xref: /linux/drivers/media/platform/st/stm32/stm32-dcmi.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for STM32 Digital Camera Memory Interface
4  *
5  * Copyright (C) STMicroelectronics SA 2017
6  * Authors: Yannick Fertre <yannick.fertre@st.com>
7  *          Hugues Fruchet <hugues.fruchet@st.com>
8  *          for STMicroelectronics.
9  *
10  * This driver is based on atmel_isi.c
11  *
12  */
13 
14 #include <linux/clk.h>
15 #include <linux/completion.h>
16 #include <linux/delay.h>
17 #include <linux/dmaengine.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/of_graph.h>
24 #include <linux/pinctrl/consumer.h>
25 #include <linux/platform_device.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/reset.h>
28 #include <linux/videodev2.h>
29 
30 #include <media/v4l2-ctrls.h>
31 #include <media/v4l2-dev.h>
32 #include <media/v4l2-device.h>
33 #include <media/v4l2-event.h>
34 #include <media/v4l2-fwnode.h>
35 #include <media/v4l2-image-sizes.h>
36 #include <media/v4l2-ioctl.h>
37 #include <media/v4l2-rect.h>
38 #include <media/videobuf2-dma-contig.h>
39 
40 #define DRV_NAME "stm32-dcmi"
41 
42 /* Registers offset for DCMI */
43 #define DCMI_CR		0x00 /* Control Register */
44 #define DCMI_SR		0x04 /* Status Register */
45 #define DCMI_RIS	0x08 /* Raw Interrupt Status register */
46 #define DCMI_IER	0x0C /* Interrupt Enable Register */
47 #define DCMI_MIS	0x10 /* Masked Interrupt Status register */
48 #define DCMI_ICR	0x14 /* Interrupt Clear Register */
49 #define DCMI_ESCR	0x18 /* Embedded Synchronization Code Register */
50 #define DCMI_ESUR	0x1C /* Embedded Synchronization Unmask Register */
51 #define DCMI_CWSTRT	0x20 /* Crop Window STaRT */
52 #define DCMI_CWSIZE	0x24 /* Crop Window SIZE */
53 #define DCMI_DR		0x28 /* Data Register */
54 #define DCMI_IDR	0x2C /* IDentifier Register */
55 
56 /* Bits definition for control register (DCMI_CR) */
57 #define CR_CAPTURE	BIT(0)
58 #define CR_CM		BIT(1)
59 #define CR_CROP		BIT(2)
60 #define CR_JPEG		BIT(3)
61 #define CR_ESS		BIT(4)
62 #define CR_PCKPOL	BIT(5)
63 #define CR_HSPOL	BIT(6)
64 #define CR_VSPOL	BIT(7)
65 #define CR_FCRC_0	BIT(8)
66 #define CR_FCRC_1	BIT(9)
67 #define CR_EDM_0	BIT(10)
68 #define CR_EDM_1	BIT(11)
69 #define CR_ENABLE	BIT(14)
70 
71 /* Bits definition for status register (DCMI_SR) */
72 #define SR_HSYNC	BIT(0)
73 #define SR_VSYNC	BIT(1)
74 #define SR_FNE		BIT(2)
75 
76 /*
77  * Bits definition for interrupt registers
78  * (DCMI_RIS, DCMI_IER, DCMI_MIS, DCMI_ICR)
79  */
80 #define IT_FRAME	BIT(0)
81 #define IT_OVR		BIT(1)
82 #define IT_ERR		BIT(2)
83 #define IT_VSYNC	BIT(3)
84 #define IT_LINE		BIT(4)
85 
86 enum state {
87 	STOPPED = 0,
88 	WAIT_FOR_BUFFER,
89 	RUNNING,
90 };
91 
92 #define MIN_WIDTH	16U
93 #define MAX_WIDTH	2592U
94 #define MIN_HEIGHT	16U
95 #define MAX_HEIGHT	2592U
96 
97 #define TIMEOUT_MS	1000
98 
99 #define OVERRUN_ERROR_THRESHOLD	3
100 
101 struct dcmi_format {
102 	u32	fourcc;
103 	u32	mbus_code;
104 	u8	bpp;
105 };
106 
107 struct dcmi_framesize {
108 	u32	width;
109 	u32	height;
110 };
111 
112 struct dcmi_buf {
113 	struct vb2_v4l2_buffer	vb;
114 	bool			prepared;
115 	struct sg_table		sgt;
116 	size_t			size;
117 	struct list_head	list;
118 };
119 
120 struct stm32_dcmi {
121 	/* Protects the access of variables shared within the interrupt */
122 	spinlock_t			irqlock;
123 	struct device			*dev;
124 	void __iomem			*regs;
125 	struct resource			*res;
126 	struct reset_control		*rstc;
127 	int				sequence;
128 	struct list_head		buffers;
129 	struct dcmi_buf			*active;
130 	int			irq;
131 
132 	struct v4l2_device		v4l2_dev;
133 	struct video_device		*vdev;
134 	struct v4l2_async_notifier	notifier;
135 	struct v4l2_subdev		*source;
136 	struct v4l2_subdev		*s_subdev;
137 	struct v4l2_format		fmt;
138 	struct v4l2_rect		crop;
139 	bool				do_crop;
140 
141 	const struct dcmi_format	**sd_formats;
142 	unsigned int			num_of_sd_formats;
143 	const struct dcmi_format	*sd_format;
144 	struct dcmi_framesize		*sd_framesizes;
145 	unsigned int			num_of_sd_framesizes;
146 	struct dcmi_framesize		sd_framesize;
147 	struct v4l2_rect		sd_bounds;
148 
149 	/* Protect this data structure */
150 	struct mutex			lock;
151 	struct vb2_queue		queue;
152 
153 	struct v4l2_mbus_config_parallel	bus;
154 	enum v4l2_mbus_type		bus_type;
155 	struct completion		complete;
156 	struct clk			*mclk;
157 	enum state			state;
158 	struct dma_chan			*dma_chan;
159 	dma_cookie_t			dma_cookie;
160 	u32				dma_max_burst;
161 	u32				misr;
162 	int				errors_count;
163 	int				overrun_count;
164 	int				buffers_count;
165 
166 	/* Ensure DMA operations atomicity */
167 	struct mutex			dma_lock;
168 
169 	struct media_device		mdev;
170 	struct media_pad		vid_cap_pad;
171 	struct media_pipeline		pipeline;
172 };
173 
174 static inline struct stm32_dcmi *notifier_to_dcmi(struct v4l2_async_notifier *n)
175 {
176 	return container_of(n, struct stm32_dcmi, notifier);
177 }
178 
179 static inline u32 reg_read(void __iomem *base, u32 reg)
180 {
181 	return readl_relaxed(base + reg);
182 }
183 
184 static inline void reg_write(void __iomem *base, u32 reg, u32 val)
185 {
186 	writel_relaxed(val, base + reg);
187 }
188 
189 static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
190 {
191 	reg_write(base, reg, reg_read(base, reg) | mask);
192 }
193 
194 static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
195 {
196 	reg_write(base, reg, reg_read(base, reg) & ~mask);
197 }
198 
199 static int dcmi_start_capture(struct stm32_dcmi *dcmi, struct dcmi_buf *buf);
200 
201 static void dcmi_buffer_done(struct stm32_dcmi *dcmi,
202 			     struct dcmi_buf *buf,
203 			     size_t bytesused,
204 			     int err)
205 {
206 	struct vb2_v4l2_buffer *vbuf;
207 
208 	if (!buf)
209 		return;
210 
211 	list_del_init(&buf->list);
212 
213 	vbuf = &buf->vb;
214 
215 	vbuf->sequence = dcmi->sequence++;
216 	vbuf->field = V4L2_FIELD_NONE;
217 	vbuf->vb2_buf.timestamp = ktime_get_ns();
218 	vb2_set_plane_payload(&vbuf->vb2_buf, 0, bytesused);
219 	vb2_buffer_done(&vbuf->vb2_buf,
220 			err ? VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
221 	dev_dbg(dcmi->dev, "buffer[%d] done seq=%d, bytesused=%zu\n",
222 		vbuf->vb2_buf.index, vbuf->sequence, bytesused);
223 
224 	dcmi->buffers_count++;
225 	dcmi->active = NULL;
226 }
227 
228 static int dcmi_restart_capture(struct stm32_dcmi *dcmi)
229 {
230 	struct dcmi_buf *buf;
231 
232 	spin_lock_irq(&dcmi->irqlock);
233 
234 	if (dcmi->state != RUNNING) {
235 		spin_unlock_irq(&dcmi->irqlock);
236 		return -EINVAL;
237 	}
238 
239 	/* Restart a new DMA transfer with next buffer */
240 	if (list_empty(&dcmi->buffers)) {
241 		dev_dbg(dcmi->dev, "Capture restart is deferred to next buffer queueing\n");
242 		dcmi->state = WAIT_FOR_BUFFER;
243 		spin_unlock_irq(&dcmi->irqlock);
244 		return 0;
245 	}
246 	buf = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
247 	dcmi->active = buf;
248 
249 	spin_unlock_irq(&dcmi->irqlock);
250 
251 	return dcmi_start_capture(dcmi, buf);
252 }
253 
254 static void dcmi_dma_callback(void *param)
255 {
256 	struct stm32_dcmi *dcmi = (struct stm32_dcmi *)param;
257 	struct dma_tx_state state;
258 	enum dma_status status;
259 	struct dcmi_buf *buf = dcmi->active;
260 
261 	spin_lock_irq(&dcmi->irqlock);
262 
263 	/* Check DMA status */
264 	status = dmaengine_tx_status(dcmi->dma_chan, dcmi->dma_cookie, &state);
265 
266 	switch (status) {
267 	case DMA_IN_PROGRESS:
268 		dev_dbg(dcmi->dev, "%s: Received DMA_IN_PROGRESS\n", __func__);
269 		break;
270 	case DMA_PAUSED:
271 		dev_err(dcmi->dev, "%s: Received DMA_PAUSED\n", __func__);
272 		break;
273 	case DMA_ERROR:
274 		dev_err(dcmi->dev, "%s: Received DMA_ERROR\n", __func__);
275 
276 		/* Return buffer to V4L2 in error state */
277 		dcmi_buffer_done(dcmi, buf, 0, -EIO);
278 		break;
279 	case DMA_COMPLETE:
280 		dev_dbg(dcmi->dev, "%s: Received DMA_COMPLETE\n", __func__);
281 
282 		/* Return buffer to V4L2 */
283 		dcmi_buffer_done(dcmi, buf, buf->size, 0);
284 
285 		spin_unlock_irq(&dcmi->irqlock);
286 
287 		/* Restart capture */
288 		if (dcmi_restart_capture(dcmi))
289 			dev_err(dcmi->dev, "%s: Cannot restart capture on DMA complete\n",
290 				__func__);
291 		return;
292 	default:
293 		dev_err(dcmi->dev, "%s: Received unknown status\n", __func__);
294 		break;
295 	}
296 
297 	spin_unlock_irq(&dcmi->irqlock);
298 }
299 
300 static int dcmi_start_dma(struct stm32_dcmi *dcmi,
301 			  struct dcmi_buf *buf)
302 {
303 	struct dma_async_tx_descriptor *desc = NULL;
304 	struct dma_slave_config config;
305 	int ret;
306 
307 	memset(&config, 0, sizeof(config));
308 
309 	config.src_addr = (dma_addr_t)dcmi->res->start + DCMI_DR;
310 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
311 	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
312 	config.dst_maxburst = 4;
313 
314 	/* Configure DMA channel */
315 	ret = dmaengine_slave_config(dcmi->dma_chan, &config);
316 	if (ret < 0) {
317 		dev_err(dcmi->dev, "%s: DMA channel config failed (%d)\n",
318 			__func__, ret);
319 		return ret;
320 	}
321 
322 	/*
323 	 * Avoid call of dmaengine_terminate_sync() between
324 	 * dmaengine_prep_slave_single() and dmaengine_submit()
325 	 * by locking the whole DMA submission sequence
326 	 */
327 	mutex_lock(&dcmi->dma_lock);
328 
329 	/* Prepare a DMA transaction */
330 	desc = dmaengine_prep_slave_sg(dcmi->dma_chan, buf->sgt.sgl, buf->sgt.nents,
331 				       DMA_DEV_TO_MEM,
332 				       DMA_PREP_INTERRUPT);
333 	if (!desc) {
334 		dev_err(dcmi->dev, "%s: DMA dmaengine_prep_slave_sg failed\n", __func__);
335 		mutex_unlock(&dcmi->dma_lock);
336 		return -EINVAL;
337 	}
338 
339 	/* Set completion callback routine for notification */
340 	desc->callback = dcmi_dma_callback;
341 	desc->callback_param = dcmi;
342 
343 	/* Push current DMA transaction in the pending queue */
344 	dcmi->dma_cookie = dmaengine_submit(desc);
345 	if (dma_submit_error(dcmi->dma_cookie)) {
346 		dev_err(dcmi->dev, "%s: DMA submission failed\n", __func__);
347 		mutex_unlock(&dcmi->dma_lock);
348 		return -ENXIO;
349 	}
350 
351 	mutex_unlock(&dcmi->dma_lock);
352 
353 	dma_async_issue_pending(dcmi->dma_chan);
354 
355 	return 0;
356 }
357 
358 static int dcmi_start_capture(struct stm32_dcmi *dcmi, struct dcmi_buf *buf)
359 {
360 	int ret;
361 
362 	if (!buf)
363 		return -EINVAL;
364 
365 	ret = dcmi_start_dma(dcmi, buf);
366 	if (ret) {
367 		dcmi->errors_count++;
368 		return ret;
369 	}
370 
371 	/* Enable capture */
372 	reg_set(dcmi->regs, DCMI_CR, CR_CAPTURE);
373 
374 	return 0;
375 }
376 
377 static void dcmi_set_crop(struct stm32_dcmi *dcmi)
378 {
379 	u32 size, start;
380 
381 	/* Crop resolution */
382 	size = ((dcmi->crop.height - 1) << 16) |
383 		((dcmi->crop.width << 1) - 1);
384 	reg_write(dcmi->regs, DCMI_CWSIZE, size);
385 
386 	/* Crop start point */
387 	start = ((dcmi->crop.top) << 16) |
388 		 ((dcmi->crop.left << 1));
389 	reg_write(dcmi->regs, DCMI_CWSTRT, start);
390 
391 	dev_dbg(dcmi->dev, "Cropping to %ux%u@%u:%u\n",
392 		dcmi->crop.width, dcmi->crop.height,
393 		dcmi->crop.left, dcmi->crop.top);
394 
395 	/* Enable crop */
396 	reg_set(dcmi->regs, DCMI_CR, CR_CROP);
397 }
398 
399 static void dcmi_process_jpeg(struct stm32_dcmi *dcmi)
400 {
401 	struct dma_tx_state state;
402 	enum dma_status status;
403 	struct dcmi_buf *buf = dcmi->active;
404 
405 	if (!buf)
406 		return;
407 
408 	/*
409 	 * Because of variable JPEG buffer size sent by sensor,
410 	 * DMA transfer never completes due to transfer size never reached.
411 	 * In order to ensure that all the JPEG data are transferred
412 	 * in active buffer memory, DMA is drained.
413 	 * Then DMA tx status gives the amount of data transferred
414 	 * to memory, which is then returned to V4L2 through the active
415 	 * buffer payload.
416 	 */
417 
418 	/* Drain DMA */
419 	dmaengine_synchronize(dcmi->dma_chan);
420 
421 	/* Get DMA residue to get JPEG size */
422 	status = dmaengine_tx_status(dcmi->dma_chan, dcmi->dma_cookie, &state);
423 	if (status != DMA_ERROR && state.residue < buf->size) {
424 		/* Return JPEG buffer to V4L2 with received JPEG buffer size */
425 		dcmi_buffer_done(dcmi, buf, buf->size - state.residue, 0);
426 	} else {
427 		dcmi->errors_count++;
428 		dev_err(dcmi->dev, "%s: Cannot get JPEG size from DMA\n",
429 			__func__);
430 		/* Return JPEG buffer to V4L2 in ERROR state */
431 		dcmi_buffer_done(dcmi, buf, 0, -EIO);
432 	}
433 
434 	/* Abort DMA operation */
435 	dmaengine_terminate_sync(dcmi->dma_chan);
436 
437 	/* Restart capture */
438 	if (dcmi_restart_capture(dcmi))
439 		dev_err(dcmi->dev, "%s: Cannot restart capture on JPEG received\n",
440 			__func__);
441 }
442 
443 static irqreturn_t dcmi_irq_thread(int irq, void *arg)
444 {
445 	struct stm32_dcmi *dcmi = arg;
446 
447 	spin_lock_irq(&dcmi->irqlock);
448 
449 	if (dcmi->misr & IT_OVR) {
450 		dcmi->overrun_count++;
451 		if (dcmi->overrun_count > OVERRUN_ERROR_THRESHOLD)
452 			dcmi->errors_count++;
453 	}
454 	if (dcmi->misr & IT_ERR)
455 		dcmi->errors_count++;
456 
457 	if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG &&
458 	    dcmi->misr & IT_FRAME) {
459 		/* JPEG received */
460 		spin_unlock_irq(&dcmi->irqlock);
461 		dcmi_process_jpeg(dcmi);
462 		return IRQ_HANDLED;
463 	}
464 
465 	spin_unlock_irq(&dcmi->irqlock);
466 	return IRQ_HANDLED;
467 }
468 
469 static irqreturn_t dcmi_irq_callback(int irq, void *arg)
470 {
471 	struct stm32_dcmi *dcmi = arg;
472 	unsigned long flags;
473 
474 	spin_lock_irqsave(&dcmi->irqlock, flags);
475 
476 	dcmi->misr = reg_read(dcmi->regs, DCMI_MIS);
477 
478 	/* Clear interrupt */
479 	reg_set(dcmi->regs, DCMI_ICR, IT_FRAME | IT_OVR | IT_ERR);
480 
481 	spin_unlock_irqrestore(&dcmi->irqlock, flags);
482 
483 	return IRQ_WAKE_THREAD;
484 }
485 
486 static int dcmi_queue_setup(struct vb2_queue *vq,
487 			    unsigned int *nbuffers,
488 			    unsigned int *nplanes,
489 			    unsigned int sizes[],
490 			    struct device *alloc_devs[])
491 {
492 	struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);
493 	unsigned int size;
494 
495 	size = dcmi->fmt.fmt.pix.sizeimage;
496 
497 	/* Make sure the image size is large enough */
498 	if (*nplanes)
499 		return sizes[0] < size ? -EINVAL : 0;
500 
501 	*nplanes = 1;
502 	sizes[0] = size;
503 
504 	dev_dbg(dcmi->dev, "Setup queue, count=%d, size=%d\n",
505 		*nbuffers, size);
506 
507 	return 0;
508 }
509 
510 static int dcmi_buf_init(struct vb2_buffer *vb)
511 {
512 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
513 	struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
514 
515 	INIT_LIST_HEAD(&buf->list);
516 
517 	return 0;
518 }
519 
520 static int dcmi_buf_prepare(struct vb2_buffer *vb)
521 {
522 	struct stm32_dcmi *dcmi =  vb2_get_drv_priv(vb->vb2_queue);
523 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
524 	struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
525 	unsigned long size;
526 	unsigned int num_sgs = 1;
527 	dma_addr_t dma_buf;
528 	struct scatterlist *sg;
529 	int i, ret;
530 
531 	size = dcmi->fmt.fmt.pix.sizeimage;
532 
533 	if (vb2_plane_size(vb, 0) < size) {
534 		dev_err(dcmi->dev, "%s data will not fit into plane (%lu < %lu)\n",
535 			__func__, vb2_plane_size(vb, 0), size);
536 		return -EINVAL;
537 	}
538 
539 	vb2_set_plane_payload(vb, 0, size);
540 
541 	if (!buf->prepared) {
542 		/* Get memory addresses */
543 		buf->size = vb2_plane_size(&buf->vb.vb2_buf, 0);
544 		if (buf->size > dcmi->dma_max_burst)
545 			num_sgs = DIV_ROUND_UP(buf->size, dcmi->dma_max_burst);
546 
547 		ret = sg_alloc_table(&buf->sgt, num_sgs, GFP_ATOMIC);
548 		if (ret) {
549 			dev_err(dcmi->dev, "sg table alloc failed\n");
550 			return ret;
551 		}
552 
553 		dma_buf = vb2_dma_contig_plane_dma_addr(&buf->vb.vb2_buf, 0);
554 
555 		dev_dbg(dcmi->dev, "buffer[%d] phy=%pad size=%zu\n",
556 			vb->index, &dma_buf, buf->size);
557 
558 		for_each_sg(buf->sgt.sgl, sg, num_sgs, i) {
559 			size_t bytes = min_t(size_t, size, dcmi->dma_max_burst);
560 
561 			sg_dma_address(sg) = dma_buf;
562 			sg_dma_len(sg) = bytes;
563 			dma_buf += bytes;
564 			size -= bytes;
565 		}
566 
567 		buf->prepared = true;
568 
569 		vb2_set_plane_payload(&buf->vb.vb2_buf, 0, buf->size);
570 	}
571 
572 	return 0;
573 }
574 
575 static void dcmi_buf_queue(struct vb2_buffer *vb)
576 {
577 	struct stm32_dcmi *dcmi =  vb2_get_drv_priv(vb->vb2_queue);
578 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
579 	struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
580 
581 	spin_lock_irq(&dcmi->irqlock);
582 
583 	/* Enqueue to video buffers list */
584 	list_add_tail(&buf->list, &dcmi->buffers);
585 
586 	if (dcmi->state == WAIT_FOR_BUFFER) {
587 		dcmi->state = RUNNING;
588 		dcmi->active = buf;
589 
590 		dev_dbg(dcmi->dev, "Starting capture on buffer[%d] queued\n",
591 			buf->vb.vb2_buf.index);
592 
593 		spin_unlock_irq(&dcmi->irqlock);
594 		if (dcmi_start_capture(dcmi, buf))
595 			dev_err(dcmi->dev, "%s: Cannot restart capture on overflow or error\n",
596 				__func__);
597 		return;
598 	}
599 
600 	spin_unlock_irq(&dcmi->irqlock);
601 }
602 
603 static struct media_entity *dcmi_find_source(struct stm32_dcmi *dcmi)
604 {
605 	struct media_entity *entity = &dcmi->vdev->entity;
606 	struct media_pad *pad;
607 
608 	/* Walk searching for entity having no sink */
609 	while (1) {
610 		pad = &entity->pads[0];
611 		if (!(pad->flags & MEDIA_PAD_FL_SINK))
612 			break;
613 
614 		pad = media_pad_remote_pad_first(pad);
615 		if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
616 			break;
617 
618 		entity = pad->entity;
619 	}
620 
621 	return entity;
622 }
623 
624 static int dcmi_pipeline_s_fmt(struct stm32_dcmi *dcmi,
625 			       struct v4l2_subdev_format *format)
626 {
627 	struct media_entity *entity = &dcmi->source->entity;
628 	struct v4l2_subdev *subdev;
629 	struct media_pad *sink_pad = NULL;
630 	struct media_pad *src_pad = NULL;
631 	struct media_pad *pad = NULL;
632 	struct v4l2_subdev_format fmt = *format;
633 	bool found = false;
634 	int ret;
635 
636 	/*
637 	 * Starting from sensor subdevice, walk within
638 	 * pipeline and set format on each subdevice
639 	 */
640 	while (1) {
641 		unsigned int i;
642 
643 		/* Search if current entity has a source pad */
644 		for (i = 0; i < entity->num_pads; i++) {
645 			pad = &entity->pads[i];
646 			if (pad->flags & MEDIA_PAD_FL_SOURCE) {
647 				src_pad = pad;
648 				found = true;
649 				break;
650 			}
651 		}
652 		if (!found)
653 			break;
654 
655 		subdev = media_entity_to_v4l2_subdev(entity);
656 
657 		/* Propagate format on sink pad if any, otherwise source pad */
658 		if (sink_pad)
659 			pad = sink_pad;
660 
661 		dev_dbg(dcmi->dev, "\"%s\":%d pad format set to 0x%x %ux%u\n",
662 			subdev->name, pad->index, format->format.code,
663 			format->format.width, format->format.height);
664 
665 		fmt.pad = pad->index;
666 		ret = v4l2_subdev_call(subdev, pad, set_fmt, NULL, &fmt);
667 		if (ret < 0) {
668 			dev_err(dcmi->dev, "%s: Failed to set format 0x%x %ux%u on \"%s\":%d pad (%d)\n",
669 				__func__, format->format.code,
670 				format->format.width, format->format.height,
671 				subdev->name, pad->index, ret);
672 			return ret;
673 		}
674 
675 		if (fmt.format.code != format->format.code ||
676 		    fmt.format.width != format->format.width ||
677 		    fmt.format.height != format->format.height) {
678 			dev_dbg(dcmi->dev, "\"%s\":%d pad format has been changed to 0x%x %ux%u\n",
679 				subdev->name, pad->index, fmt.format.code,
680 				fmt.format.width, fmt.format.height);
681 		}
682 
683 		/* Walk to next entity */
684 		sink_pad = media_pad_remote_pad_first(src_pad);
685 		if (!sink_pad || !is_media_entity_v4l2_subdev(sink_pad->entity))
686 			break;
687 
688 		entity = sink_pad->entity;
689 	}
690 	*format = fmt;
691 
692 	return 0;
693 }
694 
695 static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
696 {
697 	struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);
698 	struct dcmi_buf *buf, *node;
699 	u32 val = 0;
700 	int ret;
701 
702 	ret = pm_runtime_resume_and_get(dcmi->dev);
703 	if (ret < 0) {
704 		dev_err(dcmi->dev, "%s: Failed to start streaming, cannot get sync (%d)\n",
705 			__func__, ret);
706 		goto err_unlocked;
707 	}
708 
709 	ret = video_device_pipeline_start(dcmi->vdev, &dcmi->pipeline);
710 	if (ret < 0) {
711 		dev_err(dcmi->dev, "%s: Failed to start streaming, media pipeline start error (%d)\n",
712 			__func__, ret);
713 		goto err_pm_put;
714 	}
715 
716 	ret = v4l2_subdev_call(dcmi->s_subdev, video, s_stream, 1);
717 	if (ret < 0) {
718 		dev_err(dcmi->dev, "%s: Failed to start source subdev, error (%d)\n",
719 			__func__, ret);
720 		goto err_media_pipeline_stop;
721 	}
722 
723 	spin_lock_irq(&dcmi->irqlock);
724 
725 	/* Set bus width */
726 	switch (dcmi->bus.bus_width) {
727 	case 14:
728 		val |= CR_EDM_0 | CR_EDM_1;
729 		break;
730 	case 12:
731 		val |= CR_EDM_1;
732 		break;
733 	case 10:
734 		val |= CR_EDM_0;
735 		break;
736 	default:
737 		/* Set bus width to 8 bits by default */
738 		break;
739 	}
740 
741 	/* Set vertical synchronization polarity */
742 	if (dcmi->bus.flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
743 		val |= CR_VSPOL;
744 
745 	/* Set horizontal synchronization polarity */
746 	if (dcmi->bus.flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
747 		val |= CR_HSPOL;
748 
749 	/* Set pixel clock polarity */
750 	if (dcmi->bus.flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
751 		val |= CR_PCKPOL;
752 
753 	/*
754 	 * BT656 embedded synchronisation bus mode.
755 	 *
756 	 * Default SAV/EAV mode is supported here with default codes
757 	 * SAV=0xff000080 & EAV=0xff00009d.
758 	 * With DCMI this means LSC=SAV=0x80 & LEC=EAV=0x9d.
759 	 */
760 	if (dcmi->bus_type == V4L2_MBUS_BT656) {
761 		val |= CR_ESS;
762 
763 		/* Unmask all codes */
764 		reg_write(dcmi->regs, DCMI_ESUR, 0xffffffff);/* FEC:LEC:LSC:FSC */
765 
766 		/* Trig on LSC=0x80 & LEC=0x9d codes, ignore FSC and FEC */
767 		reg_write(dcmi->regs, DCMI_ESCR, 0xff9d80ff);/* FEC:LEC:LSC:FSC */
768 	}
769 
770 	reg_write(dcmi->regs, DCMI_CR, val);
771 
772 	/* Set crop */
773 	if (dcmi->do_crop)
774 		dcmi_set_crop(dcmi);
775 
776 	/* Enable jpeg capture */
777 	if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG)
778 		reg_set(dcmi->regs, DCMI_CR, CR_CM);/* Snapshot mode */
779 
780 	/* Enable dcmi */
781 	reg_set(dcmi->regs, DCMI_CR, CR_ENABLE);
782 
783 	dcmi->sequence = 0;
784 	dcmi->errors_count = 0;
785 	dcmi->overrun_count = 0;
786 	dcmi->buffers_count = 0;
787 
788 	/*
789 	 * Start transfer if at least one buffer has been queued,
790 	 * otherwise transfer is deferred at buffer queueing
791 	 */
792 	if (list_empty(&dcmi->buffers)) {
793 		dev_dbg(dcmi->dev, "Start streaming is deferred to next buffer queueing\n");
794 		dcmi->state = WAIT_FOR_BUFFER;
795 		spin_unlock_irq(&dcmi->irqlock);
796 		return 0;
797 	}
798 
799 	buf = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
800 	dcmi->active = buf;
801 
802 	dcmi->state = RUNNING;
803 
804 	dev_dbg(dcmi->dev, "Start streaming, starting capture\n");
805 
806 	spin_unlock_irq(&dcmi->irqlock);
807 	ret = dcmi_start_capture(dcmi, buf);
808 	if (ret) {
809 		dev_err(dcmi->dev, "%s: Start streaming failed, cannot start capture\n",
810 			__func__);
811 		goto err_pipeline_stop;
812 	}
813 
814 	/* Enable interruptions */
815 	if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG)
816 		reg_set(dcmi->regs, DCMI_IER, IT_FRAME | IT_OVR | IT_ERR);
817 	else
818 		reg_set(dcmi->regs, DCMI_IER, IT_OVR | IT_ERR);
819 
820 	return 0;
821 
822 err_pipeline_stop:
823 	v4l2_subdev_call(dcmi->s_subdev, video, s_stream, 0);
824 
825 err_media_pipeline_stop:
826 	video_device_pipeline_stop(dcmi->vdev);
827 
828 err_pm_put:
829 	pm_runtime_put(dcmi->dev);
830 err_unlocked:
831 	spin_lock_irq(&dcmi->irqlock);
832 	/*
833 	 * Return all buffers to vb2 in QUEUED state.
834 	 * This will give ownership back to userspace
835 	 */
836 	list_for_each_entry_safe(buf, node, &dcmi->buffers, list) {
837 		list_del_init(&buf->list);
838 		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
839 	}
840 	dcmi->active = NULL;
841 	spin_unlock_irq(&dcmi->irqlock);
842 
843 	return ret;
844 }
845 
846 static void dcmi_stop_streaming(struct vb2_queue *vq)
847 {
848 	struct stm32_dcmi *dcmi = vb2_get_drv_priv(vq);
849 	struct dcmi_buf *buf, *node;
850 	int ret;
851 
852 	ret = v4l2_subdev_call(dcmi->s_subdev, video, s_stream, 0);
853 	if (ret < 0)
854 		dev_err(dcmi->dev, "%s: Failed to stop source subdev, error (%d)\n",
855 			__func__, ret);
856 
857 	video_device_pipeline_stop(dcmi->vdev);
858 
859 	spin_lock_irq(&dcmi->irqlock);
860 
861 	/* Disable interruptions */
862 	reg_clear(dcmi->regs, DCMI_IER, IT_FRAME | IT_OVR | IT_ERR);
863 
864 	/* Disable DCMI */
865 	reg_clear(dcmi->regs, DCMI_CR, CR_ENABLE);
866 
867 	/* Return all queued buffers to vb2 in ERROR state */
868 	list_for_each_entry_safe(buf, node, &dcmi->buffers, list) {
869 		list_del_init(&buf->list);
870 		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
871 	}
872 
873 	dcmi->active = NULL;
874 	dcmi->state = STOPPED;
875 
876 	spin_unlock_irq(&dcmi->irqlock);
877 
878 	/* Stop all pending DMA operations */
879 	mutex_lock(&dcmi->dma_lock);
880 	dmaengine_terminate_sync(dcmi->dma_chan);
881 	mutex_unlock(&dcmi->dma_lock);
882 
883 	pm_runtime_put(dcmi->dev);
884 
885 	if (dcmi->errors_count)
886 		dev_warn(dcmi->dev, "Some errors found while streaming: errors=%d (overrun=%d), buffers=%d\n",
887 			 dcmi->errors_count, dcmi->overrun_count,
888 			 dcmi->buffers_count);
889 	dev_dbg(dcmi->dev, "Stop streaming, errors=%d (overrun=%d), buffers=%d\n",
890 		dcmi->errors_count, dcmi->overrun_count,
891 		dcmi->buffers_count);
892 }
893 
894 static const struct vb2_ops dcmi_video_qops = {
895 	.queue_setup		= dcmi_queue_setup,
896 	.buf_init		= dcmi_buf_init,
897 	.buf_prepare		= dcmi_buf_prepare,
898 	.buf_queue		= dcmi_buf_queue,
899 	.start_streaming	= dcmi_start_streaming,
900 	.stop_streaming		= dcmi_stop_streaming,
901 };
902 
903 static int dcmi_g_fmt_vid_cap(struct file *file, void *priv,
904 			      struct v4l2_format *fmt)
905 {
906 	struct stm32_dcmi *dcmi = video_drvdata(file);
907 
908 	*fmt = dcmi->fmt;
909 
910 	return 0;
911 }
912 
913 static const struct dcmi_format *find_format_by_fourcc(struct stm32_dcmi *dcmi,
914 						       unsigned int fourcc)
915 {
916 	unsigned int num_formats = dcmi->num_of_sd_formats;
917 	const struct dcmi_format *fmt;
918 	unsigned int i;
919 
920 	for (i = 0; i < num_formats; i++) {
921 		fmt = dcmi->sd_formats[i];
922 		if (fmt->fourcc == fourcc)
923 			return fmt;
924 	}
925 
926 	return NULL;
927 }
928 
929 static void __find_outer_frame_size(struct stm32_dcmi *dcmi,
930 				    struct v4l2_pix_format *pix,
931 				    struct dcmi_framesize *framesize)
932 {
933 	struct dcmi_framesize *match = NULL;
934 	unsigned int i;
935 	unsigned int min_err = UINT_MAX;
936 
937 	for (i = 0; i < dcmi->num_of_sd_framesizes; i++) {
938 		struct dcmi_framesize *fsize = &dcmi->sd_framesizes[i];
939 		int w_err = (fsize->width - pix->width);
940 		int h_err = (fsize->height - pix->height);
941 		int err = w_err + h_err;
942 
943 		if (w_err >= 0 && h_err >= 0 && err < min_err) {
944 			min_err = err;
945 			match = fsize;
946 		}
947 	}
948 	if (!match)
949 		match = &dcmi->sd_framesizes[0];
950 
951 	*framesize = *match;
952 }
953 
954 static int dcmi_try_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f,
955 			const struct dcmi_format **sd_format,
956 			struct dcmi_framesize *sd_framesize)
957 {
958 	const struct dcmi_format *sd_fmt;
959 	struct dcmi_framesize sd_fsize;
960 	struct v4l2_pix_format *pix = &f->fmt.pix;
961 	struct v4l2_subdev_format format = {
962 		.which = V4L2_SUBDEV_FORMAT_TRY,
963 	};
964 	bool do_crop;
965 	int ret;
966 
967 	sd_fmt = find_format_by_fourcc(dcmi, pix->pixelformat);
968 	if (!sd_fmt) {
969 		if (!dcmi->num_of_sd_formats)
970 			return -ENODATA;
971 
972 		sd_fmt = dcmi->sd_formats[dcmi->num_of_sd_formats - 1];
973 		pix->pixelformat = sd_fmt->fourcc;
974 	}
975 
976 	/* Limit to hardware capabilities */
977 	pix->width = clamp(pix->width, MIN_WIDTH, MAX_WIDTH);
978 	pix->height = clamp(pix->height, MIN_HEIGHT, MAX_HEIGHT);
979 
980 	/* No crop if JPEG is requested */
981 	do_crop = dcmi->do_crop && (pix->pixelformat != V4L2_PIX_FMT_JPEG);
982 
983 	if (do_crop && dcmi->num_of_sd_framesizes) {
984 		struct dcmi_framesize outer_sd_fsize;
985 		/*
986 		 * If crop is requested and sensor have discrete frame sizes,
987 		 * select the frame size that is just larger than request
988 		 */
989 		__find_outer_frame_size(dcmi, pix, &outer_sd_fsize);
990 		pix->width = outer_sd_fsize.width;
991 		pix->height = outer_sd_fsize.height;
992 	}
993 
994 	v4l2_fill_mbus_format(&format.format, pix, sd_fmt->mbus_code);
995 	ret = v4l2_subdev_call_state_try(dcmi->source, pad, set_fmt, &format);
996 	if (ret < 0)
997 		return ret;
998 
999 	/* Update pix regarding to what sensor can do */
1000 	v4l2_fill_pix_format(pix, &format.format);
1001 
1002 	/* Save resolution that sensor can actually do */
1003 	sd_fsize.width = pix->width;
1004 	sd_fsize.height = pix->height;
1005 
1006 	if (do_crop) {
1007 		struct v4l2_rect c = dcmi->crop;
1008 		struct v4l2_rect max_rect;
1009 
1010 		/*
1011 		 * Adjust crop by making the intersection between
1012 		 * format resolution request and crop request
1013 		 */
1014 		max_rect.top = 0;
1015 		max_rect.left = 0;
1016 		max_rect.width = pix->width;
1017 		max_rect.height = pix->height;
1018 		v4l2_rect_map_inside(&c, &max_rect);
1019 		c.top  = clamp_t(s32, c.top, 0, pix->height - c.height);
1020 		c.left = clamp_t(s32, c.left, 0, pix->width - c.width);
1021 		dcmi->crop = c;
1022 
1023 		/* Adjust format resolution request to crop */
1024 		pix->width = dcmi->crop.width;
1025 		pix->height = dcmi->crop.height;
1026 	}
1027 
1028 	pix->field = V4L2_FIELD_NONE;
1029 	pix->bytesperline = pix->width * sd_fmt->bpp;
1030 	pix->sizeimage = pix->bytesperline * pix->height;
1031 
1032 	if (sd_format)
1033 		*sd_format = sd_fmt;
1034 	if (sd_framesize)
1035 		*sd_framesize = sd_fsize;
1036 
1037 	return 0;
1038 }
1039 
1040 static int dcmi_set_fmt(struct stm32_dcmi *dcmi, struct v4l2_format *f)
1041 {
1042 	struct v4l2_subdev_format format = {
1043 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1044 	};
1045 	const struct dcmi_format *sd_format;
1046 	struct dcmi_framesize sd_framesize;
1047 	struct v4l2_mbus_framefmt *mf = &format.format;
1048 	struct v4l2_pix_format *pix = &f->fmt.pix;
1049 	int ret;
1050 
1051 	/*
1052 	 * Try format, fmt.width/height could have been changed
1053 	 * to match sensor capability or crop request
1054 	 * sd_format & sd_framesize will contain what subdev
1055 	 * can do for this request.
1056 	 */
1057 	ret = dcmi_try_fmt(dcmi, f, &sd_format, &sd_framesize);
1058 	if (ret)
1059 		return ret;
1060 
1061 	/* Disable crop if JPEG is requested or BT656 bus is selected */
1062 	if (pix->pixelformat == V4L2_PIX_FMT_JPEG &&
1063 	    dcmi->bus_type != V4L2_MBUS_BT656)
1064 		dcmi->do_crop = false;
1065 
1066 	/* pix to mbus format */
1067 	v4l2_fill_mbus_format(mf, pix,
1068 			      sd_format->mbus_code);
1069 	mf->width = sd_framesize.width;
1070 	mf->height = sd_framesize.height;
1071 
1072 	ret = dcmi_pipeline_s_fmt(dcmi, &format);
1073 	if (ret < 0)
1074 		return ret;
1075 
1076 	dev_dbg(dcmi->dev, "Sensor format set to 0x%x %ux%u\n",
1077 		mf->code, mf->width, mf->height);
1078 	dev_dbg(dcmi->dev, "Buffer format set to %4.4s %ux%u\n",
1079 		(char *)&pix->pixelformat,
1080 		pix->width, pix->height);
1081 
1082 	dcmi->fmt = *f;
1083 	dcmi->sd_format = sd_format;
1084 	dcmi->sd_framesize = sd_framesize;
1085 
1086 	return 0;
1087 }
1088 
1089 static int dcmi_s_fmt_vid_cap(struct file *file, void *priv,
1090 			      struct v4l2_format *f)
1091 {
1092 	struct stm32_dcmi *dcmi = video_drvdata(file);
1093 
1094 	if (vb2_is_streaming(&dcmi->queue))
1095 		return -EBUSY;
1096 
1097 	return dcmi_set_fmt(dcmi, f);
1098 }
1099 
1100 static int dcmi_try_fmt_vid_cap(struct file *file, void *priv,
1101 				struct v4l2_format *f)
1102 {
1103 	struct stm32_dcmi *dcmi = video_drvdata(file);
1104 
1105 	return dcmi_try_fmt(dcmi, f, NULL, NULL);
1106 }
1107 
1108 static int dcmi_enum_fmt_vid_cap(struct file *file, void  *priv,
1109 				 struct v4l2_fmtdesc *f)
1110 {
1111 	struct stm32_dcmi *dcmi = video_drvdata(file);
1112 
1113 	if (f->index >= dcmi->num_of_sd_formats)
1114 		return -EINVAL;
1115 
1116 	f->pixelformat = dcmi->sd_formats[f->index]->fourcc;
1117 	return 0;
1118 }
1119 
1120 static int dcmi_get_sensor_format(struct stm32_dcmi *dcmi,
1121 				  struct v4l2_pix_format *pix)
1122 {
1123 	struct v4l2_subdev_format fmt = {
1124 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1125 	};
1126 	int ret;
1127 
1128 	ret = v4l2_subdev_call(dcmi->source, pad, get_fmt, NULL, &fmt);
1129 	if (ret)
1130 		return ret;
1131 
1132 	v4l2_fill_pix_format(pix, &fmt.format);
1133 
1134 	return 0;
1135 }
1136 
1137 static int dcmi_set_sensor_format(struct stm32_dcmi *dcmi,
1138 				  struct v4l2_pix_format *pix)
1139 {
1140 	const struct dcmi_format *sd_fmt;
1141 	struct v4l2_subdev_format format = {
1142 		.which = V4L2_SUBDEV_FORMAT_TRY,
1143 	};
1144 	int ret;
1145 
1146 	sd_fmt = find_format_by_fourcc(dcmi, pix->pixelformat);
1147 	if (!sd_fmt) {
1148 		if (!dcmi->num_of_sd_formats)
1149 			return -ENODATA;
1150 
1151 		sd_fmt = dcmi->sd_formats[dcmi->num_of_sd_formats - 1];
1152 		pix->pixelformat = sd_fmt->fourcc;
1153 	}
1154 
1155 	v4l2_fill_mbus_format(&format.format, pix, sd_fmt->mbus_code);
1156 	ret = v4l2_subdev_call_state_try(dcmi->source, pad, set_fmt, &format);
1157 	if (ret < 0)
1158 		return ret;
1159 
1160 	return 0;
1161 }
1162 
1163 static int dcmi_get_sensor_bounds(struct stm32_dcmi *dcmi,
1164 				  struct v4l2_rect *r)
1165 {
1166 	struct v4l2_subdev_selection bounds = {
1167 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1168 		.target = V4L2_SEL_TGT_CROP_BOUNDS,
1169 	};
1170 	unsigned int max_width, max_height, max_pixsize;
1171 	struct v4l2_pix_format pix;
1172 	unsigned int i;
1173 	int ret;
1174 
1175 	/*
1176 	 * Get sensor bounds first
1177 	 */
1178 	ret = v4l2_subdev_call(dcmi->source, pad, get_selection,
1179 			       NULL, &bounds);
1180 	if (!ret)
1181 		*r = bounds.r;
1182 	if (ret != -ENOIOCTLCMD)
1183 		return ret;
1184 
1185 	/*
1186 	 * If selection is not implemented,
1187 	 * fallback by enumerating sensor frame sizes
1188 	 * and take the largest one
1189 	 */
1190 	max_width = 0;
1191 	max_height = 0;
1192 	max_pixsize = 0;
1193 	for (i = 0; i < dcmi->num_of_sd_framesizes; i++) {
1194 		struct dcmi_framesize *fsize = &dcmi->sd_framesizes[i];
1195 		unsigned int pixsize = fsize->width * fsize->height;
1196 
1197 		if (pixsize > max_pixsize) {
1198 			max_pixsize = pixsize;
1199 			max_width = fsize->width;
1200 			max_height = fsize->height;
1201 		}
1202 	}
1203 	if (max_pixsize > 0) {
1204 		r->top = 0;
1205 		r->left = 0;
1206 		r->width = max_width;
1207 		r->height = max_height;
1208 		return 0;
1209 	}
1210 
1211 	/*
1212 	 * If frame sizes enumeration is not implemented,
1213 	 * fallback by getting current sensor frame size
1214 	 */
1215 	ret = dcmi_get_sensor_format(dcmi, &pix);
1216 	if (ret)
1217 		return ret;
1218 
1219 	r->top = 0;
1220 	r->left = 0;
1221 	r->width = pix.width;
1222 	r->height = pix.height;
1223 
1224 	return 0;
1225 }
1226 
1227 static int dcmi_g_selection(struct file *file, void *fh,
1228 			    struct v4l2_selection *s)
1229 {
1230 	struct stm32_dcmi *dcmi = video_drvdata(file);
1231 
1232 	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
1233 		return -EINVAL;
1234 
1235 	switch (s->target) {
1236 	case V4L2_SEL_TGT_CROP_DEFAULT:
1237 	case V4L2_SEL_TGT_CROP_BOUNDS:
1238 		s->r = dcmi->sd_bounds;
1239 		return 0;
1240 	case V4L2_SEL_TGT_CROP:
1241 		if (dcmi->do_crop) {
1242 			s->r = dcmi->crop;
1243 		} else {
1244 			s->r.top = 0;
1245 			s->r.left = 0;
1246 			s->r.width = dcmi->fmt.fmt.pix.width;
1247 			s->r.height = dcmi->fmt.fmt.pix.height;
1248 		}
1249 		break;
1250 	default:
1251 		return -EINVAL;
1252 	}
1253 
1254 	return 0;
1255 }
1256 
1257 static int dcmi_s_selection(struct file *file, void *priv,
1258 			    struct v4l2_selection *s)
1259 {
1260 	struct stm32_dcmi *dcmi = video_drvdata(file);
1261 	struct v4l2_rect r = s->r;
1262 	struct v4l2_rect max_rect;
1263 	struct v4l2_pix_format pix;
1264 
1265 	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
1266 	    s->target != V4L2_SEL_TGT_CROP)
1267 		return -EINVAL;
1268 
1269 	/* Reset sensor resolution to max resolution */
1270 	pix.pixelformat = dcmi->fmt.fmt.pix.pixelformat;
1271 	pix.width = dcmi->sd_bounds.width;
1272 	pix.height = dcmi->sd_bounds.height;
1273 	dcmi_set_sensor_format(dcmi, &pix);
1274 
1275 	/*
1276 	 * Make the intersection between
1277 	 * sensor resolution
1278 	 * and crop request
1279 	 */
1280 	max_rect.top = 0;
1281 	max_rect.left = 0;
1282 	max_rect.width = pix.width;
1283 	max_rect.height = pix.height;
1284 	v4l2_rect_map_inside(&r, &max_rect);
1285 	r.top  = clamp_t(s32, r.top, 0, pix.height - r.height);
1286 	r.left = clamp_t(s32, r.left, 0, pix.width - r.width);
1287 
1288 	if (!(r.top == dcmi->sd_bounds.top &&
1289 	      r.left == dcmi->sd_bounds.left &&
1290 	      r.width == dcmi->sd_bounds.width &&
1291 	      r.height == dcmi->sd_bounds.height)) {
1292 		/* Crop if request is different than sensor resolution */
1293 		dcmi->do_crop = true;
1294 		dcmi->crop = r;
1295 		dev_dbg(dcmi->dev, "s_selection: crop %ux%u@(%u,%u) from %ux%u\n",
1296 			r.width, r.height, r.left, r.top,
1297 			pix.width, pix.height);
1298 	} else {
1299 		/* Disable crop */
1300 		dcmi->do_crop = false;
1301 		dev_dbg(dcmi->dev, "s_selection: crop is disabled\n");
1302 	}
1303 
1304 	s->r = r;
1305 	return 0;
1306 }
1307 
1308 static int dcmi_querycap(struct file *file, void *priv,
1309 			 struct v4l2_capability *cap)
1310 {
1311 	strscpy(cap->driver, DRV_NAME, sizeof(cap->driver));
1312 	strscpy(cap->card, "STM32 Camera Memory Interface",
1313 		sizeof(cap->card));
1314 	strscpy(cap->bus_info, "platform:dcmi", sizeof(cap->bus_info));
1315 	return 0;
1316 }
1317 
1318 static int dcmi_enum_input(struct file *file, void *priv,
1319 			   struct v4l2_input *i)
1320 {
1321 	if (i->index != 0)
1322 		return -EINVAL;
1323 
1324 	i->type = V4L2_INPUT_TYPE_CAMERA;
1325 	strscpy(i->name, "Camera", sizeof(i->name));
1326 	return 0;
1327 }
1328 
1329 static int dcmi_g_input(struct file *file, void *priv, unsigned int *i)
1330 {
1331 	*i = 0;
1332 	return 0;
1333 }
1334 
1335 static int dcmi_s_input(struct file *file, void *priv, unsigned int i)
1336 {
1337 	if (i > 0)
1338 		return -EINVAL;
1339 	return 0;
1340 }
1341 
1342 static int dcmi_enum_framesizes(struct file *file, void *fh,
1343 				struct v4l2_frmsizeenum *fsize)
1344 {
1345 	struct stm32_dcmi *dcmi = video_drvdata(file);
1346 	const struct dcmi_format *sd_fmt;
1347 	struct v4l2_subdev_frame_size_enum fse = {
1348 		.index = fsize->index,
1349 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1350 	};
1351 	int ret;
1352 
1353 	sd_fmt = find_format_by_fourcc(dcmi, fsize->pixel_format);
1354 	if (!sd_fmt)
1355 		return -EINVAL;
1356 
1357 	fse.code = sd_fmt->mbus_code;
1358 
1359 	ret = v4l2_subdev_call(dcmi->source, pad, enum_frame_size,
1360 			       NULL, &fse);
1361 	if (ret)
1362 		return ret;
1363 
1364 	fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
1365 	fsize->discrete.width = fse.max_width;
1366 	fsize->discrete.height = fse.max_height;
1367 
1368 	return 0;
1369 }
1370 
1371 static int dcmi_g_parm(struct file *file, void *priv,
1372 		       struct v4l2_streamparm *p)
1373 {
1374 	struct stm32_dcmi *dcmi = video_drvdata(file);
1375 
1376 	return v4l2_g_parm_cap(video_devdata(file), dcmi->source, p);
1377 }
1378 
1379 static int dcmi_s_parm(struct file *file, void *priv,
1380 		       struct v4l2_streamparm *p)
1381 {
1382 	struct stm32_dcmi *dcmi = video_drvdata(file);
1383 
1384 	return v4l2_s_parm_cap(video_devdata(file), dcmi->source, p);
1385 }
1386 
1387 static int dcmi_enum_frameintervals(struct file *file, void *fh,
1388 				    struct v4l2_frmivalenum *fival)
1389 {
1390 	struct stm32_dcmi *dcmi = video_drvdata(file);
1391 	const struct dcmi_format *sd_fmt;
1392 	struct v4l2_subdev_frame_interval_enum fie = {
1393 		.index = fival->index,
1394 		.width = fival->width,
1395 		.height = fival->height,
1396 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1397 	};
1398 	int ret;
1399 
1400 	sd_fmt = find_format_by_fourcc(dcmi, fival->pixel_format);
1401 	if (!sd_fmt)
1402 		return -EINVAL;
1403 
1404 	fie.code = sd_fmt->mbus_code;
1405 
1406 	ret = v4l2_subdev_call(dcmi->source, pad,
1407 			       enum_frame_interval, NULL, &fie);
1408 	if (ret)
1409 		return ret;
1410 
1411 	fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
1412 	fival->discrete = fie.interval;
1413 
1414 	return 0;
1415 }
1416 
1417 static const struct of_device_id stm32_dcmi_of_match[] = {
1418 	{ .compatible = "st,stm32-dcmi"},
1419 	{ /* end node */ },
1420 };
1421 MODULE_DEVICE_TABLE(of, stm32_dcmi_of_match);
1422 
1423 static int dcmi_open(struct file *file)
1424 {
1425 	struct stm32_dcmi *dcmi = video_drvdata(file);
1426 	struct v4l2_subdev *sd = dcmi->source;
1427 	int ret;
1428 
1429 	if (mutex_lock_interruptible(&dcmi->lock))
1430 		return -ERESTARTSYS;
1431 
1432 	ret = v4l2_fh_open(file);
1433 	if (ret < 0)
1434 		goto unlock;
1435 
1436 	if (!v4l2_fh_is_singular_file(file))
1437 		goto fh_rel;
1438 
1439 	ret = v4l2_subdev_call(sd, core, s_power, 1);
1440 	if (ret < 0 && ret != -ENOIOCTLCMD)
1441 		goto fh_rel;
1442 
1443 	ret = dcmi_set_fmt(dcmi, &dcmi->fmt);
1444 	if (ret)
1445 		v4l2_subdev_call(sd, core, s_power, 0);
1446 fh_rel:
1447 	if (ret)
1448 		v4l2_fh_release(file);
1449 unlock:
1450 	mutex_unlock(&dcmi->lock);
1451 	return ret;
1452 }
1453 
1454 static int dcmi_release(struct file *file)
1455 {
1456 	struct stm32_dcmi *dcmi = video_drvdata(file);
1457 	struct v4l2_subdev *sd = dcmi->source;
1458 	bool fh_singular;
1459 	int ret;
1460 
1461 	mutex_lock(&dcmi->lock);
1462 
1463 	fh_singular = v4l2_fh_is_singular_file(file);
1464 
1465 	ret = _vb2_fop_release(file, NULL);
1466 
1467 	if (fh_singular)
1468 		v4l2_subdev_call(sd, core, s_power, 0);
1469 
1470 	mutex_unlock(&dcmi->lock);
1471 
1472 	return ret;
1473 }
1474 
1475 static const struct v4l2_ioctl_ops dcmi_ioctl_ops = {
1476 	.vidioc_querycap		= dcmi_querycap,
1477 
1478 	.vidioc_try_fmt_vid_cap		= dcmi_try_fmt_vid_cap,
1479 	.vidioc_g_fmt_vid_cap		= dcmi_g_fmt_vid_cap,
1480 	.vidioc_s_fmt_vid_cap		= dcmi_s_fmt_vid_cap,
1481 	.vidioc_enum_fmt_vid_cap	= dcmi_enum_fmt_vid_cap,
1482 	.vidioc_g_selection		= dcmi_g_selection,
1483 	.vidioc_s_selection		= dcmi_s_selection,
1484 
1485 	.vidioc_enum_input		= dcmi_enum_input,
1486 	.vidioc_g_input			= dcmi_g_input,
1487 	.vidioc_s_input			= dcmi_s_input,
1488 
1489 	.vidioc_g_parm			= dcmi_g_parm,
1490 	.vidioc_s_parm			= dcmi_s_parm,
1491 
1492 	.vidioc_enum_framesizes		= dcmi_enum_framesizes,
1493 	.vidioc_enum_frameintervals	= dcmi_enum_frameintervals,
1494 
1495 	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
1496 	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
1497 	.vidioc_querybuf		= vb2_ioctl_querybuf,
1498 	.vidioc_qbuf			= vb2_ioctl_qbuf,
1499 	.vidioc_dqbuf			= vb2_ioctl_dqbuf,
1500 	.vidioc_expbuf			= vb2_ioctl_expbuf,
1501 	.vidioc_prepare_buf		= vb2_ioctl_prepare_buf,
1502 	.vidioc_streamon		= vb2_ioctl_streamon,
1503 	.vidioc_streamoff		= vb2_ioctl_streamoff,
1504 
1505 	.vidioc_log_status		= v4l2_ctrl_log_status,
1506 	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
1507 	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
1508 };
1509 
1510 static const struct v4l2_file_operations dcmi_fops = {
1511 	.owner		= THIS_MODULE,
1512 	.unlocked_ioctl	= video_ioctl2,
1513 	.open		= dcmi_open,
1514 	.release	= dcmi_release,
1515 	.poll		= vb2_fop_poll,
1516 	.mmap		= vb2_fop_mmap,
1517 #ifndef CONFIG_MMU
1518 	.get_unmapped_area = vb2_fop_get_unmapped_area,
1519 #endif
1520 	.read		= vb2_fop_read,
1521 };
1522 
1523 static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
1524 {
1525 	struct v4l2_format f = {
1526 		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
1527 		.fmt.pix = {
1528 			.width		= CIF_WIDTH,
1529 			.height		= CIF_HEIGHT,
1530 			.field		= V4L2_FIELD_NONE,
1531 			.pixelformat	= dcmi->sd_formats[0]->fourcc,
1532 		},
1533 	};
1534 	int ret;
1535 
1536 	ret = dcmi_try_fmt(dcmi, &f, NULL, NULL);
1537 	if (ret)
1538 		return ret;
1539 	dcmi->sd_format = dcmi->sd_formats[0];
1540 	dcmi->fmt = f;
1541 	return 0;
1542 }
1543 
1544 static const struct dcmi_format dcmi_formats[] = {
1545 	{
1546 		.fourcc = V4L2_PIX_FMT_RGB565,
1547 		.mbus_code = MEDIA_BUS_FMT_RGB565_2X8_LE,
1548 		.bpp = 2,
1549 	}, {
1550 		.fourcc = V4L2_PIX_FMT_RGB565,
1551 		.mbus_code = MEDIA_BUS_FMT_RGB565_1X16,
1552 		.bpp = 2,
1553 	}, {
1554 		.fourcc = V4L2_PIX_FMT_YUYV,
1555 		.mbus_code = MEDIA_BUS_FMT_YUYV8_2X8,
1556 		.bpp = 2,
1557 	}, {
1558 		.fourcc = V4L2_PIX_FMT_YUYV,
1559 		.mbus_code = MEDIA_BUS_FMT_YUYV8_1X16,
1560 		.bpp = 2,
1561 	}, {
1562 		.fourcc = V4L2_PIX_FMT_UYVY,
1563 		.mbus_code = MEDIA_BUS_FMT_UYVY8_2X8,
1564 		.bpp = 2,
1565 	}, {
1566 		.fourcc = V4L2_PIX_FMT_UYVY,
1567 		.mbus_code = MEDIA_BUS_FMT_UYVY8_1X16,
1568 		.bpp = 2,
1569 	}, {
1570 		.fourcc = V4L2_PIX_FMT_JPEG,
1571 		.mbus_code = MEDIA_BUS_FMT_JPEG_1X8,
1572 		.bpp = 1,
1573 	}, {
1574 		.fourcc = V4L2_PIX_FMT_SBGGR8,
1575 		.mbus_code = MEDIA_BUS_FMT_SBGGR8_1X8,
1576 		.bpp = 1,
1577 	}, {
1578 		.fourcc = V4L2_PIX_FMT_SGBRG8,
1579 		.mbus_code = MEDIA_BUS_FMT_SGBRG8_1X8,
1580 		.bpp = 1,
1581 	}, {
1582 		.fourcc = V4L2_PIX_FMT_SGRBG8,
1583 		.mbus_code = MEDIA_BUS_FMT_SGRBG8_1X8,
1584 		.bpp = 1,
1585 	}, {
1586 		.fourcc = V4L2_PIX_FMT_SRGGB8,
1587 		.mbus_code = MEDIA_BUS_FMT_SRGGB8_1X8,
1588 		.bpp = 1,
1589 	}, {
1590 		.fourcc = V4L2_PIX_FMT_SBGGR10,
1591 		.mbus_code = MEDIA_BUS_FMT_SBGGR10_1X10,
1592 		.bpp = 2,
1593 	}, {
1594 		.fourcc = V4L2_PIX_FMT_SGBRG10,
1595 		.mbus_code = MEDIA_BUS_FMT_SGBRG10_1X10,
1596 		.bpp = 2,
1597 	}, {
1598 		.fourcc = V4L2_PIX_FMT_SGRBG10,
1599 		.mbus_code = MEDIA_BUS_FMT_SGRBG10_1X10,
1600 		.bpp = 2,
1601 	}, {
1602 		.fourcc = V4L2_PIX_FMT_SRGGB10,
1603 		.mbus_code = MEDIA_BUS_FMT_SRGGB10_1X10,
1604 		.bpp = 2,
1605 	}, {
1606 		.fourcc = V4L2_PIX_FMT_SBGGR12,
1607 		.mbus_code = MEDIA_BUS_FMT_SBGGR12_1X12,
1608 		.bpp = 2,
1609 	}, {
1610 		.fourcc = V4L2_PIX_FMT_SGBRG12,
1611 		.mbus_code = MEDIA_BUS_FMT_SGBRG12_1X12,
1612 		.bpp = 2,
1613 	}, {
1614 		.fourcc = V4L2_PIX_FMT_SGRBG12,
1615 		.mbus_code = MEDIA_BUS_FMT_SGRBG12_1X12,
1616 		.bpp = 2,
1617 	}, {
1618 		.fourcc = V4L2_PIX_FMT_SRGGB12,
1619 		.mbus_code = MEDIA_BUS_FMT_SRGGB12_1X12,
1620 		.bpp = 2,
1621 	}, {
1622 		.fourcc = V4L2_PIX_FMT_SBGGR14,
1623 		.mbus_code = MEDIA_BUS_FMT_SBGGR14_1X14,
1624 		.bpp = 2,
1625 	}, {
1626 		.fourcc = V4L2_PIX_FMT_SGBRG14,
1627 		.mbus_code = MEDIA_BUS_FMT_SGBRG14_1X14,
1628 		.bpp = 2,
1629 	}, {
1630 		.fourcc = V4L2_PIX_FMT_SGRBG14,
1631 		.mbus_code = MEDIA_BUS_FMT_SGRBG14_1X14,
1632 		.bpp = 2,
1633 	}, {
1634 		.fourcc = V4L2_PIX_FMT_SRGGB14,
1635 		.mbus_code = MEDIA_BUS_FMT_SRGGB14_1X14,
1636 		.bpp = 2,
1637 	},
1638 };
1639 
1640 static int dcmi_formats_init(struct stm32_dcmi *dcmi)
1641 {
1642 	const struct dcmi_format *sd_fmts[ARRAY_SIZE(dcmi_formats)];
1643 	unsigned int num_fmts = 0, i, j;
1644 	struct v4l2_subdev *subdev = dcmi->source;
1645 	struct v4l2_subdev_mbus_code_enum mbus_code = {
1646 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1647 	};
1648 
1649 	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
1650 				 NULL, &mbus_code)) {
1651 		for (i = 0; i < ARRAY_SIZE(dcmi_formats); i++) {
1652 			if (dcmi_formats[i].mbus_code != mbus_code.code)
1653 				continue;
1654 
1655 			/* Exclude JPEG if BT656 bus is selected */
1656 			if (dcmi_formats[i].fourcc == V4L2_PIX_FMT_JPEG &&
1657 			    dcmi->bus_type == V4L2_MBUS_BT656)
1658 				continue;
1659 
1660 			/* Code supported, have we got this fourcc yet? */
1661 			for (j = 0; j < num_fmts; j++)
1662 				if (sd_fmts[j]->fourcc ==
1663 						dcmi_formats[i].fourcc) {
1664 					/* Already available */
1665 					dev_dbg(dcmi->dev, "Skipping fourcc/code: %4.4s/0x%x\n",
1666 						(char *)&sd_fmts[j]->fourcc,
1667 						mbus_code.code);
1668 					break;
1669 				}
1670 			if (j == num_fmts) {
1671 				/* New */
1672 				sd_fmts[num_fmts++] = dcmi_formats + i;
1673 				dev_dbg(dcmi->dev, "Supported fourcc/code: %4.4s/0x%x\n",
1674 					(char *)&sd_fmts[num_fmts - 1]->fourcc,
1675 					sd_fmts[num_fmts - 1]->mbus_code);
1676 			}
1677 		}
1678 		mbus_code.index++;
1679 	}
1680 
1681 	if (!num_fmts)
1682 		return -ENXIO;
1683 
1684 	dcmi->num_of_sd_formats = num_fmts;
1685 	dcmi->sd_formats = devm_kcalloc(dcmi->dev,
1686 					num_fmts, sizeof(struct dcmi_format *),
1687 					GFP_KERNEL);
1688 	if (!dcmi->sd_formats) {
1689 		dev_err(dcmi->dev, "Could not allocate memory\n");
1690 		return -ENOMEM;
1691 	}
1692 
1693 	memcpy(dcmi->sd_formats, sd_fmts,
1694 	       num_fmts * sizeof(struct dcmi_format *));
1695 	dcmi->sd_format = dcmi->sd_formats[0];
1696 
1697 	return 0;
1698 }
1699 
1700 static int dcmi_framesizes_init(struct stm32_dcmi *dcmi)
1701 {
1702 	unsigned int num_fsize = 0;
1703 	struct v4l2_subdev *subdev = dcmi->source;
1704 	struct v4l2_subdev_frame_size_enum fse = {
1705 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
1706 		.code = dcmi->sd_format->mbus_code,
1707 	};
1708 	unsigned int ret;
1709 	unsigned int i;
1710 
1711 	/* Allocate discrete framesizes array */
1712 	while (!v4l2_subdev_call(subdev, pad, enum_frame_size,
1713 				 NULL, &fse))
1714 		fse.index++;
1715 
1716 	num_fsize = fse.index;
1717 	if (!num_fsize)
1718 		return 0;
1719 
1720 	dcmi->num_of_sd_framesizes = num_fsize;
1721 	dcmi->sd_framesizes = devm_kcalloc(dcmi->dev, num_fsize,
1722 					   sizeof(struct dcmi_framesize),
1723 					   GFP_KERNEL);
1724 	if (!dcmi->sd_framesizes) {
1725 		dev_err(dcmi->dev, "Could not allocate memory\n");
1726 		return -ENOMEM;
1727 	}
1728 
1729 	/* Fill array with sensor supported framesizes */
1730 	dev_dbg(dcmi->dev, "Sensor supports %u frame sizes:\n", num_fsize);
1731 	for (i = 0; i < dcmi->num_of_sd_framesizes; i++) {
1732 		fse.index = i;
1733 		ret = v4l2_subdev_call(subdev, pad, enum_frame_size,
1734 				       NULL, &fse);
1735 		if (ret)
1736 			return ret;
1737 		dcmi->sd_framesizes[fse.index].width = fse.max_width;
1738 		dcmi->sd_framesizes[fse.index].height = fse.max_height;
1739 		dev_dbg(dcmi->dev, "%ux%u\n", fse.max_width, fse.max_height);
1740 	}
1741 
1742 	return 0;
1743 }
1744 
1745 static int dcmi_graph_notify_complete(struct v4l2_async_notifier *notifier)
1746 {
1747 	struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier);
1748 	int ret;
1749 
1750 	/*
1751 	 * Now that the graph is complete,
1752 	 * we search for the source subdevice
1753 	 * in order to expose it through V4L2 interface
1754 	 */
1755 	dcmi->source = media_entity_to_v4l2_subdev(dcmi_find_source(dcmi));
1756 	if (!dcmi->source) {
1757 		dev_err(dcmi->dev, "Source subdevice not found\n");
1758 		return -ENODEV;
1759 	}
1760 
1761 	dcmi->vdev->ctrl_handler = dcmi->source->ctrl_handler;
1762 
1763 	ret = dcmi_formats_init(dcmi);
1764 	if (ret) {
1765 		dev_err(dcmi->dev, "No supported mediabus format found\n");
1766 		return ret;
1767 	}
1768 
1769 	ret = dcmi_framesizes_init(dcmi);
1770 	if (ret) {
1771 		dev_err(dcmi->dev, "Could not initialize framesizes\n");
1772 		return ret;
1773 	}
1774 
1775 	ret = dcmi_get_sensor_bounds(dcmi, &dcmi->sd_bounds);
1776 	if (ret) {
1777 		dev_err(dcmi->dev, "Could not get sensor bounds\n");
1778 		return ret;
1779 	}
1780 
1781 	ret = dcmi_set_default_fmt(dcmi);
1782 	if (ret) {
1783 		dev_err(dcmi->dev, "Could not set default format\n");
1784 		return ret;
1785 	}
1786 
1787 	ret = devm_request_threaded_irq(dcmi->dev, dcmi->irq, dcmi_irq_callback,
1788 					dcmi_irq_thread, IRQF_ONESHOT,
1789 					dev_name(dcmi->dev), dcmi);
1790 	if (ret) {
1791 		dev_err(dcmi->dev, "Unable to request irq %d\n", dcmi->irq);
1792 		return ret;
1793 	}
1794 
1795 	return 0;
1796 }
1797 
1798 static void dcmi_graph_notify_unbind(struct v4l2_async_notifier *notifier,
1799 				     struct v4l2_subdev *sd,
1800 				     struct v4l2_async_connection *asd)
1801 {
1802 	struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier);
1803 
1804 	dev_dbg(dcmi->dev, "Removing %s\n", video_device_node_name(dcmi->vdev));
1805 
1806 	/* Checks internally if vdev has been init or not */
1807 	video_unregister_device(dcmi->vdev);
1808 }
1809 
1810 static int dcmi_graph_notify_bound(struct v4l2_async_notifier *notifier,
1811 				   struct v4l2_subdev *subdev,
1812 				   struct v4l2_async_connection *asd)
1813 {
1814 	struct stm32_dcmi *dcmi = notifier_to_dcmi(notifier);
1815 	unsigned int ret;
1816 	int src_pad;
1817 
1818 	dev_dbg(dcmi->dev, "Subdev \"%s\" bound\n", subdev->name);
1819 
1820 	/*
1821 	 * Link this sub-device to DCMI, it could be
1822 	 * a parallel camera sensor or a bridge
1823 	 */
1824 	src_pad = media_entity_get_fwnode_pad(&subdev->entity,
1825 					      subdev->fwnode,
1826 					      MEDIA_PAD_FL_SOURCE);
1827 
1828 	ret = media_create_pad_link(&subdev->entity, src_pad,
1829 				    &dcmi->vdev->entity, 0,
1830 				    MEDIA_LNK_FL_IMMUTABLE |
1831 				    MEDIA_LNK_FL_ENABLED);
1832 	if (ret)
1833 		dev_err(dcmi->dev, "Failed to create media pad link with subdev \"%s\"\n",
1834 			subdev->name);
1835 	else
1836 		dev_dbg(dcmi->dev, "DCMI is now linked to \"%s\"\n",
1837 			subdev->name);
1838 
1839 	dcmi->s_subdev = subdev;
1840 
1841 	return ret;
1842 }
1843 
1844 static const struct v4l2_async_notifier_operations dcmi_graph_notify_ops = {
1845 	.bound = dcmi_graph_notify_bound,
1846 	.unbind = dcmi_graph_notify_unbind,
1847 	.complete = dcmi_graph_notify_complete,
1848 };
1849 
1850 static int dcmi_graph_init(struct stm32_dcmi *dcmi)
1851 {
1852 	struct v4l2_async_connection *asd;
1853 	struct device_node *ep;
1854 	int ret;
1855 
1856 	ep = of_graph_get_endpoint_by_regs(dcmi->dev->of_node, 0, -1);
1857 	if (!ep) {
1858 		dev_err(dcmi->dev, "Failed to get next endpoint\n");
1859 		return -EINVAL;
1860 	}
1861 
1862 	v4l2_async_nf_init(&dcmi->notifier, &dcmi->v4l2_dev);
1863 
1864 	asd = v4l2_async_nf_add_fwnode_remote(&dcmi->notifier,
1865 					      of_fwnode_handle(ep),
1866 					      struct v4l2_async_connection);
1867 
1868 	of_node_put(ep);
1869 
1870 	if (IS_ERR(asd)) {
1871 		dev_err(dcmi->dev, "Failed to add subdev notifier\n");
1872 		return PTR_ERR(asd);
1873 	}
1874 
1875 	dcmi->notifier.ops = &dcmi_graph_notify_ops;
1876 
1877 	ret = v4l2_async_nf_register(&dcmi->notifier);
1878 	if (ret < 0) {
1879 		dev_err(dcmi->dev, "Failed to register notifier\n");
1880 		v4l2_async_nf_cleanup(&dcmi->notifier);
1881 		return ret;
1882 	}
1883 
1884 	return 0;
1885 }
1886 
1887 static int dcmi_probe(struct platform_device *pdev)
1888 {
1889 	struct device_node *np = pdev->dev.of_node;
1890 	struct v4l2_fwnode_endpoint ep = { .bus_type = 0 };
1891 	struct stm32_dcmi *dcmi;
1892 	struct vb2_queue *q;
1893 	struct dma_chan *chan;
1894 	struct dma_slave_caps caps;
1895 	struct clk *mclk;
1896 	int ret = 0;
1897 
1898 	dcmi = devm_kzalloc(&pdev->dev, sizeof(struct stm32_dcmi), GFP_KERNEL);
1899 	if (!dcmi)
1900 		return -ENOMEM;
1901 
1902 	dcmi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
1903 	if (IS_ERR(dcmi->rstc))
1904 		return dev_err_probe(&pdev->dev, PTR_ERR(dcmi->rstc),
1905 				     "Could not get reset control\n");
1906 
1907 	/* Get bus characteristics from devicetree */
1908 	np = of_graph_get_endpoint_by_regs(np, 0, -1);
1909 	if (!np) {
1910 		dev_err(&pdev->dev, "Could not find the endpoint\n");
1911 		return -ENODEV;
1912 	}
1913 
1914 	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(np), &ep);
1915 	of_node_put(np);
1916 	if (ret) {
1917 		dev_err(&pdev->dev, "Could not parse the endpoint\n");
1918 		return ret;
1919 	}
1920 
1921 	if (ep.bus_type == V4L2_MBUS_CSI2_DPHY) {
1922 		dev_err(&pdev->dev, "CSI bus not supported\n");
1923 		return -ENODEV;
1924 	}
1925 
1926 	if (ep.bus_type == V4L2_MBUS_BT656 &&
1927 	    ep.bus.parallel.bus_width != 8) {
1928 		dev_err(&pdev->dev, "BT656 bus conflicts with %u bits bus width (8 bits required)\n",
1929 			ep.bus.parallel.bus_width);
1930 		return -ENODEV;
1931 	}
1932 
1933 	dcmi->bus.flags = ep.bus.parallel.flags;
1934 	dcmi->bus.bus_width = ep.bus.parallel.bus_width;
1935 	dcmi->bus.data_shift = ep.bus.parallel.data_shift;
1936 	dcmi->bus_type = ep.bus_type;
1937 
1938 	dcmi->irq = platform_get_irq(pdev, 0);
1939 	if (dcmi->irq < 0)
1940 		return dcmi->irq;
1941 
1942 	dcmi->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &dcmi->res);
1943 	if (IS_ERR(dcmi->regs))
1944 		return PTR_ERR(dcmi->regs);
1945 
1946 	mclk = devm_clk_get(&pdev->dev, "mclk");
1947 	if (IS_ERR(mclk))
1948 		return dev_err_probe(&pdev->dev, PTR_ERR(mclk),
1949 				     "Unable to get mclk\n");
1950 
1951 	chan = dma_request_chan(&pdev->dev, "tx");
1952 	if (IS_ERR(chan))
1953 		return dev_err_probe(&pdev->dev, PTR_ERR(chan),
1954 				     "Failed to request DMA channel\n");
1955 
1956 	dcmi->dma_max_burst = UINT_MAX;
1957 	ret = dma_get_slave_caps(chan, &caps);
1958 	if (!ret && caps.max_sg_burst)
1959 		dcmi->dma_max_burst = caps.max_sg_burst	* DMA_SLAVE_BUSWIDTH_4_BYTES;
1960 
1961 	spin_lock_init(&dcmi->irqlock);
1962 	mutex_init(&dcmi->lock);
1963 	mutex_init(&dcmi->dma_lock);
1964 	init_completion(&dcmi->complete);
1965 	INIT_LIST_HEAD(&dcmi->buffers);
1966 
1967 	dcmi->dev = &pdev->dev;
1968 	dcmi->mclk = mclk;
1969 	dcmi->state = STOPPED;
1970 	dcmi->dma_chan = chan;
1971 
1972 	q = &dcmi->queue;
1973 
1974 	dcmi->v4l2_dev.mdev = &dcmi->mdev;
1975 
1976 	/* Initialize media device */
1977 	strscpy(dcmi->mdev.model, DRV_NAME, sizeof(dcmi->mdev.model));
1978 	dcmi->mdev.dev = &pdev->dev;
1979 	media_device_init(&dcmi->mdev);
1980 
1981 	/* Initialize the top-level structure */
1982 	ret = v4l2_device_register(&pdev->dev, &dcmi->v4l2_dev);
1983 	if (ret)
1984 		goto err_media_device_cleanup;
1985 
1986 	dcmi->vdev = video_device_alloc();
1987 	if (!dcmi->vdev) {
1988 		ret = -ENOMEM;
1989 		goto err_device_unregister;
1990 	}
1991 
1992 	/* Video node */
1993 	dcmi->vdev->fops = &dcmi_fops;
1994 	dcmi->vdev->v4l2_dev = &dcmi->v4l2_dev;
1995 	dcmi->vdev->queue = &dcmi->queue;
1996 	strscpy(dcmi->vdev->name, KBUILD_MODNAME, sizeof(dcmi->vdev->name));
1997 	dcmi->vdev->release = video_device_release;
1998 	dcmi->vdev->ioctl_ops = &dcmi_ioctl_ops;
1999 	dcmi->vdev->lock = &dcmi->lock;
2000 	dcmi->vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
2001 				  V4L2_CAP_READWRITE;
2002 	video_set_drvdata(dcmi->vdev, dcmi);
2003 
2004 	/* Media entity pads */
2005 	dcmi->vid_cap_pad.flags = MEDIA_PAD_FL_SINK;
2006 	ret = media_entity_pads_init(&dcmi->vdev->entity,
2007 				     1, &dcmi->vid_cap_pad);
2008 	if (ret) {
2009 		dev_err(dcmi->dev, "Failed to init media entity pad\n");
2010 		goto err_device_release;
2011 	}
2012 	dcmi->vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
2013 
2014 	ret = video_register_device(dcmi->vdev, VFL_TYPE_VIDEO, -1);
2015 	if (ret) {
2016 		dev_err(dcmi->dev, "Failed to register video device\n");
2017 		goto err_media_entity_cleanup;
2018 	}
2019 
2020 	dev_dbg(dcmi->dev, "Device registered as %s\n",
2021 		video_device_node_name(dcmi->vdev));
2022 
2023 	/* Buffer queue */
2024 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
2025 	q->io_modes = VB2_MMAP | VB2_READ | VB2_DMABUF;
2026 	q->lock = &dcmi->lock;
2027 	q->drv_priv = dcmi;
2028 	q->buf_struct_size = sizeof(struct dcmi_buf);
2029 	q->ops = &dcmi_video_qops;
2030 	q->mem_ops = &vb2_dma_contig_memops;
2031 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
2032 	q->min_queued_buffers = 2;
2033 	q->allow_cache_hints = 1;
2034 	q->dev = &pdev->dev;
2035 
2036 	ret = vb2_queue_init(q);
2037 	if (ret < 0) {
2038 		dev_err(&pdev->dev, "Failed to initialize vb2 queue\n");
2039 		goto err_media_entity_cleanup;
2040 	}
2041 
2042 	ret = dcmi_graph_init(dcmi);
2043 	if (ret < 0)
2044 		goto err_media_entity_cleanup;
2045 
2046 	/* Reset device */
2047 	ret = reset_control_assert(dcmi->rstc);
2048 	if (ret) {
2049 		dev_err(&pdev->dev, "Failed to assert the reset line\n");
2050 		goto err_cleanup;
2051 	}
2052 
2053 	usleep_range(3000, 5000);
2054 
2055 	ret = reset_control_deassert(dcmi->rstc);
2056 	if (ret) {
2057 		dev_err(&pdev->dev, "Failed to deassert the reset line\n");
2058 		goto err_cleanup;
2059 	}
2060 
2061 	dev_info(&pdev->dev, "Probe done\n");
2062 
2063 	platform_set_drvdata(pdev, dcmi);
2064 
2065 	pm_runtime_enable(&pdev->dev);
2066 
2067 	return 0;
2068 
2069 err_cleanup:
2070 	v4l2_async_nf_cleanup(&dcmi->notifier);
2071 err_media_entity_cleanup:
2072 	media_entity_cleanup(&dcmi->vdev->entity);
2073 err_device_release:
2074 	video_device_release(dcmi->vdev);
2075 err_device_unregister:
2076 	v4l2_device_unregister(&dcmi->v4l2_dev);
2077 err_media_device_cleanup:
2078 	media_device_cleanup(&dcmi->mdev);
2079 	dma_release_channel(dcmi->dma_chan);
2080 
2081 	return ret;
2082 }
2083 
2084 static void dcmi_remove(struct platform_device *pdev)
2085 {
2086 	struct stm32_dcmi *dcmi = platform_get_drvdata(pdev);
2087 
2088 	pm_runtime_disable(&pdev->dev);
2089 
2090 	v4l2_async_nf_unregister(&dcmi->notifier);
2091 	v4l2_async_nf_cleanup(&dcmi->notifier);
2092 	media_entity_cleanup(&dcmi->vdev->entity);
2093 	v4l2_device_unregister(&dcmi->v4l2_dev);
2094 	media_device_cleanup(&dcmi->mdev);
2095 
2096 	dma_release_channel(dcmi->dma_chan);
2097 }
2098 
2099 static __maybe_unused int dcmi_runtime_suspend(struct device *dev)
2100 {
2101 	struct stm32_dcmi *dcmi = dev_get_drvdata(dev);
2102 
2103 	clk_disable_unprepare(dcmi->mclk);
2104 
2105 	return 0;
2106 }
2107 
2108 static __maybe_unused int dcmi_runtime_resume(struct device *dev)
2109 {
2110 	struct stm32_dcmi *dcmi = dev_get_drvdata(dev);
2111 	int ret;
2112 
2113 	ret = clk_prepare_enable(dcmi->mclk);
2114 	if (ret)
2115 		dev_err(dev, "%s: Failed to prepare_enable clock\n", __func__);
2116 
2117 	return ret;
2118 }
2119 
2120 static __maybe_unused int dcmi_suspend(struct device *dev)
2121 {
2122 	/* disable clock */
2123 	pm_runtime_force_suspend(dev);
2124 
2125 	/* change pinctrl state */
2126 	pinctrl_pm_select_sleep_state(dev);
2127 
2128 	return 0;
2129 }
2130 
2131 static __maybe_unused int dcmi_resume(struct device *dev)
2132 {
2133 	/* restore pinctl default state */
2134 	pinctrl_pm_select_default_state(dev);
2135 
2136 	/* clock enable */
2137 	pm_runtime_force_resume(dev);
2138 
2139 	return 0;
2140 }
2141 
2142 static const struct dev_pm_ops dcmi_pm_ops = {
2143 	SET_SYSTEM_SLEEP_PM_OPS(dcmi_suspend, dcmi_resume)
2144 	SET_RUNTIME_PM_OPS(dcmi_runtime_suspend,
2145 			   dcmi_runtime_resume, NULL)
2146 };
2147 
2148 static struct platform_driver stm32_dcmi_driver = {
2149 	.probe		= dcmi_probe,
2150 	.remove		= dcmi_remove,
2151 	.driver		= {
2152 		.name = DRV_NAME,
2153 		.of_match_table = of_match_ptr(stm32_dcmi_of_match),
2154 		.pm = &dcmi_pm_ops,
2155 	},
2156 };
2157 
2158 module_platform_driver(stm32_dcmi_driver);
2159 
2160 MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
2161 MODULE_AUTHOR("Hugues Fruchet <hugues.fruchet@st.com>");
2162 MODULE_DESCRIPTION("STMicroelectronics STM32 Digital Camera Memory Interface driver");
2163 MODULE_LICENSE("GPL");
2164