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/media-bus-format.h> 6 #include <linux/of.h> 7 #include <linux/of_graph.h> 8 9 #include <drm/drm_bridge.h> 10 #include <drm/drm_crtc.h> 11 #include <drm/drm_device.h> 12 #include <drm/drm_encoder.h> 13 #include <drm/drm_mipi_dsi.h> 14 #include <drm/drm_of.h> 15 #include <drm/drm_panel.h> 16 17 /** 18 * DOC: overview 19 * 20 * A set of helper functions to aid DRM drivers in parsing standard DT 21 * properties. 22 */ 23 24 /** 25 * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node 26 * @dev: DRM device 27 * @port: port OF node 28 * 29 * Given a port OF node, return the possible mask of the corresponding 30 * CRTC within a device's list of CRTCs. Returns zero if not found. 31 */ 32 uint32_t drm_of_crtc_port_mask(struct drm_device *dev, 33 struct device_node *port) 34 { 35 unsigned int index = 0; 36 struct drm_crtc *tmp; 37 38 drm_for_each_crtc(tmp, dev) { 39 if (tmp->port == port) 40 return 1 << index; 41 42 index++; 43 } 44 45 return 0; 46 } 47 EXPORT_SYMBOL(drm_of_crtc_port_mask); 48 49 /** 50 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port 51 * @dev: DRM device 52 * @port: encoder port to scan for endpoints 53 * 54 * Scan all endpoints attached to a port, locate their attached CRTCs, 55 * and generate the DRM mask of CRTCs which may be attached to this 56 * encoder. 57 * 58 * See https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/graph.yaml 59 * for the bindings. 60 */ 61 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev, 62 struct device_node *port) 63 { 64 struct device_node *remote_port, *ep; 65 uint32_t possible_crtcs = 0; 66 67 for_each_endpoint_of_node(port, ep) { 68 remote_port = of_graph_get_remote_port(ep); 69 if (!remote_port) { 70 of_node_put(ep); 71 return 0; 72 } 73 74 possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port); 75 76 of_node_put(remote_port); 77 } 78 79 return possible_crtcs; 80 } 81 EXPORT_SYMBOL(drm_of_find_possible_crtcs); 82 83 /** 84 * drm_of_component_match_add - Add a component helper OF node match rule 85 * @master: master device 86 * @matchptr: component match pointer 87 * @compare: compare function used for matching component 88 * @node: of_node 89 */ 90 void drm_of_component_match_add(struct device *master, 91 struct component_match **matchptr, 92 int (*compare)(struct device *, void *), 93 struct device_node *node) 94 { 95 of_node_get(node); 96 component_match_add_release(master, matchptr, component_release_of, 97 compare, node); 98 } 99 EXPORT_SYMBOL_GPL(drm_of_component_match_add); 100 101 /** 102 * drm_of_component_probe - Generic probe function for a component based master 103 * @dev: master device containing the OF node 104 * @compare_of: compare function used for matching components 105 * @m_ops: component master ops to be used 106 * 107 * Parse the platform device OF node and bind all the components associated 108 * with the master. Interface ports are added before the encoders in order to 109 * satisfy their .bind requirements 110 * 111 * See https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/graph.yaml 112 * for the bindings. 113 * 114 * Returns zero if successful, or one of the standard error codes if it fails. 115 */ 116 int drm_of_component_probe(struct device *dev, 117 int (*compare_of)(struct device *, void *), 118 const struct component_master_ops *m_ops) 119 { 120 struct device_node *ep, *port, *remote; 121 struct component_match *match = NULL; 122 int i; 123 124 if (!dev->of_node) 125 return -EINVAL; 126 127 /* 128 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs() 129 * called from encoder's .bind callbacks works as expected 130 */ 131 for (i = 0; ; i++) { 132 port = of_parse_phandle(dev->of_node, "ports", i); 133 if (!port) 134 break; 135 136 if (of_device_is_available(port->parent)) 137 drm_of_component_match_add(dev, &match, compare_of, 138 port); 139 140 of_node_put(port); 141 } 142 143 if (i == 0) { 144 dev_err(dev, "missing 'ports' property\n"); 145 return -ENODEV; 146 } 147 148 if (!match) { 149 dev_err(dev, "no available port\n"); 150 return -ENODEV; 151 } 152 153 /* 154 * For bound crtcs, bind the encoders attached to their remote endpoint 155 */ 156 for (i = 0; ; i++) { 157 port = of_parse_phandle(dev->of_node, "ports", i); 158 if (!port) 159 break; 160 161 if (!of_device_is_available(port->parent)) { 162 of_node_put(port); 163 continue; 164 } 165 166 for_each_child_of_node(port, ep) { 167 remote = of_graph_get_remote_port_parent(ep); 168 if (!remote || !of_device_is_available(remote)) { 169 of_node_put(remote); 170 continue; 171 } else if (!of_device_is_available(remote->parent)) { 172 dev_warn(dev, "parent device of %pOF is not available\n", 173 remote); 174 of_node_put(remote); 175 continue; 176 } 177 178 drm_of_component_match_add(dev, &match, compare_of, 179 remote); 180 of_node_put(remote); 181 } 182 of_node_put(port); 183 } 184 185 return component_master_add_with_match(dev, m_ops, match); 186 } 187 EXPORT_SYMBOL(drm_of_component_probe); 188 189 /* 190 * drm_of_encoder_active_endpoint - return the active encoder endpoint 191 * @node: device tree node containing encoder input ports 192 * @encoder: drm_encoder 193 * 194 * Given an encoder device node and a drm_encoder with a connected crtc, 195 * parse the encoder endpoint connecting to the crtc port. 196 */ 197 int drm_of_encoder_active_endpoint(struct device_node *node, 198 struct drm_encoder *encoder, 199 struct of_endpoint *endpoint) 200 { 201 struct device_node *ep; 202 struct drm_crtc *crtc = encoder->crtc; 203 struct device_node *port; 204 int ret; 205 206 if (!node || !crtc) 207 return -EINVAL; 208 209 for_each_endpoint_of_node(node, ep) { 210 port = of_graph_get_remote_port(ep); 211 of_node_put(port); 212 if (port == crtc->port) { 213 ret = of_graph_parse_endpoint(ep, endpoint); 214 of_node_put(ep); 215 return ret; 216 } 217 } 218 219 return -EINVAL; 220 } 221 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); 222 223 /** 224 * drm_of_find_panel_or_bridge - return connected panel or bridge device 225 * @np: device tree node containing encoder output ports 226 * @port: port in the device tree node 227 * @endpoint: endpoint in the device tree node 228 * @panel: pointer to hold returned drm_panel 229 * @bridge: pointer to hold returned drm_bridge 230 * 231 * Given a DT node's port and endpoint number, find the connected node and 232 * return either the associated struct drm_panel or drm_bridge device. Either 233 * @panel or @bridge must not be NULL. 234 * 235 * This function is deprecated and should not be used in new drivers. Use 236 * devm_drm_of_get_bridge() instead. 237 * 238 * Returns zero if successful, or one of the standard error codes if it fails. 239 */ 240 int drm_of_find_panel_or_bridge(const struct device_node *np, 241 int port, int endpoint, 242 struct drm_panel **panel, 243 struct drm_bridge **bridge) 244 { 245 int ret = -EPROBE_DEFER; 246 struct device_node *remote; 247 248 if (!panel && !bridge) 249 return -EINVAL; 250 if (panel) 251 *panel = NULL; 252 253 /* 254 * of_graph_get_remote_node() produces a noisy error message if port 255 * node isn't found and the absence of the port is a legit case here, 256 * so at first we silently check whether graph presents in the 257 * device-tree node. 258 */ 259 if (!of_graph_is_present(np)) 260 return -ENODEV; 261 262 remote = of_graph_get_remote_node(np, port, endpoint); 263 if (!remote) 264 return -ENODEV; 265 266 if (panel) { 267 *panel = of_drm_find_panel(remote); 268 if (!IS_ERR(*panel)) 269 ret = 0; 270 else 271 *panel = NULL; 272 } 273 274 if (bridge) { 275 if (ret) { 276 /* No panel found yet, check for a bridge next. */ 277 *bridge = of_drm_find_bridge(remote); 278 if (*bridge) 279 ret = 0; 280 } else { 281 *bridge = NULL; 282 } 283 284 } 285 286 of_node_put(remote); 287 return ret; 288 } 289 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge); 290 291 enum drm_of_lvds_pixels { 292 DRM_OF_LVDS_EVEN = BIT(0), 293 DRM_OF_LVDS_ODD = BIT(1), 294 }; 295 296 static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node) 297 { 298 bool even_pixels = 299 of_property_read_bool(port_node, "dual-lvds-even-pixels"); 300 bool odd_pixels = 301 of_property_read_bool(port_node, "dual-lvds-odd-pixels"); 302 303 return (even_pixels ? DRM_OF_LVDS_EVEN : 0) | 304 (odd_pixels ? DRM_OF_LVDS_ODD : 0); 305 } 306 307 static int drm_of_lvds_get_remote_pixels_type( 308 const struct device_node *port_node) 309 { 310 struct device_node *endpoint = NULL; 311 int pixels_type = -EPIPE; 312 313 for_each_child_of_node(port_node, endpoint) { 314 struct device_node *remote_port; 315 int current_pt; 316 317 if (!of_node_name_eq(endpoint, "endpoint")) 318 continue; 319 320 remote_port = of_graph_get_remote_port(endpoint); 321 if (!remote_port) { 322 of_node_put(endpoint); 323 return -EPIPE; 324 } 325 326 current_pt = drm_of_lvds_get_port_pixels_type(remote_port); 327 of_node_put(remote_port); 328 if (pixels_type < 0) 329 pixels_type = current_pt; 330 331 /* 332 * Sanity check, ensure that all remote endpoints have the same 333 * pixel type. We may lift this restriction later if we need to 334 * support multiple sinks with different dual-link 335 * configurations by passing the endpoints explicitly to 336 * drm_of_lvds_get_dual_link_pixel_order(). 337 */ 338 if (!current_pt || pixels_type != current_pt) { 339 of_node_put(endpoint); 340 return -EINVAL; 341 } 342 } 343 344 return pixels_type; 345 } 346 347 static int __drm_of_lvds_get_dual_link_pixel_order(int p1_pt, int p2_pt) 348 { 349 /* 350 * A valid dual-lVDS bus is found when one port is marked with 351 * "dual-lvds-even-pixels", and the other port is marked with 352 * "dual-lvds-odd-pixels", bail out if the markers are not right. 353 */ 354 if (p1_pt + p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD) 355 return -EINVAL; 356 357 return p1_pt == DRM_OF_LVDS_EVEN ? 358 DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS : 359 DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS; 360 } 361 362 /** 363 * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link source pixel order 364 * @port1: First DT port node of the Dual-link LVDS source 365 * @port2: Second DT port node of the Dual-link LVDS source 366 * 367 * An LVDS dual-link connection is made of two links, with even pixels 368 * transitting on one link, and odd pixels on the other link. This function 369 * returns, for two ports of an LVDS dual-link source, which port shall transmit 370 * the even and odd pixels, based on the requirements of the connected sink. 371 * 372 * The pixel order is determined from the dual-lvds-even-pixels and 373 * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those 374 * properties are not present, or if their usage is not valid, this function 375 * returns -EINVAL. 376 * 377 * If either port is not connected, this function returns -EPIPE. 378 * 379 * @port1 and @port2 are typically DT sibling nodes, but may have different 380 * parents when, for instance, two separate LVDS encoders carry the even and odd 381 * pixels. 382 * 383 * Return: 384 * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2 385 * carries odd pixels 386 * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 carries odd pixels and @port2 387 * carries even pixels 388 * * -EINVAL - @port1 and @port2 are not connected to a dual-link LVDS sink, or 389 * the sink configuration is invalid 390 * * -EPIPE - when @port1 or @port2 are not connected 391 */ 392 int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1, 393 const struct device_node *port2) 394 { 395 int remote_p1_pt, remote_p2_pt; 396 397 if (!port1 || !port2) 398 return -EINVAL; 399 400 remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1); 401 if (remote_p1_pt < 0) 402 return remote_p1_pt; 403 404 remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2); 405 if (remote_p2_pt < 0) 406 return remote_p2_pt; 407 408 return __drm_of_lvds_get_dual_link_pixel_order(remote_p1_pt, remote_p2_pt); 409 } 410 EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order); 411 412 /** 413 * drm_of_lvds_get_dual_link_pixel_order_sink - Get LVDS dual-link sink pixel order 414 * @port1: First DT port node of the Dual-link LVDS sink 415 * @port2: Second DT port node of the Dual-link LVDS sink 416 * 417 * An LVDS dual-link connection is made of two links, with even pixels 418 * transitting on one link, and odd pixels on the other link. This function 419 * returns, for two ports of an LVDS dual-link sink, which port shall transmit 420 * the even and odd pixels, based on the requirements of the sink. 421 * 422 * The pixel order is determined from the dual-lvds-even-pixels and 423 * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those 424 * properties are not present, or if their usage is not valid, this function 425 * returns -EINVAL. 426 * 427 * If either port is not connected, this function returns -EPIPE. 428 * 429 * @port1 and @port2 are typically DT sibling nodes, but may have different 430 * parents when, for instance, two separate LVDS decoders receive the even and 431 * odd pixels. 432 * 433 * Return: 434 * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 receives even pixels and @port2 435 * receives odd pixels 436 * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 receives odd pixels and @port2 437 * receives even pixels 438 * * -EINVAL - @port1 or @port2 are NULL 439 * * -EPIPE - when @port1 or @port2 are not connected 440 */ 441 int drm_of_lvds_get_dual_link_pixel_order_sink(struct device_node *port1, 442 struct device_node *port2) 443 { 444 int sink_p1_pt, sink_p2_pt; 445 446 if (!port1 || !port2) 447 return -EINVAL; 448 449 sink_p1_pt = drm_of_lvds_get_port_pixels_type(port1); 450 if (!sink_p1_pt) 451 return -EPIPE; 452 453 sink_p2_pt = drm_of_lvds_get_port_pixels_type(port2); 454 if (!sink_p2_pt) 455 return -EPIPE; 456 457 return __drm_of_lvds_get_dual_link_pixel_order(sink_p1_pt, sink_p2_pt); 458 } 459 EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order_sink); 460 461 /** 462 * drm_of_lvds_get_data_mapping - Get LVDS data mapping 463 * @port: DT port node of the LVDS source or sink 464 * 465 * Convert DT "data-mapping" property string value into media bus format value. 466 * 467 * Return: 468 * * MEDIA_BUS_FMT_RGB666_1X7X3_SPWG - data-mapping is "jeida-18" 469 * * MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA - data-mapping is "jeida-24" 470 * * MEDIA_BUS_FMT_RGB101010_1X7X5_JEIDA - data-mapping is "jeida-30" 471 * * MEDIA_BUS_FMT_RGB888_1X7X4_SPWG - data-mapping is "vesa-24" 472 * * MEDIA_BUS_FMT_RGB101010_1X7X5_SPWG - data-mapping is "vesa-30" 473 * * -EINVAL - the "data-mapping" property is unsupported 474 * * -ENODEV - the "data-mapping" property is missing 475 */ 476 int drm_of_lvds_get_data_mapping(const struct device_node *port) 477 { 478 const char *mapping; 479 int ret; 480 481 ret = of_property_read_string(port, "data-mapping", &mapping); 482 if (ret < 0) 483 return -ENODEV; 484 485 if (!strcmp(mapping, "jeida-18")) 486 return MEDIA_BUS_FMT_RGB666_1X7X3_SPWG; 487 if (!strcmp(mapping, "jeida-24")) 488 return MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA; 489 if (!strcmp(mapping, "jeida-30")) 490 return MEDIA_BUS_FMT_RGB101010_1X7X5_JEIDA; 491 if (!strcmp(mapping, "vesa-24")) 492 return MEDIA_BUS_FMT_RGB888_1X7X4_SPWG; 493 if (!strcmp(mapping, "vesa-30")) 494 return MEDIA_BUS_FMT_RGB101010_1X7X5_SPWG; 495 496 return -EINVAL; 497 } 498 EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping); 499 500 /** 501 * drm_of_get_data_lanes_count - Get DSI/(e)DP data lane count 502 * @endpoint: DT endpoint node of the DSI/(e)DP source or sink 503 * @min: minimum supported number of data lanes 504 * @max: maximum supported number of data lanes 505 * 506 * Count DT "data-lanes" property elements and check for validity. 507 * 508 * Return: 509 * * min..max - positive integer count of "data-lanes" elements 510 * * -ve - the "data-lanes" property is missing or invalid 511 * * -EINVAL - the "data-lanes" property is unsupported 512 */ 513 int drm_of_get_data_lanes_count(const struct device_node *endpoint, 514 const unsigned int min, const unsigned int max) 515 { 516 int ret; 517 518 ret = of_property_count_u32_elems(endpoint, "data-lanes"); 519 if (ret < 0) 520 return ret; 521 522 if (ret < min || ret > max) 523 return -EINVAL; 524 525 return ret; 526 } 527 EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count); 528 529 /** 530 * drm_of_get_data_lanes_count_ep - Get DSI/(e)DP data lane count by endpoint 531 * @port: DT port node of the DSI/(e)DP source or sink 532 * @port_reg: identifier (value of reg property) of the parent port node 533 * @reg: identifier (value of reg property) of the endpoint node 534 * @min: minimum supported number of data lanes 535 * @max: maximum supported number of data lanes 536 * 537 * Count DT "data-lanes" property elements and check for validity. 538 * This variant uses endpoint specifier. 539 * 540 * Return: 541 * * min..max - positive integer count of "data-lanes" elements 542 * * -EINVAL - the "data-mapping" property is unsupported 543 * * -ENODEV - the "data-mapping" property is missing 544 */ 545 int drm_of_get_data_lanes_count_ep(const struct device_node *port, 546 int port_reg, int reg, 547 const unsigned int min, 548 const unsigned int max) 549 { 550 struct device_node *endpoint; 551 int ret; 552 553 endpoint = of_graph_get_endpoint_by_regs(port, port_reg, reg); 554 ret = drm_of_get_data_lanes_count(endpoint, min, max); 555 of_node_put(endpoint); 556 557 return ret; 558 } 559 EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep); 560 561 #if IS_ENABLED(CONFIG_DRM_MIPI_DSI) 562 563 /** 564 * drm_of_get_dsi_bus - find the DSI bus for a given device 565 * @dev: parent device of display (SPI, I2C) 566 * 567 * Gets parent DSI bus for a DSI device controlled through a bus other 568 * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree. 569 * 570 * This function assumes that the device's port@0 is the DSI input. 571 * 572 * Returns pointer to mipi_dsi_host if successful, -EINVAL if the 573 * request is unsupported, -EPROBE_DEFER if the DSI host is found but 574 * not available, or -ENODEV otherwise. 575 */ 576 struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev) 577 { 578 struct mipi_dsi_host *dsi_host; 579 struct device_node *endpoint, *dsi_host_node; 580 581 /* 582 * Get first endpoint child from device. 583 */ 584 endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1); 585 if (!endpoint) 586 return ERR_PTR(-ENODEV); 587 588 /* 589 * Follow the first endpoint to get the DSI host node and then 590 * release the endpoint since we no longer need it. 591 */ 592 dsi_host_node = of_graph_get_remote_port_parent(endpoint); 593 of_node_put(endpoint); 594 if (!dsi_host_node) 595 return ERR_PTR(-ENODEV); 596 597 /* 598 * Get the DSI host from the DSI host node. If we get an error 599 * or the return is null assume we're not ready to probe just 600 * yet. Release the DSI host node since we're done with it. 601 */ 602 dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node); 603 of_node_put(dsi_host_node); 604 if (IS_ERR_OR_NULL(dsi_host)) 605 return ERR_PTR(-EPROBE_DEFER); 606 607 return dsi_host; 608 } 609 EXPORT_SYMBOL_GPL(drm_of_get_dsi_bus); 610 611 #endif /* CONFIG_DRM_MIPI_DSI */ 612