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 device_node;
  32 struct drm_connector;
  33 struct drm_device;
  34 struct drm_panel;
  35 struct display_timing;
  36
  37 /**
  38  * struct drm_panel_funcs - perform operations on a given panel
  39  *
  40  * The .prepare() function is typically called before the display controller
  41  * starts to transmit video data. Panel drivers can use this to turn the panel
  42  * on and wait for it to become ready. If additional configuration is required
  43  * (via a control bus such as I2C, SPI or DSI for example) this is a good time
  44  * to do that.
  45  *
  46  * After the display controller has started transmitting video data, it's safe
  47  * to call the .enable() function. This will typically enable the backlight to
  48  * make the image on screen visible. Some panels require a certain amount of
  49  * time or frames before the image is displayed. This function is responsible
  50  * for taking this into account before enabling the backlight to avoid visual
  51  * glitches.
  52  *
  53  * Before stopping video transmission from the display controller it can be
  54  * necessary to turn off the panel to avoid visual glitches. This is done in
  55  * the .disable() function. Analogously to .enable() this typically involves
  56  * turning off the backlight and waiting for some time to make sure no image
  57  * is visible on the panel. It is then safe for the display controller to
  58  * cease transmission of video data.
  59  *
  60  * To save power when no video data is transmitted, a driver can power down
  61  * the panel. This is the job of the .unprepare() function.
  62  */
  63 struct drm_panel_funcs {
  64         /**
  65          * @prepare:
  66          *
  67          * Turn on panel and perform set up.
  68          */
  69         int (*prepare)(struct drm_panel *panel);
  70
  71         /**
  72          * @enable:
  73          *
  74          * Enable panel (turn on back light, etc.).
  75          */
  76         int (*enable)(struct drm_panel *panel);
  77
  78         /**
  79          * @disable:
  80          *
  81          * Disable panel (turn off back light, etc.).
  82          */
  83         int (*disable)(struct drm_panel *panel);
  84
  85         /**
  86          * @unprepare:
  87          *
  88          * Turn off panel.
  89          */
  90         int (*unprepare)(struct drm_panel *panel);
  91
  92         /**
  93          * @get_modes:
  94          *
  95          * Add modes to the connector that the panel is attached to and
  96          * return the number of modes added.
  97          */
  98         int (*get_modes)(struct drm_panel *panel);
  99
 100         /**
 101          * @get_timings:
 102          *
 103          * Copy display timings into the provided array and return
 104          * the number of display timings available.
 105          */
 106         int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
 107                            struct display_timing *timings);
 108 };
 109
 110 /**
 111  * struct drm_panel - DRM panel object
 112  */
 113 struct drm_panel {
 114         /**
 115          * @drm:
 116          *
 117          * DRM device owning the panel.
 118          */
 119         struct drm_device *drm;
 120
 121         /**
 122          * @connector:
 123          *
 124          * DRM connector that the panel is attached to.
 125          */
 126         struct drm_connector *connector;
 127
 128         /**
 129          * @dev:
 130          *
 131          * Parent device of the panel.
 132          */
 133         struct device *dev;
 134
 135         /**
 136          * @funcs:
 137          *
 138          * Operations that can be performed on the panel.
 139          */
 140         const struct drm_panel_funcs *funcs;
 141
 142         /**
 143          * @connector_type:
 144          *
 145          * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
 146          * initialise the drm_connector corresponding to the panel with the
 147          * correct connector type.
 148          */
 149         int connector_type;
 150
 151         /**
 152          * @list:
 153          *
 154          * Panel entry in registry.
 155          */
 156         struct list_head list;
 157 };
 158
 159 void drm_panel_init(struct drm_panel *panel, struct device *dev,
 160                     const struct drm_panel_funcs *funcs,
 161                     int connector_type);
 162
 163 int drm_panel_add(struct drm_panel *panel);
 164 void drm_panel_remove(struct drm_panel *panel);
 165
 166 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector);
 167 void drm_panel_detach(struct drm_panel *panel);
 168
 169 int drm_panel_prepare(struct drm_panel *panel);
 170 int drm_panel_unprepare(struct drm_panel *panel);
 171
 172 int drm_panel_enable(struct drm_panel *panel);
 173 int drm_panel_disable(struct drm_panel *panel);
 174
 175 int drm_panel_get_modes(struct drm_panel *panel);
 176
 177 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
 178 struct drm_panel *of_drm_find_panel(const struct device_node *np);
 179 #else
 180 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
 181 {
 182         return ERR_PTR(-ENODEV);
 183 }
 184 #endif
 185
 186 #endif