(struct drm_panel *panel);
int (*enable)(struct drm_panel *panel);
int (*get_modes)(struct drm_panel *panel);
int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
struct display_timing *timings);
};
/**
* struct drm_panel - DRM panel object
* @drm: DRM device owning the panel
* @connector: DRM connector that the panel is attached to
* @dev: parent device of the panel
* @funcs: operations that can be performed on the panel
* @list: panel entry in registry
*/
struct drm_panel {
struct drm_device *drm;
struct drm_connector *connector;
struct device *dev;
struct device_link *link;
const struct drm_panel_funcs *funcs;
struct list_head list;
};
/**
* drm_disable_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.
*/
static inline int drm_panel_unprepare(struct drm_panel *panel)
{
if (panel && panel->funcs && panel->funcs->unprepare)
return panel->funcs->unprepare(panel);
return panel ? -ENOSYS : -EINVAL;
}
/**
* 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.
*/
static inline int drm_panel_disable(struct drm_panel *panel)
{
if (panel && panel->funcs && panel->funcs->disable)
return panel->funcs->disable(panel);
return panel ? -ENOSYS : -EINVAL;
}
/**
* 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.
*/
static inline int drm_panel_prepare(struct drm_panel *panel)
{
if (panel && panel->funcs && panel->funcs->prepare)
return panel->funcs->prepare(panel);
return panel ? -ENOSYS : -EINVAL;
}
/**
* 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.
*/
static inline int drm_panel_enable(struct drm_panel *panel)
{
if (panel && panel->funcs && panel->funcs->enable)
return panel->funcs->enable(panel);
return panel ? -ENOSYS : -EINVAL;
}
/**
* drm_panel_get_modes - probe the available display modes of a panel
* @panel: DRM panel
*
* 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.
*/
static inline int drm_panel_get_modes(struct drm_panel *panel)
{
if (panel && panel->funcs && panel->funcs->get_modes)
return panel->funcs->get_modes(panel);
return panel ? -ENOSYS : -EINVAL;
}
void drm_panel_init(struct drm_panel *panel);
int drm_panel_add(struct drm_panel *panel);
void drm_panel_remove(struct drm_panel *panel);
int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
int drm_panel_detach(struct drm_panel *panel);
#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
struct drm_panel *of_drm_find_panel(const struct device_node *np);
#else
static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
{
return ERR_PTR(-ENODEV);
}
#endif
#endif
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