1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Maxim MAX9286 GMSL Deserializer Driver
4 *
5 * Copyright (C) 2017-2019 Jacopo Mondi
6 * Copyright (C) 2017-2019 Kieran Bingham
7 * Copyright (C) 2017-2019 Laurent Pinchart
8 * Copyright (C) 2017-2019 Niklas Söderlund
9 * Copyright (C) 2016 Renesas Electronics Corporation
10 * Copyright (C) 2015 Cogent Embedded, Inc.
11 */
12
13#include <linux/delay.h>
14#include <linux/device.h>
15#include <linux/fwnode.h>
16#include <linux/gpio/consumer.h>
17#include <linux/gpio/driver.h>
18#include <linux/i2c.h>
19#include <linux/i2c-mux.h>
20#include <linux/module.h>
21#include <linux/mutex.h>
22#include <linux/of_graph.h>
23#include <linux/regulator/consumer.h>
24#include <linux/slab.h>
25
26#include <media/v4l2-async.h>
27#include <media/v4l2-ctrls.h>
28#include <media/v4l2-device.h>
29#include <media/v4l2-fwnode.h>
30#include <media/v4l2-subdev.h>
31
32/* Register 0x00 */
33#define MAX9286_MSTLINKSEL_AUTO		(7 << 5)
34#define MAX9286_MSTLINKSEL(n)		((n) << 5)
35#define MAX9286_EN_VS_GEN		BIT(4)
36#define MAX9286_LINKEN(n)		(1 << (n))
37/* Register 0x01 */
38#define MAX9286_FSYNCMODE_ECU		(3 << 6)
39#define MAX9286_FSYNCMODE_EXT		(2 << 6)
40#define MAX9286_FSYNCMODE_INT_OUT	(1 << 6)
41#define MAX9286_FSYNCMODE_INT_HIZ	(0 << 6)
42#define MAX9286_GPIEN			BIT(5)
43#define MAX9286_ENLMO_RSTFSYNC		BIT(2)
44#define MAX9286_FSYNCMETH_AUTO		(2 << 0)
45#define MAX9286_FSYNCMETH_SEMI_AUTO	(1 << 0)
46#define MAX9286_FSYNCMETH_MANUAL	(0 << 0)
47#define MAX9286_REG_FSYNC_PERIOD_L	0x06
48#define MAX9286_REG_FSYNC_PERIOD_M	0x07
49#define MAX9286_REG_FSYNC_PERIOD_H	0x08
50/* Register 0x0a */
51#define MAX9286_FWDCCEN(n)		(1 << ((n) + 4))
52#define MAX9286_REVCCEN(n)		(1 << (n))
53/* Register 0x0c */
54#define MAX9286_HVEN			BIT(7)
55#define MAX9286_EDC_6BIT_HAMMING	(2 << 5)
56#define MAX9286_EDC_6BIT_CRC		(1 << 5)
57#define MAX9286_EDC_1BIT_PARITY		(0 << 5)
58#define MAX9286_DESEL			BIT(4)
59#define MAX9286_INVVS			BIT(3)
60#define MAX9286_INVHS			BIT(2)
61#define MAX9286_HVSRC_D0		(2 << 0)
62#define MAX9286_HVSRC_D14		(1 << 0)
63#define MAX9286_HVSRC_D18		(0 << 0)
64/* Register 0x0f */
65#define MAX9286_0X0F_RESERVED		BIT(3)
66/* Register 0x12 */
67#define MAX9286_CSILANECNT(n)		(((n) - 1) << 6)
68#define MAX9286_CSIDBL			BIT(5)
69#define MAX9286_DBL			BIT(4)
70#define MAX9286_DATATYPE_USER_8BIT	(11 << 0)
71#define MAX9286_DATATYPE_USER_YUV_12BIT	(10 << 0)
72#define MAX9286_DATATYPE_USER_24BIT	(9 << 0)
73#define MAX9286_DATATYPE_RAW14		(8 << 0)
74#define MAX9286_DATATYPE_RAW11		(7 << 0)
75#define MAX9286_DATATYPE_RAW10		(6 << 0)
76#define MAX9286_DATATYPE_RAW8		(5 << 0)
77#define MAX9286_DATATYPE_YUV422_10BIT	(4 << 0)
78#define MAX9286_DATATYPE_YUV422_8BIT	(3 << 0)
79#define MAX9286_DATATYPE_RGB555		(2 << 0)
80#define MAX9286_DATATYPE_RGB565		(1 << 0)
81#define MAX9286_DATATYPE_RGB888		(0 << 0)
82/* Register 0x15 */
83#define MAX9286_VC(n)			((n) << 5)
84#define MAX9286_VCTYPE			BIT(4)
85#define MAX9286_CSIOUTEN		BIT(3)
86#define MAX9286_0X15_RESV		(3 << 0)
87/* Register 0x1b */
88#define MAX9286_SWITCHIN(n)		(1 << ((n) + 4))
89#define MAX9286_ENEQ(n)			(1 << (n))
90/* Register 0x27 */
91#define MAX9286_LOCKED			BIT(7)
92/* Register 0x31 */
93#define MAX9286_FSYNC_LOCKED		BIT(6)
94/* Register 0x34 */
95#define MAX9286_I2CLOCACK		BIT(7)
96#define MAX9286_I2CSLVSH_1046NS_469NS	(3 << 5)
97#define MAX9286_I2CSLVSH_938NS_352NS	(2 << 5)
98#define MAX9286_I2CSLVSH_469NS_234NS	(1 << 5)
99#define MAX9286_I2CSLVSH_352NS_117NS	(0 << 5)
100#define MAX9286_I2CMSTBT_837KBPS	(7 << 2)
101#define MAX9286_I2CMSTBT_533KBPS	(6 << 2)
102#define MAX9286_I2CMSTBT_339KBPS	(5 << 2)
103#define MAX9286_I2CMSTBT_173KBPS	(4 << 2)
104#define MAX9286_I2CMSTBT_105KBPS	(3 << 2)
105#define MAX9286_I2CMSTBT_84KBPS		(2 << 2)
106#define MAX9286_I2CMSTBT_28KBPS		(1 << 2)
107#define MAX9286_I2CMSTBT_8KBPS		(0 << 2)
108#define MAX9286_I2CSLVTO_NONE		(3 << 0)
109#define MAX9286_I2CSLVTO_1024US		(2 << 0)
110#define MAX9286_I2CSLVTO_256US		(1 << 0)
111#define MAX9286_I2CSLVTO_64US		(0 << 0)
112/* Register 0x3b */
113#define MAX9286_REV_TRF(n)		((n) << 4)
114#define MAX9286_REV_AMP(n)		((((n) - 30) / 10) << 1) /* in mV */
115#define MAX9286_REV_AMP_X		BIT(0)
116/* Register 0x3f */
117#define MAX9286_EN_REV_CFG		BIT(6)
118#define MAX9286_REV_FLEN(n)		((n) - 20)
119/* Register 0x49 */
120#define MAX9286_VIDEO_DETECT_MASK	0x0f
121/* Register 0x69 */
122#define MAX9286_LFLTBMONMASKED		BIT(7)
123#define MAX9286_LOCKMONMASKED		BIT(6)
124#define MAX9286_AUTOCOMBACKEN		BIT(5)
125#define MAX9286_AUTOMASKEN		BIT(4)
126#define MAX9286_MASKLINK(n)		((n) << 0)
127
128/*
129 * The sink and source pads are created to match the OF graph port numbers so
130 * that their indexes can be used interchangeably.
131 */
132#define MAX9286_NUM_GMSL		4
133#define MAX9286_N_SINKS			4
134#define MAX9286_N_PADS			5
135#define MAX9286_SRC_PAD			4
136
137struct max9286_source {
138	struct v4l2_subdev *sd;
139	struct fwnode_handle *fwnode;
140};
141
142struct max9286_asd {
143	struct v4l2_async_subdev base;
144	struct max9286_source *source;
145};
146
147static inline struct max9286_asd *to_max9286_asd(struct v4l2_async_subdev *asd)
148{
149	return container_of(asd, struct max9286_asd, base);
150}
151
152struct max9286_priv {
153	struct i2c_client *client;
154	struct gpio_desc *gpiod_pwdn;
155	struct v4l2_subdev sd;
156	struct media_pad pads[MAX9286_N_PADS];
157	struct regulator *regulator;
158
159	struct gpio_chip gpio;
160	u8 gpio_state;
161
162	struct i2c_mux_core *mux;
163	unsigned int mux_channel;
164	bool mux_open;
165
166	struct v4l2_ctrl_handler ctrls;
167	struct v4l2_ctrl *pixelrate;
168
169	struct v4l2_mbus_framefmt fmt[MAX9286_N_SINKS];
170
171	/* Protects controls and fmt structures */
172	struct mutex mutex;
173
174	unsigned int nsources;
175	unsigned int source_mask;
176	unsigned int route_mask;
177	unsigned int bound_sources;
178	unsigned int csi2_data_lanes;
179	struct max9286_source sources[MAX9286_NUM_GMSL];
180	struct v4l2_async_notifier notifier;
181};
182
183static struct max9286_source *next_source(struct max9286_priv *priv,
184					  struct max9286_source *source)
185{
186	if (!source)
187		source = &priv->sources[0];
188	else
189		source++;
190
191	for (; source < &priv->sources[MAX9286_NUM_GMSL]; source++) {
192		if (source->fwnode)
193			return source;
194	}
195
196	return NULL;
197}
198
199#define for_each_source(priv, source) \
200	for ((source) = NULL; ((source) = next_source((priv), (source))); )
201
202#define to_index(priv, source) ((source) - &(priv)->sources[0])
203
204static inline struct max9286_priv *sd_to_max9286(struct v4l2_subdev *sd)
205{
206	return container_of(sd, struct max9286_priv, sd);
207}
208
209/* -----------------------------------------------------------------------------
210 * I2C IO
211 */
212
213static int max9286_read(struct max9286_priv *priv, u8 reg)
214{
215	int ret;
216
217	ret = i2c_smbus_read_byte_data(priv->client, reg);
218	if (ret < 0)
219		dev_err(&priv->client->dev,
220			"%s: register 0x%02x read failed (%d)\n",
221			__func__, reg, ret);
222
223	return ret;
224}
225
226static int max9286_write(struct max9286_priv *priv, u8 reg, u8 val)
227{
228	int ret;
229
230	ret = i2c_smbus_write_byte_data(priv->client, reg, val);
231	if (ret < 0)
232		dev_err(&priv->client->dev,
233			"%s: register 0x%02x write failed (%d)\n",
234			__func__, reg, ret);
235
236	return ret;
237}
238
239/* -----------------------------------------------------------------------------
240 * I2C Multiplexer
241 */
242
243static void max9286_i2c_mux_configure(struct max9286_priv *priv, u8 conf)
244{
245	max9286_write(priv, 0x0a, conf);
246
247	/*
248	 * We must sleep after any change to the forward or reverse channel
249	 * configuration.
250	 */
251	usleep_range(3000, 5000);
252}
253
254static void max9286_i2c_mux_open(struct max9286_priv *priv)
255{
256	/* Open all channels on the MAX9286 */
257	max9286_i2c_mux_configure(priv, 0xff);
258
259	priv->mux_open = true;
260}
261
262static void max9286_i2c_mux_close(struct max9286_priv *priv)
263{
264	/*
265	 * Ensure that both the forward and reverse channel are disabled on the
266	 * mux, and that the channel ID is invalidated to ensure we reconfigure
267	 * on the next max9286_i2c_mux_select() call.
268	 */
269	max9286_i2c_mux_configure(priv, 0x00);
270
271	priv->mux_open = false;
272	priv->mux_channel = -1;
273}
274
275static int max9286_i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
276{
277	struct max9286_priv *priv = i2c_mux_priv(muxc);
278
279	/* Channel select is disabled when configured in the opened state. */
280	if (priv->mux_open)
281		return 0;
282
283	if (priv->mux_channel == chan)
284		return 0;
285
286	priv->mux_channel = chan;
287
288	max9286_i2c_mux_configure(priv,
289				  MAX9286_FWDCCEN(chan) |
290				  MAX9286_REVCCEN(chan));
291
292	return 0;
293}
294
295static int max9286_i2c_mux_init(struct max9286_priv *priv)
296{
297	struct max9286_source *source;
298	int ret;
299
300	if (!i2c_check_functionality(priv->client->adapter,
301				     I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
302		return -ENODEV;
303
304	priv->mux = i2c_mux_alloc(priv->client->adapter, &priv->client->dev,
305				  priv->nsources, 0, I2C_MUX_LOCKED,
306				  max9286_i2c_mux_select, NULL);
307	if (!priv->mux)
308		return -ENOMEM;
309
310	priv->mux->priv = priv;
311
312	for_each_source(priv, source) {
313		unsigned int index = to_index(priv, source);
314
315		ret = i2c_mux_add_adapter(priv->mux, 0, index, 0);
316		if (ret < 0)
317			goto error;
318	}
319
320	return 0;
321
322error:
323	i2c_mux_del_adapters(priv->mux);
324	return ret;
325}
326
327static void max9286_configure_i2c(struct max9286_priv *priv, bool localack)
328{
329	u8 config = MAX9286_I2CSLVSH_469NS_234NS | MAX9286_I2CSLVTO_1024US |
330		    MAX9286_I2CMSTBT_105KBPS;
331
332	if (localack)
333		config |= MAX9286_I2CLOCACK;
334
335	max9286_write(priv, 0x34, config);
336	usleep_range(3000, 5000);
337}
338
339/*
340 * max9286_check_video_links() - Make sure video links are detected and locked
341 *
342 * Performs safety checks on video link status. Make sure they are detected
343 * and all enabled links are locked.
344 *
345 * Returns 0 for success, -EIO for errors.
346 */
347static int max9286_check_video_links(struct max9286_priv *priv)
348{
349	unsigned int i;
350	int ret;
351
352	/*
353	 * Make sure valid video links are detected.
354	 * The delay is not characterized in de-serializer manual, wait up
355	 * to 5 ms.
356	 */
357	for (i = 0; i < 10; i++) {
358		ret = max9286_read(priv, 0x49);
359		if (ret < 0)
360			return -EIO;
361
362		if ((ret & MAX9286_VIDEO_DETECT_MASK) == priv->source_mask)
363			break;
364
365		usleep_range(350, 500);
366	}
367
368	if (i == 10) {
369		dev_err(&priv->client->dev,
370			"Unable to detect video links: 0x%02x\n", ret);
371		return -EIO;
372	}
373
374	/* Make sure all enabled links are locked (4ms max). */
375	for (i = 0; i < 10; i++) {
376		ret = max9286_read(priv, 0x27);
377		if (ret < 0)
378			return -EIO;
379
380		if (ret & MAX9286_LOCKED)
381			break;
382
383		usleep_range(350, 450);
384	}
385
386	if (i == 10) {
387		dev_err(&priv->client->dev, "Not all enabled links locked\n");
388		return -EIO;
389	}
390
391	return 0;
392}
393
394/*
395 * max9286_check_config_link() - Detect and wait for configuration links
396 *
397 * Determine if the configuration channel is up and settled for a link.
398 *
399 * Returns 0 for success, -EIO for errors.
400 */
401static int max9286_check_config_link(struct max9286_priv *priv,
402				     unsigned int source_mask)
403{
404	unsigned int conflink_mask = (source_mask & 0x0f) << 4;
405	unsigned int i;
406	int ret;
407
408	/*
409	 * Make sure requested configuration links are detected.
410	 * The delay is not characterized in the chip manual: wait up
411	 * to 5 milliseconds.
412	 */
413	for (i = 0; i < 10; i++) {
414		ret = max9286_read(priv, 0x49);
415		if (ret < 0)
416			return -EIO;
417
418		ret &= 0xf0;
419		if (ret == conflink_mask)
420			break;
421
422		usleep_range(350, 500);
423	}
424
425	if (ret != conflink_mask) {
426		dev_err(&priv->client->dev,
427			"Unable to detect configuration links: 0x%02x expected 0x%02x\n",
428			ret, conflink_mask);
429		return -EIO;
430	}
431
432	dev_info(&priv->client->dev,
433		 "Successfully detected configuration links after %u loops: 0x%02x\n",
434		 i, conflink_mask);
435
436	return 0;
437}
438
439/* -----------------------------------------------------------------------------
440 * V4L2 Subdev
441 */
442
443static int max9286_set_pixelrate(struct max9286_priv *priv)
444{
445	struct max9286_source *source = NULL;
446	u64 pixelrate = 0;
447
448	for_each_source(priv, source) {
449		struct v4l2_ctrl *ctrl;
450		u64 source_rate = 0;
451
452		/* Pixel rate is mandatory to be reported by sources. */
453		ctrl = v4l2_ctrl_find(source->sd->ctrl_handler,
454				      V4L2_CID_PIXEL_RATE);
455		if (!ctrl) {
456			pixelrate = 0;
457			break;
458		}
459
460		/* All source must report the same pixel rate. */
461		source_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
462		if (!pixelrate) {
463			pixelrate = source_rate;
464		} else if (pixelrate != source_rate) {
465			dev_err(&priv->client->dev,
466				"Unable to calculate pixel rate\n");
467			return -EINVAL;
468		}
469	}
470
471	if (!pixelrate) {
472		dev_err(&priv->client->dev,
473			"No pixel rate control available in sources\n");
474		return -EINVAL;
475	}
476
477	/*
478	 * The CSI-2 transmitter pixel rate is the single source rate multiplied
479	 * by the number of available sources.
480	 */
481	return v4l2_ctrl_s_ctrl_int64(priv->pixelrate,
482				      pixelrate * priv->nsources);
483}
484
485static int max9286_notify_bound(struct v4l2_async_notifier *notifier,
486				struct v4l2_subdev *subdev,
487				struct v4l2_async_subdev *asd)
488{
489	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
490	struct max9286_source *source = to_max9286_asd(asd)->source;
491	unsigned int index = to_index(priv, source);
492	unsigned int src_pad;
493	int ret;
494
495	ret = media_entity_get_fwnode_pad(&subdev->entity,
496					  source->fwnode,
497					  MEDIA_PAD_FL_SOURCE);
498	if (ret < 0) {
499		dev_err(&priv->client->dev,
500			"Failed to find pad for %s\n", subdev->name);
501		return ret;
502	}
503
504	priv->bound_sources |= BIT(index);
505	source->sd = subdev;
506	src_pad = ret;
507
508	ret = media_create_pad_link(&source->sd->entity, src_pad,
509				    &priv->sd.entity, index,
510				    MEDIA_LNK_FL_ENABLED |
511				    MEDIA_LNK_FL_IMMUTABLE);
512	if (ret) {
513		dev_err(&priv->client->dev,
514			"Unable to link %s:%u -> %s:%u\n",
515			source->sd->name, src_pad, priv->sd.name, index);
516		return ret;
517	}
518
519	dev_dbg(&priv->client->dev, "Bound %s pad: %u on index %u\n",
520		subdev->name, src_pad, index);
521
522	/*
523	 * We can only register v4l2_async_notifiers, which do not provide a
524	 * means to register a complete callback. bound_sources allows us to
525	 * identify when all remote serializers have completed their probe.
526	 */
527	if (priv->bound_sources != priv->source_mask)
528		return 0;
529
530	/*
531	 * All enabled sources have probed and enabled their reverse control
532	 * channels:
533	 *
534	 * - Verify all configuration links are properly detected
535	 * - Disable auto-ack as communication on the control channel are now
536	 *   stable.
537	 */
538	max9286_check_config_link(priv, priv->source_mask);
539
540	/*
541	 * Re-configure I2C with local acknowledge disabled after cameras have
542	 * probed.
543	 */
544	max9286_configure_i2c(priv, false);
545
546	return max9286_set_pixelrate(priv);
547}
548
549static void max9286_notify_unbind(struct v4l2_async_notifier *notifier,
550				  struct v4l2_subdev *subdev,
551				  struct v4l2_async_subdev *asd)
552{
553	struct max9286_priv *priv = sd_to_max9286(notifier->sd);
554	struct max9286_source *source = to_max9286_asd(asd)->source;
555	unsigned int index = to_index(priv, source);
556
557	source->sd = NULL;
558	priv->bound_sources &= ~BIT(index);
559}
560
561static const struct v4l2_async_notifier_operations max9286_notify_ops = {
562	.bound = max9286_notify_bound,
563	.unbind = max9286_notify_unbind,
564};
565
566static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
567{
568	struct device *dev = &priv->client->dev;
569	struct max9286_source *source = NULL;
570	int ret;
571
572	if (!priv->nsources)
573		return 0;
574
575	v4l2_async_notifier_init(&priv->notifier);
576
577	for_each_source(priv, source) {
578		unsigned int i = to_index(priv, source);
579		struct v4l2_async_subdev *asd;
580
581		asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier,
582							    source->fwnode,
583							    sizeof(struct max9286_asd));
584		if (IS_ERR(asd)) {
585			dev_err(dev, "Failed to add subdev for source %u: %ld",
586				i, PTR_ERR(asd));
587			v4l2_async_notifier_cleanup(&priv->notifier);
588			return PTR_ERR(asd);
589		}
590
591		to_max9286_asd(asd)->source = source;
592	}
593
594	priv->notifier.ops = &max9286_notify_ops;
595
596	ret = v4l2_async_subdev_notifier_register(&priv->sd, &priv->notifier);
597	if (ret) {
598		dev_err(dev, "Failed to register subdev_notifier");
599		v4l2_async_notifier_cleanup(&priv->notifier);
600		return ret;
601	}
602
603	return 0;
604}
605
606static void max9286_v4l2_notifier_unregister(struct max9286_priv *priv)
607{
608	if (!priv->nsources)
609		return;
610
611	v4l2_async_notifier_unregister(&priv->notifier);
612	v4l2_async_notifier_cleanup(&priv->notifier);
613}
614
615static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
616{
617	struct max9286_priv *priv = sd_to_max9286(sd);
618	struct max9286_source *source;
619	unsigned int i;
620	bool sync = false;
621	int ret;
622
623	if (enable) {
624		/*
625		 * The frame sync between cameras is transmitted across the
626		 * reverse channel as GPIO. We must open all channels while
627		 * streaming to allow this synchronisation signal to be shared.
628		 */
629		max9286_i2c_mux_open(priv);
630
631		/* Start all cameras. */
632		for_each_source(priv, source) {
633			ret = v4l2_subdev_call(source->sd, video, s_stream, 1);
634			if (ret)
635				return ret;
636		}
637
638		ret = max9286_check_video_links(priv);
639		if (ret)
640			return ret;
641
642		/*
643		 * Wait until frame synchronization is locked.
644		 *
645		 * Manual says frame sync locking should take ~6 VTS.
646		 * From practical experience at least 8 are required. Give
647		 * 12 complete frames time (~400ms at 30 fps) to achieve frame
648		 * locking before returning error.
649		 */
650		for (i = 0; i < 40; i++) {
651			if (max9286_read(priv, 0x31) & MAX9286_FSYNC_LOCKED) {
652				sync = true;
653				break;
654			}
655			usleep_range(9000, 11000);
656		}
657
658		if (!sync) {
659			dev_err(&priv->client->dev,
660				"Failed to get frame synchronization\n");
661			return -EXDEV; /* Invalid cross-device link */
662		}
663
664		/*
665		 * Enable CSI output, VC set according to link number.
666		 * Bit 7 must be set (chip manual says it's 0 and reserved).
667		 */
668		max9286_write(priv, 0x15, 0x80 | MAX9286_VCTYPE |
669			      MAX9286_CSIOUTEN | MAX9286_0X15_RESV);
670	} else {
671		max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
672
673		/* Stop all cameras. */
674		for_each_source(priv, source)
675			v4l2_subdev_call(source->sd, video, s_stream, 0);
676
677		max9286_i2c_mux_close(priv);
678	}
679
680	return 0;
681}
682
683static int max9286_enum_mbus_code(struct v4l2_subdev *sd,
684				  struct v4l2_subdev_pad_config *cfg,
685				  struct v4l2_subdev_mbus_code_enum *code)
686{
687	if (code->pad || code->index > 0)
688		return -EINVAL;
689
690	code->code = MEDIA_BUS_FMT_UYVY8_1X16;
691
692	return 0;
693}
694
695static struct v4l2_mbus_framefmt *
696max9286_get_pad_format(struct max9286_priv *priv,
697		       struct v4l2_subdev_pad_config *cfg,
698		       unsigned int pad, u32 which)
699{
700	switch (which) {
701	case V4L2_SUBDEV_FORMAT_TRY:
702		return v4l2_subdev_get_try_format(&priv->sd, cfg, pad);
703	case V4L2_SUBDEV_FORMAT_ACTIVE:
704		return &priv->fmt[pad];
705	default:
706		return NULL;
707	}
708}
709
710static int max9286_set_fmt(struct v4l2_subdev *sd,
711			   struct v4l2_subdev_pad_config *cfg,
712			   struct v4l2_subdev_format *format)
713{
714	struct max9286_priv *priv = sd_to_max9286(sd);
715	struct v4l2_mbus_framefmt *cfg_fmt;
716
717	if (format->pad == MAX9286_SRC_PAD)
718		return -EINVAL;
719
720	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
721	switch (format->format.code) {
722	case MEDIA_BUS_FMT_UYVY8_1X16:
723	case MEDIA_BUS_FMT_VYUY8_1X16:
724	case MEDIA_BUS_FMT_YUYV8_1X16:
725	case MEDIA_BUS_FMT_YVYU8_1X16:
726		break;
727	default:
728		format->format.code = MEDIA_BUS_FMT_UYVY8_1X16;
729		break;
730	}
731
732	cfg_fmt = max9286_get_pad_format(priv, cfg, format->pad, format->which);
733	if (!cfg_fmt)
734		return -EINVAL;
735
736	mutex_lock(&priv->mutex);
737	*cfg_fmt = format->format;
738	mutex_unlock(&priv->mutex);
739
740	return 0;
741}
742
743static int max9286_get_fmt(struct v4l2_subdev *sd,
744			   struct v4l2_subdev_pad_config *cfg,
745			   struct v4l2_subdev_format *format)
746{
747	struct max9286_priv *priv = sd_to_max9286(sd);
748	struct v4l2_mbus_framefmt *cfg_fmt;
749	unsigned int pad = format->pad;
750
751	/*
752	 * Multiplexed Stream Support: Support link validation by returning the
753	 * format of the first bound link. All links must have the same format,
754	 * as we do not support mixing and matching of cameras connected to the
755	 * max9286.
756	 */
757	if (pad == MAX9286_SRC_PAD)
758		pad = __ffs(priv->bound_sources);
759
760	cfg_fmt = max9286_get_pad_format(priv, cfg, pad, format->which);
761	if (!cfg_fmt)
762		return -EINVAL;
763
764	mutex_lock(&priv->mutex);
765	format->format = *cfg_fmt;
766	mutex_unlock(&priv->mutex);
767
768	return 0;
769}
770
771static const struct v4l2_subdev_video_ops max9286_video_ops = {
772	.s_stream	= max9286_s_stream,
773};
774
775static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
776	.enum_mbus_code = max9286_enum_mbus_code,
777	.get_fmt	= max9286_get_fmt,
778	.set_fmt	= max9286_set_fmt,
779};
780
781static const struct v4l2_subdev_ops max9286_subdev_ops = {
782	.video		= &max9286_video_ops,
783	.pad		= &max9286_pad_ops,
784};
785
786static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
787{
788	fmt->width		= 1280;
789	fmt->height		= 800;
790	fmt->code		= MEDIA_BUS_FMT_UYVY8_1X16;
791	fmt->colorspace		= V4L2_COLORSPACE_SRGB;
792	fmt->field		= V4L2_FIELD_NONE;
793	fmt->ycbcr_enc		= V4L2_YCBCR_ENC_DEFAULT;
794	fmt->quantization	= V4L2_QUANTIZATION_DEFAULT;
795	fmt->xfer_func		= V4L2_XFER_FUNC_DEFAULT;
796}
797
798static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
799{
800	struct v4l2_mbus_framefmt *format;
801	unsigned int i;
802
803	for (i = 0; i < MAX9286_N_SINKS; i++) {
804		format = v4l2_subdev_get_try_format(subdev, fh->pad, i);
805		max9286_init_format(format);
806	}
807
808	return 0;
809}
810
811static const struct v4l2_subdev_internal_ops max9286_subdev_internal_ops = {
812	.open = max9286_open,
813};
814
815static int max9286_s_ctrl(struct v4l2_ctrl *ctrl)
816{
817	switch (ctrl->id) {
818	case V4L2_CID_PIXEL_RATE:
819		return 0;
820	default:
821		return -EINVAL;
822	}
823}
824
825static const struct v4l2_ctrl_ops max9286_ctrl_ops = {
826	.s_ctrl = max9286_s_ctrl,
827};
828
829static int max9286_v4l2_register(struct max9286_priv *priv)
830{
831	struct device *dev = &priv->client->dev;
832	struct fwnode_handle *ep;
833	int ret;
834	int i;
835
836	/* Register v4l2 async notifiers for connected Camera subdevices */
837	ret = max9286_v4l2_notifier_register(priv);
838	if (ret) {
839		dev_err(dev, "Unable to register V4L2 async notifiers\n");
840		return ret;
841	}
842
843	/* Configure V4L2 for the MAX9286 itself */
844
845	for (i = 0; i < MAX9286_N_SINKS; i++)
846		max9286_init_format(&priv->fmt[i]);
847
848	v4l2_i2c_subdev_init(&priv->sd, priv->client, &max9286_subdev_ops);
849	priv->sd.internal_ops = &max9286_subdev_internal_ops;
850	priv->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
851
852	v4l2_ctrl_handler_init(&priv->ctrls, 1);
853	priv->pixelrate = v4l2_ctrl_new_std(&priv->ctrls,
854					    &max9286_ctrl_ops,
855					    V4L2_CID_PIXEL_RATE,
856					    1, INT_MAX, 1, 50000000);
857
858	priv->sd.ctrl_handler = &priv->ctrls;
859	ret = priv->ctrls.error;
860	if (ret)
861		goto err_async;
862
863	priv->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
864
865	priv->pads[MAX9286_SRC_PAD].flags = MEDIA_PAD_FL_SOURCE;
866	for (i = 0; i < MAX9286_SRC_PAD; i++)
867		priv->pads[i].flags = MEDIA_PAD_FL_SINK;
868	ret = media_entity_pads_init(&priv->sd.entity, MAX9286_N_PADS,
869				     priv->pads);
870	if (ret)
871		goto err_async;
872
873	ep = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), MAX9286_SRC_PAD,
874					     0, 0);
875	if (!ep) {
876		dev_err(dev, "Unable to retrieve endpoint on \"port@4\"\n");
877		ret = -ENOENT;
878		goto err_async;
879	}
880	priv->sd.fwnode = ep;
881
882	ret = v4l2_async_register_subdev(&priv->sd);
883	if (ret < 0) {
884		dev_err(dev, "Unable to register subdevice\n");
885		goto err_put_node;
886	}
887
888	return 0;
889
890err_put_node:
891	fwnode_handle_put(ep);
892err_async:
893	v4l2_ctrl_handler_free(&priv->ctrls);
894	max9286_v4l2_notifier_unregister(priv);
895
896	return ret;
897}
898
899static void max9286_v4l2_unregister(struct max9286_priv *priv)
900{
901	fwnode_handle_put(priv->sd.fwnode);
902	v4l2_ctrl_handler_free(&priv->ctrls);
903	v4l2_async_unregister_subdev(&priv->sd);
904	max9286_v4l2_notifier_unregister(priv);
905}
906
907/* -----------------------------------------------------------------------------
908 * Probe/Remove
909 */
910
911static int max9286_setup(struct max9286_priv *priv)
912{
913	/*
914	 * Link ordering values for all enabled links combinations. Orders must
915	 * be assigned sequentially from 0 to the number of enabled links
916	 * without leaving any hole for disabled links. We thus assign orders to
917	 * enabled links first, and use the remaining order values for disabled
918	 * links are all links must have a different order value;
919	 */
920	static const u8 link_order[] = {
921		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxxx */
922		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xxx0 */
923		(3 << 6) | (2 << 4) | (0 << 2) | (1 << 0), /* xx0x */
924		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* xx10 */
925		(3 << 6) | (0 << 4) | (2 << 2) | (1 << 0), /* x0xx */
926		(3 << 6) | (1 << 4) | (2 << 2) | (0 << 0), /* x1x0 */
927		(3 << 6) | (1 << 4) | (0 << 2) | (2 << 0), /* x10x */
928		(3 << 6) | (1 << 4) | (1 << 2) | (0 << 0), /* x210 */
929		(0 << 6) | (3 << 4) | (2 << 2) | (1 << 0), /* 0xxx */
930		(1 << 6) | (3 << 4) | (2 << 2) | (0 << 0), /* 1xx0 */
931		(1 << 6) | (3 << 4) | (0 << 2) | (2 << 0), /* 1x0x */
932		(2 << 6) | (3 << 4) | (1 << 2) | (0 << 0), /* 2x10 */
933		(1 << 6) | (0 << 4) | (3 << 2) | (2 << 0), /* 10xx */
934		(2 << 6) | (1 << 4) | (3 << 2) | (0 << 0), /* 21x0 */
935		(2 << 6) | (1 << 4) | (0 << 2) | (3 << 0), /* 210x */
936		(3 << 6) | (2 << 4) | (1 << 2) | (0 << 0), /* 3210 */
937	};
938
939	/*
940	 * Set the I2C bus speed.
941	 *
942	 * Enable I2C Local Acknowledge during the probe sequences of the camera
943	 * only. This should be disabled after the mux is initialised.
944	 */
945	max9286_configure_i2c(priv, true);
946
947	/*
948	 * Reverse channel setup.
949	 *
950	 * - Enable custom reverse channel configuration (through register 0x3f)
951	 *   and set the first pulse length to 35 clock cycles.
952	 * - Increase the reverse channel amplitude to 170mV to accommodate the
953	 *   high threshold enabled by the serializer driver.
954	 */
955	max9286_write(priv, 0x3f, MAX9286_EN_REV_CFG | MAX9286_REV_FLEN(35));
956	max9286_write(priv, 0x3b, MAX9286_REV_TRF(1) | MAX9286_REV_AMP(70) |
957		      MAX9286_REV_AMP_X);
958	usleep_range(2000, 2500);
959
960	/*
961	 * Enable GMSL links, mask unused ones and autodetect link
962	 * used as CSI clock source.
963	 */
964	max9286_write(priv, 0x00, MAX9286_MSTLINKSEL_AUTO | priv->route_mask);
965	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
966	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
967
968	/*
969	 * Video format setup:
970	 * Disable CSI output, VC is set according to Link number.
971	 */
972	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
973
974	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
975	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
976		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
977		      MAX9286_DATATYPE_YUV422_8BIT);
978
979	/* Automatic: FRAMESYNC taken from the slowest Link. */
980	max9286_write(priv, 0x01, MAX9286_FSYNCMODE_INT_HIZ |
981		      MAX9286_FSYNCMETH_AUTO);
982
983	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
984	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
985		      MAX9286_HVSRC_D14);
986
987	/*
988	 * The overlap window seems to provide additional validation by tracking
989	 * the delay between vsync and frame sync, generating an error if the
990	 * delay is bigger than the programmed window, though it's not yet clear
991	 * what value should be set.
992	 *
993	 * As it's an optional value and can be disabled, we do so by setting
994	 * a 0 overlap value.
995	 */
996	max9286_write(priv, 0x63, 0);
997	max9286_write(priv, 0x64, 0);
998
999	/*
1000	 * Wait for 2ms to allow the link to resynchronize after the
1001	 * configuration change.
1002	 */
1003	usleep_range(2000, 5000);
1004
1005	return 0;
1006}
1007
1008static void max9286_gpio_set(struct gpio_chip *chip,
1009			     unsigned int offset, int value)
1010{
1011	struct max9286_priv *priv = gpiochip_get_data(chip);
1012
1013	if (value)
1014		priv->gpio_state |= BIT(offset);
1015	else
1016		priv->gpio_state &= ~BIT(offset);
1017
1018	max9286_write(priv, 0x0f, MAX9286_0X0F_RESERVED | priv->gpio_state);
1019}
1020
1021static int max9286_gpio_get(struct gpio_chip *chip, unsigned int offset)
1022{
1023	struct max9286_priv *priv = gpiochip_get_data(chip);
1024
1025	return priv->gpio_state & BIT(offset);
1026}
1027
1028static int max9286_register_gpio(struct max9286_priv *priv)
1029{
1030	struct device *dev = &priv->client->dev;
1031	struct gpio_chip *gpio = &priv->gpio;
1032	int ret;
1033
1034	/* Configure the GPIO */
1035	gpio->label = dev_name(dev);
1036	gpio->parent = dev;
1037	gpio->owner = THIS_MODULE;
1038	gpio->of_node = dev->of_node;
1039	gpio->ngpio = 2;
1040	gpio->base = -1;
1041	gpio->set = max9286_gpio_set;
1042	gpio->get = max9286_gpio_get;
1043	gpio->can_sleep = true;
1044
1045	/* GPIO values default to high */
1046	priv->gpio_state = BIT(0) | BIT(1);
1047
1048	ret = devm_gpiochip_add_data(dev, gpio, priv);
1049	if (ret)
1050		dev_err(dev, "Unable to create gpio_chip\n");
1051
1052	return ret;
1053}
1054
1055static int max9286_init(struct device *dev)
1056{
1057	struct max9286_priv *priv;
1058	struct i2c_client *client;
1059	int ret;
1060
1061	client = to_i2c_client(dev);
1062	priv = i2c_get_clientdata(client);
1063
1064	/* Enable the bus power. */
1065	ret = regulator_enable(priv->regulator);
1066	if (ret < 0) {
1067		dev_err(&client->dev, "Unable to turn PoC on\n");
1068		return ret;
1069	}
1070
1071	ret = max9286_setup(priv);
1072	if (ret) {
1073		dev_err(dev, "Unable to setup max9286\n");
1074		goto err_regulator;
1075	}
1076
1077	/*
1078	 * Register all V4L2 interactions for the MAX9286 and notifiers for
1079	 * any subdevices connected.
1080	 */
1081	ret = max9286_v4l2_register(priv);
1082	if (ret) {
1083		dev_err(dev, "Failed to register with V4L2\n");
1084		goto err_regulator;
1085	}
1086
1087	ret = max9286_i2c_mux_init(priv);
1088	if (ret) {
1089		dev_err(dev, "Unable to initialize I2C multiplexer\n");
1090		goto err_v4l2_register;
1091	}
1092
1093	/* Leave the mux channels disabled until they are selected. */
1094	max9286_i2c_mux_close(priv);
1095
1096	return 0;
1097
1098err_v4l2_register:
1099	max9286_v4l2_unregister(priv);
1100err_regulator:
1101	regulator_disable(priv->regulator);
1102
1103	return ret;
1104}
1105
1106static void max9286_cleanup_dt(struct max9286_priv *priv)
1107{
1108	struct max9286_source *source;
1109
1110	for_each_source(priv, source) {
1111		fwnode_handle_put(source->fwnode);
1112		source->fwnode = NULL;
1113	}
1114}
1115
1116static int max9286_parse_dt(struct max9286_priv *priv)
1117{
1118	struct device *dev = &priv->client->dev;
1119	struct device_node *i2c_mux;
1120	struct device_node *node = NULL;
1121	unsigned int i2c_mux_mask = 0;
1122
1123	/* Balance the of_node_put() performed by of_find_node_by_name(). */
1124	of_node_get(dev->of_node);
1125	i2c_mux = of_find_node_by_name(dev->of_node, "i2c-mux");
1126	if (!i2c_mux) {
1127		dev_err(dev, "Failed to find i2c-mux node\n");
1128		return -EINVAL;
1129	}
1130
1131	/* Identify which i2c-mux channels are enabled */
1132	for_each_child_of_node(i2c_mux, node) {
1133		u32 id = 0;
1134
1135		of_property_read_u32(node, "reg", &id);
1136		if (id >= MAX9286_NUM_GMSL)
1137			continue;
1138
1139		if (!of_device_is_available(node)) {
1140			dev_dbg(dev, "Skipping disabled I2C bus port %u\n", id);
1141			continue;
1142		}
1143
1144		i2c_mux_mask |= BIT(id);
1145	}
1146	of_node_put(i2c_mux);
1147
1148	/* Parse the endpoints */
1149	for_each_endpoint_of_node(dev->of_node, node) {
1150		struct max9286_source *source;
1151		struct of_endpoint ep;
1152
1153		of_graph_parse_endpoint(node, &ep);
1154		dev_dbg(dev, "Endpoint %pOF on port %d",
1155			ep.local_node, ep.port);
1156
1157		if (ep.port > MAX9286_NUM_GMSL) {
1158			dev_err(dev, "Invalid endpoint %s on port %d",
1159				of_node_full_name(ep.local_node), ep.port);
1160			continue;
1161		}
1162
1163		/* For the source endpoint just parse the bus configuration. */
1164		if (ep.port == MAX9286_SRC_PAD) {
1165			struct v4l2_fwnode_endpoint vep = {
1166				.bus_type = V4L2_MBUS_CSI2_DPHY
1167			};
1168			int ret;
1169
1170			ret = v4l2_fwnode_endpoint_parse(
1171					of_fwnode_handle(node), &vep);
1172			if (ret) {
1173				of_node_put(node);
1174				return ret;
1175			}
1176
1177			priv->csi2_data_lanes =
1178				vep.bus.mipi_csi2.num_data_lanes;
1179
1180			continue;
1181		}
1182
1183		/* Skip if the corresponding GMSL link is unavailable. */
1184		if (!(i2c_mux_mask & BIT(ep.port)))
1185			continue;
1186
1187		if (priv->sources[ep.port].fwnode) {
1188			dev_err(dev,
1189				"Multiple port endpoints are not supported: %d",
1190				ep.port);
1191
1192			continue;
1193		}
1194
1195		source = &priv->sources[ep.port];
1196		source->fwnode = fwnode_graph_get_remote_endpoint(
1197						of_fwnode_handle(node));
1198		if (!source->fwnode) {
1199			dev_err(dev,
1200				"Endpoint %pOF has no remote endpoint connection\n",
1201				ep.local_node);
1202
1203			continue;
1204		}
1205
1206		priv->source_mask |= BIT(ep.port);
1207		priv->nsources++;
1208	}
1209
1210	priv->route_mask = priv->source_mask;
1211
1212	return 0;
1213}
1214
1215static int max9286_probe(struct i2c_client *client)
1216{
1217	struct max9286_priv *priv;
1218	int ret;
1219
1220	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
1221	if (!priv)
1222		return -ENOMEM;
1223
1224	mutex_init(&priv->mutex);
1225
1226	priv->client = client;
1227	i2c_set_clientdata(client, priv);
1228
1229	priv->gpiod_pwdn = devm_gpiod_get_optional(&client->dev, "enable",
1230						   GPIOD_OUT_HIGH);
1231	if (IS_ERR(priv->gpiod_pwdn))
1232		return PTR_ERR(priv->gpiod_pwdn);
1233
1234	gpiod_set_consumer_name(priv->gpiod_pwdn, "max9286-pwdn");
1235	gpiod_set_value_cansleep(priv->gpiod_pwdn, 1);
1236
1237	/* Wait at least 4ms before the I2C lines latch to the address */
1238	if (priv->gpiod_pwdn)
1239		usleep_range(4000, 5000);
1240
1241	/*
1242	 * The MAX9286 starts by default with all ports enabled, we disable all
1243	 * ports early to ensure that all channels are disabled if we error out
1244	 * and keep the bus consistent.
1245	 */
1246	max9286_i2c_mux_close(priv);
1247
1248	/*
1249	 * The MAX9286 initialises with auto-acknowledge enabled by default.
1250	 * This can be invasive to other transactions on the same bus, so
1251	 * disable it early. It will be enabled only as and when needed.
1252	 */
1253	max9286_configure_i2c(priv, false);
1254
1255	ret = max9286_register_gpio(priv);
1256	if (ret)
1257		goto err_powerdown;
1258
1259	priv->regulator = devm_regulator_get(&client->dev, "poc");
1260	if (IS_ERR(priv->regulator)) {
1261		if (PTR_ERR(priv->regulator) != -EPROBE_DEFER)
1262			dev_err(&client->dev,
1263				"Unable to get PoC regulator (%ld)\n",
1264				PTR_ERR(priv->regulator));
1265		ret = PTR_ERR(priv->regulator);
1266		goto err_powerdown;
1267	}
1268
1269	ret = max9286_parse_dt(priv);
1270	if (ret)
1271		goto err_powerdown;
1272
1273	ret = max9286_init(&client->dev);
1274	if (ret < 0)
1275		goto err_cleanup_dt;
1276
1277	return 0;
1278
1279err_cleanup_dt:
1280	max9286_cleanup_dt(priv);
1281err_powerdown:
1282	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
1283
1284	return ret;
1285}
1286
1287static int max9286_remove(struct i2c_client *client)
1288{
1289	struct max9286_priv *priv = i2c_get_clientdata(client);
1290
1291	i2c_mux_del_adapters(priv->mux);
1292
1293	max9286_v4l2_unregister(priv);
1294
1295	regulator_disable(priv->regulator);
1296
1297	gpiod_set_value_cansleep(priv->gpiod_pwdn, 0);
1298
1299	max9286_cleanup_dt(priv);
1300
1301	return 0;
1302}
1303
1304static const struct of_device_id max9286_dt_ids[] = {
1305	{ .compatible = "maxim,max9286" },
1306	{},
1307};
1308MODULE_DEVICE_TABLE(of, max9286_dt_ids);
1309
1310static struct i2c_driver max9286_i2c_driver = {
1311	.driver	= {
1312		.name		= "max9286",
1313		.of_match_table	= of_match_ptr(max9286_dt_ids),
1314	},
1315	.probe_new	= max9286_probe,
1316	.remove		= max9286_remove,
1317};
1318
1319module_i2c_driver(max9286_i2c_driver);
1320
1321MODULE_DESCRIPTION("Maxim MAX9286 GMSL Deserializer Driver");
1322MODULE_AUTHOR("Jacopo Mondi, Kieran Bingham, Laurent Pinchart, Niklas Söderlund, Vladimir Barinov");
1323MODULE_LICENSE("GPL");
1324