1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/component.h> 3 #include <linux/export.h> 4 #include <linux/list.h> 5 #include <linux/of_graph.h> 6 7 #include <drm/drm_bridge.h> 8 #include <drm/drm_crtc.h> 9 #include <drm/drm_device.h> 10 #include <drm/drm_encoder.h> 11 #include <drm/drm_of.h> 12 #include <drm/drm_panel.h> 13 14 /** 15 * DOC: overview 16 * 17 * A set of helper functions to aid DRM drivers in parsing standard DT 18 * properties. 19 */ 20 21 /** 22 * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node 23 * @dev: DRM device 24 * @port: port OF node 25 * 26 * Given a port OF node, return the possible mask of the corresponding 27 * CRTC within a device's list of CRTCs. Returns zero if not found. 28 */ 29 uint32_t drm_of_crtc_port_mask(struct drm_device *dev, 30 struct device_node *port) 31 { 32 unsigned int index = 0; 33 struct drm_crtc *tmp; 34 35 drm_for_each_crtc(tmp, dev) { 36 if (tmp->port == port) 37 return 1 << index; 38 39 index++; 40 } 41 42 return 0; 43 } 44 EXPORT_SYMBOL(drm_of_crtc_port_mask); 45 46 /** 47 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port 48 * @dev: DRM device 49 * @port: encoder port to scan for endpoints 50 * 51 * Scan all endpoints attached to a port, locate their attached CRTCs, 52 * and generate the DRM mask of CRTCs which may be attached to this 53 * encoder. 54 * 55 * See Documentation/devicetree/bindings/graph.txt for the bindings. 56 */ 57 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev, 58 struct device_node *port) 59 { 60 struct device_node *remote_port, *ep; 61 uint32_t possible_crtcs = 0; 62 63 for_each_endpoint_of_node(port, ep) { 64 remote_port = of_graph_get_remote_port(ep); 65 if (!remote_port) { 66 of_node_put(ep); 67 return 0; 68 } 69 70 possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port); 71 72 of_node_put(remote_port); 73 } 74 75 return possible_crtcs; 76 } 77 EXPORT_SYMBOL(drm_of_find_possible_crtcs); 78 79 /** 80 * drm_of_component_match_add - Add a component helper OF node match rule 81 * @master: master device 82 * @matchptr: component match pointer 83 * @compare: compare function used for matching component 84 * @node: of_node 85 */ 86 void drm_of_component_match_add(struct device *master, 87 struct component_match **matchptr, 88 int (*compare)(struct device *, void *), 89 struct device_node *node) 90 { 91 of_node_get(node); 92 component_match_add_release(master, matchptr, component_release_of, 93 compare, node); 94 } 95 EXPORT_SYMBOL_GPL(drm_of_component_match_add); 96 97 /** 98 * drm_of_component_probe - Generic probe function for a component based master 99 * @dev: master device containing the OF node 100 * @compare_of: compare function used for matching components 101 * @m_ops: component master ops to be used 102 * 103 * Parse the platform device OF node and bind all the components associated 104 * with the master. Interface ports are added before the encoders in order to 105 * satisfy their .bind requirements 106 * See Documentation/devicetree/bindings/graph.txt for the bindings. 107 * 108 * Returns zero if successful, or one of the standard error codes if it fails. 109 */ 110 int drm_of_component_probe(struct device *dev, 111 int (*compare_of)(struct device *, void *), 112 const struct component_master_ops *m_ops) 113 { 114 struct device_node *ep, *port, *remote; 115 struct component_match *match = NULL; 116 int i; 117 118 if (!dev->of_node) 119 return -EINVAL; 120 121 /* 122 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs() 123 * called from encoder's .bind callbacks works as expected 124 */ 125 for (i = 0; ; i++) { 126 port = of_parse_phandle(dev->of_node, "ports", i); 127 if (!port) 128 break; 129 130 if (of_device_is_available(port->parent)) 131 drm_of_component_match_add(dev, &match, compare_of, 132 port); 133 134 of_node_put(port); 135 } 136 137 if (i == 0) { 138 dev_err(dev, "missing 'ports' property\n"); 139 return -ENODEV; 140 } 141 142 if (!match) { 143 dev_err(dev, "no available port\n"); 144 return -ENODEV; 145 } 146 147 /* 148 * For bound crtcs, bind the encoders attached to their remote endpoint 149 */ 150 for (i = 0; ; i++) { 151 port = of_parse_phandle(dev->of_node, "ports", i); 152 if (!port) 153 break; 154 155 if (!of_device_is_available(port->parent)) { 156 of_node_put(port); 157 continue; 158 } 159 160 for_each_child_of_node(port, ep) { 161 remote = of_graph_get_remote_port_parent(ep); 162 if (!remote || !of_device_is_available(remote)) { 163 of_node_put(remote); 164 continue; 165 } else if (!of_device_is_available(remote->parent)) { 166 dev_warn(dev, "parent device of %pOF is not available\n", 167 remote); 168 of_node_put(remote); 169 continue; 170 } 171 172 drm_of_component_match_add(dev, &match, compare_of, 173 remote); 174 of_node_put(remote); 175 } 176 of_node_put(port); 177 } 178 179 return component_master_add_with_match(dev, m_ops, match); 180 } 181 EXPORT_SYMBOL(drm_of_component_probe); 182 183 /* 184 * drm_of_encoder_active_endpoint - return the active encoder endpoint 185 * @node: device tree node containing encoder input ports 186 * @encoder: drm_encoder 187 * 188 * Given an encoder device node and a drm_encoder with a connected crtc, 189 * parse the encoder endpoint connecting to the crtc port. 190 */ 191 int drm_of_encoder_active_endpoint(struct device_node *node, 192 struct drm_encoder *encoder, 193 struct of_endpoint *endpoint) 194 { 195 struct device_node *ep; 196 struct drm_crtc *crtc = encoder->crtc; 197 struct device_node *port; 198 int ret; 199 200 if (!node || !crtc) 201 return -EINVAL; 202 203 for_each_endpoint_of_node(node, ep) { 204 port = of_graph_get_remote_port(ep); 205 of_node_put(port); 206 if (port == crtc->port) { 207 ret = of_graph_parse_endpoint(ep, endpoint); 208 of_node_put(ep); 209 return ret; 210 } 211 } 212 213 return -EINVAL; 214 } 215 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); 216 217 /** 218 * drm_of_find_panel_or_bridge - return connected panel or bridge device 219 * @np: device tree node containing encoder output ports 220 * @port: port in the device tree node 221 * @endpoint: endpoint in the device tree node 222 * @panel: pointer to hold returned drm_panel 223 * @bridge: pointer to hold returned drm_bridge 224 * 225 * Given a DT node's port and endpoint number, find the connected node and 226 * return either the associated struct drm_panel or drm_bridge device. Either 227 * @panel or @bridge must not be NULL. 228 * 229 * This function is deprecated and should not be used in new drivers. Use 230 * devm_drm_of_get_bridge() instead. 231 * 232 * Returns zero if successful, or one of the standard error codes if it fails. 233 */ 234 int drm_of_find_panel_or_bridge(const struct device_node *np, 235 int port, int endpoint, 236 struct drm_panel **panel, 237 struct drm_bridge **bridge) 238 { 239 int ret = -EPROBE_DEFER; 240 struct device_node *remote; 241 242 if (!panel && !bridge) 243 return -EINVAL; 244 if (panel) 245 *panel = NULL; 246 247 /* 248 * of_graph_get_remote_node() produces a noisy error message if port 249 * node isn't found and the absence of the port is a legit case here, 250 * so at first we silently check whether graph presents in the 251 * device-tree node. 252 */ 253 if (!of_graph_is_present(np)) 254 return -ENODEV; 255 256 remote = of_graph_get_remote_node(np, port, endpoint); 257 if (!remote) 258 return -ENODEV; 259 260 if (panel) { 261 *panel = of_drm_find_panel(remote); 262 if (!IS_ERR(*panel)) 263 ret = 0; 264 else 265 *panel = NULL; 266 } 267 268 /* No panel found yet, check for a bridge next. */ 269 if (bridge) { 270 if (ret) { 271 *bridge = of_drm_find_bridge(remote); 272 if (*bridge) 273 ret = 0; 274 } else { 275 *bridge = NULL; 276 } 277 278 } 279 280 of_node_put(remote); 281 return ret; 282 } 283 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge); 284 285 enum drm_of_lvds_pixels { 286 DRM_OF_LVDS_EVEN = BIT(0), 287 DRM_OF_LVDS_ODD = BIT(1), 288 }; 289 290 static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node) 291 { 292 bool even_pixels = 293 of_property_read_bool(port_node, "dual-lvds-even-pixels"); 294 bool odd_pixels = 295 of_property_read_bool(port_node, "dual-lvds-odd-pixels"); 296 297 return (even_pixels ? DRM_OF_LVDS_EVEN : 0) | 298 (odd_pixels ? DRM_OF_LVDS_ODD : 0); 299 } 300 301 static int drm_of_lvds_get_remote_pixels_type( 302 const struct device_node *port_node) 303 { 304 struct device_node *endpoint = NULL; 305 int pixels_type = -EPIPE; 306 307 for_each_child_of_node(port_node, endpoint) { 308 struct device_node *remote_port; 309 int current_pt; 310 311 if (!of_node_name_eq(endpoint, "endpoint")) 312 continue; 313 314 remote_port = of_graph_get_remote_port(endpoint); 315 if (!remote_port) { 316 of_node_put(endpoint); 317 return -EPIPE; 318 } 319 320 current_pt = drm_of_lvds_get_port_pixels_type(remote_port); 321 of_node_put(remote_port); 322 if (pixels_type < 0) 323 pixels_type = current_pt; 324 325 /* 326 * Sanity check, ensure that all remote endpoints have the same 327 * pixel type. We may lift this restriction later if we need to 328 * support multiple sinks with different dual-link 329 * configurations by passing the endpoints explicitly to 330 * drm_of_lvds_get_dual_link_pixel_order(). 331 */ 332 if (!current_pt || pixels_type != current_pt) { 333 of_node_put(endpoint); 334 return -EINVAL; 335 } 336 } 337 338 return pixels_type; 339 } 340 341 /** 342 * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link pixel order 343 * @port1: First DT port node of the Dual-link LVDS source 344 * @port2: Second DT port node of the Dual-link LVDS source 345 * 346 * An LVDS dual-link connection is made of two links, with even pixels 347 * transitting on one link, and odd pixels on the other link. This function 348 * returns, for two ports of an LVDS dual-link source, which port shall transmit 349 * the even and odd pixels, based on the requirements of the connected sink. 350 * 351 * The pixel order is determined from the dual-lvds-even-pixels and 352 * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those 353 * properties are not present, or if their usage is not valid, this function 354 * returns -EINVAL. 355 * 356 * If either port is not connected, this function returns -EPIPE. 357 * 358 * @port1 and @port2 are typically DT sibling nodes, but may have different 359 * parents when, for instance, two separate LVDS encoders carry the even and odd 360 * pixels. 361 * 362 * Return: 363 * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2 364 * carries odd pixels 365 * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 carries odd pixels and @port2 366 * carries even pixels 367 * * -EINVAL - @port1 and @port2 are not connected to a dual-link LVDS sink, or 368 * the sink configuration is invalid 369 * * -EPIPE - when @port1 or @port2 are not connected 370 */ 371 int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1, 372 const struct device_node *port2) 373 { 374 int remote_p1_pt, remote_p2_pt; 375 376 if (!port1 || !port2) 377 return -EINVAL; 378 379 remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1); 380 if (remote_p1_pt < 0) 381 return remote_p1_pt; 382 383 remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2); 384 if (remote_p2_pt < 0) 385 return remote_p2_pt; 386 387 /* 388 * A valid dual-lVDS bus is found when one remote port is marked with 389 * "dual-lvds-even-pixels", and the other remote port is marked with 390 * "dual-lvds-odd-pixels", bail out if the markers are not right. 391 */ 392 if (remote_p1_pt + remote_p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD) 393 return -EINVAL; 394 395 return remote_p1_pt == DRM_OF_LVDS_EVEN ? 396 DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS : 397 DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS; 398 } 399 EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order); 400 401 /** 402 * drm_of_lvds_get_data_mapping - Get LVDS data mapping 403 * @port: DT port node of the LVDS source or sink 404 * 405 * Convert DT "data-mapping" property string value into media bus format value. 406 * 407 * Return: 408 * * MEDIA_BUS_FMT_RGB666_1X7X3_SPWG - data-mapping is "jeida-18" 409 * * MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA - data-mapping is "jeida-24" 410 * * MEDIA_BUS_FMT_RGB888_1X7X4_SPWG - data-mapping is "vesa-24" 411 * * -EINVAL - the "data-mapping" property is unsupported 412 * * -ENODEV - the "data-mapping" property is missing 413 */ 414 int drm_of_lvds_get_data_mapping(const struct device_node *port) 415 { 416 const char *mapping; 417 int ret; 418 419 ret = of_property_read_string(port, "data-mapping", &mapping); 420 if (ret < 0) 421 return -ENODEV; 422 423 if (!strcmp(mapping, "jeida-18")) 424 return MEDIA_BUS_FMT_RGB666_1X7X3_SPWG; 425 if (!strcmp(mapping, "jeida-24")) 426 return MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA; 427 if (!strcmp(mapping, "vesa-24")) 428 return MEDIA_BUS_FMT_RGB888_1X7X4_SPWG; 429 430 return -EINVAL; 431 } 432 EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping); 433