xref: /linux/drivers/media/i2c/ds90ub913.c (revision 9f7861c56b51b84d30114e7fea9d744a9d5ba9b7)
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 	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_PARALLEL;
366 
367 	state = v4l2_subdev_lock_and_get_active_state(sd);
368 
369 	routing = &state->routing;
370 
371 	for_each_active_route(routing, route) {
372 		unsigned int i;
373 
374 		if (route->source_pad != pad)
375 			continue;
376 
377 		for (i = 0; i < source_fd.num_entries; i++) {
378 			if (source_fd.entry[i].stream == route->sink_stream)
379 				break;
380 		}
381 
382 		if (i == source_fd.num_entries) {
383 			dev_err(&priv->client->dev,
384 				"Failed to find stream from source frame desc\n");
385 			ret = -EPIPE;
386 			goto out_unlock;
387 		}
388 
389 		fd->entry[fd->num_entries].stream = route->source_stream;
390 		fd->entry[fd->num_entries].flags = source_fd.entry[i].flags;
391 		fd->entry[fd->num_entries].length = source_fd.entry[i].length;
392 		fd->entry[fd->num_entries].pixelcode =
393 			source_fd.entry[i].pixelcode;
394 
395 		fd->num_entries++;
396 	}
397 
398 out_unlock:
399 	v4l2_subdev_unlock_state(state);
400 
401 	return ret;
402 }
403 
404 static int ub913_set_fmt(struct v4l2_subdev *sd,
405 			 struct v4l2_subdev_state *state,
406 			 struct v4l2_subdev_format *format)
407 {
408 	struct ub913_data *priv = sd_to_ub913(sd);
409 	struct v4l2_mbus_framefmt *fmt;
410 	const struct ub913_format_info *finfo;
411 
412 	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE &&
413 	    priv->enabled_source_streams)
414 		return -EBUSY;
415 
416 	/* Source format is fully defined by the sink format, so not settable */
417 	if (format->pad == UB913_PAD_SOURCE)
418 		return v4l2_subdev_get_fmt(sd, state, format);
419 
420 	finfo = ub913_find_format(format->format.code);
421 	if (!finfo) {
422 		finfo = &ub913_formats[0];
423 		format->format.code = finfo->incode;
424 	}
425 
426 	/* Set sink format */
427 	fmt = v4l2_subdev_state_get_stream_format(state, format->pad,
428 						  format->stream);
429 	if (!fmt)
430 		return -EINVAL;
431 
432 	*fmt = format->format;
433 
434 	/* Propagate to source format, and adjust the mbus code */
435 	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
436 							   format->stream);
437 	if (!fmt)
438 		return -EINVAL;
439 
440 	format->format.code = finfo->outcode;
441 
442 	*fmt = format->format;
443 
444 	return 0;
445 }
446 
447 static int ub913_init_cfg(struct v4l2_subdev *sd,
448 			  struct v4l2_subdev_state *state)
449 {
450 	struct v4l2_subdev_route routes[] = {
451 		{
452 			.sink_pad = UB913_PAD_SINK,
453 			.sink_stream = 0,
454 			.source_pad = UB913_PAD_SOURCE,
455 			.source_stream = 0,
456 			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
457 		},
458 	};
459 
460 	struct v4l2_subdev_krouting routing = {
461 		.num_routes = ARRAY_SIZE(routes),
462 		.routes = routes,
463 	};
464 
465 	return _ub913_set_routing(sd, state, &routing);
466 }
467 
468 static int ub913_log_status(struct v4l2_subdev *sd)
469 {
470 	struct ub913_data *priv = sd_to_ub913(sd);
471 	struct device *dev = &priv->client->dev;
472 	u8 v = 0, v1 = 0, v2 = 0;
473 
474 	ub913_read(priv, UB913_REG_MODE_SEL, &v);
475 	dev_info(dev, "MODE_SEL %#02x\n", v);
476 
477 	ub913_read(priv, UB913_REG_CRC_ERRORS_LSB, &v1);
478 	ub913_read(priv, UB913_REG_CRC_ERRORS_MSB, &v2);
479 	dev_info(dev, "CRC errors %u\n", v1 | (v2 << 8));
480 
481 	/* clear CRC errors */
482 	ub913_read(priv, UB913_REG_GENERAL_CFG, &v);
483 	ub913_write(priv, UB913_REG_GENERAL_CFG,
484 		    v | UB913_REG_GENERAL_CFG_CRC_ERR_RESET);
485 	ub913_write(priv, UB913_REG_GENERAL_CFG, v);
486 
487 	ub913_read(priv, UB913_REG_GENERAL_STATUS, &v);
488 	dev_info(dev, "GENERAL_STATUS %#02x\n", v);
489 
490 	ub913_read(priv, UB913_REG_PLL_OVR, &v);
491 	dev_info(dev, "PLL_OVR %#02x\n", v);
492 
493 	return 0;
494 }
495 
496 static const struct v4l2_subdev_core_ops ub913_subdev_core_ops = {
497 	.log_status = ub913_log_status,
498 };
499 
500 static const struct v4l2_subdev_pad_ops ub913_pad_ops = {
501 	.enable_streams = ub913_enable_streams,
502 	.disable_streams = ub913_disable_streams,
503 	.set_routing = ub913_set_routing,
504 	.get_frame_desc = ub913_get_frame_desc,
505 	.get_fmt = v4l2_subdev_get_fmt,
506 	.set_fmt = ub913_set_fmt,
507 	.init_cfg = ub913_init_cfg,
508 };
509 
510 static const struct v4l2_subdev_ops ub913_subdev_ops = {
511 	.core = &ub913_subdev_core_ops,
512 	.pad = &ub913_pad_ops,
513 };
514 
515 static const struct media_entity_operations ub913_entity_ops = {
516 	.link_validate = v4l2_subdev_link_validate,
517 };
518 
519 static int ub913_notify_bound(struct v4l2_async_notifier *notifier,
520 			      struct v4l2_subdev *source_subdev,
521 			      struct v4l2_async_connection *asd)
522 {
523 	struct ub913_data *priv = sd_to_ub913(notifier->sd);
524 	struct device *dev = &priv->client->dev;
525 	int ret;
526 
527 	ret = media_entity_get_fwnode_pad(&source_subdev->entity,
528 					  source_subdev->fwnode,
529 					  MEDIA_PAD_FL_SOURCE);
530 	if (ret < 0) {
531 		dev_err(dev, "Failed to find pad for %s\n",
532 			source_subdev->name);
533 		return ret;
534 	}
535 
536 	priv->source_sd = source_subdev;
537 	priv->source_sd_pad = ret;
538 
539 	ret = media_create_pad_link(&source_subdev->entity, priv->source_sd_pad,
540 				    &priv->sd.entity, UB913_PAD_SINK,
541 				    MEDIA_LNK_FL_ENABLED |
542 					    MEDIA_LNK_FL_IMMUTABLE);
543 	if (ret) {
544 		dev_err(dev, "Unable to link %s:%u -> %s:0\n",
545 			source_subdev->name, priv->source_sd_pad,
546 			priv->sd.name);
547 		return ret;
548 	}
549 
550 	return 0;
551 }
552 
553 static const struct v4l2_async_notifier_operations ub913_notify_ops = {
554 	.bound = ub913_notify_bound,
555 };
556 
557 static int ub913_v4l2_notifier_register(struct ub913_data *priv)
558 {
559 	struct device *dev = &priv->client->dev;
560 	struct v4l2_async_connection *asd;
561 	struct fwnode_handle *ep_fwnode;
562 	int ret;
563 
564 	ep_fwnode = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
565 						    UB913_PAD_SINK, 0, 0);
566 	if (!ep_fwnode) {
567 		dev_err(dev, "No graph endpoint\n");
568 		return -ENODEV;
569 	}
570 
571 	v4l2_async_subdev_nf_init(&priv->notifier, &priv->sd);
572 
573 	asd = v4l2_async_nf_add_fwnode_remote(&priv->notifier, ep_fwnode,
574 					      struct v4l2_async_connection);
575 
576 	fwnode_handle_put(ep_fwnode);
577 
578 	if (IS_ERR(asd)) {
579 		dev_err(dev, "Failed to add subdev: %ld", PTR_ERR(asd));
580 		v4l2_async_nf_cleanup(&priv->notifier);
581 		return PTR_ERR(asd);
582 	}
583 
584 	priv->notifier.ops = &ub913_notify_ops;
585 
586 	ret = v4l2_async_nf_register(&priv->notifier);
587 	if (ret) {
588 		dev_err(dev, "Failed to register subdev_notifier");
589 		v4l2_async_nf_cleanup(&priv->notifier);
590 		return ret;
591 	}
592 
593 	return 0;
594 }
595 
596 static void ub913_v4l2_nf_unregister(struct ub913_data *priv)
597 {
598 	v4l2_async_nf_unregister(&priv->notifier);
599 	v4l2_async_nf_cleanup(&priv->notifier);
600 }
601 
602 static int ub913_register_clkout(struct ub913_data *priv)
603 {
604 	struct device *dev = &priv->client->dev;
605 	const char *name;
606 	int ret;
607 
608 	name = kasprintf(GFP_KERNEL, "ds90ub913.%s.clk_out", dev_name(dev));
609 	if (!name)
610 		return -ENOMEM;
611 
612 	priv->clkout_clk_hw = devm_clk_hw_register_fixed_factor(dev, name,
613 		__clk_get_name(priv->clkin), 0, 1, 2);
614 
615 	kfree(name);
616 
617 	if (IS_ERR(priv->clkout_clk_hw))
618 		return dev_err_probe(dev, PTR_ERR(priv->clkout_clk_hw),
619 				     "Cannot register clkout hw\n");
620 
621 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
622 					  priv->clkout_clk_hw);
623 	if (ret)
624 		return dev_err_probe(dev, ret,
625 				     "Cannot add OF clock provider\n");
626 
627 	return 0;
628 }
629 
630 static int ub913_i2c_master_init(struct ub913_data *priv)
631 {
632 	/* i2c fast mode */
633 	u32 scl_high = 600 + 300; /* high period + rise time, ns */
634 	u32 scl_low = 1300 + 300; /* low period + fall time, ns */
635 	unsigned long ref;
636 	int ret;
637 
638 	ref = clk_get_rate(priv->clkin) / 2;
639 
640 	scl_high = div64_u64((u64)scl_high * ref, 1000000000);
641 	scl_low = div64_u64((u64)scl_low * ref, 1000000000);
642 
643 	ret = ub913_write(priv, UB913_REG_SCL_HIGH_TIME, scl_high);
644 	if (ret)
645 		return ret;
646 
647 	ret = ub913_write(priv, UB913_REG_SCL_LOW_TIME, scl_low);
648 	if (ret)
649 		return ret;
650 
651 	return 0;
652 }
653 
654 static int ub913_add_i2c_adapter(struct ub913_data *priv)
655 {
656 	struct device *dev = &priv->client->dev;
657 	struct fwnode_handle *i2c_handle;
658 	int ret;
659 
660 	i2c_handle = device_get_named_child_node(dev, "i2c");
661 	if (!i2c_handle)
662 		return 0;
663 
664 	ret = i2c_atr_add_adapter(priv->plat_data->atr, priv->plat_data->port,
665 				  dev, i2c_handle);
666 
667 	fwnode_handle_put(i2c_handle);
668 
669 	if (ret)
670 		return ret;
671 
672 	return 0;
673 }
674 
675 static int ub913_parse_dt(struct ub913_data *priv)
676 {
677 	struct device *dev = &priv->client->dev;
678 	struct v4l2_fwnode_endpoint vep = {
679 		.bus_type = V4L2_MBUS_PARALLEL,
680 	};
681 	struct fwnode_handle *ep_fwnode;
682 	int ret;
683 
684 	ep_fwnode = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
685 						    UB913_PAD_SINK, 0, 0);
686 	if (!ep_fwnode)
687 		return dev_err_probe(dev, -ENOENT, "No sink endpoint\n");
688 
689 	ret = v4l2_fwnode_endpoint_parse(ep_fwnode, &vep);
690 
691 	fwnode_handle_put(ep_fwnode);
692 
693 	if (ret)
694 		return dev_err_probe(dev, ret,
695 				     "failed to parse sink endpoint data\n");
696 
697 	if (vep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
698 		priv->pclk_polarity_rising = true;
699 	else if (vep.bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
700 		priv->pclk_polarity_rising = false;
701 	else
702 		return dev_err_probe(dev, -EINVAL,
703 				     "bad value for 'pclk-sample'\n");
704 
705 	return 0;
706 }
707 
708 static int ub913_hw_init(struct ub913_data *priv)
709 {
710 	struct device *dev = &priv->client->dev;
711 	bool mode_override;
712 	u8 mode;
713 	int ret;
714 	u8 v;
715 
716 	ret = ub913_read(priv, UB913_REG_MODE_SEL, &v);
717 	if (ret)
718 		return ret;
719 
720 	if (!(v & UB913_REG_MODE_SEL_MODE_UP_TO_DATE))
721 		return dev_err_probe(dev, -ENODEV,
722 				     "Mode value not stabilized\n");
723 
724 	mode_override = v & UB913_REG_MODE_SEL_MODE_OVERRIDE;
725 	mode = v & UB913_REG_MODE_SEL_MODE_MASK;
726 
727 	dev_dbg(dev, "mode from %s: %#x\n",
728 		mode_override ? "reg" : "deserializer", mode);
729 
730 	ret = ub913_i2c_master_init(priv);
731 	if (ret)
732 		return dev_err_probe(dev, ret, "i2c master init failed\n");
733 
734 	ub913_read(priv, UB913_REG_GENERAL_CFG, &v);
735 	v &= ~UB913_REG_GENERAL_CFG_PCLK_RISING;
736 	v |= priv->pclk_polarity_rising ? UB913_REG_GENERAL_CFG_PCLK_RISING : 0;
737 	ub913_write(priv, UB913_REG_GENERAL_CFG, v);
738 
739 	return 0;
740 }
741 
742 static int ub913_subdev_init(struct ub913_data *priv)
743 {
744 	struct device *dev = &priv->client->dev;
745 	int ret;
746 
747 	v4l2_i2c_subdev_init(&priv->sd, priv->client, &ub913_subdev_ops);
748 	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_STREAMS;
749 	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
750 	priv->sd.entity.ops = &ub913_entity_ops;
751 
752 	priv->pads[0].flags = MEDIA_PAD_FL_SINK;
753 	priv->pads[1].flags = MEDIA_PAD_FL_SOURCE;
754 
755 	ret = media_entity_pads_init(&priv->sd.entity, 2, priv->pads);
756 	if (ret)
757 		return dev_err_probe(dev, ret, "Failed to init pads\n");
758 
759 	ret = v4l2_subdev_init_finalize(&priv->sd);
760 	if (ret)
761 		goto err_entity_cleanup;
762 
763 	ret = ub913_v4l2_notifier_register(priv);
764 	if (ret) {
765 		dev_err_probe(dev, ret,
766 			      "v4l2 subdev notifier register failed\n");
767 		goto err_subdev_cleanup;
768 	}
769 
770 	ret = v4l2_async_register_subdev(&priv->sd);
771 	if (ret) {
772 		dev_err_probe(dev, ret, "v4l2_async_register_subdev error\n");
773 		goto err_unreg_notif;
774 	}
775 
776 	return 0;
777 
778 err_unreg_notif:
779 	ub913_v4l2_nf_unregister(priv);
780 err_subdev_cleanup:
781 	v4l2_subdev_cleanup(&priv->sd);
782 err_entity_cleanup:
783 	media_entity_cleanup(&priv->sd.entity);
784 
785 	return ret;
786 }
787 
788 static void ub913_subdev_uninit(struct ub913_data *priv)
789 {
790 	v4l2_async_unregister_subdev(&priv->sd);
791 	ub913_v4l2_nf_unregister(priv);
792 	v4l2_subdev_cleanup(&priv->sd);
793 	fwnode_handle_put(priv->sd.fwnode);
794 	media_entity_cleanup(&priv->sd.entity);
795 }
796 
797 static int ub913_probe(struct i2c_client *client)
798 {
799 	struct device *dev = &client->dev;
800 	struct ub913_data *priv;
801 	int ret;
802 
803 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
804 	if (!priv)
805 		return -ENOMEM;
806 
807 	priv->client = client;
808 
809 	priv->plat_data = dev_get_platdata(&client->dev);
810 	if (!priv->plat_data)
811 		return dev_err_probe(dev, -ENODEV, "Platform data missing\n");
812 
813 	priv->regmap = devm_regmap_init_i2c(client, &ub913_regmap_config);
814 	if (IS_ERR(priv->regmap))
815 		return dev_err_probe(dev, PTR_ERR(priv->regmap),
816 				     "Failed to init regmap\n");
817 
818 	/*
819 	 * ub913 can also work without ext clock, but that is not supported by
820 	 * the driver yet.
821 	 */
822 	priv->clkin = devm_clk_get(dev, "clkin");
823 	if (IS_ERR(priv->clkin))
824 		return dev_err_probe(dev, PTR_ERR(priv->clkin),
825 				     "Cannot get CLKIN\n");
826 
827 	ret = ub913_parse_dt(priv);
828 	if (ret)
829 		return ret;
830 
831 	ret = ub913_hw_init(priv);
832 	if (ret)
833 		return ret;
834 
835 	ret = ub913_gpiochip_probe(priv);
836 	if (ret)
837 		return dev_err_probe(dev, ret, "Failed to init gpiochip\n");
838 
839 	ret = ub913_register_clkout(priv);
840 	if (ret) {
841 		dev_err_probe(dev, ret, "Failed to register clkout\n");
842 		goto err_gpiochip_remove;
843 	}
844 
845 	ret = ub913_subdev_init(priv);
846 	if (ret)
847 		goto err_gpiochip_remove;
848 
849 	ret = ub913_add_i2c_adapter(priv);
850 	if (ret) {
851 		dev_err_probe(dev, ret, "failed to add remote i2c adapter\n");
852 		goto err_subdev_uninit;
853 	}
854 
855 	return 0;
856 
857 err_subdev_uninit:
858 	ub913_subdev_uninit(priv);
859 err_gpiochip_remove:
860 	ub913_gpiochip_remove(priv);
861 
862 	return ret;
863 }
864 
865 static void ub913_remove(struct i2c_client *client)
866 {
867 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
868 	struct ub913_data *priv = sd_to_ub913(sd);
869 
870 	i2c_atr_del_adapter(priv->plat_data->atr, priv->plat_data->port);
871 
872 	ub913_subdev_uninit(priv);
873 
874 	ub913_gpiochip_remove(priv);
875 }
876 
877 static const struct i2c_device_id ub913_id[] = { { "ds90ub913a-q1", 0 }, {} };
878 MODULE_DEVICE_TABLE(i2c, ub913_id);
879 
880 static const struct of_device_id ub913_dt_ids[] = {
881 	{ .compatible = "ti,ds90ub913a-q1" },
882 	{}
883 };
884 MODULE_DEVICE_TABLE(of, ub913_dt_ids);
885 
886 static struct i2c_driver ds90ub913_driver = {
887 	.probe		= ub913_probe,
888 	.remove		= ub913_remove,
889 	.id_table	= ub913_id,
890 	.driver = {
891 		.name	= "ds90ub913a",
892 		.of_match_table = ub913_dt_ids,
893 	},
894 };
895 module_i2c_driver(ds90ub913_driver);
896 
897 MODULE_LICENSE("GPL");
898 MODULE_DESCRIPTION("Texas Instruments DS90UB913 FPD-Link III Serializer Driver");
899 MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>");
900 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>");
901 MODULE_IMPORT_NS(I2C_ATR);
902