1 /* 2 * Copyright (c) 2016 Intel Corporation 3 * 4 * Permission to use, copy, modify, distribute, and sell this software and its 5 * documentation for any purpose is hereby granted without fee, provided that 6 * the above copyright notice appear in all copies and that both that copyright 7 * notice and this permission notice appear in supporting documentation, and 8 * that the name of the copyright holders not be used in advertising or 9 * publicity pertaining to distribution of the software without specific, 10 * written prior permission. The copyright holders make no representations 11 * about the suitability of this software for any purpose. It is provided "as 12 * is" without express or implied warranty. 13 * 14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 20 * OF THIS SOFTWARE. 21 */ 22 23 #ifndef __DRM_BRIDGE_H__ 24 #define __DRM_BRIDGE_H__ 25 26 #include <linux/list.h> 27 #include <linux/ctype.h> 28 #include <drm/drm_mode_object.h> 29 #include <drm/drm_modes.h> 30 31 struct drm_bridge; 32 struct drm_panel; 33 34 /** 35 * struct drm_bridge_funcs - drm_bridge control functions 36 */ 37 struct drm_bridge_funcs { 38 /** 39 * @attach: 40 * 41 * This callback is invoked whenever our bridge is being attached to a 42 * &drm_encoder. 43 * 44 * The attach callback is optional. 45 * 46 * RETURNS: 47 * 48 * Zero on success, error code on failure. 49 */ 50 int (*attach)(struct drm_bridge *bridge); 51 52 /** 53 * @detach: 54 * 55 * This callback is invoked whenever our bridge is being detached from a 56 * &drm_encoder. 57 * 58 * The detach callback is optional. 59 */ 60 void (*detach)(struct drm_bridge *bridge); 61 62 /** 63 * @mode_valid: 64 * 65 * This callback is used to check if a specific mode is valid in this 66 * bridge. This should be implemented if the bridge has some sort of 67 * restriction in the modes it can display. For example, a given bridge 68 * may be responsible to set a clock value. If the clock can not 69 * produce all the values for the available modes then this callback 70 * can be used to restrict the number of modes to only the ones that 71 * can be displayed. 72 * 73 * This hook is used by the probe helpers to filter the mode list in 74 * drm_helper_probe_single_connector_modes(), and it is used by the 75 * atomic helpers to validate modes supplied by userspace in 76 * drm_atomic_helper_check_modeset(). 77 * 78 * This function is optional. 79 * 80 * NOTE: 81 * 82 * Since this function is both called from the check phase of an atomic 83 * commit, and the mode validation in the probe paths it is not allowed 84 * to look at anything else but the passed-in mode, and validate it 85 * against configuration-invariant hardward constraints. Any further 86 * limits which depend upon the configuration can only be checked in 87 * @mode_fixup. 88 * 89 * RETURNS: 90 * 91 * drm_mode_status Enum 92 */ 93 enum drm_mode_status (*mode_valid)(struct drm_bridge *crtc, 94 const struct drm_display_mode *mode); 95 96 /** 97 * @mode_fixup: 98 * 99 * This callback is used to validate and adjust a mode. The paramater 100 * mode is the display mode that should be fed to the next element in 101 * the display chain, either the final &drm_connector or the next 102 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge 103 * requires. It can be modified by this callback and does not need to 104 * match mode. See also &drm_crtc_state.adjusted_mode for more details. 105 * 106 * This is the only hook that allows a bridge to reject a modeset. If 107 * this function passes all other callbacks must succeed for this 108 * configuration. 109 * 110 * The mode_fixup callback is optional. 111 * 112 * NOTE: 113 * 114 * This function is called in the check phase of atomic modesets, which 115 * can be aborted for any reason (including on userspace's request to 116 * just check whether a configuration would be possible). Drivers MUST 117 * NOT touch any persistent state (hardware or software) or data 118 * structures except the passed in @state parameter. 119 * 120 * Also beware that userspace can request its own custom modes, neither 121 * core nor helpers filter modes to the list of probe modes reported by 122 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 123 * that modes are filtered consistently put any bridge constraints and 124 * limits checks into @mode_valid. 125 * 126 * RETURNS: 127 * 128 * True if an acceptable configuration is possible, false if the modeset 129 * operation should be rejected. 130 */ 131 bool (*mode_fixup)(struct drm_bridge *bridge, 132 const struct drm_display_mode *mode, 133 struct drm_display_mode *adjusted_mode); 134 /** 135 * @disable: 136 * 137 * This callback should disable the bridge. It is called right before 138 * the preceding element in the display pipe is disabled. If the 139 * preceding element is a bridge this means it's called before that 140 * bridge's @disable vfunc. If the preceding element is a &drm_encoder 141 * it's called right before the &drm_encoder_helper_funcs.disable, 142 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms 143 * hook. 144 * 145 * The bridge can assume that the display pipe (i.e. clocks and timing 146 * signals) feeding it is still running when this callback is called. 147 * 148 * The disable callback is optional. 149 */ 150 void (*disable)(struct drm_bridge *bridge); 151 152 /** 153 * @post_disable: 154 * 155 * This callback should disable the bridge. It is called right after the 156 * preceding element in the display pipe is disabled. If the preceding 157 * element is a bridge this means it's called after that bridge's 158 * @post_disable function. If the preceding element is a &drm_encoder 159 * it's called right after the encoder's 160 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare 161 * or &drm_encoder_helper_funcs.dpms hook. 162 * 163 * The bridge must assume that the display pipe (i.e. clocks and timing 164 * singals) feeding it is no longer running when this callback is 165 * called. 166 * 167 * The post_disable callback is optional. 168 */ 169 void (*post_disable)(struct drm_bridge *bridge); 170 171 /** 172 * @mode_set: 173 * 174 * This callback should set the given mode on the bridge. It is called 175 * after the @mode_set callback for the preceding element in the display 176 * pipeline has been called already. If the bridge is the first element 177 * then this would be &drm_encoder_helper_funcs.mode_set. The display 178 * pipe (i.e. clocks and timing signals) is off when this function is 179 * called. 180 */ 181 void (*mode_set)(struct drm_bridge *bridge, 182 struct drm_display_mode *mode, 183 struct drm_display_mode *adjusted_mode); 184 /** 185 * @pre_enable: 186 * 187 * This callback should enable the bridge. It is called right before 188 * the preceding element in the display pipe is enabled. If the 189 * preceding element is a bridge this means it's called before that 190 * bridge's @pre_enable function. If the preceding element is a 191 * &drm_encoder it's called right before the encoder's 192 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or 193 * &drm_encoder_helper_funcs.dpms hook. 194 * 195 * The display pipe (i.e. clocks and timing signals) feeding this bridge 196 * will not yet be running when this callback is called. The bridge must 197 * not enable the display link feeding the next bridge in the chain (if 198 * there is one) when this callback is called. 199 * 200 * The pre_enable callback is optional. 201 */ 202 void (*pre_enable)(struct drm_bridge *bridge); 203 204 /** 205 * @enable: 206 * 207 * This callback should enable the bridge. It is called right after 208 * the preceding element in the display pipe is enabled. If the 209 * preceding element is a bridge this means it's called after that 210 * bridge's @enable function. If the preceding element is a 211 * &drm_encoder it's called right after the encoder's 212 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or 213 * &drm_encoder_helper_funcs.dpms hook. 214 * 215 * The bridge can assume that the display pipe (i.e. clocks and timing 216 * signals) feeding it is running when this callback is called. This 217 * callback must enable the display link feeding the next bridge in the 218 * chain if there is one. 219 * 220 * The enable callback is optional. 221 */ 222 void (*enable)(struct drm_bridge *bridge); 223 }; 224 225 /** 226 * struct drm_bridge - central DRM bridge control structure 227 * @dev: DRM device this bridge belongs to 228 * @encoder: encoder to which this bridge is connected 229 * @next: the next bridge in the encoder chain 230 * @of_node: device node pointer to the bridge 231 * @list: to keep track of all added bridges 232 * @funcs: control functions 233 * @driver_private: pointer to the bridge driver's internal context 234 */ 235 struct drm_bridge { 236 struct drm_device *dev; 237 struct drm_encoder *encoder; 238 struct drm_bridge *next; 239 #ifdef CONFIG_OF 240 struct device_node *of_node; 241 #endif 242 struct list_head list; 243 244 const struct drm_bridge_funcs *funcs; 245 void *driver_private; 246 }; 247 248 void drm_bridge_add(struct drm_bridge *bridge); 249 void drm_bridge_remove(struct drm_bridge *bridge); 250 struct drm_bridge *of_drm_find_bridge(struct device_node *np); 251 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, 252 struct drm_bridge *previous); 253 254 bool drm_bridge_mode_fixup(struct drm_bridge *bridge, 255 const struct drm_display_mode *mode, 256 struct drm_display_mode *adjusted_mode); 257 enum drm_mode_status drm_bridge_mode_valid(struct drm_bridge *bridge, 258 const struct drm_display_mode *mode); 259 void drm_bridge_disable(struct drm_bridge *bridge); 260 void drm_bridge_post_disable(struct drm_bridge *bridge); 261 void drm_bridge_mode_set(struct drm_bridge *bridge, 262 struct drm_display_mode *mode, 263 struct drm_display_mode *adjusted_mode); 264 void drm_bridge_pre_enable(struct drm_bridge *bridge); 265 void drm_bridge_enable(struct drm_bridge *bridge); 266 267 #ifdef CONFIG_DRM_PANEL_BRIDGE 268 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel, 269 u32 connector_type); 270 void drm_panel_bridge_remove(struct drm_bridge *bridge); 271 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev, 272 struct drm_panel *panel, 273 u32 connector_type); 274 #endif 275 276 #endif 277