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/err.h>
  28 #include <linux/errno.h>
  29 #include <linux/list.h>
  30
  31 struct backlight_device;
  32 struct device_node;
  33 struct drm_connector;
  34 struct drm_device;
  35 struct drm_panel;
  36 struct display_timing;
  37
  38 enum drm_panel_orientation;
  39
  40 /**
  41  * struct drm_panel_funcs - perform operations on a given panel
  42  *
  43  * The .prepare() function is typically called before the display controller
  44  * starts to transmit video data. Panel drivers can use this to turn the panel
  45  * on and wait for it to become ready. If additional configuration is required
  46  * (via a control bus such as I2C, SPI or DSI for example) this is a good time
  47  * to do that.
  48  *
  49  * After the display controller has started transmitting video data, it's safe
  50  * to call the .enable() function. This will typically enable the backlight to
  51  * make the image on screen visible. Some panels require a certain amount of
  52  * time or frames before the image is displayed. This function is responsible
  53  * for taking this into account before enabling the backlight to avoid visual
  54  * glitches.
  55  *
  56  * Before stopping video transmission from the display controller it can be
  57  * necessary to turn off the panel to avoid visual glitches. This is done in
  58  * the .disable() function. Analogously to .enable() this typically involves
  59  * turning off the backlight and waiting for some time to make sure no image
  60  * is visible on the panel. It is then safe for the display controller to
  61  * cease transmission of video data.
  62  *
  63  * To save power when no video data is transmitted, a driver can power down
  64  * the panel. This is the job of the .unprepare() function.
  65  *
  66  * Backlight can be handled automatically if configured using
  67  * drm_panel_of_backlight(). Then the driver does not need to implement the
  68  * functionality to enable/disable backlight.
  69  */
  70 struct drm_panel_funcs {
  71         /**
  72          * @prepare:
  73          *
  74          * Turn on panel and perform set up.
  75          *
  76          * This function is optional.
  77          */
  78         int (*prepare)(struct drm_panel *panel);
  79
  80         /**
  81          * @enable:
  82          *
  83          * Enable panel (turn on back light, etc.).
  84          *
  85          * This function is optional.
  86          */
  87         int (*enable)(struct drm_panel *panel);
  88
  89         /**
  90          * @disable:
  91          *
  92          * Disable panel (turn off back light, etc.).
  93          *
  94          * This function is optional.
  95          */
  96         int (*disable)(struct drm_panel *panel);
  97
  98         /**
  99          * @unprepare:
 100          *
 101          * Turn off panel.
 102          *
 103          * This function is optional.
 104          */
 105         int (*unprepare)(struct drm_panel *panel);
 106
 107         /**
 108          * @get_modes:
 109          *
 110          * Add modes to the connector that the panel is attached to
 111          * and returns the number of modes added.
 112          *
 113          * This function is mandatory.
 114          */
 115         int (*get_modes)(struct drm_panel *panel,
 116                          struct drm_connector *connector);
 117
 118         /**
 119          * @get_timings:
 120          *
 121          * Copy display timings into the provided array and return
 122          * the number of display timings available.
 123          *
 124          * This function is optional.
 125          */
 126         int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
 127                            struct display_timing *timings);
 128 };
 129
 130 /**
 131  * struct drm_panel - DRM panel object
 132  */
 133 struct drm_panel {
 134         /**
 135          * @dev:
 136          *
 137          * Parent device of the panel.
 138          */
 139         struct device *dev;
 140
 141         /**
 142          * @backlight:
 143          *
 144          * Backlight device, used to turn on backlight after the call
 145          * to enable(), and to turn off backlight before the call to
 146          * disable().
 147          * backlight is set by drm_panel_of_backlight() and drivers
 148          * shall not assign it.
 149          */
 150         struct backlight_device *backlight;
 151
 152         /**
 153          * @funcs:
 154          *
 155          * Operations that can be performed on the panel.
 156          */
 157         const struct drm_panel_funcs *funcs;
 158
 159         /**
 160          * @connector_type:
 161          *
 162          * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
 163          * initialise the drm_connector corresponding to the panel with the
 164          * correct connector type.
 165          */
 166         int connector_type;
 167
 168         /**
 169          * @list:
 170          *
 171          * Panel entry in registry.
 172          */
 173         struct list_head list;
 174 };
 175
 176 void drm_panel_init(struct drm_panel *panel, struct device *dev,
 177                     const struct drm_panel_funcs *funcs,
 178                     int connector_type);
 179
 180 void drm_panel_add(struct drm_panel *panel);
 181 void drm_panel_remove(struct drm_panel *panel);
 182
 183 int drm_panel_prepare(struct drm_panel *panel);
 184 int drm_panel_unprepare(struct drm_panel *panel);
 185
 186 int drm_panel_enable(struct drm_panel *panel);
 187 int drm_panel_disable(struct drm_panel *panel);
 188
 189 int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
 190
 191 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
 192 struct drm_panel *of_drm_find_panel(const struct device_node *np);
 193 int of_drm_get_panel_orientation(const struct device_node *np,
 194                                  enum drm_panel_orientation *orientation);
 195 #else
 196 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
 197 {
 198         return ERR_PTR(-ENODEV);
 199 }
 200
 201 static inline int of_drm_get_panel_orientation(const struct device_node *np,
 202                                                enum drm_panel_orientation *orientation)
 203 {
 204         return -ENODEV;
 205 }
 206 #endif
 207
 208 #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
 209         (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
 210 int drm_panel_of_backlight(struct drm_panel *panel);
 211 #else
 212 static inline int drm_panel_of_backlight(struct drm_panel *panel)
 213 {
 214         return 0;
 215 }
 216 #endif
 217
 218 #endif