1 /* $NetBSD: drm_panel.h,v 1.3 2020/01/03 21:01:16 jmcneill Exp $ */ 2 3 /* 4 * Copyright (C) 2013, NVIDIA Corporation. All rights reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sub license, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the 14 * next paragraph) shall be included in all copies or substantial portions 15 * of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 23 * DEALINGS IN THE SOFTWARE. 24 */ 25 26 #ifndef __DRM_PANEL_H__ 27 #define __DRM_PANEL_H__ 28 29 #include <linux/list.h> 30 31 struct drm_connector; 32 struct drm_device; 33 struct drm_panel; 34 struct display_timing; 35 36 /** 37 * struct drm_panel_funcs - perform operations on a given panel 38 * @disable: disable panel (turn off back light, etc.) 39 * @unprepare: turn off panel 40 * @prepare: turn on panel and perform set up 41 * @enable: enable panel (turn on back light, etc.) 42 * @get_modes: add modes to the connector that the panel is attached to and 43 * return the number of modes added 44 * @get_timings: copy display timings into the provided array and return 45 * the number of display timings available 46 * 47 * The .prepare() function is typically called before the display controller 48 * starts to transmit video data. Panel drivers can use this to turn the panel 49 * on and wait for it to become ready. If additional configuration is required 50 * (via a control bus such as I2C, SPI or DSI for example) this is a good time 51 * to do that. 52 * 53 * After the display controller has started transmitting video data, it's safe 54 * to call the .enable() function. This will typically enable the backlight to 55 * make the image on screen visible. Some panels require a certain amount of 56 * time or frames before the image is displayed. This function is responsible 57 * for taking this into account before enabling the backlight to avoid visual 58 * glitches. 59 * 60 * Before stopping video transmission from the display controller it can be 61 * necessary to turn off the panel to avoid visual glitches. This is done in 62 * the .disable() function. Analogously to .enable() this typically involves 63 * turning off the backlight and waiting for some time to make sure no image 64 * is visible on the panel. It is then safe for the display controller to 65 * cease transmission of video data. 66 * 67 * To save power when no video data is transmitted, a driver can power down 68 * the panel. This is the job of the .unprepare() function. 69 */ 70 struct drm_panel_funcs { 71 int (*disable)(struct drm_panel *panel); 72 int (*unprepare)(struct drm_panel *panel); 73 int (*prepare)(struct drm_panel *panel); 74 int (*enable)(struct drm_panel *panel); 75 int (*get_modes)(struct drm_panel *panel); 76 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings, 77 struct display_timing *timings); 78 }; 79 80 struct drm_panel { 81 struct drm_device *drm; 82 struct drm_connector *connector; 83 struct device *dev; 84 85 const struct drm_panel_funcs *funcs; 86 87 struct list_head list; 88 }; 89 90 static inline int drm_panel_unprepare(struct drm_panel *panel) 91 { 92 if (panel && panel->funcs && panel->funcs->unprepare) 93 return panel->funcs->unprepare(panel); 94 95 return panel ? -ENOSYS : -EINVAL; 96 } 97 98 static inline int drm_panel_disable(struct drm_panel *panel) 99 { 100 if (panel && panel->funcs && panel->funcs->disable) 101 return panel->funcs->disable(panel); 102 103 return panel ? -ENOSYS : -EINVAL; 104 } 105 106 static inline int drm_panel_prepare(struct drm_panel *panel) 107 { 108 if (panel && panel->funcs && panel->funcs->prepare) 109 return panel->funcs->prepare(panel); 110 111 return panel ? -ENOSYS : -EINVAL; 112 } 113 114 static inline int drm_panel_enable(struct drm_panel *panel) 115 { 116 if (panel && panel->funcs && panel->funcs->enable) 117 return panel->funcs->enable(panel); 118 119 return panel ? -ENOSYS : -EINVAL; 120 } 121 122 static inline int drm_panel_get_modes(struct drm_panel *panel) 123 { 124 if (panel && panel->funcs && panel->funcs->get_modes) 125 return panel->funcs->get_modes(panel); 126 127 return panel ? -ENOSYS : -EINVAL; 128 } 129 130 #ifdef __NetBSD__ 131 void drm_panel_init_lock(void); 132 void drm_panel_fini_lock(void); 133 #endif 134 135 void drm_panel_init(struct drm_panel *panel); 136 137 int drm_panel_add(struct drm_panel *panel); 138 void drm_panel_remove(struct drm_panel *panel); 139 140 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector); 141 int drm_panel_detach(struct drm_panel *panel); 142 143 #ifdef CONFIG_OF 144 struct drm_panel *of_drm_find_panel(struct device_node *np); 145 #else 146 static inline struct drm_panel *of_drm_find_panel(struct device_node *np) 147 { 148 return NULL; 149 } 150 #endif 151 152 #endif 153