1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Driver for Cadence MIPI-CSI2 TX Controller
4  *
5  * Copyright (C) 2017-2019 Cadence Design Systems Inc.
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/delay.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/of.h>
14 #include <linux/of_graph.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 
18 #include <media/v4l2-ctrls.h>
19 #include <media/v4l2-device.h>
20 #include <media/v4l2-fwnode.h>
21 #include <media/v4l2-subdev.h>
22 
23 #define CSI2TX_DEVICE_CONFIG_REG	0x00
24 #define CSI2TX_DEVICE_CONFIG_STREAMS_MASK	GENMASK(6, 4)
25 #define CSI2TX_DEVICE_CONFIG_HAS_DPHY		BIT(3)
26 #define CSI2TX_DEVICE_CONFIG_LANES_MASK		GENMASK(2, 0)
27 
28 #define CSI2TX_CONFIG_REG		0x20
29 #define CSI2TX_CONFIG_CFG_REQ			BIT(2)
30 #define CSI2TX_CONFIG_SRST_REQ			BIT(1)
31 
32 #define CSI2TX_DPHY_CFG_REG		0x28
33 #define CSI2TX_DPHY_CFG_CLK_RESET		BIT(16)
34 #define CSI2TX_DPHY_CFG_LANE_RESET(n)		BIT((n) + 12)
35 #define CSI2TX_DPHY_CFG_MODE_MASK		GENMASK(9, 8)
36 #define CSI2TX_DPHY_CFG_MODE_LPDT		(2 << 8)
37 #define CSI2TX_DPHY_CFG_MODE_HS			(1 << 8)
38 #define CSI2TX_DPHY_CFG_MODE_ULPS		(0 << 8)
39 #define CSI2TX_DPHY_CFG_CLK_ENABLE		BIT(4)
40 #define CSI2TX_DPHY_CFG_LANE_ENABLE(n)		BIT(n)
41 
42 #define CSI2TX_DPHY_CLK_WAKEUP_REG	0x2c
43 #define CSI2TX_DPHY_CLK_WAKEUP_ULPS_CYCLES(n)	((n) & 0xffff)
44 
45 #define CSI2TX_DT_CFG_REG(n)		(0x80 + (n) * 8)
46 #define CSI2TX_DT_CFG_DT(n)			(((n) & 0x3f) << 2)
47 
48 #define CSI2TX_DT_FORMAT_REG(n)		(0x84 + (n) * 8)
49 #define CSI2TX_DT_FORMAT_BYTES_PER_LINE(n)	(((n) & 0xffff) << 16)
50 #define CSI2TX_DT_FORMAT_MAX_LINE_NUM(n)	((n) & 0xffff)
51 
52 #define CSI2TX_STREAM_IF_CFG_REG(n)	(0x100 + (n) * 4)
53 #define CSI2TX_STREAM_IF_CFG_FILL_LEVEL(n)	((n) & 0x1f)
54 
55 /* CSI2TX V2 Registers */
56 #define CSI2TX_V2_DPHY_CFG_REG			0x28
57 #define CSI2TX_V2_DPHY_CFG_RESET		BIT(16)
58 #define CSI2TX_V2_DPHY_CFG_CLOCK_MODE		BIT(10)
59 #define CSI2TX_V2_DPHY_CFG_MODE_MASK		GENMASK(9, 8)
60 #define CSI2TX_V2_DPHY_CFG_MODE_LPDT		(2 << 8)
61 #define CSI2TX_V2_DPHY_CFG_MODE_HS		(1 << 8)
62 #define CSI2TX_V2_DPHY_CFG_MODE_ULPS		(0 << 8)
63 #define CSI2TX_V2_DPHY_CFG_CLK_ENABLE		BIT(4)
64 #define CSI2TX_V2_DPHY_CFG_LANE_ENABLE(n)	BIT(n)
65 
66 #define CSI2TX_LANES_MAX	4
67 #define CSI2TX_STREAMS_MAX	4
68 
69 enum csi2tx_pads {
70 	CSI2TX_PAD_SOURCE,
71 	CSI2TX_PAD_SINK_STREAM0,
72 	CSI2TX_PAD_SINK_STREAM1,
73 	CSI2TX_PAD_SINK_STREAM2,
74 	CSI2TX_PAD_SINK_STREAM3,
75 	CSI2TX_PAD_MAX,
76 };
77 
78 struct csi2tx_fmt {
79 	u32	mbus;
80 	u32	dt;
81 	u32	bpp;
82 };
83 
84 struct csi2tx_priv;
85 
86 /* CSI2TX Variant Operations */
87 struct csi2tx_vops {
88 	void (*dphy_setup)(struct csi2tx_priv *csi2tx);
89 };
90 
91 struct csi2tx_priv {
92 	struct device			*dev;
93 	unsigned int			count;
94 
95 	/*
96 	 * Used to prevent race conditions between multiple,
97 	 * concurrent calls to start and stop.
98 	 */
99 	struct mutex			lock;
100 
101 	void __iomem			*base;
102 
103 	struct csi2tx_vops		*vops;
104 
105 	struct clk			*esc_clk;
106 	struct clk			*p_clk;
107 	struct clk			*pixel_clk[CSI2TX_STREAMS_MAX];
108 
109 	struct v4l2_subdev		subdev;
110 	struct media_pad		pads[CSI2TX_PAD_MAX];
111 	struct v4l2_mbus_framefmt	pad_fmts[CSI2TX_PAD_MAX];
112 
113 	bool				has_internal_dphy;
114 	u8				lanes[CSI2TX_LANES_MAX];
115 	unsigned int			num_lanes;
116 	unsigned int			max_lanes;
117 	unsigned int			max_streams;
118 };
119 
120 static const struct csi2tx_fmt csi2tx_formats[] = {
121 	{
122 		.mbus	= MEDIA_BUS_FMT_UYVY8_1X16,
123 		.bpp	= 2,
124 		.dt	= 0x1e,
125 	},
126 	{
127 		.mbus	= MEDIA_BUS_FMT_RGB888_1X24,
128 		.bpp	= 3,
129 		.dt	= 0x24,
130 	},
131 };
132 
133 static const struct v4l2_mbus_framefmt fmt_default = {
134 	.width		= 1280,
135 	.height		= 720,
136 	.code		= MEDIA_BUS_FMT_RGB888_1X24,
137 	.field		= V4L2_FIELD_NONE,
138 	.colorspace	= V4L2_COLORSPACE_DEFAULT,
139 };
140 
141 static inline
142 struct csi2tx_priv *v4l2_subdev_to_csi2tx(struct v4l2_subdev *subdev)
143 {
144 	return container_of(subdev, struct csi2tx_priv, subdev);
145 }
146 
147 static const struct csi2tx_fmt *csi2tx_get_fmt_from_mbus(u32 mbus)
148 {
149 	unsigned int i;
150 
151 	for (i = 0; i < ARRAY_SIZE(csi2tx_formats); i++)
152 		if (csi2tx_formats[i].mbus == mbus)
153 			return &csi2tx_formats[i];
154 
155 	return NULL;
156 }
157 
158 static int csi2tx_enum_mbus_code(struct v4l2_subdev *subdev,
159 				 struct v4l2_subdev_state *sd_state,
160 				 struct v4l2_subdev_mbus_code_enum *code)
161 {
162 	if (code->pad || code->index >= ARRAY_SIZE(csi2tx_formats))
163 		return -EINVAL;
164 
165 	code->code = csi2tx_formats[code->index].mbus;
166 
167 	return 0;
168 }
169 
170 static struct v4l2_mbus_framefmt *
171 __csi2tx_get_pad_format(struct v4l2_subdev *subdev,
172 			struct v4l2_subdev_state *sd_state,
173 			struct v4l2_subdev_format *fmt)
174 {
175 	struct csi2tx_priv *csi2tx = v4l2_subdev_to_csi2tx(subdev);
176 
177 	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
178 		return v4l2_subdev_get_try_format(subdev, sd_state,
179 						  fmt->pad);
180 
181 	return &csi2tx->pad_fmts[fmt->pad];
182 }
183 
184 static int csi2tx_get_pad_format(struct v4l2_subdev *subdev,
185 				 struct v4l2_subdev_state *sd_state,
186 				 struct v4l2_subdev_format *fmt)
187 {
188 	const struct v4l2_mbus_framefmt *format;
189 
190 	/* Multiplexed pad? */
191 	if (fmt->pad == CSI2TX_PAD_SOURCE)
192 		return -EINVAL;
193 
194 	format = __csi2tx_get_pad_format(subdev, sd_state, fmt);
195 	if (!format)
196 		return -EINVAL;
197 
198 	fmt->format = *format;
199 
200 	return 0;
201 }
202 
203 static int csi2tx_set_pad_format(struct v4l2_subdev *subdev,
204 				 struct v4l2_subdev_state *sd_state,
205 				 struct v4l2_subdev_format *fmt)
206 {
207 	const struct v4l2_mbus_framefmt *src_format = &fmt->format;
208 	struct v4l2_mbus_framefmt *dst_format;
209 
210 	/* Multiplexed pad? */
211 	if (fmt->pad == CSI2TX_PAD_SOURCE)
212 		return -EINVAL;
213 
214 	if (!csi2tx_get_fmt_from_mbus(fmt->format.code))
215 		src_format = &fmt_default;
216 
217 	dst_format = __csi2tx_get_pad_format(subdev, sd_state, fmt);
218 	if (!dst_format)
219 		return -EINVAL;
220 
221 	*dst_format = *src_format;
222 
223 	return 0;
224 }
225 
226 static const struct v4l2_subdev_pad_ops csi2tx_pad_ops = {
227 	.enum_mbus_code	= csi2tx_enum_mbus_code,
228 	.get_fmt	= csi2tx_get_pad_format,
229 	.set_fmt	= csi2tx_set_pad_format,
230 };
231 
232 /* Set Wake Up value in the D-PHY */
233 static void csi2tx_dphy_set_wakeup(struct csi2tx_priv *csi2tx)
234 {
235 	writel(CSI2TX_DPHY_CLK_WAKEUP_ULPS_CYCLES(32),
236 	       csi2tx->base + CSI2TX_DPHY_CLK_WAKEUP_REG);
237 }
238 
239 /*
240  * Finishes the D-PHY initialization
241  * reg dphy cfg value to be used
242  */
243 static void csi2tx_dphy_init_finish(struct csi2tx_priv *csi2tx, u32 reg)
244 {
245 	unsigned int i;
246 
247 	udelay(10);
248 
249 	/* Enable our (clock and data) lanes */
250 	reg |= CSI2TX_DPHY_CFG_CLK_ENABLE;
251 	for (i = 0; i < csi2tx->num_lanes; i++)
252 		reg |= CSI2TX_DPHY_CFG_LANE_ENABLE(csi2tx->lanes[i] - 1);
253 	writel(reg, csi2tx->base + CSI2TX_DPHY_CFG_REG);
254 
255 	udelay(10);
256 
257 	/* Switch to HS mode */
258 	reg &= ~CSI2TX_DPHY_CFG_MODE_MASK;
259 	writel(reg | CSI2TX_DPHY_CFG_MODE_HS,
260 	       csi2tx->base + CSI2TX_DPHY_CFG_REG);
261 }
262 
263 /* Configures D-PHY in CSIv1.3 */
264 static void csi2tx_dphy_setup(struct csi2tx_priv *csi2tx)
265 {
266 	u32 reg;
267 	unsigned int i;
268 
269 	csi2tx_dphy_set_wakeup(csi2tx);
270 
271 	/* Put our lanes (clock and data) out of reset */
272 	reg = CSI2TX_DPHY_CFG_CLK_RESET | CSI2TX_DPHY_CFG_MODE_LPDT;
273 	for (i = 0; i < csi2tx->num_lanes; i++)
274 		reg |= CSI2TX_DPHY_CFG_LANE_RESET(csi2tx->lanes[i] - 1);
275 	writel(reg, csi2tx->base + CSI2TX_DPHY_CFG_REG);
276 
277 	csi2tx_dphy_init_finish(csi2tx, reg);
278 }
279 
280 /* Configures D-PHY in CSIv2 */
281 static void csi2tx_v2_dphy_setup(struct csi2tx_priv *csi2tx)
282 {
283 	u32 reg;
284 
285 	csi2tx_dphy_set_wakeup(csi2tx);
286 
287 	/* Put our lanes (clock and data) out of reset */
288 	reg = CSI2TX_V2_DPHY_CFG_RESET | CSI2TX_V2_DPHY_CFG_MODE_LPDT;
289 	writel(reg, csi2tx->base + CSI2TX_V2_DPHY_CFG_REG);
290 
291 	csi2tx_dphy_init_finish(csi2tx, reg);
292 }
293 
294 static void csi2tx_reset(struct csi2tx_priv *csi2tx)
295 {
296 	writel(CSI2TX_CONFIG_SRST_REQ, csi2tx->base + CSI2TX_CONFIG_REG);
297 
298 	udelay(10);
299 }
300 
301 static int csi2tx_start(struct csi2tx_priv *csi2tx)
302 {
303 	struct media_entity *entity = &csi2tx->subdev.entity;
304 	struct media_link *link;
305 	unsigned int i;
306 
307 	csi2tx_reset(csi2tx);
308 
309 	writel(CSI2TX_CONFIG_CFG_REQ, csi2tx->base + CSI2TX_CONFIG_REG);
310 
311 	udelay(10);
312 
313 	if (csi2tx->vops && csi2tx->vops->dphy_setup) {
314 		csi2tx->vops->dphy_setup(csi2tx);
315 		udelay(10);
316 	}
317 
318 	/*
319 	 * Create a static mapping between the CSI virtual channels
320 	 * and the input streams.
321 	 *
322 	 * This should be enhanced, but v4l2 lacks the support for
323 	 * changing that mapping dynamically at the moment.
324 	 *
325 	 * We're protected from the userspace setting up links at the
326 	 * same time by the upper layer having called
327 	 * media_pipeline_start().
328 	 */
329 	list_for_each_entry(link, &entity->links, list) {
330 		struct v4l2_mbus_framefmt *mfmt;
331 		const struct csi2tx_fmt *fmt;
332 		unsigned int stream;
333 		int pad_idx = -1;
334 
335 		/* Only consider our enabled input pads */
336 		for (i = CSI2TX_PAD_SINK_STREAM0; i < CSI2TX_PAD_MAX; i++) {
337 			struct media_pad *pad = &csi2tx->pads[i];
338 
339 			if ((pad == link->sink) &&
340 			    (link->flags & MEDIA_LNK_FL_ENABLED)) {
341 				pad_idx = i;
342 				break;
343 			}
344 		}
345 
346 		if (pad_idx < 0)
347 			continue;
348 
349 		mfmt = &csi2tx->pad_fmts[pad_idx];
350 		fmt = csi2tx_get_fmt_from_mbus(mfmt->code);
351 		if (!fmt)
352 			continue;
353 
354 		stream = pad_idx - CSI2TX_PAD_SINK_STREAM0;
355 
356 		/*
357 		 * We use the stream ID there, but it's wrong.
358 		 *
359 		 * A stream could very well send a data type that is
360 		 * not equal to its stream ID. We need to find a
361 		 * proper way to address it.
362 		 */
363 		writel(CSI2TX_DT_CFG_DT(fmt->dt),
364 		       csi2tx->base + CSI2TX_DT_CFG_REG(stream));
365 
366 		writel(CSI2TX_DT_FORMAT_BYTES_PER_LINE(mfmt->width * fmt->bpp) |
367 		       CSI2TX_DT_FORMAT_MAX_LINE_NUM(mfmt->height + 1),
368 		       csi2tx->base + CSI2TX_DT_FORMAT_REG(stream));
369 
370 		/*
371 		 * TODO: This needs to be calculated based on the
372 		 * output CSI2 clock rate.
373 		 */
374 		writel(CSI2TX_STREAM_IF_CFG_FILL_LEVEL(4),
375 		       csi2tx->base + CSI2TX_STREAM_IF_CFG_REG(stream));
376 	}
377 
378 	/* Disable the configuration mode */
379 	writel(0, csi2tx->base + CSI2TX_CONFIG_REG);
380 
381 	return 0;
382 }
383 
384 static void csi2tx_stop(struct csi2tx_priv *csi2tx)
385 {
386 	writel(CSI2TX_CONFIG_CFG_REQ | CSI2TX_CONFIG_SRST_REQ,
387 	       csi2tx->base + CSI2TX_CONFIG_REG);
388 }
389 
390 static int csi2tx_s_stream(struct v4l2_subdev *subdev, int enable)
391 {
392 	struct csi2tx_priv *csi2tx = v4l2_subdev_to_csi2tx(subdev);
393 	int ret = 0;
394 
395 	mutex_lock(&csi2tx->lock);
396 
397 	if (enable) {
398 		/*
399 		 * If we're not the first users, there's no need to
400 		 * enable the whole controller.
401 		 */
402 		if (!csi2tx->count) {
403 			ret = csi2tx_start(csi2tx);
404 			if (ret)
405 				goto out;
406 		}
407 
408 		csi2tx->count++;
409 	} else {
410 		csi2tx->count--;
411 
412 		/*
413 		 * Let the last user turn off the lights.
414 		 */
415 		if (!csi2tx->count)
416 			csi2tx_stop(csi2tx);
417 	}
418 
419 out:
420 	mutex_unlock(&csi2tx->lock);
421 	return ret;
422 }
423 
424 static const struct v4l2_subdev_video_ops csi2tx_video_ops = {
425 	.s_stream	= csi2tx_s_stream,
426 };
427 
428 static const struct v4l2_subdev_ops csi2tx_subdev_ops = {
429 	.pad		= &csi2tx_pad_ops,
430 	.video		= &csi2tx_video_ops,
431 };
432 
433 static int csi2tx_get_resources(struct csi2tx_priv *csi2tx,
434 				struct platform_device *pdev)
435 {
436 	struct resource *res;
437 	unsigned int i;
438 	u32 dev_cfg;
439 	int ret;
440 
441 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
442 	csi2tx->base = devm_ioremap_resource(&pdev->dev, res);
443 	if (IS_ERR(csi2tx->base))
444 		return PTR_ERR(csi2tx->base);
445 
446 	csi2tx->p_clk = devm_clk_get(&pdev->dev, "p_clk");
447 	if (IS_ERR(csi2tx->p_clk)) {
448 		dev_err(&pdev->dev, "Couldn't get p_clk\n");
449 		return PTR_ERR(csi2tx->p_clk);
450 	}
451 
452 	csi2tx->esc_clk = devm_clk_get(&pdev->dev, "esc_clk");
453 	if (IS_ERR(csi2tx->esc_clk)) {
454 		dev_err(&pdev->dev, "Couldn't get the esc_clk\n");
455 		return PTR_ERR(csi2tx->esc_clk);
456 	}
457 
458 	ret = clk_prepare_enable(csi2tx->p_clk);
459 	if (ret) {
460 		dev_err(&pdev->dev, "Couldn't prepare and enable p_clk\n");
461 		return ret;
462 	}
463 
464 	dev_cfg = readl(csi2tx->base + CSI2TX_DEVICE_CONFIG_REG);
465 	clk_disable_unprepare(csi2tx->p_clk);
466 
467 	csi2tx->max_lanes = dev_cfg & CSI2TX_DEVICE_CONFIG_LANES_MASK;
468 	if (csi2tx->max_lanes > CSI2TX_LANES_MAX) {
469 		dev_err(&pdev->dev, "Invalid number of lanes: %u\n",
470 			csi2tx->max_lanes);
471 		return -EINVAL;
472 	}
473 
474 	csi2tx->max_streams = (dev_cfg & CSI2TX_DEVICE_CONFIG_STREAMS_MASK) >> 4;
475 	if (csi2tx->max_streams > CSI2TX_STREAMS_MAX) {
476 		dev_err(&pdev->dev, "Invalid number of streams: %u\n",
477 			csi2tx->max_streams);
478 		return -EINVAL;
479 	}
480 
481 	csi2tx->has_internal_dphy = !!(dev_cfg & CSI2TX_DEVICE_CONFIG_HAS_DPHY);
482 
483 	for (i = 0; i < csi2tx->max_streams; i++) {
484 		char clk_name[16];
485 
486 		snprintf(clk_name, sizeof(clk_name), "pixel_if%u_clk", i);
487 		csi2tx->pixel_clk[i] = devm_clk_get(&pdev->dev, clk_name);
488 		if (IS_ERR(csi2tx->pixel_clk[i])) {
489 			dev_err(&pdev->dev, "Couldn't get clock %s\n",
490 				clk_name);
491 			return PTR_ERR(csi2tx->pixel_clk[i]);
492 		}
493 	}
494 
495 	return 0;
496 }
497 
498 static int csi2tx_check_lanes(struct csi2tx_priv *csi2tx)
499 {
500 	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
501 	struct device_node *ep;
502 	int ret, i;
503 
504 	ep = of_graph_get_endpoint_by_regs(csi2tx->dev->of_node, 0, 0);
505 	if (!ep)
506 		return -EINVAL;
507 
508 	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &v4l2_ep);
509 	if (ret) {
510 		dev_err(csi2tx->dev, "Could not parse v4l2 endpoint\n");
511 		goto out;
512 	}
513 
514 	if (v4l2_ep.bus_type != V4L2_MBUS_CSI2_DPHY) {
515 		dev_err(csi2tx->dev, "Unsupported media bus type: 0x%x\n",
516 			v4l2_ep.bus_type);
517 		ret = -EINVAL;
518 		goto out;
519 	}
520 
521 	csi2tx->num_lanes = v4l2_ep.bus.mipi_csi2.num_data_lanes;
522 	if (csi2tx->num_lanes > csi2tx->max_lanes) {
523 		dev_err(csi2tx->dev,
524 			"Current configuration uses more lanes than supported\n");
525 		ret = -EINVAL;
526 		goto out;
527 	}
528 
529 	for (i = 0; i < csi2tx->num_lanes; i++) {
530 		if (v4l2_ep.bus.mipi_csi2.data_lanes[i] < 1) {
531 			dev_err(csi2tx->dev, "Invalid lane[%d] number: %u\n",
532 				i, v4l2_ep.bus.mipi_csi2.data_lanes[i]);
533 			ret = -EINVAL;
534 			goto out;
535 		}
536 	}
537 
538 	memcpy(csi2tx->lanes, v4l2_ep.bus.mipi_csi2.data_lanes,
539 	       sizeof(csi2tx->lanes));
540 
541 out:
542 	of_node_put(ep);
543 	return ret;
544 }
545 
546 static const struct csi2tx_vops csi2tx_vops = {
547 	.dphy_setup = csi2tx_dphy_setup,
548 };
549 
550 static const struct csi2tx_vops csi2tx_v2_vops = {
551 	.dphy_setup = csi2tx_v2_dphy_setup,
552 };
553 
554 static const struct of_device_id csi2tx_of_table[] = {
555 	{
556 		.compatible = "cdns,csi2tx",
557 		.data = &csi2tx_vops
558 	},
559 	{
560 		.compatible = "cdns,csi2tx-1.3",
561 		.data = &csi2tx_vops
562 	},
563 	{
564 		.compatible = "cdns,csi2tx-2.1",
565 		.data = &csi2tx_v2_vops
566 	},
567 	{ }
568 };
569 MODULE_DEVICE_TABLE(of, csi2tx_of_table);
570 
571 static int csi2tx_probe(struct platform_device *pdev)
572 {
573 	struct csi2tx_priv *csi2tx;
574 	const struct of_device_id *of_id;
575 	unsigned int i;
576 	int ret;
577 
578 	csi2tx = kzalloc(sizeof(*csi2tx), GFP_KERNEL);
579 	if (!csi2tx)
580 		return -ENOMEM;
581 	platform_set_drvdata(pdev, csi2tx);
582 	mutex_init(&csi2tx->lock);
583 	csi2tx->dev = &pdev->dev;
584 
585 	ret = csi2tx_get_resources(csi2tx, pdev);
586 	if (ret)
587 		goto err_free_priv;
588 
589 	of_id = of_match_node(csi2tx_of_table, pdev->dev.of_node);
590 	csi2tx->vops = (struct csi2tx_vops *)of_id->data;
591 
592 	v4l2_subdev_init(&csi2tx->subdev, &csi2tx_subdev_ops);
593 	csi2tx->subdev.owner = THIS_MODULE;
594 	csi2tx->subdev.dev = &pdev->dev;
595 	csi2tx->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
596 	snprintf(csi2tx->subdev.name, V4L2_SUBDEV_NAME_SIZE, "%s.%s",
597 		 KBUILD_MODNAME, dev_name(&pdev->dev));
598 
599 	ret = csi2tx_check_lanes(csi2tx);
600 	if (ret)
601 		goto err_free_priv;
602 
603 	/* Create our media pads */
604 	csi2tx->subdev.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
605 	csi2tx->pads[CSI2TX_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
606 	for (i = CSI2TX_PAD_SINK_STREAM0; i < CSI2TX_PAD_MAX; i++)
607 		csi2tx->pads[i].flags = MEDIA_PAD_FL_SINK;
608 
609 	/*
610 	 * Only the input pads are considered to have a format at the
611 	 * moment. The CSI link can multiplex various streams with
612 	 * different formats, and we can't expose this in v4l2 right
613 	 * now.
614 	 */
615 	for (i = CSI2TX_PAD_SINK_STREAM0; i < CSI2TX_PAD_MAX; i++)
616 		csi2tx->pad_fmts[i] = fmt_default;
617 
618 	ret = media_entity_pads_init(&csi2tx->subdev.entity, CSI2TX_PAD_MAX,
619 				     csi2tx->pads);
620 	if (ret)
621 		goto err_free_priv;
622 
623 	ret = v4l2_async_register_subdev(&csi2tx->subdev);
624 	if (ret < 0)
625 		goto err_free_priv;
626 
627 	dev_info(&pdev->dev,
628 		 "Probed CSI2TX with %u/%u lanes, %u streams, %s D-PHY\n",
629 		 csi2tx->num_lanes, csi2tx->max_lanes, csi2tx->max_streams,
630 		 csi2tx->has_internal_dphy ? "internal" : "no");
631 
632 	return 0;
633 
634 err_free_priv:
635 	kfree(csi2tx);
636 	return ret;
637 }
638 
639 static int csi2tx_remove(struct platform_device *pdev)
640 {
641 	struct csi2tx_priv *csi2tx = platform_get_drvdata(pdev);
642 
643 	v4l2_async_unregister_subdev(&csi2tx->subdev);
644 	kfree(csi2tx);
645 
646 	return 0;
647 }
648 
649 static struct platform_driver csi2tx_driver = {
650 	.probe	= csi2tx_probe,
651 	.remove	= csi2tx_remove,
652 
653 	.driver	= {
654 		.name		= "cdns-csi2tx",
655 		.of_match_table	= csi2tx_of_table,
656 	},
657 };
658 module_platform_driver(csi2tx_driver);
659 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@bootlin.com>");
660 MODULE_DESCRIPTION("Cadence CSI2-TX controller");
661 MODULE_LICENSE("GPL");
662