drm_panel.h 6.6 KB

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