include/drm/drm_panel.h

0001 /*
0002  * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sub license,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice (including the
0012  * next paragraph) shall be included in all copies or substantial portions
0013  * of the Software.
0014  *
0015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0016  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0017  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
0018  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
0019  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
0020  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
0021  * DEALINGS IN THE SOFTWARE.
0022  */
0023
0024 #ifndef __DRM_PANEL_H__
0025 #define __DRM_PANEL_H__
0026
0027 #include <linux/err.h>
0028 #include <linux/errno.h>
0029 #include <linux/list.h>
0030
0031 struct backlight_device;
0032 struct dentry;
0033 struct device_node;
0034 struct drm_connector;
0035 struct drm_device;
0036 struct drm_panel;
0037 struct display_timing;
0038
0039 enum drm_panel_orientation;
0040
0041 /**
0042  * struct drm_panel_funcs - perform operations on a given panel
0043  *
0044  * The .prepare() function is typically called before the display controller
0045  * starts to transmit video data. Panel drivers can use this to turn the panel
0046  * on and wait for it to become ready. If additional configuration is required
0047  * (via a control bus such as I2C, SPI or DSI for example) this is a good time
0048  * to do that.
0049  *
0050  * After the display controller has started transmitting video data, it's safe
0051  * to call the .enable() function. This will typically enable the backlight to
0052  * make the image on screen visible. Some panels require a certain amount of
0053  * time or frames before the image is displayed. This function is responsible
0054  * for taking this into account before enabling the backlight to avoid visual
0055  * glitches.
0056  *
0057  * Before stopping video transmission from the display controller it can be
0058  * necessary to turn off the panel to avoid visual glitches. This is done in
0059  * the .disable() function. Analogously to .enable() this typically involves
0060  * turning off the backlight and waiting for some time to make sure no image
0061  * is visible on the panel. It is then safe for the display controller to
0062  * cease transmission of video data.
0063  *
0064  * To save power when no video data is transmitted, a driver can power down
0065  * the panel. This is the job of the .unprepare() function.
0066  *
0067  * Backlight can be handled automatically if configured using
0068  * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver
0069  * does not need to implement the functionality to enable/disable backlight.
0070  */
0071 struct drm_panel_funcs {
0072     /**
0073      * @prepare:
0074      *
0075      * Turn on panel and perform set up.
0076      *
0077      * This function is optional.
0078      */
0079     int (*prepare)(struct drm_panel *panel);
0080
0081     /**
0082      * @enable:
0083      *
0084      * Enable panel (turn on back light, etc.).
0085      *
0086      * This function is optional.
0087      */
0088     int (*enable)(struct drm_panel *panel);
0089
0090     /**
0091      * @disable:
0092      *
0093      * Disable panel (turn off back light, etc.).
0094      *
0095      * This function is optional.
0096      */
0097     int (*disable)(struct drm_panel *panel);
0098
0099     /**
0100      * @unprepare:
0101      *
0102      * Turn off panel.
0103      *
0104      * This function is optional.
0105      */
0106     int (*unprepare)(struct drm_panel *panel);
0107
0108     /**
0109      * @get_modes:
0110      *
0111      * Add modes to the connector that the panel is attached to
0112      * and returns the number of modes added.
0113      *
0114      * This function is mandatory.
0115      */
0116     int (*get_modes)(struct drm_panel *panel,
0117              struct drm_connector *connector);
0118
0119     /**
0120      * @get_orientation:
0121      *
0122      * Return the panel orientation set by device tree or EDID.
0123      *
0124      * This function is optional.
0125      */
0126     enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);
0127
0128     /**
0129      * @get_timings:
0130      *
0131      * Copy display timings into the provided array and return
0132      * the number of display timings available.
0133      *
0134      * This function is optional.
0135      */
0136     int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,
0137                struct display_timing *timings);
0138
0139     /**
0140      * @debugfs_init:
0141      *
0142      * Allows panels to create panels-specific debugfs files.
0143      */
0144     void (*debugfs_init)(struct drm_panel *panel, struct dentry *root);
0145 };
0146
0147 /**
0148  * struct drm_panel - DRM panel object
0149  */
0150 struct drm_panel {
0151     /**
0152      * @dev:
0153      *
0154      * Parent device of the panel.
0155      */
0156     struct device *dev;
0157
0158     /**
0159      * @backlight:
0160      *
0161      * Backlight device, used to turn on backlight after the call
0162      * to enable(), and to turn off backlight before the call to
0163      * disable().
0164      * backlight is set by drm_panel_of_backlight() or
0165      * drm_panel_dp_aux_backlight() and drivers shall not assign it.
0166      */
0167     struct backlight_device *backlight;
0168
0169     /**
0170      * @funcs:
0171      *
0172      * Operations that can be performed on the panel.
0173      */
0174     const struct drm_panel_funcs *funcs;
0175
0176     /**
0177      * @connector_type:
0178      *
0179      * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to
0180      * initialise the drm_connector corresponding to the panel with the
0181      * correct connector type.
0182      */
0183     int connector_type;
0184
0185     /**
0186      * @list:
0187      *
0188      * Panel entry in registry.
0189      */
0190     struct list_head list;
0191
0192     /**
0193      * @dsc:
0194      *
0195      * Panel DSC pps payload to be sent
0196      */
0197     struct drm_dsc_config *dsc;
0198 };
0199
0200 void drm_panel_init(struct drm_panel *panel, struct device *dev,
0201             const struct drm_panel_funcs *funcs,
0202             int connector_type);
0203
0204 void drm_panel_add(struct drm_panel *panel);
0205 void drm_panel_remove(struct drm_panel *panel);
0206
0207 int drm_panel_prepare(struct drm_panel *panel);
0208 int drm_panel_unprepare(struct drm_panel *panel);
0209
0210 int drm_panel_enable(struct drm_panel *panel);
0211 int drm_panel_disable(struct drm_panel *panel);
0212
0213 int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);
0214
0215 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)
0216 struct drm_panel *of_drm_find_panel(const struct device_node *np);
0217 int of_drm_get_panel_orientation(const struct device_node *np,
0218                  enum drm_panel_orientation *orientation);
0219 #else
0220 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)
0221 {
0222     return ERR_PTR(-ENODEV);
0223 }
0224
0225 static inline int of_drm_get_panel_orientation(const struct device_node *np,
0226                            enum drm_panel_orientation *orientation)
0227 {
0228     return -ENODEV;
0229 }
0230 #endif
0231
0232 #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
0233     (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))
0234 int drm_panel_of_backlight(struct drm_panel *panel);
0235 #else
0236 static inline int drm_panel_of_backlight(struct drm_panel *panel)
0237 {
0238     return 0;
0239 }
0240 #endif
0241
0242 #endif