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 	vep->link_frequencies = NULL;
516 }
517 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_free);
518 
519 int v4l2_fwnode_endpoint_alloc_parse(struct fwnode_handle *fwnode,
520 				     struct v4l2_fwnode_endpoint *vep)
521 {
522 	int rval;
523 
524 	rval = __v4l2_fwnode_endpoint_parse(fwnode, vep);
525 	if (rval < 0)
526 		return rval;
527 
528 	rval = fwnode_property_count_u64(fwnode, "link-frequencies");
529 	if (rval > 0) {
530 		unsigned int i;
531 
532 		vep->link_frequencies =
533 			kmalloc_array(rval, sizeof(*vep->link_frequencies),
534 				      GFP_KERNEL);
535 		if (!vep->link_frequencies)
536 			return -ENOMEM;
537 
538 		vep->nr_of_link_frequencies = rval;
539 
540 		rval = fwnode_property_read_u64_array(fwnode,
541 						      "link-frequencies",
542 						      vep->link_frequencies,
543 						      vep->nr_of_link_frequencies);
544 		if (rval < 0) {
545 			v4l2_fwnode_endpoint_free(vep);
546 			return rval;
547 		}
548 
549 		for (i = 0; i < vep->nr_of_link_frequencies; i++)
550 			pr_info("link-frequencies %u value %llu\n", i,
551 				vep->link_frequencies[i]);
552 	}
553 
554 	pr_debug("===== end V4L2 endpoint properties\n");
555 
556 	return 0;
557 }
558 EXPORT_SYMBOL_GPL(v4l2_fwnode_endpoint_alloc_parse);
559 
560 int v4l2_fwnode_parse_link(struct fwnode_handle *__fwnode,
561 			   struct v4l2_fwnode_link *link)
562 {
563 	const char *port_prop = is_of_node(__fwnode) ? "reg" : "port";
564 	struct fwnode_handle *fwnode;
565 
566 	memset(link, 0, sizeof(*link));
567 
568 	fwnode = fwnode_get_parent(__fwnode);
569 	fwnode_property_read_u32(fwnode, port_prop, &link->local_port);
570 	fwnode = fwnode_get_next_parent(fwnode);
571 	if (is_of_node(fwnode) && of_node_name_eq(to_of_node(fwnode), "ports"))
572 		fwnode = fwnode_get_next_parent(fwnode);
573 	link->local_node = fwnode;
574 
575 	fwnode = fwnode_graph_get_remote_endpoint(__fwnode);
576 	if (!fwnode) {
577 		fwnode_handle_put(fwnode);
578 		return -ENOLINK;
579 	}
580 
581 	fwnode = fwnode_get_parent(fwnode);
582 	fwnode_property_read_u32(fwnode, port_prop, &link->remote_port);
583 	fwnode = fwnode_get_next_parent(fwnode);
584 	if (is_of_node(fwnode) && of_node_name_eq(to_of_node(fwnode), "ports"))
585 		fwnode = fwnode_get_next_parent(fwnode);
586 	link->remote_node = fwnode;
587 
588 	return 0;
589 }
590 EXPORT_SYMBOL_GPL(v4l2_fwnode_parse_link);
591 
592 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link)
593 {
594 	fwnode_handle_put(link->local_node);
595 	fwnode_handle_put(link->remote_node);
596 }
597 EXPORT_SYMBOL_GPL(v4l2_fwnode_put_link);
598 
599 static int
600 v4l2_async_notifier_fwnode_parse_endpoint(struct device *dev,
601 					  struct v4l2_async_notifier *notifier,
602 					  struct fwnode_handle *endpoint,
603 					  unsigned int asd_struct_size,
604 					  parse_endpoint_func parse_endpoint)
605 {
606 	struct v4l2_fwnode_endpoint vep = { .bus_type = 0 };
607 	struct v4l2_async_subdev *asd;
608 	int ret;
609 
610 	asd = kzalloc(asd_struct_size, GFP_KERNEL);
611 	if (!asd)
612 		return -ENOMEM;
613 
614 	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
615 	asd->match.fwnode =
616 		fwnode_graph_get_remote_port_parent(endpoint);
617 	if (!asd->match.fwnode) {
618 		dev_dbg(dev, "no remote endpoint found\n");
619 		ret = -ENOTCONN;
620 		goto out_err;
621 	}
622 
623 	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &vep);
624 	if (ret) {
625 		dev_warn(dev, "unable to parse V4L2 fwnode endpoint (%d)\n",
626 			 ret);
627 		goto out_err;
628 	}
629 
630 	ret = parse_endpoint ? parse_endpoint(dev, &vep, asd) : 0;
631 	if (ret == -ENOTCONN)
632 		dev_dbg(dev, "ignoring port@%u/endpoint@%u\n", vep.base.port,
633 			vep.base.id);
634 	else if (ret < 0)
635 		dev_warn(dev,
636 			 "driver could not parse port@%u/endpoint@%u (%d)\n",
637 			 vep.base.port, vep.base.id, ret);
638 	v4l2_fwnode_endpoint_free(&vep);
639 	if (ret < 0)
640 		goto out_err;
641 
642 	ret = v4l2_async_notifier_add_subdev(notifier, asd);
643 	if (ret < 0) {
644 		/* not an error if asd already exists */
645 		if (ret == -EEXIST)
646 			ret = 0;
647 		goto out_err;
648 	}
649 
650 	return 0;
651 
652 out_err:
653 	fwnode_handle_put(asd->match.fwnode);
654 	kfree(asd);
655 
656 	return ret == -ENOTCONN ? 0 : ret;
657 }
658 
659 static int
660 __v4l2_async_notifier_parse_fwnode_ep(struct device *dev,
661 				      struct v4l2_async_notifier *notifier,
662 				      size_t asd_struct_size,
663 				      unsigned int port,
664 				      bool has_port,
665 				      parse_endpoint_func parse_endpoint)
666 {
667 	struct fwnode_handle *fwnode;
668 	int ret = 0;
669 
670 	if (WARN_ON(asd_struct_size < sizeof(struct v4l2_async_subdev)))
671 		return -EINVAL;
672 
673 	fwnode_graph_for_each_endpoint(dev_fwnode(dev), fwnode) {
674 		struct fwnode_handle *dev_fwnode;
675 		bool is_available;
676 
677 		dev_fwnode = fwnode_graph_get_port_parent(fwnode);
678 		is_available = fwnode_device_is_available(dev_fwnode);
679 		fwnode_handle_put(dev_fwnode);
680 		if (!is_available)
681 			continue;
682 
683 		if (has_port) {
684 			struct fwnode_endpoint ep;
685 
686 			ret = fwnode_graph_parse_endpoint(fwnode, &ep);
687 			if (ret)
688 				break;
689 
690 			if (ep.port != port)
691 				continue;
692 		}
693 
694 		ret = v4l2_async_notifier_fwnode_parse_endpoint(dev,
695 								notifier,
696 								fwnode,
697 								asd_struct_size,
698 								parse_endpoint);
699 		if (ret < 0)
700 			break;
701 	}
702 
703 	fwnode_handle_put(fwnode);
704 
705 	return ret;
706 }
707 
708 int
709 v4l2_async_notifier_parse_fwnode_endpoints(struct device *dev,
710 					   struct v4l2_async_notifier *notifier,
711 					   size_t asd_struct_size,
712 					   parse_endpoint_func parse_endpoint)
713 {
714 	return __v4l2_async_notifier_parse_fwnode_ep(dev, notifier,
715 						     asd_struct_size, 0,
716 						     false, parse_endpoint);
717 }
718 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints);
719 
720 int
721 v4l2_async_notifier_parse_fwnode_endpoints_by_port(struct device *dev,
722 						   struct v4l2_async_notifier *notifier,
723 						   size_t asd_struct_size,
724 						   unsigned int port,
725 						   parse_endpoint_func parse_endpoint)
726 {
727 	return __v4l2_async_notifier_parse_fwnode_ep(dev, notifier,
728 						     asd_struct_size,
729 						     port, true,
730 						     parse_endpoint);
731 }
732 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints_by_port);
733 
734 /*
735  * v4l2_fwnode_reference_parse - parse references for async sub-devices
736  * @dev: the device node the properties of which are parsed for references
737  * @notifier: the async notifier where the async subdevs will be added
738  * @prop: the name of the property
739  *
740  * Return: 0 on success
741  *	   -ENOENT if no entries were found
742  *	   -ENOMEM if memory allocation failed
743  *	   -EINVAL if property parsing failed
744  */
745 static int v4l2_fwnode_reference_parse(struct device *dev,
746 				       struct v4l2_async_notifier *notifier,
747 				       const char *prop)
748 {
749 	struct fwnode_reference_args args;
750 	unsigned int index;
751 	int ret;
752 
753 	for (index = 0;
754 	     !(ret = fwnode_property_get_reference_args(dev_fwnode(dev),
755 							prop, NULL, 0,
756 							index, &args));
757 	     index++)
758 		fwnode_handle_put(args.fwnode);
759 
760 	if (!index)
761 		return -ENOENT;
762 
763 	/*
764 	 * Note that right now both -ENODATA and -ENOENT may signal
765 	 * out-of-bounds access. Return the error in cases other than that.
766 	 */
767 	if (ret != -ENOENT && ret != -ENODATA)
768 		return ret;
769 
770 	for (index = 0;
771 	     !fwnode_property_get_reference_args(dev_fwnode(dev), prop, NULL,
772 						 0, index, &args);
773 	     index++) {
774 		struct v4l2_async_subdev *asd;
775 
776 		asd = v4l2_async_notifier_add_fwnode_subdev(notifier,
777 							    args.fwnode,
778 							    sizeof(*asd));
779 		fwnode_handle_put(args.fwnode);
780 		if (IS_ERR(asd)) {
781 			/* not an error if asd already exists */
782 			if (PTR_ERR(asd) == -EEXIST)
783 				continue;
784 
785 			return PTR_ERR(asd);
786 		}
787 	}
788 
789 	return 0;
790 }
791 
792 /*
793  * v4l2_fwnode_reference_get_int_prop - parse a reference with integer
794  *					arguments
795  * @fwnode: fwnode to read @prop from
796  * @notifier: notifier for @dev
797  * @prop: the name of the property
798  * @index: the index of the reference to get
799  * @props: the array of integer property names
800  * @nprops: the number of integer property names in @nprops
801  *
802  * First find an fwnode referred to by the reference at @index in @prop.
803  *
804  * Then under that fwnode, @nprops times, for each property in @props,
805  * iteratively follow child nodes starting from fwnode such that they have the
806  * property in @props array at the index of the child node distance from the
807  * root node and the value of that property matching with the integer argument
808  * of the reference, at the same index.
809  *
810  * The child fwnode reached at the end of the iteration is then returned to the
811  * caller.
812  *
813  * The core reason for this is that you cannot refer to just any node in ACPI.
814  * So to refer to an endpoint (easy in DT) you need to refer to a device, then
815  * provide a list of (property name, property value) tuples where each tuple
816  * uniquely identifies a child node. The first tuple identifies a child directly
817  * underneath the device fwnode, the next tuple identifies a child node
818  * underneath the fwnode identified by the previous tuple, etc. until you
819  * reached the fwnode you need.
820  *
821  * THIS EXAMPLE EXISTS MERELY TO DOCUMENT THIS FUNCTION. DO NOT USE IT AS A
822  * REFERENCE IN HOW ACPI TABLES SHOULD BE WRITTEN!! See documentation under
823  * Documentation/acpi/dsd instead and especially graph.txt,
824  * data-node-references.txt and leds.txt .
825  *
826  *	Scope (\_SB.PCI0.I2C2)
827  *	{
828  *		Device (CAM0)
829  *		{
830  *			Name (_DSD, Package () {
831  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
832  *				Package () {
833  *					Package () {
834  *						"compatible",
835  *						Package () { "nokia,smia" }
836  *					},
837  *				},
838  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
839  *				Package () {
840  *					Package () { "port0", "PRT0" },
841  *				}
842  *			})
843  *			Name (PRT0, Package() {
844  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
845  *				Package () {
846  *					Package () { "port", 0 },
847  *				},
848  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
849  *				Package () {
850  *					Package () { "endpoint0", "EP00" },
851  *				}
852  *			})
853  *			Name (EP00, Package() {
854  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
855  *				Package () {
856  *					Package () { "endpoint", 0 },
857  *					Package () {
858  *						"remote-endpoint",
859  *						Package() {
860  *							\_SB.PCI0.ISP, 4, 0
861  *						}
862  *					},
863  *				}
864  *			})
865  *		}
866  *	}
867  *
868  *	Scope (\_SB.PCI0)
869  *	{
870  *		Device (ISP)
871  *		{
872  *			Name (_DSD, Package () {
873  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
874  *				Package () {
875  *					Package () { "port4", "PRT4" },
876  *				}
877  *			})
878  *
879  *			Name (PRT4, Package() {
880  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
881  *				Package () {
882  *					Package () { "port", 4 },
883  *				},
884  *				ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"),
885  *				Package () {
886  *					Package () { "endpoint0", "EP40" },
887  *				}
888  *			})
889  *
890  *			Name (EP40, Package() {
891  *				ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
892  *				Package () {
893  *					Package () { "endpoint", 0 },
894  *					Package () {
895  *						"remote-endpoint",
896  *						Package () {
897  *							\_SB.PCI0.I2C2.CAM0,
898  *							0, 0
899  *						}
900  *					},
901  *				}
902  *			})
903  *		}
904  *	}
905  *
906  * From the EP40 node under ISP device, you could parse the graph remote
907  * endpoint using v4l2_fwnode_reference_get_int_prop with these arguments:
908  *
909  *  @fwnode: fwnode referring to EP40 under ISP.
910  *  @prop: "remote-endpoint"
911  *  @index: 0
912  *  @props: "port", "endpoint"
913  *  @nprops: 2
914  *
915  * And you'd get back fwnode referring to EP00 under CAM0.
916  *
917  * The same works the other way around: if you use EP00 under CAM0 as the
918  * fwnode, you'll get fwnode referring to EP40 under ISP.
919  *
920  * The same example in DT syntax would look like this:
921  *
922  * cam: cam0 {
923  *	compatible = "nokia,smia";
924  *
925  *	port {
926  *		port = <0>;
927  *		endpoint {
928  *			endpoint = <0>;
929  *			remote-endpoint = <&isp 4 0>;
930  *		};
931  *	};
932  * };
933  *
934  * isp: isp {
935  *	ports {
936  *		port@4 {
937  *			port = <4>;
938  *			endpoint {
939  *				endpoint = <0>;
940  *				remote-endpoint = <&cam 0 0>;
941  *			};
942  *		};
943  *	};
944  * };
945  *
946  * Return: 0 on success
947  *	   -ENOENT if no entries (or the property itself) were found
948  *	   -EINVAL if property parsing otherwise failed
949  *	   -ENOMEM if memory allocation failed
950  */
951 static struct fwnode_handle *
952 v4l2_fwnode_reference_get_int_prop(struct fwnode_handle *fwnode,
953 				   const char *prop,
954 				   unsigned int index,
955 				   const char * const *props,
956 				   unsigned int nprops)
957 {
958 	struct fwnode_reference_args fwnode_args;
959 	u64 *args = fwnode_args.args;
960 	struct fwnode_handle *child;
961 	int ret;
962 
963 	/*
964 	 * Obtain remote fwnode as well as the integer arguments.
965 	 *
966 	 * Note that right now both -ENODATA and -ENOENT may signal
967 	 * out-of-bounds access. Return -ENOENT in that case.
968 	 */
969 	ret = fwnode_property_get_reference_args(fwnode, prop, NULL, nprops,
970 						 index, &fwnode_args);
971 	if (ret)
972 		return ERR_PTR(ret == -ENODATA ? -ENOENT : ret);
973 
974 	/*
975 	 * Find a node in the tree under the referred fwnode corresponding to
976 	 * the integer arguments.
977 	 */
978 	fwnode = fwnode_args.fwnode;
979 	while (nprops--) {
980 		u32 val;
981 
982 		/* Loop over all child nodes under fwnode. */
983 		fwnode_for_each_child_node(fwnode, child) {
984 			if (fwnode_property_read_u32(child, *props, &val))
985 				continue;
986 
987 			/* Found property, see if its value matches. */
988 			if (val == *args)
989 				break;
990 		}
991 
992 		fwnode_handle_put(fwnode);
993 
994 		/* No property found; return an error here. */
995 		if (!child) {
996 			fwnode = ERR_PTR(-ENOENT);
997 			break;
998 		}
999 
1000 		props++;
1001 		args++;
1002 		fwnode = child;
1003 	}
1004 
1005 	return fwnode;
1006 }
1007 
1008 struct v4l2_fwnode_int_props {
1009 	const char *name;
1010 	const char * const *props;
1011 	unsigned int nprops;
1012 };
1013 
1014 /*
1015  * v4l2_fwnode_reference_parse_int_props - parse references for async
1016  *					   sub-devices
1017  * @dev: struct device pointer
1018  * @notifier: notifier for @dev
1019  * @prop: the name of the property
1020  * @props: the array of integer property names
1021  * @nprops: the number of integer properties
1022  *
1023  * Use v4l2_fwnode_reference_get_int_prop to find fwnodes through reference in
1024  * property @prop with integer arguments with child nodes matching in properties
1025  * @props. Then, set up V4L2 async sub-devices for those fwnodes in the notifier
1026  * accordingly.
1027  *
1028  * While it is technically possible to use this function on DT, it is only
1029  * meaningful on ACPI. On Device tree you can refer to any node in the tree but
1030  * on ACPI the references are limited to devices.
1031  *
1032  * Return: 0 on success
1033  *	   -ENOENT if no entries (or the property itself) were found
1034  *	   -EINVAL if property parsing otherwisefailed
1035  *	   -ENOMEM if memory allocation failed
1036  */
1037 static int
1038 v4l2_fwnode_reference_parse_int_props(struct device *dev,
1039 				      struct v4l2_async_notifier *notifier,
1040 				      const struct v4l2_fwnode_int_props *p)
1041 {
1042 	struct fwnode_handle *fwnode;
1043 	unsigned int index;
1044 	int ret;
1045 	const char *prop = p->name;
1046 	const char * const *props = p->props;
1047 	unsigned int nprops = p->nprops;
1048 
1049 	index = 0;
1050 	do {
1051 		fwnode = v4l2_fwnode_reference_get_int_prop(dev_fwnode(dev),
1052 							    prop, index,
1053 							    props, nprops);
1054 		if (IS_ERR(fwnode)) {
1055 			/*
1056 			 * Note that right now both -ENODATA and -ENOENT may
1057 			 * signal out-of-bounds access. Return the error in
1058 			 * cases other than that.
1059 			 */
1060 			if (PTR_ERR(fwnode) != -ENOENT &&
1061 			    PTR_ERR(fwnode) != -ENODATA)
1062 				return PTR_ERR(fwnode);
1063 			break;
1064 		}
1065 		fwnode_handle_put(fwnode);
1066 		index++;
1067 	} while (1);
1068 
1069 	for (index = 0;
1070 	     !IS_ERR((fwnode = v4l2_fwnode_reference_get_int_prop(dev_fwnode(dev),
1071 								  prop, index,
1072 								  props,
1073 								  nprops)));
1074 	     index++) {
1075 		struct v4l2_async_subdev *asd;
1076 
1077 		asd = v4l2_async_notifier_add_fwnode_subdev(notifier, fwnode,
1078 							    sizeof(*asd));
1079 		fwnode_handle_put(fwnode);
1080 		if (IS_ERR(asd)) {
1081 			ret = PTR_ERR(asd);
1082 			/* not an error if asd already exists */
1083 			if (ret == -EEXIST)
1084 				continue;
1085 
1086 			return PTR_ERR(asd);
1087 		}
1088 	}
1089 
1090 	return !fwnode || PTR_ERR(fwnode) == -ENOENT ? 0 : PTR_ERR(fwnode);
1091 }
1092 
1093 int v4l2_async_notifier_parse_fwnode_sensor_common(struct device *dev,
1094 						   struct v4l2_async_notifier *notifier)
1095 {
1096 	static const char * const led_props[] = { "led" };
1097 	static const struct v4l2_fwnode_int_props props[] = {
1098 		{ "flash-leds", led_props, ARRAY_SIZE(led_props) },
1099 		{ "lens-focus", NULL, 0 },
1100 	};
1101 	unsigned int i;
1102 
1103 	for (i = 0; i < ARRAY_SIZE(props); i++) {
1104 		int ret;
1105 
1106 		if (props[i].props && is_acpi_node(dev_fwnode(dev)))
1107 			ret = v4l2_fwnode_reference_parse_int_props(dev,
1108 								    notifier,
1109 								    &props[i]);
1110 		else
1111 			ret = v4l2_fwnode_reference_parse(dev, notifier,
1112 							  props[i].name);
1113 		if (ret && ret != -ENOENT) {
1114 			dev_warn(dev, "parsing property \"%s\" failed (%d)\n",
1115 				 props[i].name, ret);
1116 			return ret;
1117 		}
1118 	}
1119 
1120 	return 0;
1121 }
1122 EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_sensor_common);
1123 
1124 int v4l2_async_register_subdev_sensor_common(struct v4l2_subdev *sd)
1125 {
1126 	struct v4l2_async_notifier *notifier;
1127 	int ret;
1128 
1129 	if (WARN_ON(!sd->dev))
1130 		return -ENODEV;
1131 
1132 	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
1133 	if (!notifier)
1134 		return -ENOMEM;
1135 
1136 	v4l2_async_notifier_init(notifier);
1137 
1138 	ret = v4l2_async_notifier_parse_fwnode_sensor_common(sd->dev,
1139 							     notifier);
1140 	if (ret < 0)
1141 		goto out_cleanup;
1142 
1143 	ret = v4l2_async_subdev_notifier_register(sd, notifier);
1144 	if (ret < 0)
1145 		goto out_cleanup;
1146 
1147 	ret = v4l2_async_register_subdev(sd);
1148 	if (ret < 0)
1149 		goto out_unregister;
1150 
1151 	sd->subdev_notifier = notifier;
1152 
1153 	return 0;
1154 
1155 out_unregister:
1156 	v4l2_async_notifier_unregister(notifier);
1157 
1158 out_cleanup:
1159 	v4l2_async_notifier_cleanup(notifier);
1160 	kfree(notifier);
1161 
1162 	return ret;
1163 }
1164 EXPORT_SYMBOL_GPL(v4l2_async_register_subdev_sensor_common);
1165 
1166 int v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
1167 				      size_t asd_struct_size,
1168 				      unsigned int *ports,
1169 				      unsigned int num_ports,
1170 				      parse_endpoint_func parse_endpoint)
1171 {
1172 	struct v4l2_async_notifier *notifier;
1173 	struct device *dev = sd->dev;
1174 	struct fwnode_handle *fwnode;
1175 	int ret;
1176 
1177 	if (WARN_ON(!dev))
1178 		return -ENODEV;
1179 
1180 	fwnode = dev_fwnode(dev);
1181 	if (!fwnode_device_is_available(fwnode))
1182 		return -ENODEV;
1183 
1184 	notifier = kzalloc(sizeof(*notifier), GFP_KERNEL);
1185 	if (!notifier)
1186 		return -ENOMEM;
1187 
1188 	v4l2_async_notifier_init(notifier);
1189 
1190 	if (!ports) {
1191 		ret = v4l2_async_notifier_parse_fwnode_endpoints(dev, notifier,
1192 								 asd_struct_size,
1193 								 parse_endpoint);
1194 		if (ret < 0)
1195 			goto out_cleanup;
1196 	} else {
1197 		unsigned int i;
1198 
1199 		for (i = 0; i < num_ports; i++) {
1200 			ret = v4l2_async_notifier_parse_fwnode_endpoints_by_port(dev, notifier, asd_struct_size, ports[i], parse_endpoint);
1201 			if (ret < 0)
1202 				goto out_cleanup;
1203 		}
1204 	}
1205 
1206 	ret = v4l2_async_subdev_notifier_register(sd, notifier);
1207 	if (ret < 0)
1208 		goto out_cleanup;
1209 
1210 	ret = v4l2_async_register_subdev(sd);
1211 	if (ret < 0)
1212 		goto out_unregister;
1213 
1214 	sd->subdev_notifier = notifier;
1215 
1216 	return 0;
1217 
1218 out_unregister:
1219 	v4l2_async_notifier_unregister(notifier);
1220 out_cleanup:
1221 	v4l2_async_notifier_cleanup(notifier);
1222 	kfree(notifier);
1223 
1224 	return ret;
1225 }
1226 EXPORT_SYMBOL_GPL(v4l2_async_register_fwnode_subdev);
1227 
1228 MODULE_LICENSE("GPL");
1229 MODULE_AUTHOR("Sakari Ailus <sakari.ailus@linux.intel.com>");
1230 MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@samsung.com>");
1231 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
1232