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>
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>
17 * A set of helper functions to aid DRM drivers in parsing standard DT
22 * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node
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.
29 uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
30 struct device_node *port)
32 unsigned int index = 0;
35 drm_for_each_crtc(tmp, dev) {
36 if (tmp->port == port)
44 EXPORT_SYMBOL(drm_of_crtc_port_mask);
47 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
49 * @port: encoder port to scan for endpoints
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
55 * See Documentation/devicetree/bindings/graph.txt for the bindings.
57 uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
58 struct device_node *port)
60 struct device_node *remote_port, *ep;
61 uint32_t possible_crtcs = 0;
63 for_each_endpoint_of_node(port, ep) {
64 remote_port = of_graph_get_remote_port(ep);
70 possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port);
72 of_node_put(remote_port);
75 return possible_crtcs;
77 EXPORT_SYMBOL(drm_of_find_possible_crtcs);
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
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)
92 component_match_add_release(master, matchptr, component_release_of,
95 EXPORT_SYMBOL_GPL(drm_of_component_match_add);
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
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.
108 * Returns zero if successful, or one of the standard error codes if it fails.
110 int drm_of_component_probe(struct device *dev,
111 int (*compare_of)(struct device *, void *),
112 const struct component_master_ops *m_ops)
114 struct device_node *ep, *port, *remote;
115 struct component_match *match = NULL;
122 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
123 * called from encoder's .bind callbacks works as expected
126 port = of_parse_phandle(dev->of_node, "ports", i);
130 if (of_device_is_available(port->parent))
131 drm_of_component_match_add(dev, &match, compare_of,
138 dev_err(dev, "missing 'ports' property\n");
143 dev_err(dev, "no available port\n");
148 * For bound crtcs, bind the encoders attached to their remote endpoint
151 port = of_parse_phandle(dev->of_node, "ports", i);
155 if (!of_device_is_available(port->parent)) {
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)) {
165 } else if (!of_device_is_available(remote->parent)) {
166 dev_warn(dev, "parent device of %pOF is not available\n",
172 drm_of_component_match_add(dev, &match, compare_of,
179 return component_master_add_with_match(dev, m_ops, match);
181 EXPORT_SYMBOL(drm_of_component_probe);
184 * drm_of_encoder_active_endpoint - return the active encoder endpoint
185 * @node: device tree node containing encoder input ports
186 * @encoder: drm_encoder
188 * Given an encoder device node and a drm_encoder with a connected crtc,
189 * parse the encoder endpoint connecting to the crtc port.
191 int drm_of_encoder_active_endpoint(struct device_node *node,
192 struct drm_encoder *encoder,
193 struct of_endpoint *endpoint)
195 struct device_node *ep;
196 struct drm_crtc *crtc = encoder->crtc;
197 struct device_node *port;
203 for_each_endpoint_of_node(node, ep) {
204 port = of_graph_get_remote_port(ep);
206 if (port == crtc->port) {
207 ret = of_graph_parse_endpoint(ep, endpoint);
215 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
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
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.
229 * This function is deprecated and should not be used in new drivers. Use
230 * devm_drm_of_get_bridge() instead.
232 * Returns zero if successful, or one of the standard error codes if it fails.
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)
239 int ret = -EPROBE_DEFER;
240 struct device_node *remote;
242 if (!panel && !bridge)
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
253 if (!of_graph_is_present(np))
256 remote = of_graph_get_remote_node(np, port, endpoint);
261 *panel = of_drm_find_panel(remote);
268 /* No panel found yet, check for a bridge next. */
271 *bridge = of_drm_find_bridge(remote);
283 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
285 enum drm_of_lvds_pixels {
286 DRM_OF_LVDS_EVEN = BIT(0),
287 DRM_OF_LVDS_ODD = BIT(1),
290 static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node)
293 of_property_read_bool(port_node, "dual-lvds-even-pixels");
295 of_property_read_bool(port_node, "dual-lvds-odd-pixels");
297 return (even_pixels ? DRM_OF_LVDS_EVEN : 0) |
298 (odd_pixels ? DRM_OF_LVDS_ODD : 0);
301 static int drm_of_lvds_get_remote_pixels_type(
302 const struct device_node *port_node)
304 struct device_node *endpoint = NULL;
305 int pixels_type = -EPIPE;
307 for_each_child_of_node(port_node, endpoint) {
308 struct device_node *remote_port;
311 if (!of_node_name_eq(endpoint, "endpoint"))
314 remote_port = of_graph_get_remote_port(endpoint);
316 of_node_put(endpoint);
320 current_pt = drm_of_lvds_get_port_pixels_type(remote_port);
321 of_node_put(remote_port);
323 pixels_type = current_pt;
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().
332 if (!current_pt || pixels_type != current_pt) {
333 of_node_put(endpoint);
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
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.
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
356 * If either port is not connected, this function returns -EPIPE.
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
363 * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2
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
371 int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
372 const struct device_node *port2)
374 int remote_p1_pt, remote_p2_pt;
376 if (!port1 || !port2)
379 remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1);
380 if (remote_p1_pt < 0)
383 remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2);
384 if (remote_p2_pt < 0)
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.
392 if (remote_p1_pt + remote_p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD)
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;
399 EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order);
402 * drm_of_lvds_get_data_mapping - Get LVDS data mapping
403 * @port: DT port node of the LVDS source or sink
405 * Convert DT "data-mapping" property string value into media bus format value.
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
414 int drm_of_lvds_get_data_mapping(const struct device_node *port)
419 ret = of_property_read_string(port, "data-mapping", &mapping);
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;
432 EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping);