include/drm/drm_panel.h

   1 /*
   2  * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sub license,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the
  12  * next paragraph) shall be included in all copies or substantial portions
  13  * of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #ifndef __DRM_PANEL_H__
  25 #define __DRM_PANEL_H__
  26
  27 #include <linux/list.h>
  28
  29 struct drm_connector;
  30 struct drm_device;
  31 struct drm_panel;
  32
  33 /**
  34  * struct drm_panel_funcs - perform operations on a given panel
  35  * @disable: disable panel (turn off back light, etc.)
  36  * @unprepare: turn off panel
  37  * @prepare: turn on panel and perform set up
  38  * @enable: enable panel (turn on back light, etc.)
  39  * @get_modes: add modes to the connector that the panel is attached to and
  40  * return the number of modes added
  41  *
  42  * The .prepare() function is typically called before the display controller
  43  * starts to transmit video data. Panel drivers can use this to turn the panel
  44  * on and wait for it to become ready. If additional configuration is required
  45  * (via a control bus such as I2C, SPI or DSI for example) this is a good time
  46  * to do that.
  47  *
  48  * After the display controller has started transmitting video data, it's safe
  49  * to call the .enable() function. This will typically enable the backlight to
  50  * make the image on screen visible. Some panels require a certain amount of
  51  * time or frames before the image is displayed. This function is responsible
  52  * for taking this into account before enabling the backlight to avoid visual
  53  * glitches.
  54  *
  55  * Before stopping video transmission from the display controller it can be
  56  * necessary to turn off the panel to avoid visual glitches. This is done in
  57  * the .disable() function. Analogously to .enable() this typically involves
  58  * turning off the backlight and waiting for some time to make sure no image
  59  * is visible on the panel. It is then safe for the display controller to
  60  * cease transmission of video data.
  61  *
  62  * To save power when no video data is transmitted, a driver can power down
  63  * the panel. This is the job of the .unprepare() function.
  64  */
  65 struct drm_panel_funcs {
  66         int (*disable)(struct drm_panel *panel);
  67         int (*unprepare)(struct drm_panel *panel);
  68         int (*prepare)(struct drm_panel *panel);
  69         int (*enable)(struct drm_panel *panel);
  70         int (*get_modes)(struct drm_panel *panel);
  71 };
  72
  73 struct drm_panel {
  74         struct drm_device *drm;
  75         struct drm_connector *connector;
  76         struct device *dev;
  77
  78         const struct drm_panel_funcs *funcs;
  79
  80         struct list_head list;
  81 };
  82
  83 static inline int drm_panel_unprepare(struct drm_panel *panel)
  84 {
  85         if (panel && panel->funcs && panel->funcs->unprepare)
  86                 return panel->funcs->unprepare(panel);
  87
  88         return panel ? -ENOSYS : -EINVAL;
  89 }
  90
  91 static inline int drm_panel_disable(struct drm_panel *panel)
  92 {
  93         if (panel && panel->funcs && panel->funcs->disable)
  94                 return panel->funcs->disable(panel);
  95
  96         return panel ? -ENOSYS : -EINVAL;
  97 }
  98
  99 static inline int drm_panel_prepare(struct drm_panel *panel)
 100 {
 101         if (panel && panel->funcs && panel->funcs->prepare)
 102                 return panel->funcs->prepare(panel);
 103
 104         return panel ? -ENOSYS : -EINVAL;
 105 }
 106
 107 static inline int drm_panel_enable(struct drm_panel *panel)
 108 {
 109         if (panel && panel->funcs && panel->funcs->enable)
 110                 return panel->funcs->enable(panel);
 111
 112         return panel ? -ENOSYS : -EINVAL;
 113 }
 114
 115 static inline int drm_panel_get_modes(struct drm_panel *panel)
 116 {
 117         if (panel && panel->funcs && panel->funcs->get_modes)
 118                 return panel->funcs->get_modes(panel);
 119
 120         return panel ? -ENOSYS : -EINVAL;
 121 }
 122
 123 void drm_panel_init(struct drm_panel *panel);
 124
 125 int drm_panel_add(struct drm_panel *panel);
 126 void drm_panel_remove(struct drm_panel *panel);
 127
 128 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
 129 int drm_panel_detach(struct drm_panel *panel);
 130
 131 #ifdef CONFIG_OF
 132 struct drm_panel *of_drm_find_panel(struct device_node *np);
 133 #else
 134 static inline struct drm_panel *of_drm_find_panel(struct device_node *np)
 135 {
 136         return NULL;
 137 }
 138 #endif
 139
 140 #endif