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v4.17
 
  1#include <linux/component.h>
  2#include <linux/export.h>
  3#include <linux/list.h>
 
 
  4#include <linux/of_graph.h>
  5#include <drm/drmP.h>
  6#include <drm/drm_bridge.h>
  7#include <drm/drm_crtc.h>
 
  8#include <drm/drm_encoder.h>
  9#include <drm/drm_panel.h>
 10#include <drm/drm_of.h>
 
 11
 12static void drm_release_of(struct device *dev, void *data)
 13{
 14	of_node_put(data);
 15}
 
 
 16
 17/**
 18 * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
 19 * @dev: DRM device
 20 * @port: port OF node
 21 *
 22 * Given a port OF node, return the possible mask of the corresponding
 23 * CRTC within a device's list of CRTCs.  Returns zero if not found.
 24 */
 25static uint32_t drm_crtc_port_mask(struct drm_device *dev,
 26				   struct device_node *port)
 27{
 28	unsigned int index = 0;
 29	struct drm_crtc *tmp;
 30
 31	drm_for_each_crtc(tmp, dev) {
 32		if (tmp->port == port)
 33			return 1 << index;
 34
 35		index++;
 36	}
 37
 38	return 0;
 39}
 
 40
 41/**
 42 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
 43 * @dev: DRM device
 44 * @port: encoder port to scan for endpoints
 45 *
 46 * Scan all endpoints attached to a port, locate their attached CRTCs,
 47 * and generate the DRM mask of CRTCs which may be attached to this
 48 * encoder.
 49 *
 50 * See Documentation/devicetree/bindings/graph.txt for the bindings.
 51 */
 52uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
 53				    struct device_node *port)
 54{
 55	struct device_node *remote_port, *ep;
 56	uint32_t possible_crtcs = 0;
 57
 58	for_each_endpoint_of_node(port, ep) {
 59		remote_port = of_graph_get_remote_port(ep);
 60		if (!remote_port) {
 61			of_node_put(ep);
 62			return 0;
 63		}
 64
 65		possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
 66
 67		of_node_put(remote_port);
 68	}
 69
 70	return possible_crtcs;
 71}
 72EXPORT_SYMBOL(drm_of_find_possible_crtcs);
 73
 74/**
 75 * drm_of_component_match_add - Add a component helper OF node match rule
 76 * @master: master device
 77 * @matchptr: component match pointer
 78 * @compare: compare function used for matching component
 79 * @node: of_node
 80 */
 81void drm_of_component_match_add(struct device *master,
 82				struct component_match **matchptr,
 83				int (*compare)(struct device *, void *),
 84				struct device_node *node)
 85{
 86	of_node_get(node);
 87	component_match_add_release(master, matchptr, drm_release_of,
 88				    compare, node);
 89}
 90EXPORT_SYMBOL_GPL(drm_of_component_match_add);
 91
 92/**
 93 * drm_of_component_probe - Generic probe function for a component based master
 94 * @dev: master device containing the OF node
 95 * @compare_of: compare function used for matching components
 96 * @master_ops: component master ops to be used
 97 *
 98 * Parse the platform device OF node and bind all the components associated
 99 * with the master. Interface ports are added before the encoders in order to
100 * satisfy their .bind requirements
101 * See Documentation/devicetree/bindings/graph.txt for the bindings.
102 *
103 * Returns zero if successful, or one of the standard error codes if it fails.
104 */
105int drm_of_component_probe(struct device *dev,
106			   int (*compare_of)(struct device *, void *),
107			   const struct component_master_ops *m_ops)
108{
109	struct device_node *ep, *port, *remote;
110	struct component_match *match = NULL;
111	int i;
112
113	if (!dev->of_node)
114		return -EINVAL;
115
116	/*
117	 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
118	 * called from encoder's .bind callbacks works as expected
119	 */
120	for (i = 0; ; i++) {
121		port = of_parse_phandle(dev->of_node, "ports", i);
122		if (!port)
123			break;
124
125		if (of_device_is_available(port->parent))
126			drm_of_component_match_add(dev, &match, compare_of,
127						   port);
128
129		of_node_put(port);
130	}
131
132	if (i == 0) {
133		dev_err(dev, "missing 'ports' property\n");
134		return -ENODEV;
135	}
136
137	if (!match) {
138		dev_err(dev, "no available port\n");
139		return -ENODEV;
140	}
141
142	/*
143	 * For bound crtcs, bind the encoders attached to their remote endpoint
144	 */
145	for (i = 0; ; i++) {
146		port = of_parse_phandle(dev->of_node, "ports", i);
147		if (!port)
148			break;
149
150		if (!of_device_is_available(port->parent)) {
151			of_node_put(port);
152			continue;
153		}
154
155		for_each_child_of_node(port, ep) {
156			remote = of_graph_get_remote_port_parent(ep);
157			if (!remote || !of_device_is_available(remote)) {
158				of_node_put(remote);
159				continue;
160			} else if (!of_device_is_available(remote->parent)) {
161				dev_warn(dev, "parent device of %pOF is not available\n",
162					 remote);
163				of_node_put(remote);
164				continue;
165			}
166
167			drm_of_component_match_add(dev, &match, compare_of,
168						   remote);
169			of_node_put(remote);
170		}
171		of_node_put(port);
172	}
173
174	return component_master_add_with_match(dev, m_ops, match);
175}
176EXPORT_SYMBOL(drm_of_component_probe);
177
178/*
179 * drm_of_encoder_active_endpoint - return the active encoder endpoint
180 * @node: device tree node containing encoder input ports
181 * @encoder: drm_encoder
182 *
183 * Given an encoder device node and a drm_encoder with a connected crtc,
184 * parse the encoder endpoint connecting to the crtc port.
185 */
186int drm_of_encoder_active_endpoint(struct device_node *node,
187				   struct drm_encoder *encoder,
188				   struct of_endpoint *endpoint)
189{
190	struct device_node *ep;
191	struct drm_crtc *crtc = encoder->crtc;
192	struct device_node *port;
193	int ret;
194
195	if (!node || !crtc)
196		return -EINVAL;
197
198	for_each_endpoint_of_node(node, ep) {
199		port = of_graph_get_remote_port(ep);
200		of_node_put(port);
201		if (port == crtc->port) {
202			ret = of_graph_parse_endpoint(ep, endpoint);
203			of_node_put(ep);
204			return ret;
205		}
206	}
207
208	return -EINVAL;
209}
210EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
211
212/*
213 * drm_of_find_panel_or_bridge - return connected panel or bridge device
214 * @np: device tree node containing encoder output ports
 
 
215 * @panel: pointer to hold returned drm_panel
216 * @bridge: pointer to hold returned drm_bridge
217 *
218 * Given a DT node's port and endpoint number, find the connected node and
219 * return either the associated struct drm_panel or drm_bridge device. Either
220 * @panel or @bridge must not be NULL.
221 *
 
 
 
222 * Returns zero if successful, or one of the standard error codes if it fails.
223 */
224int drm_of_find_panel_or_bridge(const struct device_node *np,
225				int port, int endpoint,
226				struct drm_panel **panel,
227				struct drm_bridge **bridge)
228{
229	int ret = -EPROBE_DEFER;
230	struct device_node *remote;
231
232	if (!panel && !bridge)
233		return -EINVAL;
234	if (panel)
235		*panel = NULL;
236
 
 
 
 
 
 
 
 
 
237	remote = of_graph_get_remote_node(np, port, endpoint);
238	if (!remote)
239		return -ENODEV;
240
241	if (panel) {
242		*panel = of_drm_find_panel(remote);
243		if (*panel)
244			ret = 0;
 
 
245	}
246
247	/* No panel found yet, check for a bridge next. */
248	if (bridge) {
249		if (ret) {
250			*bridge = of_drm_find_bridge(remote);
251			if (*bridge)
252				ret = 0;
253		} else {
254			*bridge = NULL;
255		}
256
257	}
258
259	of_node_put(remote);
260	return ret;
261}
262EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
v6.2
  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_of.h>
 14#include <drm/drm_panel.h>
 15
 16/**
 17 * DOC: overview
 18 *
 19 * A set of helper functions to aid DRM drivers in parsing standard DT
 20 * properties.
 21 */
 22
 23/**
 24 * drm_of_crtc_port_mask - find the mask of a registered CRTC by port OF node
 25 * @dev: DRM device
 26 * @port: port OF node
 27 *
 28 * Given a port OF node, return the possible mask of the corresponding
 29 * CRTC within a device's list of CRTCs.  Returns zero if not found.
 30 */
 31uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
 32			    struct device_node *port)
 33{
 34	unsigned int index = 0;
 35	struct drm_crtc *tmp;
 36
 37	drm_for_each_crtc(tmp, dev) {
 38		if (tmp->port == port)
 39			return 1 << index;
 40
 41		index++;
 42	}
 43
 44	return 0;
 45}
 46EXPORT_SYMBOL(drm_of_crtc_port_mask);
 47
 48/**
 49 * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
 50 * @dev: DRM device
 51 * @port: encoder port to scan for endpoints
 52 *
 53 * Scan all endpoints attached to a port, locate their attached CRTCs,
 54 * and generate the DRM mask of CRTCs which may be attached to this
 55 * encoder.
 56 *
 57 * See Documentation/devicetree/bindings/graph.txt for the bindings.
 58 */
 59uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
 60				    struct device_node *port)
 61{
 62	struct device_node *remote_port, *ep;
 63	uint32_t possible_crtcs = 0;
 64
 65	for_each_endpoint_of_node(port, ep) {
 66		remote_port = of_graph_get_remote_port(ep);
 67		if (!remote_port) {
 68			of_node_put(ep);
 69			return 0;
 70		}
 71
 72		possible_crtcs |= drm_of_crtc_port_mask(dev, remote_port);
 73
 74		of_node_put(remote_port);
 75	}
 76
 77	return possible_crtcs;
 78}
 79EXPORT_SYMBOL(drm_of_find_possible_crtcs);
 80
 81/**
 82 * drm_of_component_match_add - Add a component helper OF node match rule
 83 * @master: master device
 84 * @matchptr: component match pointer
 85 * @compare: compare function used for matching component
 86 * @node: of_node
 87 */
 88void drm_of_component_match_add(struct device *master,
 89				struct component_match **matchptr,
 90				int (*compare)(struct device *, void *),
 91				struct device_node *node)
 92{
 93	of_node_get(node);
 94	component_match_add_release(master, matchptr, component_release_of,
 95				    compare, node);
 96}
 97EXPORT_SYMBOL_GPL(drm_of_component_match_add);
 98
 99/**
100 * drm_of_component_probe - Generic probe function for a component based master
101 * @dev: master device containing the OF node
102 * @compare_of: compare function used for matching components
103 * @m_ops: component master ops to be used
104 *
105 * Parse the platform device OF node and bind all the components associated
106 * with the master. Interface ports are added before the encoders in order to
107 * satisfy their .bind requirements
108 * See Documentation/devicetree/bindings/graph.txt for the bindings.
109 *
110 * Returns zero if successful, or one of the standard error codes if it fails.
111 */
112int drm_of_component_probe(struct device *dev,
113			   int (*compare_of)(struct device *, void *),
114			   const struct component_master_ops *m_ops)
115{
116	struct device_node *ep, *port, *remote;
117	struct component_match *match = NULL;
118	int i;
119
120	if (!dev->of_node)
121		return -EINVAL;
122
123	/*
124	 * Bind the crtc's ports first, so that drm_of_find_possible_crtcs()
125	 * called from encoder's .bind callbacks works as expected
126	 */
127	for (i = 0; ; i++) {
128		port = of_parse_phandle(dev->of_node, "ports", i);
129		if (!port)
130			break;
131
132		if (of_device_is_available(port->parent))
133			drm_of_component_match_add(dev, &match, compare_of,
134						   port);
135
136		of_node_put(port);
137	}
138
139	if (i == 0) {
140		dev_err(dev, "missing 'ports' property\n");
141		return -ENODEV;
142	}
143
144	if (!match) {
145		dev_err(dev, "no available port\n");
146		return -ENODEV;
147	}
148
149	/*
150	 * For bound crtcs, bind the encoders attached to their remote endpoint
151	 */
152	for (i = 0; ; i++) {
153		port = of_parse_phandle(dev->of_node, "ports", i);
154		if (!port)
155			break;
156
157		if (!of_device_is_available(port->parent)) {
158			of_node_put(port);
159			continue;
160		}
161
162		for_each_child_of_node(port, ep) {
163			remote = of_graph_get_remote_port_parent(ep);
164			if (!remote || !of_device_is_available(remote)) {
165				of_node_put(remote);
166				continue;
167			} else if (!of_device_is_available(remote->parent)) {
168				dev_warn(dev, "parent device of %pOF is not available\n",
169					 remote);
170				of_node_put(remote);
171				continue;
172			}
173
174			drm_of_component_match_add(dev, &match, compare_of,
175						   remote);
176			of_node_put(remote);
177		}
178		of_node_put(port);
179	}
180
181	return component_master_add_with_match(dev, m_ops, match);
182}
183EXPORT_SYMBOL(drm_of_component_probe);
184
185/*
186 * drm_of_encoder_active_endpoint - return the active encoder endpoint
187 * @node: device tree node containing encoder input ports
188 * @encoder: drm_encoder
189 *
190 * Given an encoder device node and a drm_encoder with a connected crtc,
191 * parse the encoder endpoint connecting to the crtc port.
192 */
193int drm_of_encoder_active_endpoint(struct device_node *node,
194				   struct drm_encoder *encoder,
195				   struct of_endpoint *endpoint)
196{
197	struct device_node *ep;
198	struct drm_crtc *crtc = encoder->crtc;
199	struct device_node *port;
200	int ret;
201
202	if (!node || !crtc)
203		return -EINVAL;
204
205	for_each_endpoint_of_node(node, ep) {
206		port = of_graph_get_remote_port(ep);
207		of_node_put(port);
208		if (port == crtc->port) {
209			ret = of_graph_parse_endpoint(ep, endpoint);
210			of_node_put(ep);
211			return ret;
212		}
213	}
214
215	return -EINVAL;
216}
217EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
218
219/**
220 * drm_of_find_panel_or_bridge - return connected panel or bridge device
221 * @np: device tree node containing encoder output ports
222 * @port: port in the device tree node
223 * @endpoint: endpoint in the device tree node
224 * @panel: pointer to hold returned drm_panel
225 * @bridge: pointer to hold returned drm_bridge
226 *
227 * Given a DT node's port and endpoint number, find the connected node and
228 * return either the associated struct drm_panel or drm_bridge device. Either
229 * @panel or @bridge must not be NULL.
230 *
231 * This function is deprecated and should not be used in new drivers. Use
232 * devm_drm_of_get_bridge() instead.
233 *
234 * Returns zero if successful, or one of the standard error codes if it fails.
235 */
236int drm_of_find_panel_or_bridge(const struct device_node *np,
237				int port, int endpoint,
238				struct drm_panel **panel,
239				struct drm_bridge **bridge)
240{
241	int ret = -EPROBE_DEFER;
242	struct device_node *remote;
243
244	if (!panel && !bridge)
245		return -EINVAL;
246	if (panel)
247		*panel = NULL;
248
249	/*
250	 * of_graph_get_remote_node() produces a noisy error message if port
251	 * node isn't found and the absence of the port is a legit case here,
252	 * so at first we silently check whether graph presents in the
253	 * device-tree node.
254	 */
255	if (!of_graph_is_present(np))
256		return -ENODEV;
257
258	remote = of_graph_get_remote_node(np, port, endpoint);
259	if (!remote)
260		return -ENODEV;
261
262	if (panel) {
263		*panel = of_drm_find_panel(remote);
264		if (!IS_ERR(*panel))
265			ret = 0;
266		else
267			*panel = NULL;
268	}
269
270	/* No panel found yet, check for a bridge next. */
271	if (bridge) {
272		if (ret) {
273			*bridge = of_drm_find_bridge(remote);
274			if (*bridge)
275				ret = 0;
276		} else {
277			*bridge = NULL;
278		}
279
280	}
281
282	of_node_put(remote);
283	return ret;
284}
285EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
286
287enum drm_of_lvds_pixels {
288	DRM_OF_LVDS_EVEN = BIT(0),
289	DRM_OF_LVDS_ODD = BIT(1),
290};
291
292static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node)
293{
294	bool even_pixels =
295		of_property_read_bool(port_node, "dual-lvds-even-pixels");
296	bool odd_pixels =
297		of_property_read_bool(port_node, "dual-lvds-odd-pixels");
298
299	return (even_pixels ? DRM_OF_LVDS_EVEN : 0) |
300	       (odd_pixels ? DRM_OF_LVDS_ODD : 0);
301}
302
303static int drm_of_lvds_get_remote_pixels_type(
304			const struct device_node *port_node)
305{
306	struct device_node *endpoint = NULL;
307	int pixels_type = -EPIPE;
308
309	for_each_child_of_node(port_node, endpoint) {
310		struct device_node *remote_port;
311		int current_pt;
312
313		if (!of_node_name_eq(endpoint, "endpoint"))
314			continue;
315
316		remote_port = of_graph_get_remote_port(endpoint);
317		if (!remote_port) {
318			of_node_put(endpoint);
319			return -EPIPE;
320		}
321
322		current_pt = drm_of_lvds_get_port_pixels_type(remote_port);
323		of_node_put(remote_port);
324		if (pixels_type < 0)
325			pixels_type = current_pt;
326
327		/*
328		 * Sanity check, ensure that all remote endpoints have the same
329		 * pixel type. We may lift this restriction later if we need to
330		 * support multiple sinks with different dual-link
331		 * configurations by passing the endpoints explicitly to
332		 * drm_of_lvds_get_dual_link_pixel_order().
333		 */
334		if (!current_pt || pixels_type != current_pt) {
335			of_node_put(endpoint);
336			return -EINVAL;
337		}
338	}
339
340	return pixels_type;
341}
342
343/**
344 * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link pixel order
345 * @port1: First DT port node of the Dual-link LVDS source
346 * @port2: Second DT port node of the Dual-link LVDS source
347 *
348 * An LVDS dual-link connection is made of two links, with even pixels
349 * transitting on one link, and odd pixels on the other link. This function
350 * returns, for two ports of an LVDS dual-link source, which port shall transmit
351 * the even and odd pixels, based on the requirements of the connected sink.
352 *
353 * The pixel order is determined from the dual-lvds-even-pixels and
354 * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those
355 * properties are not present, or if their usage is not valid, this function
356 * returns -EINVAL.
357 *
358 * If either port is not connected, this function returns -EPIPE.
359 *
360 * @port1 and @port2 are typically DT sibling nodes, but may have different
361 * parents when, for instance, two separate LVDS encoders carry the even and odd
362 * pixels.
363 *
364 * Return:
365 * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2
366 *   carries odd pixels
367 * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 carries odd pixels and @port2
368 *   carries even pixels
369 * * -EINVAL - @port1 and @port2 are not connected to a dual-link LVDS sink, or
370 *   the sink configuration is invalid
371 * * -EPIPE - when @port1 or @port2 are not connected
372 */
373int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
374					  const struct device_node *port2)
375{
376	int remote_p1_pt, remote_p2_pt;
377
378	if (!port1 || !port2)
379		return -EINVAL;
380
381	remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1);
382	if (remote_p1_pt < 0)
383		return remote_p1_pt;
384
385	remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2);
386	if (remote_p2_pt < 0)
387		return remote_p2_pt;
388
389	/*
390	 * A valid dual-lVDS bus is found when one remote port is marked with
391	 * "dual-lvds-even-pixels", and the other remote port is marked with
392	 * "dual-lvds-odd-pixels", bail out if the markers are not right.
393	 */
394	if (remote_p1_pt + remote_p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD)
395		return -EINVAL;
396
397	return remote_p1_pt == DRM_OF_LVDS_EVEN ?
398		DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS :
399		DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
400}
401EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order);
402
403/**
404 * drm_of_lvds_get_data_mapping - Get LVDS data mapping
405 * @port: DT port node of the LVDS source or sink
406 *
407 * Convert DT "data-mapping" property string value into media bus format value.
408 *
409 * Return:
410 * * MEDIA_BUS_FMT_RGB666_1X7X3_SPWG - data-mapping is "jeida-18"
411 * * MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA - data-mapping is "jeida-24"
412 * * MEDIA_BUS_FMT_RGB888_1X7X4_SPWG - data-mapping is "vesa-24"
413 * * -EINVAL - the "data-mapping" property is unsupported
414 * * -ENODEV - the "data-mapping" property is missing
415 */
416int drm_of_lvds_get_data_mapping(const struct device_node *port)
417{
418	const char *mapping;
419	int ret;
420
421	ret = of_property_read_string(port, "data-mapping", &mapping);
422	if (ret < 0)
423		return -ENODEV;
424
425	if (!strcmp(mapping, "jeida-18"))
426		return MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
427	if (!strcmp(mapping, "jeida-24"))
428		return MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
429	if (!strcmp(mapping, "vesa-24"))
430		return MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
431
432	return -EINVAL;
433}
434EXPORT_SYMBOL_GPL(drm_of_lvds_get_data_mapping);
435
436/**
437 * drm_of_get_data_lanes_count - Get DSI/(e)DP data lane count
438 * @endpoint: DT endpoint node of the DSI/(e)DP source or sink
439 * @min: minimum supported number of data lanes
440 * @max: maximum supported number of data lanes
441 *
442 * Count DT "data-lanes" property elements and check for validity.
443 *
444 * Return:
445 * * min..max - positive integer count of "data-lanes" elements
446 * * -ve - the "data-lanes" property is missing or invalid
447 * * -EINVAL - the "data-lanes" property is unsupported
448 */
449int drm_of_get_data_lanes_count(const struct device_node *endpoint,
450				const unsigned int min, const unsigned int max)
451{
452	int ret;
453
454	ret = of_property_count_u32_elems(endpoint, "data-lanes");
455	if (ret < 0)
456		return ret;
457
458	if (ret < min || ret > max)
459		return -EINVAL;
460
461	return ret;
462}
463EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count);
464
465/**
466 * drm_of_get_data_lanes_count_ep - Get DSI/(e)DP data lane count by endpoint
467 * @port: DT port node of the DSI/(e)DP source or sink
468 * @port_reg: identifier (value of reg property) of the parent port node
469 * @reg: identifier (value of reg property) of the endpoint node
470 * @min: minimum supported number of data lanes
471 * @max: maximum supported number of data lanes
472 *
473 * Count DT "data-lanes" property elements and check for validity.
474 * This variant uses endpoint specifier.
475 *
476 * Return:
477 * * min..max - positive integer count of "data-lanes" elements
478 * * -EINVAL - the "data-mapping" property is unsupported
479 * * -ENODEV - the "data-mapping" property is missing
480 */
481int drm_of_get_data_lanes_count_ep(const struct device_node *port,
482				   int port_reg, int reg,
483				   const unsigned int min,
484				   const unsigned int max)
485{
486	struct device_node *endpoint;
487	int ret;
488
489	endpoint = of_graph_get_endpoint_by_regs(port, port_reg, reg);
490	ret = drm_of_get_data_lanes_count(endpoint, min, max);
491	of_node_put(endpoint);
492
493	return ret;
494}
495EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep);