xref: /openbmc/linux/drivers/media/i2c/ds90ub913.c (revision 17bfcd6a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for the Texas Instruments DS90UB913 video serializer
4  *
5  * Based on a driver from Luca Ceresoli <luca@lucaceresoli.net>
6  *
7  * Copyright (c) 2019 Luca Ceresoli <luca@lucaceresoli.net>
8  * Copyright (c) 2023 Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
9  */
10 
11 #include <linux/clk-provider.h>
12 #include <linux/clk.h>
13 #include <linux/delay.h>
14 #include <linux/fwnode.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/i2c-atr.h>
17 #include <linux/i2c.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/property.h>
21 #include <linux/regmap.h>
22 
23 #include <media/i2c/ds90ub9xx.h>
24 #include <media/v4l2-fwnode.h>
25 #include <media/v4l2-mediabus.h>
26 #include <media/v4l2-subdev.h>
27 
28 #define UB913_PAD_SINK			0
29 #define UB913_PAD_SOURCE		1
30 
31 /*
32  * UB913 has 4 gpios, but gpios 3 and 4 are reserved for external oscillator
33  * mode. Thus we only support 2 gpios for now.
34  */
35 #define UB913_NUM_GPIOS			2
36 
37 #define UB913_REG_RESET_CTL			0x01
38 #define UB913_REG_RESET_CTL_DIGITAL_RESET_1	BIT(1)
39 #define UB913_REG_RESET_CTL_DIGITAL_RESET_0	BIT(0)
40 
41 #define UB913_REG_GENERAL_CFG			0x03
42 #define UB913_REG_GENERAL_CFG_CRC_ERR_RESET	BIT(5)
43 #define UB913_REG_GENERAL_CFG_PCLK_RISING	BIT(0)
44 
45 #define UB913_REG_MODE_SEL			0x05
46 #define UB913_REG_MODE_SEL_MODE_OVERRIDE	BIT(5)
47 #define UB913_REG_MODE_SEL_MODE_UP_TO_DATE	BIT(4)
48 #define UB913_REG_MODE_SEL_MODE_MASK		GENMASK(3, 0)
49 
50 #define UB913_REG_CRC_ERRORS_LSB		0x0a
51 #define UB913_REG_CRC_ERRORS_MSB		0x0b
52 
53 #define UB913_REG_GENERAL_STATUS		0x0c
54 
55 #define UB913_REG_GPIO_CFG(n)			(0x0d + (n))
56 #define UB913_REG_GPIO_CFG_ENABLE(n)		BIT(0 + (n) * 4)
57 #define UB913_REG_GPIO_CFG_DIR_INPUT(n)		BIT(1 + (n) * 4)
58 #define UB913_REG_GPIO_CFG_REMOTE_EN(n)		BIT(2 + (n) * 4)
59 #define UB913_REG_GPIO_CFG_OUT_VAL(n)		BIT(3 + (n) * 4)
60 #define UB913_REG_GPIO_CFG_MASK(n)		(0xf << ((n) * 4))
61 
62 #define UB913_REG_SCL_HIGH_TIME			0x11
63 #define UB913_REG_SCL_LOW_TIME			0x12
64 
65 #define UB913_REG_PLL_OVR			0x35
66 
67 struct ub913_data {
68 	struct i2c_client	*client;
69 	struct regmap		*regmap;
70 	struct clk		*clkin;
71 
72 	struct gpio_chip	gpio_chip;
73 
74 	struct v4l2_subdev	sd;
75 	struct media_pad	pads[2];
76 
77 	struct v4l2_async_notifier	notifier;
78 
79 	struct v4l2_subdev	*source_sd;
80 	u16			source_sd_pad;
81 
82 	u64			enabled_source_streams;
83 
84 	struct clk_hw		*clkout_clk_hw;
85 
86 	struct ds90ub9xx_platform_data *plat_data;
87 
88 	bool			pclk_polarity_rising;
89 };
90 
91 static inline struct ub913_data *sd_to_ub913(struct v4l2_subdev *sd)
92 {
93 	return container_of(sd, struct ub913_data, sd);
94 }
95 
96 struct ub913_format_info {
97 	u32 incode;
98 	u32 outcode;
99 };
100 
101 static const struct ub913_format_info ub913_formats[] = {
102 	/* Only RAW10 with 8-bit payload is supported at the moment */
103 	{ .incode = MEDIA_BUS_FMT_YUYV8_2X8, .outcode = MEDIA_BUS_FMT_YUYV8_1X16 },
104 	{ .incode = MEDIA_BUS_FMT_UYVY8_2X8, .outcode = MEDIA_BUS_FMT_UYVY8_1X16 },
105 	{ .incode = MEDIA_BUS_FMT_VYUY8_2X8, .outcode = MEDIA_BUS_FMT_VYUY8_1X16 },
106 	{ .incode = MEDIA_BUS_FMT_YVYU8_2X8, .outcode = MEDIA_BUS_FMT_YVYU8_1X16 },
107 };
108 
109 static const struct ub913_format_info *ub913_find_format(u32 incode)
110 {
111 	unsigned int i;
112 
113 	for (i = 0; i < ARRAY_SIZE(ub913_formats); i++) {
114 		if (ub913_formats[i].incode == incode)
115 			return &ub913_formats[i];
116 	}
117 
118 	return NULL;
119 }
120 
121 static int ub913_read(const struct ub913_data *priv, u8 reg, u8 *val)
122 {
123 	unsigned int v;
124 	int ret;
125 
126 	ret = regmap_read(priv->regmap, reg, &v);
127 	if (ret < 0) {
128 		dev_err(&priv->client->dev,
129 			"Cannot read register 0x%02x: %d!\n", reg, ret);
130 		return ret;
131 	}
132 
133 	*val = v;
134 	return 0;
135 }
136 
137 static int ub913_write(const struct ub913_data *priv, u8 reg, u8 val)
138 {
139 	int ret;
140 
141 	ret = regmap_write(priv->regmap, reg, val);
142 	if (ret < 0)
143 		dev_err(&priv->client->dev,
144 			"Cannot write register 0x%02x: %d!\n", reg, ret);
145 
146 	return ret;
147 }
148 
149 /*
150  * GPIO chip
151  */
152 static int ub913_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
153 {
154 	return GPIO_LINE_DIRECTION_OUT;
155 }
156 
157 static int ub913_gpio_direction_out(struct gpio_chip *gc, unsigned int offset,
158 				    int value)
159 {
160 	struct ub913_data *priv = gpiochip_get_data(gc);
161 	unsigned int reg_idx = offset / 2;
162 	unsigned int field_idx = offset % 2;
163 
164 	return regmap_update_bits(priv->regmap, UB913_REG_GPIO_CFG(reg_idx),
165 				  UB913_REG_GPIO_CFG_MASK(field_idx),
166 				  UB913_REG_GPIO_CFG_ENABLE(field_idx) |
167 					  (value ? UB913_REG_GPIO_CFG_OUT_VAL(field_idx) :
168 						   0));
169 }
170 
171 static void ub913_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
172 {
173 	ub913_gpio_direction_out(gc, offset, value);
174 }
175 
176 static int ub913_gpio_of_xlate(struct gpio_chip *gc,
177 			       const struct of_phandle_args *gpiospec,
178 			       u32 *flags)
179 {
180 	if (flags)
181 		*flags = gpiospec->args[1];
182 
183 	return gpiospec->args[0];
184 }
185 
186 static int ub913_gpiochip_probe(struct ub913_data *priv)
187 {
188 	struct device *dev = &priv->client->dev;
189 	struct gpio_chip *gc = &priv->gpio_chip;
190 	int ret;
191 
192 	/* Initialize GPIOs 0 and 1 to local control, tri-state */
193 	ub913_write(priv, UB913_REG_GPIO_CFG(0), 0);
194 
195 	gc->label = dev_name(dev);
196 	gc->parent = dev;
197 	gc->owner = THIS_MODULE;
198 	gc->base = -1;
199 	gc->can_sleep = true;
200 	gc->ngpio = UB913_NUM_GPIOS;
201 	gc->get_direction = ub913_gpio_get_direction;
202 	gc->direction_output = ub913_gpio_direction_out;
203 	gc->set = ub913_gpio_set;
204 	gc->of_xlate = ub913_gpio_of_xlate;
205 	gc->of_gpio_n_cells = 2;
206 
207 	ret = gpiochip_add_data(gc, priv);
208 	if (ret) {
209 		dev_err(dev, "Failed to add GPIOs: %d\n", ret);
210 		return ret;
211 	}
212 
213 	return 0;
214 }
215 
216 static void ub913_gpiochip_remove(struct ub913_data *priv)
217 {
218 	gpiochip_remove(&priv->gpio_chip);
219 }
220 
221 static const struct regmap_config ub913_regmap_config = {
222 	.name = "ds90ub913",
223 	.reg_bits = 8,
224 	.val_bits = 8,
225 	.reg_format_endian = REGMAP_ENDIAN_DEFAULT,
226 	.val_format_endian = REGMAP_ENDIAN_DEFAULT,
227 };
228 
229 /*
230  * V4L2
231  */
232 
233 static int ub913_enable_streams(struct v4l2_subdev *sd,
234 				struct v4l2_subdev_state *state, u32 pad,
235 				u64 streams_mask)
236 {
237 	struct ub913_data *priv = sd_to_ub913(sd);
238 	u64 sink_streams;
239 	int ret;
240 
241 	sink_streams = v4l2_subdev_state_xlate_streams(state, UB913_PAD_SOURCE,
242 						       UB913_PAD_SINK,
243 						       &streams_mask);
244 
245 	ret = v4l2_subdev_enable_streams(priv->source_sd, priv->source_sd_pad,
246 					 sink_streams);
247 	if (ret)
248 		return ret;
249 
250 	priv->enabled_source_streams |= streams_mask;
251 
252 	return 0;
253 }
254 
255 static int ub913_disable_streams(struct v4l2_subdev *sd,
256 				 struct v4l2_subdev_state *state, u32 pad,
257 				 u64 streams_mask)
258 {
259 	struct ub913_data *priv = sd_to_ub913(sd);
260 	u64 sink_streams;
261 	int ret;
262 
263 	sink_streams = v4l2_subdev_state_xlate_streams(state, UB913_PAD_SOURCE,
264 						       UB913_PAD_SINK,
265 						       &streams_mask);
266 
267 	ret = v4l2_subdev_disable_streams(priv->source_sd, priv->source_sd_pad,
268 					  sink_streams);
269 	if (ret)
270 		return ret;
271 
272 	priv->enabled_source_streams &= ~streams_mask;
273 
274 	return 0;
275 }
276 
277 static int _ub913_set_routing(struct v4l2_subdev *sd,
278 			      struct v4l2_subdev_state *state,
279 			      struct v4l2_subdev_krouting *routing)
280 {
281 	static const struct v4l2_mbus_framefmt in_format = {
282 		.width = 640,
283 		.height = 480,
284 		.code = MEDIA_BUS_FMT_UYVY8_2X8,
285 		.field = V4L2_FIELD_NONE,
286 		.colorspace = V4L2_COLORSPACE_SRGB,
287 		.ycbcr_enc = V4L2_YCBCR_ENC_601,
288 		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
289 		.xfer_func = V4L2_XFER_FUNC_SRGB,
290 	};
291 	static const struct v4l2_mbus_framefmt out_format = {
292 		.width = 640,
293 		.height = 480,
294 		.code = MEDIA_BUS_FMT_UYVY8_1X16,
295 		.field = V4L2_FIELD_NONE,
296 		.colorspace = V4L2_COLORSPACE_SRGB,
297 		.ycbcr_enc = V4L2_YCBCR_ENC_601,
298 		.quantization = V4L2_QUANTIZATION_LIM_RANGE,
299 		.xfer_func = V4L2_XFER_FUNC_SRGB,
300 	};
301 	struct v4l2_subdev_stream_configs *stream_configs;
302 	unsigned int i;
303 	int ret;
304 
305 	/*
306 	 * Note: we can only support up to V4L2_FRAME_DESC_ENTRY_MAX, until
307 	 * frame desc is made dynamically allocated.
308 	 */
309 
310 	if (routing->num_routes > V4L2_FRAME_DESC_ENTRY_MAX)
311 		return -EINVAL;
312 
313 	ret = v4l2_subdev_routing_validate(sd, routing,
314 					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
315 	if (ret)
316 		return ret;
317 
318 	ret = v4l2_subdev_set_routing(sd, state, routing);
319 	if (ret)
320 		return ret;
321 
322 	stream_configs = &state->stream_configs;
323 
324 	for (i = 0; i < stream_configs->num_configs; i++) {
325 		if (stream_configs->configs[i].pad == UB913_PAD_SINK)
326 			stream_configs->configs[i].fmt = in_format;
327 		else
328 			stream_configs->configs[i].fmt = out_format;
329 	}
330 
331 	return 0;
332 }
333 
334 static int ub913_set_routing(struct v4l2_subdev *sd,
335 			     struct v4l2_subdev_state *state,
336 			     enum v4l2_subdev_format_whence which,
337 			     struct v4l2_subdev_krouting *routing)
338 {
339 	struct ub913_data *priv = sd_to_ub913(sd);
340 
341 	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && priv->enabled_source_streams)
342 		return -EBUSY;
343 
344 	return _ub913_set_routing(sd, state, routing);
345 }
346 
347 static int ub913_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
348 				struct v4l2_mbus_frame_desc *fd)
349 {
350 	struct ub913_data *priv = sd_to_ub913(sd);
351 	const struct v4l2_subdev_krouting *routing;
352 	struct v4l2_mbus_frame_desc source_fd;
353 	struct v4l2_subdev_route *route;
354 	struct v4l2_subdev_state *state;
355 	int ret;
356 
357 	if (pad != UB913_PAD_SOURCE)
358 		return -EINVAL;
359 
360 	ret = v4l2_subdev_call(priv->source_sd, pad, get_frame_desc,
361 			       priv->source_sd_pad, &source_fd);
362 	if (ret)
363 		return ret;
364 
365 	memset(fd, 0, sizeof(*fd));
366 
367 	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_PARALLEL;
368 
369 	state = v4l2_subdev_lock_and_get_active_state(sd);
370 
371 	routing = &state->routing;
372 
373 	for_each_active_route(routing, route) {
374 		unsigned int i;
375 
376 		if (route->source_pad != pad)
377 			continue;
378 
379 		for (i = 0; i < source_fd.num_entries; i++) {
380 			if (source_fd.entry[i].stream == route->sink_stream)
381 				break;
382 		}
383 
384 		if (i == source_fd.num_entries) {
385 			dev_err(&priv->client->dev,
386 				"Failed to find stream from source frame desc\n");
387 			ret = -EPIPE;
388 			goto out_unlock;
389 		}
390 
391 		fd->entry[fd->num_entries].stream = route->source_stream;
392 		fd->entry[fd->num_entries].flags = source_fd.entry[i].flags;
393 		fd->entry[fd->num_entries].length = source_fd.entry[i].length;
394 		fd->entry[fd->num_entries].pixelcode =
395 			source_fd.entry[i].pixelcode;
396 
397 		fd->num_entries++;
398 	}
399 
400 out_unlock:
401 	v4l2_subdev_unlock_state(state);
402 
403 	return ret;
404 }
405 
406 static int ub913_set_fmt(struct v4l2_subdev *sd,
407 			 struct v4l2_subdev_state *state,
408 			 struct v4l2_subdev_format *format)
409 {
410 	struct ub913_data *priv = sd_to_ub913(sd);
411 	struct v4l2_mbus_framefmt *fmt;
412 	const struct ub913_format_info *finfo;
413 
414 	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE &&
415 	    priv->enabled_source_streams)
416 		return -EBUSY;
417 
418 	/* Source format is fully defined by the sink format, so not settable */
419 	if (format->pad == UB913_PAD_SOURCE)
420 		return v4l2_subdev_get_fmt(sd, state, format);
421 
422 	finfo = ub913_find_format(format->format.code);
423 	if (!finfo) {
424 		finfo = &ub913_formats[0];
425 		format->format.code = finfo->incode;
426 	}
427 
428 	/* Set sink format */
429 	fmt = v4l2_subdev_state_get_stream_format(state, format->pad,
430 						  format->stream);
431 	if (!fmt)
432 		return -EINVAL;
433 
434 	*fmt = format->format;
435 
436 	/* Propagate to source format, and adjust the mbus code */
437 	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
438 							   format->stream);
439 	if (!fmt)
440 		return -EINVAL;
441 
442 	format->format.code = finfo->outcode;
443 
444 	*fmt = format->format;
445 
446 	return 0;
447 }
448 
449 static int ub913_init_cfg(struct v4l2_subdev *sd,
450 			  struct v4l2_subdev_state *state)
451 {
452 	struct v4l2_subdev_route routes[] = {
453 		{
454 			.sink_pad = UB913_PAD_SINK,
455 			.sink_stream = 0,
456 			.source_pad = UB913_PAD_SOURCE,
457 			.source_stream = 0,
458 			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
459 		},
460 	};
461 
462 	struct v4l2_subdev_krouting routing = {
463 		.num_routes = ARRAY_SIZE(routes),
464 		.routes = routes,
465 	};
466 
467 	return _ub913_set_routing(sd, state, &routing);
468 }
469 
470 static int ub913_log_status(struct v4l2_subdev *sd)
471 {
472 	struct ub913_data *priv = sd_to_ub913(sd);
473 	struct device *dev = &priv->client->dev;
474 	u8 v = 0, v1 = 0, v2 = 0;
475 
476 	ub913_read(priv, UB913_REG_MODE_SEL, &v);
477 	dev_info(dev, "MODE_SEL %#02x\n", v);
478 
479 	ub913_read(priv, UB913_REG_CRC_ERRORS_LSB, &v1);
480 	ub913_read(priv, UB913_REG_CRC_ERRORS_MSB, &v2);
481 	dev_info(dev, "CRC errors %u\n", v1 | (v2 << 8));
482 
483 	/* clear CRC errors */
484 	ub913_read(priv, UB913_REG_GENERAL_CFG, &v);
485 	ub913_write(priv, UB913_REG_GENERAL_CFG,
486 		    v | UB913_REG_GENERAL_CFG_CRC_ERR_RESET);
487 	ub913_write(priv, UB913_REG_GENERAL_CFG, v);
488 
489 	ub913_read(priv, UB913_REG_GENERAL_STATUS, &v);
490 	dev_info(dev, "GENERAL_STATUS %#02x\n", v);
491 
492 	ub913_read(priv, UB913_REG_PLL_OVR, &v);
493 	dev_info(dev, "PLL_OVR %#02x\n", v);
494 
495 	return 0;
496 }
497 
498 static const struct v4l2_subdev_core_ops ub913_subdev_core_ops = {
499 	.log_status = ub913_log_status,
500 };
501 
502 static const struct v4l2_subdev_pad_ops ub913_pad_ops = {
503 	.enable_streams = ub913_enable_streams,
504 	.disable_streams = ub913_disable_streams,
505 	.set_routing = ub913_set_routing,
506 	.get_frame_desc = ub913_get_frame_desc,
507 	.get_fmt = v4l2_subdev_get_fmt,
508 	.set_fmt = ub913_set_fmt,
509 	.init_cfg = ub913_init_cfg,
510 };
511 
512 static const struct v4l2_subdev_ops ub913_subdev_ops = {
513 	.core = &ub913_subdev_core_ops,
514 	.pad = &ub913_pad_ops,
515 };
516 
517 static const struct media_entity_operations ub913_entity_ops = {
518 	.link_validate = v4l2_subdev_link_validate,
519 };
520 
521 static int ub913_notify_bound(struct v4l2_async_notifier *notifier,
522 			      struct v4l2_subdev *source_subdev,
523 			      struct v4l2_async_connection *asd)
524 {
525 	struct ub913_data *priv = sd_to_ub913(notifier->sd);
526 	struct device *dev = &priv->client->dev;
527 	int ret;
528 
529 	ret = media_entity_get_fwnode_pad(&source_subdev->entity,
530 					  source_subdev->fwnode,
531 					  MEDIA_PAD_FL_SOURCE);
532 	if (ret < 0) {
533 		dev_err(dev, "Failed to find pad for %s\n",
534 			source_subdev->name);
535 		return ret;
536 	}
537 
538 	priv->source_sd = source_subdev;
539 	priv->source_sd_pad = ret;
540 
541 	ret = media_create_pad_link(&source_subdev->entity, priv->source_sd_pad,
542 				    &priv->sd.entity, UB913_PAD_SINK,
543 				    MEDIA_LNK_FL_ENABLED |
544 					    MEDIA_LNK_FL_IMMUTABLE);
545 	if (ret) {
546 		dev_err(dev, "Unable to link %s:%u -> %s:0\n",
547 			source_subdev->name, priv->source_sd_pad,
548 			priv->sd.name);
549 		return ret;
550 	}
551 
552 	return 0;
553 }
554 
555 static const struct v4l2_async_notifier_operations ub913_notify_ops = {
556 	.bound = ub913_notify_bound,
557 };
558 
559 static int ub913_v4l2_notifier_register(struct ub913_data *priv)
560 {
561 	struct device *dev = &priv->client->dev;
562 	struct v4l2_async_connection *asd;
563 	struct fwnode_handle *ep_fwnode;
564 	int ret;
565 
566 	ep_fwnode = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
567 						    UB913_PAD_SINK, 0, 0);
568 	if (!ep_fwnode) {
569 		dev_err(dev, "No graph endpoint\n");
570 		return -ENODEV;
571 	}
572 
573 	v4l2_async_subdev_nf_init(&priv->notifier, &priv->sd);
574 
575 	asd = v4l2_async_nf_add_fwnode_remote(&priv->notifier, ep_fwnode,
576 					      struct v4l2_async_connection);
577 
578 	fwnode_handle_put(ep_fwnode);
579 
580 	if (IS_ERR(asd)) {
581 		dev_err(dev, "Failed to add subdev: %ld", PTR_ERR(asd));
582 		v4l2_async_nf_cleanup(&priv->notifier);
583 		return PTR_ERR(asd);
584 	}
585 
586 	priv->notifier.ops = &ub913_notify_ops;
587 
588 	ret = v4l2_async_nf_register(&priv->notifier);
589 	if (ret) {
590 		dev_err(dev, "Failed to register subdev_notifier");
591 		v4l2_async_nf_cleanup(&priv->notifier);
592 		return ret;
593 	}
594 
595 	return 0;
596 }
597 
598 static void ub913_v4l2_nf_unregister(struct ub913_data *priv)
599 {
600 	v4l2_async_nf_unregister(&priv->notifier);
601 	v4l2_async_nf_cleanup(&priv->notifier);
602 }
603 
604 static int ub913_register_clkout(struct ub913_data *priv)
605 {
606 	struct device *dev = &priv->client->dev;
607 	const char *name;
608 	int ret;
609 
610 	name = kasprintf(GFP_KERNEL, "ds90ub913.%s.clk_out", dev_name(dev));
611 	if (!name)
612 		return -ENOMEM;
613 
614 	priv->clkout_clk_hw = devm_clk_hw_register_fixed_factor(dev, name,
615 		__clk_get_name(priv->clkin), 0, 1, 2);
616 
617 	kfree(name);
618 
619 	if (IS_ERR(priv->clkout_clk_hw))
620 		return dev_err_probe(dev, PTR_ERR(priv->clkout_clk_hw),
621 				     "Cannot register clkout hw\n");
622 
623 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
624 					  priv->clkout_clk_hw);
625 	if (ret)
626 		return dev_err_probe(dev, ret,
627 				     "Cannot add OF clock provider\n");
628 
629 	return 0;
630 }
631 
632 static int ub913_i2c_master_init(struct ub913_data *priv)
633 {
634 	/* i2c fast mode */
635 	u32 scl_high = 600 + 300; /* high period + rise time, ns */
636 	u32 scl_low = 1300 + 300; /* low period + fall time, ns */
637 	unsigned long ref;
638 	int ret;
639 
640 	ref = clk_get_rate(priv->clkin) / 2;
641 
642 	scl_high = div64_u64((u64)scl_high * ref, 1000000000);
643 	scl_low = div64_u64((u64)scl_low * ref, 1000000000);
644 
645 	ret = ub913_write(priv, UB913_REG_SCL_HIGH_TIME, scl_high);
646 	if (ret)
647 		return ret;
648 
649 	ret = ub913_write(priv, UB913_REG_SCL_LOW_TIME, scl_low);
650 	if (ret)
651 		return ret;
652 
653 	return 0;
654 }
655 
656 static int ub913_add_i2c_adapter(struct ub913_data *priv)
657 {
658 	struct device *dev = &priv->client->dev;
659 	struct fwnode_handle *i2c_handle;
660 	int ret;
661 
662 	i2c_handle = device_get_named_child_node(dev, "i2c");
663 	if (!i2c_handle)
664 		return 0;
665 
666 	ret = i2c_atr_add_adapter(priv->plat_data->atr, priv->plat_data->port,
667 				  dev, i2c_handle);
668 
669 	fwnode_handle_put(i2c_handle);
670 
671 	if (ret)
672 		return ret;
673 
674 	return 0;
675 }
676 
677 static int ub913_parse_dt(struct ub913_data *priv)
678 {
679 	struct device *dev = &priv->client->dev;
680 	struct v4l2_fwnode_endpoint vep = {
681 		.bus_type = V4L2_MBUS_PARALLEL,
682 	};
683 	struct fwnode_handle *ep_fwnode;
684 	int ret;
685 
686 	ep_fwnode = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
687 						    UB913_PAD_SINK, 0, 0);
688 	if (!ep_fwnode)
689 		return dev_err_probe(dev, -ENOENT, "No sink endpoint\n");
690 
691 	ret = v4l2_fwnode_endpoint_parse(ep_fwnode, &vep);
692 
693 	fwnode_handle_put(ep_fwnode);
694 
695 	if (ret)
696 		return dev_err_probe(dev, ret,
697 				     "failed to parse sink endpoint data\n");
698 
699 	if (vep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
700 		priv->pclk_polarity_rising = true;
701 	else if (vep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
702 		priv->pclk_polarity_rising = false;
703 	else
704 		return dev_err_probe(dev, -EINVAL,
705 				     "bad value for 'pclk-sample'\n");
706 
707 	return 0;
708 }
709 
710 static int ub913_hw_init(struct ub913_data *priv)
711 {
712 	struct device *dev = &priv->client->dev;
713 	bool mode_override;
714 	u8 mode;
715 	int ret;
716 	u8 v;
717 
718 	ret = ub913_read(priv, UB913_REG_MODE_SEL, &v);
719 	if (ret)
720 		return ret;
721 
722 	if (!(v & UB913_REG_MODE_SEL_MODE_UP_TO_DATE))
723 		return dev_err_probe(dev, -ENODEV,
724 				     "Mode value not stabilized\n");
725 
726 	mode_override = v & UB913_REG_MODE_SEL_MODE_OVERRIDE;
727 	mode = v & UB913_REG_MODE_SEL_MODE_MASK;
728 
729 	dev_dbg(dev, "mode from %s: %#x\n",
730 		mode_override ? "reg" : "deserializer", mode);
731 
732 	ret = ub913_i2c_master_init(priv);
733 	if (ret)
734 		return dev_err_probe(dev, ret, "i2c master init failed\n");
735 
736 	ub913_read(priv, UB913_REG_GENERAL_CFG, &v);
737 	v &= ~UB913_REG_GENERAL_CFG_PCLK_RISING;
738 	v |= priv->pclk_polarity_rising ? UB913_REG_GENERAL_CFG_PCLK_RISING : 0;
739 	ub913_write(priv, UB913_REG_GENERAL_CFG, v);
740 
741 	return 0;
742 }
743 
744 static int ub913_subdev_init(struct ub913_data *priv)
745 {
746 	struct device *dev = &priv->client->dev;
747 	int ret;
748 
749 	v4l2_i2c_subdev_init(&priv->sd, priv->client, &ub913_subdev_ops);
750 	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_STREAMS;
751 	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
752 	priv->sd.entity.ops = &ub913_entity_ops;
753 
754 	priv->pads[0].flags = MEDIA_PAD_FL_SINK;
755 	priv->pads[1].flags = MEDIA_PAD_FL_SOURCE;
756 
757 	ret = media_entity_pads_init(&priv->sd.entity, 2, priv->pads);
758 	if (ret)
759 		return dev_err_probe(dev, ret, "Failed to init pads\n");
760 
761 	ret = v4l2_subdev_init_finalize(&priv->sd);
762 	if (ret)
763 		goto err_entity_cleanup;
764 
765 	ret = ub913_v4l2_notifier_register(priv);
766 	if (ret) {
767 		dev_err_probe(dev, ret,
768 			      "v4l2 subdev notifier register failed\n");
769 		goto err_subdev_cleanup;
770 	}
771 
772 	ret = v4l2_async_register_subdev(&priv->sd);
773 	if (ret) {
774 		dev_err_probe(dev, ret, "v4l2_async_register_subdev error\n");
775 		goto err_unreg_notif;
776 	}
777 
778 	return 0;
779 
780 err_unreg_notif:
781 	ub913_v4l2_nf_unregister(priv);
782 err_subdev_cleanup:
783 	v4l2_subdev_cleanup(&priv->sd);
784 err_entity_cleanup:
785 	media_entity_cleanup(&priv->sd.entity);
786 
787 	return ret;
788 }
789 
790 static void ub913_subdev_uninit(struct ub913_data *priv)
791 {
792 	v4l2_async_unregister_subdev(&priv->sd);
793 	ub913_v4l2_nf_unregister(priv);
794 	v4l2_subdev_cleanup(&priv->sd);
795 	fwnode_handle_put(priv->sd.fwnode);
796 	media_entity_cleanup(&priv->sd.entity);
797 }
798 
799 static int ub913_probe(struct i2c_client *client)
800 {
801 	struct device *dev = &client->dev;
802 	struct ub913_data *priv;
803 	int ret;
804 
805 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
806 	if (!priv)
807 		return -ENOMEM;
808 
809 	priv->client = client;
810 
811 	priv->plat_data = dev_get_platdata(&client->dev);
812 	if (!priv->plat_data)
813 		return dev_err_probe(dev, -ENODEV, "Platform data missing\n");
814 
815 	priv->regmap = devm_regmap_init_i2c(client, &ub913_regmap_config);
816 	if (IS_ERR(priv->regmap))
817 		return dev_err_probe(dev, PTR_ERR(priv->regmap),
818 				     "Failed to init regmap\n");
819 
820 	/*
821 	 * ub913 can also work without ext clock, but that is not supported by
822 	 * the driver yet.
823 	 */
824 	priv->clkin = devm_clk_get(dev, "clkin");
825 	if (IS_ERR(priv->clkin))
826 		return dev_err_probe(dev, PTR_ERR(priv->clkin),
827 				     "Cannot get CLKIN\n");
828 
829 	ret = ub913_parse_dt(priv);
830 	if (ret)
831 		return ret;
832 
833 	ret = ub913_hw_init(priv);
834 	if (ret)
835 		return ret;
836 
837 	ret = ub913_gpiochip_probe(priv);
838 	if (ret)
839 		return dev_err_probe(dev, ret, "Failed to init gpiochip\n");
840 
841 	ret = ub913_register_clkout(priv);
842 	if (ret) {
843 		dev_err_probe(dev, ret, "Failed to register clkout\n");
844 		goto err_gpiochip_remove;
845 	}
846 
847 	ret = ub913_subdev_init(priv);
848 	if (ret)
849 		goto err_gpiochip_remove;
850 
851 	ret = ub913_add_i2c_adapter(priv);
852 	if (ret) {
853 		dev_err_probe(dev, ret, "failed to add remote i2c adapter\n");
854 		goto err_subdev_uninit;
855 	}
856 
857 	return 0;
858 
859 err_subdev_uninit:
860 	ub913_subdev_uninit(priv);
861 err_gpiochip_remove:
862 	ub913_gpiochip_remove(priv);
863 
864 	return ret;
865 }
866 
867 static void ub913_remove(struct i2c_client *client)
868 {
869 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
870 	struct ub913_data *priv = sd_to_ub913(sd);
871 
872 	i2c_atr_del_adapter(priv->plat_data->atr, priv->plat_data->port);
873 
874 	ub913_subdev_uninit(priv);
875 
876 	ub913_gpiochip_remove(priv);
877 }
878 
879 static const struct i2c_device_id ub913_id[] = { { "ds90ub913a-q1", 0 }, {} };
880 MODULE_DEVICE_TABLE(i2c, ub913_id);
881 
882 static const struct of_device_id ub913_dt_ids[] = {
883 	{ .compatible = "ti,ds90ub913a-q1" },
884 	{}
885 };
886 MODULE_DEVICE_TABLE(of, ub913_dt_ids);
887 
888 static struct i2c_driver ds90ub913_driver = {
889 	.probe		= ub913_probe,
890 	.remove		= ub913_remove,
891 	.id_table	= ub913_id,
892 	.driver = {
893 		.name	= "ds90ub913a",
894 		.of_match_table = ub913_dt_ids,
895 	},
896 };
897 module_i2c_driver(ds90ub913_driver);
898 
899 MODULE_LICENSE("GPL");
900 MODULE_DESCRIPTION("Texas Instruments DS90UB913 FPD-Link III Serializer Driver");
901 MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
902 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>");
903 MODULE_IMPORT_NS(I2C_ATR);
904