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