xref: /linux/drivers/media/v4l2-core/v4l2-fwnode.c (revision 56fb34d86e875dbb0d3e6a81c5d3d035db373031)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * V4L2 fwnode binding parsing library
4  *
5  * The origins of the V4L2 fwnode library are in V4L2 OF library that
6  * formerly was located in v4l2-of.c.
7  *
8  * Copyright (c) 2016 Intel Corporation.
9  * Author: Sakari Ailus <sakari.ailus@linux.intel.com>
10  *
11  * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
12  * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
13  *
14  * Copyright (C) 2012 Renesas Electronics Corp.
15  * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
16  */
17 #include <linux/acpi.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/property.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/types.h>
26 
27 #include <media/v4l2-async.h>
28 #include <media/v4l2-fwnode.h>
29 #include <media/v4l2-subdev.h>
30 
31 enum v4l2_fwnode_bus_type {
32 	V4L2_FWNODE_BUS_TYPE_GUESS = 0,
33 	V4L2_FWNODE_BUS_TYPE_CSI2_CPHY,
34 	V4L2_FWNODE_BUS_TYPE_CSI1,
35 	V4L2_FWNODE_BUS_TYPE_CCP2,
36 	V4L2_FWNODE_BUS_TYPE_CSI2_DPHY,
37 	V4L2_FWNODE_BUS_TYPE_PARALLEL,
38 	V4L2_FWNODE_BUS_TYPE_BT656,
39 	NR_OF_V4L2_FWNODE_BUS_TYPE,
40 };
41 
42 static const struct v4l2_fwnode_bus_conv {
43 	enum v4l2_fwnode_bus_type fwnode_bus_type;
44 	enum v4l2_mbus_type mbus_type;
45 	const char *name;
46 } buses[] = {
47 	{
48 		V4L2_FWNODE_BUS_TYPE_GUESS,
49 		V4L2_MBUS_UNKNOWN,
50 		"not specified",
51 	}, {
52 		V4L2_FWNODE_BUS_TYPE_CSI2_CPHY,
53 		V4L2_MBUS_CSI2_CPHY,
54 		"MIPI CSI-2 C-PHY",
55 	}, {
56 		V4L2_FWNODE_BUS_TYPE_CSI1,
57 		V4L2_MBUS_CSI1,
58 		"MIPI CSI-1",
59 	}, {
60 		V4L2_FWNODE_BUS_TYPE_CCP2,
61 		V4L2_MBUS_CCP2,
62 		"compact camera port 2",
63 	}, {
64 		V4L2_FWNODE_BUS_TYPE_CSI2_DPHY,
65 		V4L2_MBUS_CSI2_DPHY,
66 		"MIPI CSI-2 D-PHY",
67 	}, {
68 		V4L2_FWNODE_BUS_TYPE_PARALLEL,
69 		V4L2_MBUS_PARALLEL,
70 		"parallel",
71 	}, {
72 		V4L2_FWNODE_BUS_TYPE_BT656,
73 		V4L2_MBUS_BT656,
74 		"Bt.656",
75 	}
76 };
77 
78 static const struct v4l2_fwnode_bus_conv *
79 get_v4l2_fwnode_bus_conv_by_fwnode_bus(enum v4l2_fwnode_bus_type type)
80 {
81 	unsigned int i;
82 
83 	for (i = 0; i < ARRAY_SIZE(buses); i++)
84 		if (buses[i].fwnode_bus_type == type)
85 			return &buses[i];
86 
87 	return NULL;
88 }
89 
90 static enum v4l2_mbus_type
91 v4l2_fwnode_bus_type_to_mbus(enum v4l2_fwnode_bus_type type)
92 {
93 	const struct v4l2_fwnode_bus_conv *conv =
94 		get_v4l2_fwnode_bus_conv_by_fwnode_bus(type);
95 
96 	return conv ? conv->mbus_type : V4L2_MBUS_UNKNOWN;
97 }
98 
99 static const char *
100 v4l2_fwnode_bus_type_to_string(enum v4l2_fwnode_bus_type type)
101 {
102 	const struct v4l2_fwnode_bus_conv *conv =
103 		get_v4l2_fwnode_bus_conv_by_fwnode_bus(type);
104 
105 	return conv ? conv->name : "not found";
106 }
107 
108 static const struct v4l2_fwnode_bus_conv *
109 get_v4l2_fwnode_bus_conv_by_mbus(enum v4l2_mbus_type type)
110 {
111 	unsigned int i;
112 
113 	for (i = 0; i < ARRAY_SIZE(buses); i++)
114 		if (buses[i].mbus_type == type)
115 			return &buses[i];
116 
117 	return NULL;
118 }
119 
120 static const char *
121 v4l2_fwnode_mbus_type_to_string(enum v4l2_mbus_type type)
122 {
123 	const struct v4l2_fwnode_bus_conv *conv =
124 		get_v4l2_fwnode_bus_conv_by_mbus(type);
125 
126 	return conv ? conv->name : "not found";
127 }
128 
129 static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
130 					       struct v4l2_fwnode_endpoint *vep,
131 					       enum v4l2_mbus_type bus_type)
132 {
133 	struct v4l2_fwnode_bus_mipi_csi2 *bus = &vep->bus.mipi_csi2;
134 	bool have_clk_lane = false, have_data_lanes = false,
135 		have_lane_polarities = false;
136 	unsigned int flags = 0, lanes_used = 0;
137 	u32 array[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
138 	u32 clock_lane = 0;
139 	unsigned int num_data_lanes = 0;
140 	bool use_default_lane_mapping = false;
141 	unsigned int i;
142 	u32 v;
143 	int rval;
144 
145 	if (bus_type == V4L2_MBUS_CSI2_DPHY ||
146 	    bus_type == V4L2_MBUS_CSI2_CPHY) {
147 		use_default_lane_mapping = true;
148 
149 		num_data_lanes = min_t(u32, bus->num_data_lanes,
150 				       V4L2_FWNODE_CSI2_MAX_DATA_LANES);
151 
152 		clock_lane = bus->clock_lane;
153 		if (clock_lane)
154 			use_default_lane_mapping = false;
155 
156 		for (i = 0; i < num_data_lanes; i++) {
157 			array[i] = bus->data_lanes[i];
158 			if (array[i])
159 				use_default_lane_mapping = false;
160 		}
161 
162 		if (use_default_lane_mapping)
163 			pr_debug("no lane mapping given, using defaults\n");
164 	}
165 
166 	rval = fwnode_property_count_u32(fwnode, "data-lanes");
167 	if (rval > 0) {
168 		num_data_lanes =
169 			min_t(int, V4L2_FWNODE_CSI2_MAX_DATA_LANES, rval);
170 
171 		fwnode_property_read_u32_array(fwnode, "data-lanes", array,
172 					       num_data_lanes);
173 
174 		have_data_lanes = true;
175 		if (use_default_lane_mapping) {
176 			pr_debug("data-lanes property exists; disabling default mapping\n");
177 			use_default_lane_mapping = false;
178 		}
179 	}
180 
181 	for (i = 0; i < num_data_lanes; i++) {
182 		if (lanes_used & BIT(array[i])) {
183 			if (have_data_lanes || !use_default_lane_mapping)
184 				pr_warn("duplicated lane %u in data-lanes, using defaults\n",
185 					array[i]);
186 			use_default_lane_mapping = true;
187 		}
188 		lanes_used |= BIT(array[i]);
189 
190 		if (have_data_lanes)
191 			pr_debug("lane %u position %u\n", i, array[i]);
192 	}
193 
194 	rval = fwnode_property_count_u32(fwnode, "lane-polarities");
195 	if (rval > 0) {
196 		if (rval != 1 + num_data_lanes /* clock+data */) {
197 			pr_warn("invalid number of lane-polarities entries (need %u, got %u)\n",
198 				1 + num_data_lanes, rval);
199 			return -EINVAL;
200 		}
201 
202 		have_lane_polarities = true;
203 	}
204 
205 	if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) {
206 		clock_lane = v;
207 		pr_debug("clock lane position %u\n", v);
208 		have_clk_lane = true;
209 	}
210 
211 	if (have_clk_lane && lanes_used & BIT(clock_lane) &&
212 	    !use_default_lane_mapping) {
213 		pr_warn("duplicated lane %u in clock-lanes, using defaults\n",
214 			v);
215 		use_default_lane_mapping = true;
216 	}
217 
218 	if (fwnode_property_present(fwnode, "clock-noncontinuous")) {
219 		flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
220 		pr_debug("non-continuous clock\n");
221 	} else {
222 		flags |= V4L2_MBUS_CSI2_CONTINUOUS_CLOCK;
223 	}
224 
225 	if (bus_type == V4L2_MBUS_CSI2_DPHY ||
226 	    bus_type == V4L2_MBUS_CSI2_CPHY || lanes_used ||
227 	    have_clk_lane || (flags & ~V4L2_MBUS_CSI2_CONTINUOUS_CLOCK)) {
228 		/* Only D-PHY has a clock lane. */
229 		unsigned int dfl_data_lane_index =
230 			bus_type == V4L2_MBUS_CSI2_DPHY;
231 
232 		bus->flags = flags;
233 		if (bus_type == V4L2_MBUS_UNKNOWN)
234 			vep->bus_type = V4L2_MBUS_CSI2_DPHY;
235 		bus->num_data_lanes = num_data_lanes;
236 
237 		if (use_default_lane_mapping) {
238 			bus->clock_lane = 0;
239 			for (i = 0; i < num_data_lanes; i++)
240 				bus->data_lanes[i] = dfl_data_lane_index + i;
241 		} else {
242 			bus->clock_lane = clock_lane;
243 			for (i = 0; i < num_data_lanes; i++)
244 				bus->data_lanes[i] = array[i];
245 		}
246 
247 		if (have_lane_polarities) {
248 			fwnode_property_read_u32_array(fwnode,
249 						       "lane-polarities", array,
250 						       1 + num_data_lanes);
251 
252 			for (i = 0; i < 1 + num_data_lanes; i++) {
253 				bus->lane_polarities[i] = array[i];
254 				pr_debug("lane %u polarity %sinverted",
255 					 i, array[i] ? "" : "not ");
256 			}
257 		} else {
258 			pr_debug("no lane polarities defined, assuming not inverted\n");
259 		}
260 	}
261 
262 	return 0;
263 }
264 
265 #define PARALLEL_MBUS_FLAGS (V4L2_MBUS_HSYNC_ACTIVE_HIGH |	\
266 			     V4L2_MBUS_HSYNC_ACTIVE_LOW |	\
267 			     V4L2_MBUS_VSYNC_ACTIVE_HIGH |	\
268 			     V4L2_MBUS_VSYNC_ACTIVE_LOW |	\
269 			     V4L2_MBUS_FIELD_EVEN_HIGH |	\
270 			     V4L2_MBUS_FIELD_EVEN_LOW)
271 
272 static void
273 v4l2_fwnode_endpoint_parse_parallel_bus(struct fwnode_handle *fwnode,
274 					struct v4l2_fwnode_endpoint *vep,
275 					enum v4l2_mbus_type bus_type)
276 {
277 	struct v4l2_fwnode_bus_parallel *bus = &vep->bus.parallel;
278 	unsigned int flags = 0;
279 	u32 v;
280 
281 	if (bus_type == V4L2_MBUS_PARALLEL || bus_type == V4L2_MBUS_BT656)
282 		flags = bus->flags;
283 
284 	if (!fwnode_property_read_u32(fwnode, "hsync-active", &v)) {
285 		flags &= ~(V4L2_MBUS_HSYNC_ACTIVE_HIGH |
286 			   V4L2_MBUS_HSYNC_ACTIVE_LOW);
287 		flags |= v ? V4L2_MBUS_HSYNC_ACTIVE_HIGH :
288 			V4L2_MBUS_HSYNC_ACTIVE_LOW;
289 		pr_debug("hsync-active %s\n", v ? "high" : "low");
290 	}
291 
292 	if (!fwnode_property_read_u32(fwnode, "vsync-active", &v)) {
293 		flags &= ~(V4L2_MBUS_VSYNC_ACTIVE_HIGH |
294 			   V4L2_MBUS_VSYNC_ACTIVE_LOW);
295 		flags |= v ? V4L2_MBUS_VSYNC_ACTIVE_HIGH :
296 			V4L2_MBUS_VSYNC_ACTIVE_LOW;
297 		pr_debug("vsync-active %s\n", v ? "high" : "low");
298 	}
299 
300 	if (!fwnode_property_read_u32(fwnode, "field-even-active", &v)) {
301 		flags &= ~(V4L2_MBUS_FIELD_EVEN_HIGH |
302 			   V4L2_MBUS_FIELD_EVEN_LOW);
303 		flags |= v ? V4L2_MBUS_FIELD_EVEN_HIGH :
304 			V4L2_MBUS_FIELD_EVEN_LOW;
305 		pr_debug("field-even-active %s\n", v ? "high" : "low");
306 	}
307 
308 	if (!fwnode_property_read_u32(fwnode, "pclk-sample", &v)) {
309 		flags &= ~(V4L2_MBUS_PCLK_SAMPLE_RISING |
310 			   V4L2_MBUS_PCLK_SAMPLE_FALLING);
311 		flags |= v ? V4L2_MBUS_PCLK_SAMPLE_RISING :
312 			V4L2_MBUS_PCLK_SAMPLE_FALLING;
313 		pr_debug("pclk-sample %s\n", v ? "high" : "low");
314 	}
315 
316 	if (!fwnode_property_read_u32(fwnode, "data-active", &v)) {
317 		flags &= ~(V4L2_MBUS_DATA_ACTIVE_HIGH |
318 			   V4L2_MBUS_DATA_ACTIVE_LOW);
319 		flags |= v ? V4L2_MBUS_DATA_ACTIVE_HIGH :
320 			V4L2_MBUS_DATA_ACTIVE_LOW;
321 		pr_debug("data-active %s\n", v ? "high" : "low");
322 	}
323 
324 	if (fwnode_property_present(fwnode, "slave-mode")) {
325 		pr_debug("slave mode\n");
326 		flags &= ~V4L2_MBUS_MASTER;
327 		flags |= V4L2_MBUS_SLAVE;
328 	} else {
329 		flags &= ~V4L2_MBUS_SLAVE;
330 		flags |= V4L2_MBUS_MASTER;
331 	}
332 
333 	if (!fwnode_property_read_u32(fwnode, "bus-width", &v)) {
334 		bus->bus_width = v;
335 		pr_debug("bus-width %u\n", v);
336 	}
337 
338 	if (!fwnode_property_read_u32(fwnode, "data-shift", &v)) {
339 		bus->data_shift = v;
340 		pr_debug("data-shift %u\n", v);
341 	}
342 
343 	if (!fwnode_property_read_u32(fwnode, "sync-on-green-active", &v)) {
344 		flags &= ~(V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH |
345 			   V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW);
346 		flags |= v ? V4L2_MBUS_VIDEO_SOG_ACTIVE_HIGH :
347 			V4L2_MBUS_VIDEO_SOG_ACTIVE_LOW;
348 		pr_debug("sync-on-green-active %s\n", v ? "high" : "low");
349 	}
350 
351 	if (!fwnode_property_read_u32(fwnode, "data-enable-active", &v)) {
352 		flags &= ~(V4L2_MBUS_DATA_ENABLE_HIGH |
353 			   V4L2_MBUS_DATA_ENABLE_LOW);
354 		flags |= v ? V4L2_MBUS_DATA_ENABLE_HIGH :
355 			V4L2_MBUS_DATA_ENABLE_LOW;
356 		pr_debug("data-enable-active %s\n", v ? "high" : "low");
357 	}
358 
359 	switch (bus_type) {
360 	default:
361 		bus->flags = flags;
362 		if (flags & PARALLEL_MBUS_FLAGS)
363 			vep->bus_type = V4L2_MBUS_PARALLEL;
364 		else
365 			vep->bus_type = V4L2_MBUS_BT656;
366 		break;
367 	case V4L2_MBUS_PARALLEL:
368 		vep->bus_type = V4L2_MBUS_PARALLEL;
369 		bus->flags = flags;
370 		break;
371 	case V4L2_MBUS_BT656:
372 		vep->bus_type = V4L2_MBUS_BT656;
373 		bus->flags = flags & ~PARALLEL_MBUS_FLAGS;
374 		break;
375 	}
376 }
377 
378 static void
379 v4l2_fwnode_endpoint_parse_csi1_bus(struct fwnode_handle *fwnode,
380 				    struct v4l2_fwnode_endpoint *vep,
381 				    enum v4l2_mbus_type bus_type)
382 {
383 	struct v4l2_fwnode_bus_mipi_csi1 *bus = &vep->bus.mipi_csi1;
384 	u32 v;
385 
386 	if (!fwnode_property_read_u32(fwnode, "clock-inv", &v)) {
387 		bus->clock_inv = v;
388 		pr_debug("clock-inv %u\n", v);
389 	}
390 
391 	if (!fwnode_property_read_u32(fwnode, "strobe", &v)) {
392 		bus->strobe = v;
393 		pr_debug("strobe %u\n", v);
394 	}
395 
396 	if (!fwnode_property_read_u32(fwnode, "data-lanes", &v)) {
397 		bus->data_lane = v;
398 		pr_debug("data-lanes %u\n", v);
399 	}
400 
401 	if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) {
402 		bus->clock_lane = v;
403 		pr_debug("clock-lanes %u\n", v);
404 	}
405 
406 	if (bus_type == V4L2_MBUS_CCP2)
407 		vep->bus_type = V4L2_MBUS_CCP2;
408 	else
409 		vep->bus_type = V4L2_MBUS_CSI1;
410 }
411 
412 static int __v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
413 					struct v4l2_fwnode_endpoint *vep)
414 {
415 	u32 bus_type = V4L2_FWNODE_BUS_TYPE_GUESS;
416 	enum v4l2_mbus_type mbus_type;
417 	int rval;
418 
419 	if (vep->bus_type == V4L2_MBUS_UNKNOWN) {
420 		/* Zero fields from bus union to until the end */
421 		memset(&vep->bus, 0,
422 		       sizeof(*vep) - offsetof(typeof(*vep), bus));
423 	}
424 
425 	pr_debug("===== begin V4L2 endpoint properties\n");
426 
427 	/*
428 	 * Zero the fwnode graph endpoint memory in case we don't end up parsing
429 	 * the endpoint.
430 	 */
431 	memset(&vep->base, 0, sizeof(vep->base));
432 
433 	fwnode_property_read_u32(fwnode, "bus-type", &bus_type);
434 	pr_debug("fwnode video bus type %s (%u), mbus type %s (%u)\n",
435 		 v4l2_fwnode_bus_type_to_string(bus_type), bus_type,
436 		 v4l2_fwnode_mbus_type_to_string(vep->bus_type),
437 		 vep->bus_type);
438 	mbus_type = v4l2_fwnode_bus_type_to_mbus(bus_type);
439 
440 	if (vep->bus_type != V4L2_MBUS_UNKNOWN) {
441 		if (mbus_type != V4L2_MBUS_UNKNOWN &&
442 		    vep->bus_type != mbus_type) {
443 			pr_debug("expecting bus type %s\n",
444 				 v4l2_fwnode_mbus_type_to_string(vep->bus_type));
445 			return -ENXIO;
446 		}
447 	} else {
448 		vep->bus_type = mbus_type;
449 	}
450 
451 	switch (vep->bus_type) {
452 	case V4L2_MBUS_UNKNOWN:
453 		rval = v4l2_fwnode_endpoint_parse_csi2_bus(fwnode, vep,
454 							   V4L2_MBUS_UNKNOWN);
455 		if (rval)
456 			return rval;
457 
458 		if (vep->bus_type == V4L2_MBUS_UNKNOWN)
459 			v4l2_fwnode_endpoint_parse_parallel_bus(fwnode, vep,
460 								V4L2_MBUS_UNKNOWN);
461 
462 		pr_debug("assuming media bus type %s (%u)\n",
463 			 v4l2_fwnode_mbus_type_to_string(vep->bus_type),
464 			 vep->bus_type);
465 
466 		break;
467 	case V4L2_MBUS_CCP2:
468 	case V4L2_MBUS_CSI1:
469 		v4l2_fwnode_endpoint_parse_csi1_bus(fwnode, vep, vep->bus_type);
470 
471 		break;
472 	case V4L2_MBUS_CSI2_DPHY:
473 	case V4L2_MBUS_CSI2_CPHY:
474 		rval = v4l2_fwnode_endpoint_parse_csi2_bus(fwnode, vep,
475 							   vep->bus_type);
476 		if (rval)
477 			return rval;
478 
479 		break;
480 	case V4L2_MBUS_PARALLEL:
481 	case V4L2_MBUS_BT656:
482 		v4l2_fwnode_endpoint_parse_parallel_bus(fwnode, vep,
483 							vep->bus_type);
484 
485 		break;
486 	default:
487 		pr_warn("unsupported bus type %u\n", mbus_type);
488 		return -EINVAL;
489 	}
490 
491 	fwnode_graph_parse_endpoint(fwnode, &vep->base);
492 
493 	return 0;
494 }
495 
496 int v4l2_fwnode_endpoint_parse(struct fwnode_handle *fwnode,
497 			       struct v4l2_fwnode_endpoint *vep)
498 {
499 	int ret;
500 
501 	ret = __v4l2_fwnode_endpoint_parse(fwnode, vep);
502 
503 	pr_debug("===== end V4L2 endpoint properties\n");
504 
505 	return ret;
506 }
507 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_parse);
508 
509 void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep)
510 {
511 	if (IS_ERR_OR_NULL(vep))
512 		return;
513 
514 	kfree(vep->link_frequencies);
515 }
516 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_free);
517 
518 int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode,
519 				     struct v4l2_fwnode_endpoint *vep)
520 {
521 	int rval;
522 
523 	rval = __v4l2_fwnode_endpoint_parse(fwnode, vep);
524 	if (rval < 0)
525 		return rval;
526 
527 	rval = fwnode_property_count_u64(fwnode, "link-frequencies");
528 	if (rval > 0) {
529 		unsigned int i;
530 
531 		vep->link_frequencies =
532 			kmalloc_array(rval, sizeof(*vep->link_frequencies),
533 				      GFP_KERNEL);
534 		if (!vep->link_frequencies)
535 			return -ENOMEM;
536 
537 		vep->nr_of_link_frequencies = rval;
538 
539 		rval = fwnode_property_read_u64_array(fwnode,
540 						      "link-frequencies",
541 						      vep->link_frequencies,
542 						      vep->nr_of_link_frequencies);
543 		if (rval < 0) {
544 			v4l2_fwnode_endpoint_free(vep);
545 			return rval;
546 		}
547 
548 		for (i = 0; i < vep->nr_of_link_frequencies; i++)
549 			pr_info("link-frequencies %u value %llu\n", i,
550 				vep->link_frequencies[i]);
551 	}
552 
553 	pr_debug("===== end V4L2 endpoint properties\n");
554 
555 	return 0;
556 }
557 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_alloc_parse);
558 
559 int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
560 			   struct v4l2_fwnode_link *link)
561 {
562 	const char *port_prop = is_of_node(__fwnode) ? "reg" : "port";
563 	struct fwnode_handle *fwnode;
564 
565 	memset(link, 0, sizeof(*link));
566 
567 	fwnode = fwnode_get_parent(__fwnode);
568 	fwnode_property_read_u32(fwnode, port_prop, &link->local_port);
569 	fwnode = fwnode_get_next_parent(fwnode);
570 	if (is_of_node(fwnode) && of_node_name_eq(to_of_node(fwnode), "ports"))
571 		fwnode = fwnode_get_next_parent(fwnode);
572 	link->local_node = fwnode;
573 
574 	fwnode = fwnode_graph_get_remote_endpoint(__fwnode);
575 	if (!fwnode) {
576 		fwnode_handle_put(fwnode);
577 		return -ENOLINK;
578 	}
579 
580 	fwnode = fwnode_get_parent(fwnode);
581 	fwnode_property_read_u32(fwnode, port_prop, &link->remote_port);
582 	fwnode = fwnode_get_next_parent(fwnode);
583 	if (is_of_node(fwnode) && of_node_name_eq(to_of_node(fwnode), "ports"))
584 		fwnode = fwnode_get_next_parent(fwnode);
585 	link->remote_node = fwnode;
586 
587 	return 0;
588 }
589 EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_link);
590 
591 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
592 {
593 	fwnode_handle_put(link->local_node);
594 	fwnode_handle_put(link->remote_node);
595 }
596 EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
597 
598 static int
599 v4l2_async_notifier_fwnode_parse_endpoint(struct device *dev,
600 					  struct v4l2_async_notifier *notifier,
601 					  struct fwnode_handle *endpoint,
602 					  unsigned int asd_struct_size,
603 					  parse_endpoint_func parse_endpoint)
604 {
605 	struct v4l2_fwnode_endpoint vep = { .bus_type = 0 };
606 	struct v4l2_async_subdev *asd;
607 	int ret;
608 
609 	asd = kzalloc(asd_struct_size, GFP_KERNEL);
610 	if (!asd)
611 		return -ENOMEM;
612 
613 	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
614 	asd->match.fwnode =
615 		fwnode_graph_get_remote_port_parent(endpoint);
616 	if (!asd->match.fwnode) {
617 		dev_dbg(dev, "no remote endpoint found\n");
618 		ret = -ENOTCONN;
619 		goto out_err;
620 	}
621 
622 	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &vep);
623 	if (ret) {
624 		dev_warn(dev, "unable to parse V4L2 fwnode endpoint (%d)\n",
625 			 ret);
626 		goto out_err;
627 	}
628 
629 	ret = parse_endpoint ? parse_endpoint(dev, &vep, asd) : 0;
630 	if (ret == -ENOTCONN)
631 		dev_dbg(dev, "ignoring port@%u/endpoint@%u\n", vep.base.port,
632 			vep.base.id);
633 	else if (ret < 0)
634 		dev_warn(dev,
635 			 "driver could not parse port@%u/endpoint@%u (%d)\n",
636 			 vep.base.port, vep.base.id, ret);
637 	v4l2_fwnode_endpoint_free(&vep);
638 	if (ret < 0)
639 		goto out_err;
640 
641 	ret = v4l2_async_notifier_add_subdev(notifier, asd);
642 	if (ret < 0) {
643 		/* not an error if asd already exists */
644 		if (ret == -EEXIST)
645 			ret = 0;
646 		goto out_err;
647 	}
648 
649 	return 0;
650 
651 out_err:
652 	fwnode_handle_put(asd->match.fwnode);
653 	kfree(asd);
654 
655 	return ret == -ENOTCONN ? 0 : ret;
656 }
657 
658 static int
659 __v4l2_async_notifier_parse_fwnode_ep(struct device *dev,
660 				      struct v4l2_async_notifier *notifier,
661 				      size_t asd_struct_size,
662 				      unsigned int port,
663 				      bool has_port,
664 				      parse_endpoint_func parse_endpoint)
665 {
666 	struct fwnode_handle *fwnode;
667 	int ret = 0;
668 
669 	if (WARN_ON(asd_struct_size < sizeof(struct v4l2_async_subdev)))
670 		return -EINVAL;
671 
672 	fwnode_graph_for_each_endpoint(dev_fwnode(dev), fwnode) {
673 		struct fwnode_handle *dev_fwnode;
674 		bool is_available;
675 
676 		dev_fwnode = fwnode_graph_get_port_parent(fwnode);
677 		is_available = fwnode_device_is_available(dev_fwnode);
678 		fwnode_handle_put(dev_fwnode);
679 		if (!is_available)
680 			continue;
681 
682 		if (has_port) {
683 			struct fwnode_endpoint ep;
684 
685 			ret = fwnode_graph_parse_endpoint(fwnode, &ep);
686 			if (ret)
687 				break;
688 
689 			if (ep.port != port)
690 				continue;
691 		}
692 
693 		ret = v4l2_async_notifier_fwnode_parse_endpoint(dev,
694 								notifier,
695 								fwnode,
696 								asd_struct_size,
697 								parse_endpoint);
698 		if (ret < 0)
699 			break;
700 	}
701 
702 	fwnode_handle_put(fwnode);
703 
704 	return ret;
705 }
706 
707 int
708 v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev,
709 					   struct v4l2_async_notifier *notifier,
710 					   size_t asd_struct_size,
711 					   parse_endpoint_func parse_endpoint)
712 {
713 	return __v4l2_async_notifier_parse_fwnode_ep(dev, notifier,
714 						     asd_struct_size, 0,
715 						     false, parse_endpoint);
716 }
717 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints);
718 
719 int
720 v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev,
721 						   struct v4l2_async_notifier *notifier,
722 						   size_t asd_struct_size,
723 						   unsigned int port,
724 						   parse_endpoint_func parse_endpoint)
725 {
726 	return __v4l2_async_notifier_parse_fwnode_ep(dev, notifier,
727 						     asd_struct_size,
728 						     port, true,
729 						     parse_endpoint);
730 }
731 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints_by_port);
732 
733 /*
734  * v4l2_fwnode_reference_parse - parse references for async sub-devices
735  * @dev: the device node the properties of which are parsed for references
736  * @notifier: the async notifier where the async subdevs will be added
737  * @prop: the name of the property
738  *
739  * Return: 0 on success
740  *	   -ENOENT if no entries were found
741  *	   -ENOMEM if memory allocation failed
742  *	   -EINVAL if property parsing failed
743  */
744 static int v4l2_fwnode_reference_parse(struct device *dev,
745 				       struct v4l2_async_notifier *notifier,
746 				       const char *prop)
747 {
748 	struct fwnode_reference_args args;
749 	unsigned int index;
750 	int ret;
751 
752 	for (index = 0;
753 	     !(ret = fwnode_property_get_reference_args(dev_fwnode(dev),
754 							prop, NULL, 0,
755 							index, &args));
756 	     index++)
757 		fwnode_handle_put(args.fwnode);
758 
759 	if (!index)
760 		return -ENOENT;
761 
762 	/*
763 	 * Note that right now both -ENODATA and -ENOENT may signal
764 	 * out-of-bounds access. Return the error in cases other than that.
765 	 */
766 	if (ret != -ENOENT && ret != -ENODATA)
767 		return ret;
768 
769 	for (index = 0;
770 	     !fwnode_property_get_reference_args(dev_fwnode(dev), prop, NULL,
771 						 0, index, &args);
772 	     index++) {
773 		struct v4l2_async_subdev *asd;
774 
775 		asd = v4l2_async_notifier_add_fwnode_subdev(notifier,
776 							    args.fwnode,
777 							    sizeof(*asd));
778 		fwnode_handle_put(args.fwnode);
779 		if (IS_ERR(asd)) {
780 			/* not an error if asd already exists */
781 			if (PTR_ERR(asd) == -EEXIST)
782 				continue;
783 
784 			return PTR_ERR(asd);
785 		}
786 	}
787 
788 	return 0;
789 }
790 
791 /*
792  * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
793  *					arguments
794  * @fwnode: fwnode to read @prop from
795  * @notifier: notifier for @dev
796  * @prop: the name of the property
797  * @index: the index of the reference to get
798  * @props: the array of integer property names
799  * @nprops: the number of integer property names in @nprops
800  *
801  * First find an fwnode referred to by the reference at @index in @prop.
802  *
803  * Then under that fwnode, @nprops times, for each property in @props,
804  * iteratively follow child nodes starting from fwnode such that they have the
805  * property in @props array at the index of the child node distance from the
806  * root node and the value of that property matching with the integer argument
807  * of the reference, at the same index.
808  *
809  * The child fwnode reached at the end of the iteration is then returned to the
810  * caller.
811  *
812  * The core reason for this is that you cannot refer to just any node in ACPI.
813  * So to refer to an endpoint (easy in DT) you need to refer to a device, then
814  * provide a list of (property name, property value) tuples where each tuple
815  * uniquely identifies a child node. The first tuple identifies a child directly
816  * underneath the device fwnode, the next tuple identifies a child node
817  * underneath the fwnode identified by the previous tuple, etc. until you
818  * reached the fwnode you need.
819  *
820  * THIS EXAMPLE EXISTS MERELY TO DOCUMENT THIS FUNCTION. DO NOT USE IT AS A
821  * REFERENCE IN HOW ACPI TABLES SHOULD BE WRITTEN!! See documentation under
822  * Documentation/acpi/dsd instead and especially graph.txt,
823  * data-node-references.txt and leds.txt .
824  *
825  *	Scope (\_SB.PCI0.I2C2)
826  *	{
827  *		Device (CAM0)
828  *		{
829  *			Name (_DSD, Package () {
830  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
831  *				Package () {
832  *					Package () {
833  *						"compatible",
834  *						Package () { "nokia,smia" }
835  *					},
836  *				},
837  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
838  *				Package () {
839  *					Package () { "port0", "PRT0" },
840  *				}
841  *			})
842  *			Name (PRT0, Package() {
843  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
844  *				Package () {
845  *					Package () { "port", 0 },
846  *				},
847  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
848  *				Package () {
849  *					Package () { "endpoint0", "EP00" },
850  *				}
851  *			})
852  *			Name (EP00, Package() {
853  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
854  *				Package () {
855  *					Package () { "endpoint", 0 },
856  *					Package () {
857  *						"remote-endpoint",
858  *						Package() {
859  *							\_SB.PCI0.ISP, 4, 0
860  *						}
861  *					},
862  *				}
863  *			})
864  *		}
865  *	}
866  *
867  *	Scope (\_SB.PCI0)
868  *	{
869  *		Device (ISP)
870  *		{
871  *			Name (_DSD, Package () {
872  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
873  *				Package () {
874  *					Package () { "port4", "PRT4" },
875  *				}
876  *			})
877  *
878  *			Name (PRT4, Package() {
879  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
880  *				Package () {
881  *					Package () { "port", 4 },
882  *				},
883  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
884  *				Package () {
885  *					Package () { "endpoint0", "EP40" },
886  *				}
887  *			})
888  *
889  *			Name (EP40, Package() {
890  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
891  *				Package () {
892  *					Package () { "endpoint", 0 },
893  *					Package () {
894  *						"remote-endpoint",
895  *						Package () {
896  *							\_SB.PCI0.I2C2.CAM0,
897  *							0, 0
898  *						}
899  *					},
900  *				}
901  *			})
902  *		}
903  *	}
904  *
905  * From the EP40 node under ISP device, you could parse the graph remote
906  * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
907  *
908  *  @fwnode: fwnode referring to EP40 under ISP.
909  *  @prop: "remote-endpoint"
910  *  @index: 0
911  *  @props: "port", "endpoint"
912  *  @nprops: 2
913  *
914  * And you'd get back fwnode referring to EP00 under CAM0.
915  *
916  * The same works the other way around: if you use EP00 under CAM0 as the
917  * fwnode, you'll get fwnode referring to EP40 under ISP.
918  *
919  * The same example in DT syntax would look like this:
920  *
921  * cam: cam0 {
922  *	compatible = "nokia,smia";
923  *
924  *	port {
925  *		port = <0>;
926  *		endpoint {
927  *			endpoint = <0>;
928  *			remote-endpoint = <&isp 4 0>;
929  *		};
930  *	};
931  * };
932  *
933  * isp: isp {
934  *	ports {
935  *		port@4 {
936  *			port = <4>;
937  *			endpoint {
938  *				endpoint = <0>;
939  *				remote-endpoint = <&cam 0 0>;
940  *			};
941  *		};
942  *	};
943  * };
944  *
945  * Return: 0 on success
946  *	   -ENOENT if no entries (or the property itself) were found
947  *	   -EINVAL if property parsing otherwise failed
948  *	   -ENOMEM if memory allocation failed
949  */
950 static struct fwnode_handle *
951 v4l2_fwnode_reference_get_int_prop(struct fwnode_handle *fwnode,
952 				   const char *prop,
953 				   unsigned int index,
954 				   const char * const *props,
955 				   unsigned int nprops)
956 {
957 	struct fwnode_reference_args fwnode_args;
958 	u64 *args = fwnode_args.args;
959 	struct fwnode_handle *child;
960 	int ret;
961 
962 	/*
963 	 * Obtain remote fwnode as well as the integer arguments.
964 	 *
965 	 * Note that right now both -ENODATA and -ENOENT may signal
966 	 * out-of-bounds access. Return -ENOENT in that case.
967 	 */
968 	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
969 						 index, &fwnode_args);
970 	if (ret)
971 		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
972 
973 	/*
974 	 * Find a node in the tree under the referred fwnode corresponding to
975 	 * the integer arguments.
976 	 */
977 	fwnode = fwnode_args.fwnode;
978 	while (nprops--) {
979 		u32 val;
980 
981 		/* Loop over all child nodes under fwnode. */
982 		fwnode_for_each_child_node(fwnode, child) {
983 			if (fwnode_property_read_u32(child, *props, &val))
984 				continue;
985 
986 			/* Found property, see if its value matches. */
987 			if (val == *args)
988 				break;
989 		}
990 
991 		fwnode_handle_put(fwnode);
992 
993 		/* No property found; return an error here. */
994 		if (!child) {
995 			fwnode = ERR_PTR(-ENOENT);
996 			break;
997 		}
998 
999 		props++;
1000 		args++;
1001 		fwnode = child;
1002 	}
1003 
1004 	return fwnode;
1005 }
1006 
1007 struct v4l2_fwnode_int_props {
1008 	const char *name;
1009 	const char * const *props;
1010 	unsigned int nprops;
1011 };
1012 
1013 /*
1014  * v4l2_fwnode_reference_parse_int_props - parse references for async
1015  *					   sub-devices
1016  * @dev: struct device pointer
1017  * @notifier: notifier for @dev
1018  * @prop: the name of the property
1019  * @props: the array of integer property names
1020  * @nprops: the number of integer properties
1021  *
1022  * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
1023  * property @prop with integer arguments with child nodes matching in properties
1024  * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
1025  * accordingly.
1026  *
1027  * While it is technically possible to use this function on DT, it is only
1028  * meaningful on ACPI. On Device tree you can refer to any node in the tree but
1029  * on ACPI the references are limited to devices.
1030  *
1031  * Return: 0 on success
1032  *	   -ENOENT if no entries (or the property itself) were found
1033  *	   -EINVAL if property parsing otherwisefailed
1034  *	   -ENOMEM if memory allocation failed
1035  */
1036 static int
1037 v4l2_fwnode_reference_parse_int_props(struct device *dev,
1038 				      struct v4l2_async_notifier *notifier,
1039 				      const struct v4l2_fwnode_int_props *p)
1040 {
1041 	struct fwnode_handle *fwnode;
1042 	unsigned int index;
1043 	int ret;
1044 	const char *prop = p->name;
1045 	const char * const *props = p->props;
1046 	unsigned int nprops = p->nprops;
1047 
1048 	index = 0;
1049 	do {
1050 		fwnode = v4l2_fwnode_reference_get_int_prop(dev_fwnode(dev),
1051 							    prop, index,
1052 							    props, nprops);
1053 		if (IS_ERR(fwnode)) {
1054 			/*
1055 			 * Note that right now both -ENODATA and -ENOENT may
1056 			 * signal out-of-bounds access. Return the error in
1057 			 * cases other than that.
1058 			 */
1059 			if (PTR_ERR(fwnode) != -ENOENT &&
1060 			    PTR_ERR(fwnode) != -ENODATA)
1061 				return PTR_ERR(fwnode);
1062 			break;
1063 		}
1064 		fwnode_handle_put(fwnode);
1065 		index++;
1066 	} while (1);
1067 
1068 	for (index = 0;
1069 	     !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(dev_fwnode(dev),
1070 								  prop, index,
1071 								  props,
1072 								  nprops)));
1073 	     index++) {
1074 		struct v4l2_async_subdev *asd;
1075 
1076 		asd = v4l2_async_notifier_add_fwnode_subdev(notifier, fwnode,
1077 							    sizeof(*asd));
1078 		fwnode_handle_put(fwnode);
1079 		if (IS_ERR(asd)) {
1080 			ret = PTR_ERR(asd);
1081 			/* not an error if asd already exists */
1082 			if (ret == -EEXIST)
1083 				continue;
1084 
1085 			return PTR_ERR(asd);
1086 		}
1087 	}
1088 
1089 	return !fwnode || PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
1090 }
1091 
1092 int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev,
1093 						   struct v4l2_async_notifier *notifier)
1094 {
1095 	static const char * const led_props[] = { "led" };
1096 	static const struct v4l2_fwnode_int_props props[] = {
1097 		{ "flash-leds", led_props, ARRAY_SIZE(led_props) },
1098 		{ "lens-focus", NULL, 0 },
1099 	};
1100 	unsigned int i;
1101 
1102 	for (i = 0; i < ARRAY_SIZE(props); i++) {
1103 		int ret;
1104 
1105 		if (props[i].props && is_acpi_node(dev_fwnode(dev)))
1106 			ret = v4l2_fwnode_reference_parse_int_props(dev,
1107 								    notifier,
1108 								    &props[i]);
1109 		else
1110 			ret = v4l2_fwnode_reference_parse(dev, notifier,
1111 							  props[i].name);
1112 		if (ret && ret != -ENOENT) {
1113 			dev_warn(dev, "parsing property \"%s\" failed (%d)\n",
1114 				 props[i].name, ret);
1115 			return ret;
1116 		}
1117 	}
1118 
1119 	return 0;
1120 }
1121 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_sensor_common);
1122 
1123 int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd)
1124 {
1125 	struct v4l2_async_notifier *notifier;
1126 	int ret;
1127 
1128 	if (WARN_ON(!sd->dev))
1129 		return -ENODEV;
1130 
1131 	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
1132 	if (!notifier)
1133 		return -ENOMEM;
1134 
1135 	v4l2_async_notifier_init(notifier);
1136 
1137 	ret = v4l2_async_notifier_parse_fwnode_sensor_common(sd->dev,
1138 							     notifier);
1139 	if (ret < 0)
1140 		goto out_cleanup;
1141 
1142 	ret = v4l2_async_subdev_notifier_register(sd, notifier);
1143 	if (ret < 0)
1144 		goto out_cleanup;
1145 
1146 	ret = v4l2_async_register_subdev(sd);
1147 	if (ret < 0)
1148 		goto out_unregister;
1149 
1150 	sd->subdev_notifier = notifier;
1151 
1152 	return 0;
1153 
1154 out_unregister:
1155 	v4l2_async_notifier_unregister(notifier);
1156 
1157 out_cleanup:
1158 	v4l2_async_notifier_cleanup(notifier);
1159 	kfree(notifier);
1160 
1161 	return ret;
1162 }
1163 EXPORT_SYMBOL_GPL(v4l2_async_register_subdev_sensor_common);
1164 
1165 int v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
1166 				      size_t asd_struct_size,
1167 				      unsigned int *ports,
1168 				      unsigned int num_ports,
1169 				      parse_endpoint_func parse_endpoint)
1170 {
1171 	struct v4l2_async_notifier *notifier;
1172 	struct device *dev = sd->dev;
1173 	struct fwnode_handle *fwnode;
1174 	int ret;
1175 
1176 	if (WARN_ON(!dev))
1177 		return -ENODEV;
1178 
1179 	fwnode = dev_fwnode(dev);
1180 	if (!fwnode_device_is_available(fwnode))
1181 		return -ENODEV;
1182 
1183 	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
1184 	if (!notifier)
1185 		return -ENOMEM;
1186 
1187 	v4l2_async_notifier_init(notifier);
1188 
1189 	if (!ports) {
1190 		ret = v4l2_async_notifier_parse_fwnode_endpoints(dev, notifier,
1191 								 asd_struct_size,
1192 								 parse_endpoint);
1193 		if (ret < 0)
1194 			goto out_cleanup;
1195 	} else {
1196 		unsigned int i;
1197 
1198 		for (i = 0; i < num_ports; i++) {
1199 			ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port(dev, notifier, asd_struct_size, ports[i], parse_endpoint);
1200 			if (ret < 0)
1201 				goto out_cleanup;
1202 		}
1203 	}
1204 
1205 	ret = v4l2_async_subdev_notifier_register(sd, notifier);
1206 	if (ret < 0)
1207 		goto out_cleanup;
1208 
1209 	ret = v4l2_async_register_subdev(sd);
1210 	if (ret < 0)
1211 		goto out_unregister;
1212 
1213 	sd->subdev_notifier = notifier;
1214 
1215 	return 0;
1216 
1217 out_unregister:
1218 	v4l2_async_notifier_unregister(notifier);
1219 out_cleanup:
1220 	v4l2_async_notifier_cleanup(notifier);
1221 	kfree(notifier);
1222 
1223 	return ret;
1224 }
1225 EXPORT_SYMBOL_GPL(v4l2_async_register_fwnode_subdev);
1226 
1227 MODULE_LICENSE("GPL");
1228 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
1229 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
1230 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
1231