1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * ispstat.c
4 *
5 * TI OMAP3 ISP - Statistics core
6 *
7 * Copyright (C) 2010 Nokia Corporation
8 * Copyright (C) 2009 Texas Instruments, Inc
9 *
10 * Contacts: David Cohen <dacohen@gmail.com>
11 *	     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
12 *	     Sakari Ailus <sakari.ailus@iki.fi>
13 */
14
15#include <linux/dma-mapping.h>
16#include <linux/slab.h>
17#include <linux/timekeeping.h>
18#include <linux/uaccess.h>
19
20#include "isp.h"
21
22#define ISP_STAT_USES_DMAENGINE(stat)	((stat)->dma_ch != NULL)
23
24/*
25 * MAGIC_SIZE must always be the greatest common divisor of
26 * AEWB_PACKET_SIZE and AF_PAXEL_SIZE.
27 */
28#define MAGIC_SIZE		16
29#define MAGIC_NUM		0x55
30
31/* HACK: AF module seems to be writing one more paxel data than it should. */
32#define AF_EXTRA_DATA		OMAP3ISP_AF_PAXEL_SIZE
33
34/*
35 * HACK: H3A modules go to an invalid state after have a SBL overflow. It makes
36 * the next buffer to start to be written in the same point where the overflow
37 * occurred instead of the configured address. The only known way to make it to
38 * go back to a valid state is having a valid buffer processing. Of course it
39 * requires at least a doubled buffer size to avoid an access to invalid memory
40 * region. But it does not fix everything. It may happen more than one
41 * consecutive SBL overflows. In that case, it might be unpredictable how many
42 * buffers the allocated memory should fit. For that case, a recover
43 * configuration was created. It produces the minimum buffer size for each H3A
44 * module and decrease the change for more SBL overflows. This recover state
45 * will be enabled every time a SBL overflow occur. As the output buffer size
46 * isn't big, it's possible to have an extra size able to fit many recover
47 * buffers making it extreamily unlikely to have an access to invalid memory
48 * region.
49 */
50#define NUM_H3A_RECOVER_BUFS	10
51
52/*
53 * HACK: Because of HW issues the generic layer sometimes need to have
54 * different behaviour for different statistic modules.
55 */
56#define IS_H3A_AF(stat)		((stat) == &(stat)->isp->isp_af)
57#define IS_H3A_AEWB(stat)	((stat) == &(stat)->isp->isp_aewb)
58#define IS_H3A(stat)		(IS_H3A_AF(stat) || IS_H3A_AEWB(stat))
59
60static void __isp_stat_buf_sync_magic(struct ispstat *stat,
61				      struct ispstat_buffer *buf,
62				      u32 buf_size, enum dma_data_direction dir,
63				      void (*dma_sync)(struct device *,
64					dma_addr_t, unsigned long, size_t,
65					enum dma_data_direction))
66{
67	/* Sync the initial and final magic words. */
68	dma_sync(stat->isp->dev, buf->dma_addr, 0, MAGIC_SIZE, dir);
69	dma_sync(stat->isp->dev, buf->dma_addr + (buf_size & PAGE_MASK),
70		 buf_size & ~PAGE_MASK, MAGIC_SIZE, dir);
71}
72
73static void isp_stat_buf_sync_magic_for_device(struct ispstat *stat,
74					       struct ispstat_buffer *buf,
75					       u32 buf_size,
76					       enum dma_data_direction dir)
77{
78	if (ISP_STAT_USES_DMAENGINE(stat))
79		return;
80
81	__isp_stat_buf_sync_magic(stat, buf, buf_size, dir,
82				  dma_sync_single_range_for_device);
83}
84
85static void isp_stat_buf_sync_magic_for_cpu(struct ispstat *stat,
86					    struct ispstat_buffer *buf,
87					    u32 buf_size,
88					    enum dma_data_direction dir)
89{
90	if (ISP_STAT_USES_DMAENGINE(stat))
91		return;
92
93	__isp_stat_buf_sync_magic(stat, buf, buf_size, dir,
94				  dma_sync_single_range_for_cpu);
95}
96
97static int isp_stat_buf_check_magic(struct ispstat *stat,
98				    struct ispstat_buffer *buf)
99{
100	const u32 buf_size = IS_H3A_AF(stat) ?
101			     buf->buf_size + AF_EXTRA_DATA : buf->buf_size;
102	u8 *w;
103	u8 *end;
104	int ret = -EINVAL;
105
106	isp_stat_buf_sync_magic_for_cpu(stat, buf, buf_size, DMA_FROM_DEVICE);
107
108	/* Checking initial magic numbers. They shouldn't be here anymore. */
109	for (w = buf->virt_addr, end = w + MAGIC_SIZE; w < end; w++)
110		if (likely(*w != MAGIC_NUM))
111			ret = 0;
112
113	if (ret) {
114		dev_dbg(stat->isp->dev,
115			"%s: beginning magic check does not match.\n",
116			stat->subdev.name);
117		return ret;
118	}
119
120	/* Checking magic numbers at the end. They must be still here. */
121	for (w = buf->virt_addr + buf_size, end = w + MAGIC_SIZE;
122	     w < end; w++) {
123		if (unlikely(*w != MAGIC_NUM)) {
124			dev_dbg(stat->isp->dev,
125				"%s: ending magic check does not match.\n",
126				stat->subdev.name);
127			return -EINVAL;
128		}
129	}
130
131	isp_stat_buf_sync_magic_for_device(stat, buf, buf_size,
132					   DMA_FROM_DEVICE);
133
134	return 0;
135}
136
137static void isp_stat_buf_insert_magic(struct ispstat *stat,
138				      struct ispstat_buffer *buf)
139{
140	const u32 buf_size = IS_H3A_AF(stat) ?
141			     stat->buf_size + AF_EXTRA_DATA : stat->buf_size;
142
143	isp_stat_buf_sync_magic_for_cpu(stat, buf, buf_size, DMA_FROM_DEVICE);
144
145	/*
146	 * Inserting MAGIC_NUM at the beginning and end of the buffer.
147	 * buf->buf_size is set only after the buffer is queued. For now the
148	 * right buf_size for the current configuration is pointed by
149	 * stat->buf_size.
150	 */
151	memset(buf->virt_addr, MAGIC_NUM, MAGIC_SIZE);
152	memset(buf->virt_addr + buf_size, MAGIC_NUM, MAGIC_SIZE);
153
154	isp_stat_buf_sync_magic_for_device(stat, buf, buf_size,
155					   DMA_BIDIRECTIONAL);
156}
157
158static void isp_stat_buf_sync_for_device(struct ispstat *stat,
159					 struct ispstat_buffer *buf)
160{
161	if (ISP_STAT_USES_DMAENGINE(stat))
162		return;
163
164	dma_sync_sg_for_device(stat->isp->dev, buf->sgt.sgl,
165			       buf->sgt.nents, DMA_FROM_DEVICE);
166}
167
168static void isp_stat_buf_sync_for_cpu(struct ispstat *stat,
169				      struct ispstat_buffer *buf)
170{
171	if (ISP_STAT_USES_DMAENGINE(stat))
172		return;
173
174	dma_sync_sg_for_cpu(stat->isp->dev, buf->sgt.sgl,
175			    buf->sgt.nents, DMA_FROM_DEVICE);
176}
177
178static void isp_stat_buf_clear(struct ispstat *stat)
179{
180	int i;
181
182	for (i = 0; i < STAT_MAX_BUFS; i++)
183		stat->buf[i].empty = 1;
184}
185
186static struct ispstat_buffer *
187__isp_stat_buf_find(struct ispstat *stat, int look_empty)
188{
189	struct ispstat_buffer *found = NULL;
190	int i;
191
192	for (i = 0; i < STAT_MAX_BUFS; i++) {
193		struct ispstat_buffer *curr = &stat->buf[i];
194
195		/*
196		 * Don't select the buffer which is being copied to
197		 * userspace or used by the module.
198		 */
199		if (curr == stat->locked_buf || curr == stat->active_buf)
200			continue;
201
202		/* Don't select uninitialised buffers if it's not required */
203		if (!look_empty && curr->empty)
204			continue;
205
206		/* Pick uninitialised buffer over anything else if look_empty */
207		if (curr->empty) {
208			found = curr;
209			break;
210		}
211
212		/* Choose the oldest buffer */
213		if (!found ||
214		    (s32)curr->frame_number - (s32)found->frame_number < 0)
215			found = curr;
216	}
217
218	return found;
219}
220
221static inline struct ispstat_buffer *
222isp_stat_buf_find_oldest(struct ispstat *stat)
223{
224	return __isp_stat_buf_find(stat, 0);
225}
226
227static inline struct ispstat_buffer *
228isp_stat_buf_find_oldest_or_empty(struct ispstat *stat)
229{
230	return __isp_stat_buf_find(stat, 1);
231}
232
233static int isp_stat_buf_queue(struct ispstat *stat)
234{
235	if (!stat->active_buf)
236		return STAT_NO_BUF;
237
238	ktime_get_ts64(&stat->active_buf->ts);
239
240	stat->active_buf->buf_size = stat->buf_size;
241	if (isp_stat_buf_check_magic(stat, stat->active_buf)) {
242		dev_dbg(stat->isp->dev, "%s: data wasn't properly written.\n",
243			stat->subdev.name);
244		return STAT_NO_BUF;
245	}
246	stat->active_buf->config_counter = stat->config_counter;
247	stat->active_buf->frame_number = stat->frame_number;
248	stat->active_buf->empty = 0;
249	stat->active_buf = NULL;
250
251	return STAT_BUF_DONE;
252}
253
254/* Get next free buffer to write the statistics to and mark it active. */
255static void isp_stat_buf_next(struct ispstat *stat)
256{
257	if (unlikely(stat->active_buf))
258		/* Overwriting unused active buffer */
259		dev_dbg(stat->isp->dev,
260			"%s: new buffer requested without queuing active one.\n",
261			stat->subdev.name);
262	else
263		stat->active_buf = isp_stat_buf_find_oldest_or_empty(stat);
264}
265
266static void isp_stat_buf_release(struct ispstat *stat)
267{
268	unsigned long flags;
269
270	isp_stat_buf_sync_for_device(stat, stat->locked_buf);
271	spin_lock_irqsave(&stat->isp->stat_lock, flags);
272	stat->locked_buf = NULL;
273	spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
274}
275
276/* Get buffer to userspace. */
277static struct ispstat_buffer *isp_stat_buf_get(struct ispstat *stat,
278					       struct omap3isp_stat_data *data)
279{
280	int rval = 0;
281	unsigned long flags;
282	struct ispstat_buffer *buf;
283
284	spin_lock_irqsave(&stat->isp->stat_lock, flags);
285
286	while (1) {
287		buf = isp_stat_buf_find_oldest(stat);
288		if (!buf) {
289			spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
290			dev_dbg(stat->isp->dev, "%s: cannot find a buffer.\n",
291				stat->subdev.name);
292			return ERR_PTR(-EBUSY);
293		}
294		if (isp_stat_buf_check_magic(stat, buf)) {
295			dev_dbg(stat->isp->dev,
296				"%s: current buffer has corrupted data\n.",
297				stat->subdev.name);
298			/* Mark empty because it doesn't have valid data. */
299			buf->empty = 1;
300		} else {
301			/* Buffer isn't corrupted. */
302			break;
303		}
304	}
305
306	stat->locked_buf = buf;
307
308	spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
309
310	if (buf->buf_size > data->buf_size) {
311		dev_warn(stat->isp->dev,
312			 "%s: userspace's buffer size is not enough.\n",
313			 stat->subdev.name);
314		isp_stat_buf_release(stat);
315		return ERR_PTR(-EINVAL);
316	}
317
318	isp_stat_buf_sync_for_cpu(stat, buf);
319
320	rval = copy_to_user(data->buf,
321			    buf->virt_addr,
322			    buf->buf_size);
323
324	if (rval) {
325		dev_info(stat->isp->dev,
326			 "%s: failed copying %d bytes of stat data\n",
327			 stat->subdev.name, rval);
328		buf = ERR_PTR(-EFAULT);
329		isp_stat_buf_release(stat);
330	}
331
332	return buf;
333}
334
335static void isp_stat_bufs_free(struct ispstat *stat)
336{
337	struct device *dev = ISP_STAT_USES_DMAENGINE(stat)
338			   ? NULL : stat->isp->dev;
339	unsigned int i;
340
341	for (i = 0; i < STAT_MAX_BUFS; i++) {
342		struct ispstat_buffer *buf = &stat->buf[i];
343
344		if (!buf->virt_addr)
345			continue;
346
347		sg_free_table(&buf->sgt);
348
349		dma_free_coherent(dev, stat->buf_alloc_size, buf->virt_addr,
350				  buf->dma_addr);
351
352		buf->dma_addr = 0;
353		buf->virt_addr = NULL;
354		buf->empty = 1;
355	}
356
357	dev_dbg(stat->isp->dev, "%s: all buffers were freed.\n",
358		stat->subdev.name);
359
360	stat->buf_alloc_size = 0;
361	stat->active_buf = NULL;
362}
363
364static int isp_stat_bufs_alloc_one(struct device *dev,
365				   struct ispstat_buffer *buf,
366				   unsigned int size)
367{
368	int ret;
369
370	buf->virt_addr = dma_alloc_coherent(dev, size, &buf->dma_addr,
371					    GFP_KERNEL);
372	if (!buf->virt_addr)
373		return -ENOMEM;
374
375	ret = dma_get_sgtable(dev, &buf->sgt, buf->virt_addr, buf->dma_addr,
376			      size);
377	if (ret < 0) {
378		dma_free_coherent(dev, size, buf->virt_addr, buf->dma_addr);
379		buf->virt_addr = NULL;
380		buf->dma_addr = 0;
381		return ret;
382	}
383
384	return 0;
385}
386
387/*
388 * The device passed to the DMA API depends on whether the statistics block uses
389 * ISP DMA, external DMA or PIO to transfer data.
390 *
391 * The first case (for the AEWB and AF engines) passes the ISP device, resulting
392 * in the DMA buffers being mapped through the ISP IOMMU.
393 *
394 * The second case (for the histogram engine) should pass the DMA engine device.
395 * As that device isn't accessible through the OMAP DMA engine API the driver
396 * passes NULL instead, resulting in the buffers being mapped directly as
397 * physical pages.
398 *
399 * The third case (for the histogram engine) doesn't require any mapping. The
400 * buffers could be allocated with kmalloc/vmalloc, but we still use
401 * dma_alloc_coherent() for consistency purpose.
402 */
403static int isp_stat_bufs_alloc(struct ispstat *stat, u32 size)
404{
405	struct device *dev = ISP_STAT_USES_DMAENGINE(stat)
406			   ? NULL : stat->isp->dev;
407	unsigned long flags;
408	unsigned int i;
409
410	spin_lock_irqsave(&stat->isp->stat_lock, flags);
411
412	BUG_ON(stat->locked_buf != NULL);
413
414	/* Are the old buffers big enough? */
415	if (stat->buf_alloc_size >= size) {
416		spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
417		return 0;
418	}
419
420	if (stat->state != ISPSTAT_DISABLED || stat->buf_processing) {
421		dev_info(stat->isp->dev,
422			 "%s: trying to allocate memory when busy\n",
423			 stat->subdev.name);
424		spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
425		return -EBUSY;
426	}
427
428	spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
429
430	isp_stat_bufs_free(stat);
431
432	stat->buf_alloc_size = size;
433
434	for (i = 0; i < STAT_MAX_BUFS; i++) {
435		struct ispstat_buffer *buf = &stat->buf[i];
436		int ret;
437
438		ret = isp_stat_bufs_alloc_one(dev, buf, size);
439		if (ret < 0) {
440			dev_err(stat->isp->dev,
441				"%s: Failed to allocate DMA buffer %u\n",
442				stat->subdev.name, i);
443			isp_stat_bufs_free(stat);
444			return ret;
445		}
446
447		buf->empty = 1;
448
449		dev_dbg(stat->isp->dev,
450			"%s: buffer[%u] allocated. dma=%pad virt=%p",
451			stat->subdev.name, i, &buf->dma_addr, buf->virt_addr);
452	}
453
454	return 0;
455}
456
457static void isp_stat_queue_event(struct ispstat *stat, int err)
458{
459	struct video_device *vdev = stat->subdev.devnode;
460	struct v4l2_event event;
461	struct omap3isp_stat_event_status *status = (void *)event.u.data;
462
463	memset(&event, 0, sizeof(event));
464	if (!err) {
465		status->frame_number = stat->frame_number;
466		status->config_counter = stat->config_counter;
467	} else {
468		status->buf_err = 1;
469	}
470	event.type = stat->event_type;
471	v4l2_event_queue(vdev, &event);
472}
473
474
475/*
476 * omap3isp_stat_request_statistics - Request statistics.
477 * @data: Pointer to return statistics data.
478 *
479 * Returns 0 if successful.
480 */
481int omap3isp_stat_request_statistics(struct ispstat *stat,
482				     struct omap3isp_stat_data *data)
483{
484	struct ispstat_buffer *buf;
485
486	if (stat->state != ISPSTAT_ENABLED) {
487		dev_dbg(stat->isp->dev, "%s: engine not enabled.\n",
488			stat->subdev.name);
489		return -EINVAL;
490	}
491
492	mutex_lock(&stat->ioctl_lock);
493	buf = isp_stat_buf_get(stat, data);
494	if (IS_ERR(buf)) {
495		mutex_unlock(&stat->ioctl_lock);
496		return PTR_ERR(buf);
497	}
498
499	data->ts.tv_sec = buf->ts.tv_sec;
500	data->ts.tv_usec = buf->ts.tv_nsec / NSEC_PER_USEC;
501	data->config_counter = buf->config_counter;
502	data->frame_number = buf->frame_number;
503	data->buf_size = buf->buf_size;
504
505	buf->empty = 1;
506	isp_stat_buf_release(stat);
507	mutex_unlock(&stat->ioctl_lock);
508
509	return 0;
510}
511
512int omap3isp_stat_request_statistics_time32(struct ispstat *stat,
513					struct omap3isp_stat_data_time32 *data)
514{
515	struct omap3isp_stat_data data64;
516	int ret;
517
518	ret = omap3isp_stat_request_statistics(stat, &data64);
519	if (ret)
520		return ret;
521
522	data->ts.tv_sec = data64.ts.tv_sec;
523	data->ts.tv_usec = data64.ts.tv_usec;
524	memcpy(&data->buf, &data64.buf, sizeof(*data) - sizeof(data->ts));
525
526	return 0;
527}
528
529/*
530 * omap3isp_stat_config - Receives new statistic engine configuration.
531 * @new_conf: Pointer to config structure.
532 *
533 * Returns 0 if successful, -EINVAL if new_conf pointer is NULL, -ENOMEM if
534 * was unable to allocate memory for the buffer, or other errors if parameters
535 * are invalid.
536 */
537int omap3isp_stat_config(struct ispstat *stat, void *new_conf)
538{
539	int ret;
540	unsigned long irqflags;
541	struct ispstat_generic_config *user_cfg = new_conf;
542	u32 buf_size = user_cfg->buf_size;
543
544	mutex_lock(&stat->ioctl_lock);
545
546	dev_dbg(stat->isp->dev,
547		"%s: configuring module with buffer size=0x%08lx\n",
548		stat->subdev.name, (unsigned long)buf_size);
549
550	ret = stat->ops->validate_params(stat, new_conf);
551	if (ret) {
552		mutex_unlock(&stat->ioctl_lock);
553		dev_dbg(stat->isp->dev, "%s: configuration values are invalid.\n",
554			stat->subdev.name);
555		return ret;
556	}
557
558	if (buf_size != user_cfg->buf_size)
559		dev_dbg(stat->isp->dev,
560			"%s: driver has corrected buffer size request to 0x%08lx\n",
561			stat->subdev.name,
562			(unsigned long)user_cfg->buf_size);
563
564	/*
565	 * Hack: H3A modules may need a doubled buffer size to avoid access
566	 * to a invalid memory address after a SBL overflow.
567	 * The buffer size is always PAGE_ALIGNED.
568	 * Hack 2: MAGIC_SIZE is added to buf_size so a magic word can be
569	 * inserted at the end to data integrity check purpose.
570	 * Hack 3: AF module writes one paxel data more than it should, so
571	 * the buffer allocation must consider it to avoid invalid memory
572	 * access.
573	 * Hack 4: H3A need to allocate extra space for the recover state.
574	 */
575	if (IS_H3A(stat)) {
576		buf_size = user_cfg->buf_size * 2 + MAGIC_SIZE;
577		if (IS_H3A_AF(stat))
578			/*
579			 * Adding one extra paxel data size for each recover
580			 * buffer + 2 regular ones.
581			 */
582			buf_size += AF_EXTRA_DATA * (NUM_H3A_RECOVER_BUFS + 2);
583		if (stat->recover_priv) {
584			struct ispstat_generic_config *recover_cfg =
585				stat->recover_priv;
586			buf_size += recover_cfg->buf_size *
587				    NUM_H3A_RECOVER_BUFS;
588		}
589		buf_size = PAGE_ALIGN(buf_size);
590	} else { /* Histogram */
591		buf_size = PAGE_ALIGN(user_cfg->buf_size + MAGIC_SIZE);
592	}
593
594	ret = isp_stat_bufs_alloc(stat, buf_size);
595	if (ret) {
596		mutex_unlock(&stat->ioctl_lock);
597		return ret;
598	}
599
600	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);
601	stat->ops->set_params(stat, new_conf);
602	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
603
604	/*
605	 * Returning the right future config_counter for this setup, so
606	 * userspace can *know* when it has been applied.
607	 */
608	user_cfg->config_counter = stat->config_counter + stat->inc_config;
609
610	/* Module has a valid configuration. */
611	stat->configured = 1;
612	dev_dbg(stat->isp->dev,
613		"%s: module has been successfully configured.\n",
614		stat->subdev.name);
615
616	mutex_unlock(&stat->ioctl_lock);
617
618	return 0;
619}
620
621/*
622 * isp_stat_buf_process - Process statistic buffers.
623 * @buf_state: points out if buffer is ready to be processed. It's necessary
624 *	       because histogram needs to copy the data from internal memory
625 *	       before be able to process the buffer.
626 */
627static int isp_stat_buf_process(struct ispstat *stat, int buf_state)
628{
629	int ret = STAT_NO_BUF;
630
631	if (!atomic_add_unless(&stat->buf_err, -1, 0) &&
632	    buf_state == STAT_BUF_DONE && stat->state == ISPSTAT_ENABLED) {
633		ret = isp_stat_buf_queue(stat);
634		isp_stat_buf_next(stat);
635	}
636
637	return ret;
638}
639
640int omap3isp_stat_pcr_busy(struct ispstat *stat)
641{
642	return stat->ops->busy(stat);
643}
644
645int omap3isp_stat_busy(struct ispstat *stat)
646{
647	return omap3isp_stat_pcr_busy(stat) | stat->buf_processing |
648		(stat->state != ISPSTAT_DISABLED);
649}
650
651/*
652 * isp_stat_pcr_enable - Disables/Enables statistic engines.
653 * @pcr_enable: 0/1 - Disables/Enables the engine.
654 *
655 * Must be called from ISP driver when the module is idle and synchronized
656 * with CCDC.
657 */
658static void isp_stat_pcr_enable(struct ispstat *stat, u8 pcr_enable)
659{
660	if ((stat->state != ISPSTAT_ENABLING &&
661	     stat->state != ISPSTAT_ENABLED) && pcr_enable)
662		/* Userspace has disabled the module. Aborting. */
663		return;
664
665	stat->ops->enable(stat, pcr_enable);
666	if (stat->state == ISPSTAT_DISABLING && !pcr_enable)
667		stat->state = ISPSTAT_DISABLED;
668	else if (stat->state == ISPSTAT_ENABLING && pcr_enable)
669		stat->state = ISPSTAT_ENABLED;
670}
671
672void omap3isp_stat_suspend(struct ispstat *stat)
673{
674	unsigned long flags;
675
676	spin_lock_irqsave(&stat->isp->stat_lock, flags);
677
678	if (stat->state != ISPSTAT_DISABLED)
679		stat->ops->enable(stat, 0);
680	if (stat->state == ISPSTAT_ENABLED)
681		stat->state = ISPSTAT_SUSPENDED;
682
683	spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
684}
685
686void omap3isp_stat_resume(struct ispstat *stat)
687{
688	/* Module will be re-enabled with its pipeline */
689	if (stat->state == ISPSTAT_SUSPENDED)
690		stat->state = ISPSTAT_ENABLING;
691}
692
693static void isp_stat_try_enable(struct ispstat *stat)
694{
695	unsigned long irqflags;
696
697	if (stat->priv == NULL)
698		/* driver wasn't initialised */
699		return;
700
701	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);
702	if (stat->state == ISPSTAT_ENABLING && !stat->buf_processing &&
703	    stat->buf_alloc_size) {
704		/*
705		 * Userspace's requested to enable the engine but it wasn't yet.
706		 * Let's do that now.
707		 */
708		stat->update = 1;
709		isp_stat_buf_next(stat);
710		stat->ops->setup_regs(stat, stat->priv);
711		isp_stat_buf_insert_magic(stat, stat->active_buf);
712
713		/*
714		 * H3A module has some hw issues which forces the driver to
715		 * ignore next buffers even if it was disabled in the meantime.
716		 * On the other hand, Histogram shouldn't ignore buffers anymore
717		 * if it's being enabled.
718		 */
719		if (!IS_H3A(stat))
720			atomic_set(&stat->buf_err, 0);
721
722		isp_stat_pcr_enable(stat, 1);
723		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
724		dev_dbg(stat->isp->dev, "%s: module is enabled.\n",
725			stat->subdev.name);
726	} else {
727		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
728	}
729}
730
731void omap3isp_stat_isr_frame_sync(struct ispstat *stat)
732{
733	isp_stat_try_enable(stat);
734}
735
736void omap3isp_stat_sbl_overflow(struct ispstat *stat)
737{
738	unsigned long irqflags;
739
740	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);
741	/*
742	 * Due to a H3A hw issue which prevents the next buffer to start from
743	 * the correct memory address, 2 buffers must be ignored.
744	 */
745	atomic_set(&stat->buf_err, 2);
746
747	/*
748	 * If more than one SBL overflow happen in a row, H3A module may access
749	 * invalid memory region.
750	 * stat->sbl_ovl_recover is set to tell to the driver to temporarily use
751	 * a soft configuration which helps to avoid consecutive overflows.
752	 */
753	if (stat->recover_priv)
754		stat->sbl_ovl_recover = 1;
755	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
756}
757
758/*
759 * omap3isp_stat_enable - Disable/Enable statistic engine as soon as possible
760 * @enable: 0/1 - Disables/Enables the engine.
761 *
762 * Client should configure all the module registers before this.
763 * This function can be called from a userspace request.
764 */
765int omap3isp_stat_enable(struct ispstat *stat, u8 enable)
766{
767	unsigned long irqflags;
768
769	dev_dbg(stat->isp->dev, "%s: user wants to %s module.\n",
770		stat->subdev.name, enable ? "enable" : "disable");
771
772	/* Prevent enabling while configuring */
773	mutex_lock(&stat->ioctl_lock);
774
775	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);
776
777	if (!stat->configured && enable) {
778		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
779		mutex_unlock(&stat->ioctl_lock);
780		dev_dbg(stat->isp->dev,
781			"%s: cannot enable module as it's never been successfully configured so far.\n",
782			stat->subdev.name);
783		return -EINVAL;
784	}
785
786	if (enable) {
787		if (stat->state == ISPSTAT_DISABLING)
788			/* Previous disabling request wasn't done yet */
789			stat->state = ISPSTAT_ENABLED;
790		else if (stat->state == ISPSTAT_DISABLED)
791			/* Module is now being enabled */
792			stat->state = ISPSTAT_ENABLING;
793	} else {
794		if (stat->state == ISPSTAT_ENABLING) {
795			/* Previous enabling request wasn't done yet */
796			stat->state = ISPSTAT_DISABLED;
797		} else if (stat->state == ISPSTAT_ENABLED) {
798			/* Module is now being disabled */
799			stat->state = ISPSTAT_DISABLING;
800			isp_stat_buf_clear(stat);
801		}
802	}
803
804	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
805	mutex_unlock(&stat->ioctl_lock);
806
807	return 0;
808}
809
810int omap3isp_stat_s_stream(struct v4l2_subdev *subdev, int enable)
811{
812	struct ispstat *stat = v4l2_get_subdevdata(subdev);
813
814	if (enable) {
815		/*
816		 * Only set enable PCR bit if the module was previously
817		 * enabled through ioctl.
818		 */
819		isp_stat_try_enable(stat);
820	} else {
821		unsigned long flags;
822		/* Disable PCR bit and config enable field */
823		omap3isp_stat_enable(stat, 0);
824		spin_lock_irqsave(&stat->isp->stat_lock, flags);
825		stat->ops->enable(stat, 0);
826		spin_unlock_irqrestore(&stat->isp->stat_lock, flags);
827
828		/*
829		 * If module isn't busy, a new interrupt may come or not to
830		 * set the state to DISABLED. As Histogram needs to read its
831		 * internal memory to clear it, let interrupt handler
832		 * responsible of changing state to DISABLED. If the last
833		 * interrupt is coming, it's still safe as the handler will
834		 * ignore the second time when state is already set to DISABLED.
835		 * It's necessary to synchronize Histogram with streamoff, once
836		 * the module may be considered idle before last SDMA transfer
837		 * starts if we return here.
838		 */
839		if (!omap3isp_stat_pcr_busy(stat))
840			omap3isp_stat_isr(stat);
841
842		dev_dbg(stat->isp->dev, "%s: module is being disabled\n",
843			stat->subdev.name);
844	}
845
846	return 0;
847}
848
849/*
850 * __stat_isr - Interrupt handler for statistic drivers
851 */
852static void __stat_isr(struct ispstat *stat, int from_dma)
853{
854	int ret = STAT_BUF_DONE;
855	int buf_processing;
856	unsigned long irqflags;
857	struct isp_pipeline *pipe;
858
859	/*
860	 * stat->buf_processing must be set before disable module. It's
861	 * necessary to not inform too early the buffers aren't busy in case
862	 * of SDMA is going to be used.
863	 */
864	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);
865	if (stat->state == ISPSTAT_DISABLED) {
866		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
867		return;
868	}
869	buf_processing = stat->buf_processing;
870	stat->buf_processing = 1;
871	stat->ops->enable(stat, 0);
872
873	if (buf_processing && !from_dma) {
874		if (stat->state == ISPSTAT_ENABLED) {
875			spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
876			dev_err(stat->isp->dev,
877				"%s: interrupt occurred when module was still processing a buffer.\n",
878				stat->subdev.name);
879			ret = STAT_NO_BUF;
880			goto out;
881		} else {
882			/*
883			 * Interrupt handler was called from streamoff when
884			 * the module wasn't busy anymore to ensure it is being
885			 * disabled after process last buffer. If such buffer
886			 * processing has already started, no need to do
887			 * anything else.
888			 */
889			spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
890			return;
891		}
892	}
893	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
894
895	/* If it's busy we can't process this buffer anymore */
896	if (!omap3isp_stat_pcr_busy(stat)) {
897		if (!from_dma && stat->ops->buf_process)
898			/* Module still need to copy data to buffer. */
899			ret = stat->ops->buf_process(stat);
900		if (ret == STAT_BUF_WAITING_DMA)
901			/* Buffer is not ready yet */
902			return;
903
904		spin_lock_irqsave(&stat->isp->stat_lock, irqflags);
905
906		/*
907		 * Histogram needs to read its internal memory to clear it
908		 * before be disabled. For that reason, common statistic layer
909		 * can return only after call stat's buf_process() operator.
910		 */
911		if (stat->state == ISPSTAT_DISABLING) {
912			stat->state = ISPSTAT_DISABLED;
913			spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
914			stat->buf_processing = 0;
915			return;
916		}
917		pipe = to_isp_pipeline(&stat->subdev.entity);
918		stat->frame_number = atomic_read(&pipe->frame_number);
919
920		/*
921		 * Before this point, 'ret' stores the buffer's status if it's
922		 * ready to be processed. Afterwards, it holds the status if
923		 * it was processed successfully.
924		 */
925		ret = isp_stat_buf_process(stat, ret);
926
927		if (likely(!stat->sbl_ovl_recover)) {
928			stat->ops->setup_regs(stat, stat->priv);
929		} else {
930			/*
931			 * Using recover config to increase the chance to have
932			 * a good buffer processing and make the H3A module to
933			 * go back to a valid state.
934			 */
935			stat->update = 1;
936			stat->ops->setup_regs(stat, stat->recover_priv);
937			stat->sbl_ovl_recover = 0;
938
939			/*
940			 * Set 'update' in case of the module needs to use
941			 * regular configuration after next buffer.
942			 */
943			stat->update = 1;
944		}
945
946		isp_stat_buf_insert_magic(stat, stat->active_buf);
947
948		/*
949		 * Hack: H3A modules may access invalid memory address or send
950		 * corrupted data to userspace if more than 1 SBL overflow
951		 * happens in a row without re-writing its buffer's start memory
952		 * address in the meantime. Such situation is avoided if the
953		 * module is not immediately re-enabled when the ISR misses the
954		 * timing to process the buffer and to setup the registers.
955		 * Because of that, pcr_enable(1) was moved to inside this 'if'
956		 * block. But the next interruption will still happen as during
957		 * pcr_enable(0) the module was busy.
958		 */
959		isp_stat_pcr_enable(stat, 1);
960		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);
961	} else {
962		/*
963		 * If a SBL overflow occurs and the H3A driver misses the timing
964		 * to process the buffer, stat->buf_err is set and won't be
965		 * cleared now. So the next buffer will be correctly ignored.
966		 * It's necessary due to a hw issue which makes the next H3A
967		 * buffer to start from the memory address where the previous
968		 * one stopped, instead of start where it was configured to.
969		 * Do not "stat->buf_err = 0" here.
970		 */
971
972		if (stat->ops->buf_process)
973			/*
974			 * Driver may need to erase current data prior to
975			 * process a new buffer. If it misses the timing, the
976			 * next buffer might be wrong. So should be ignored.
977			 * It happens only for Histogram.
978			 */
979			atomic_set(&stat->buf_err, 1);
980
981		ret = STAT_NO_BUF;
982		dev_dbg(stat->isp->dev,
983			"%s: cannot process buffer, device is busy.\n",
984			stat->subdev.name);
985	}
986
987out:
988	stat->buf_processing = 0;
989	isp_stat_queue_event(stat, ret != STAT_BUF_DONE);
990}
991
992void omap3isp_stat_isr(struct ispstat *stat)
993{
994	__stat_isr(stat, 0);
995}
996
997void omap3isp_stat_dma_isr(struct ispstat *stat)
998{
999	__stat_isr(stat, 1);
1000}
1001
1002int omap3isp_stat_subscribe_event(struct v4l2_subdev *subdev,
1003				  struct v4l2_fh *fh,
1004				  struct v4l2_event_subscription *sub)
1005{
1006	struct ispstat *stat = v4l2_get_subdevdata(subdev);
1007
1008	if (sub->type != stat->event_type)
1009		return -EINVAL;
1010
1011	return v4l2_event_subscribe(fh, sub, STAT_NEVENTS, NULL);
1012}
1013
1014int omap3isp_stat_unsubscribe_event(struct v4l2_subdev *subdev,
1015				    struct v4l2_fh *fh,
1016				    struct v4l2_event_subscription *sub)
1017{
1018	return v4l2_event_unsubscribe(fh, sub);
1019}
1020
1021void omap3isp_stat_unregister_entities(struct ispstat *stat)
1022{
1023	v4l2_device_unregister_subdev(&stat->subdev);
1024}
1025
1026int omap3isp_stat_register_entities(struct ispstat *stat,
1027				    struct v4l2_device *vdev)
1028{
1029	stat->subdev.dev = vdev->mdev->dev;
1030
1031	return v4l2_device_register_subdev(vdev, &stat->subdev);
1032}
1033
1034static int isp_stat_init_entities(struct ispstat *stat, const char *name,
1035				  const struct v4l2_subdev_ops *sd_ops)
1036{
1037	struct v4l2_subdev *subdev = &stat->subdev;
1038	struct media_entity *me = &subdev->entity;
1039
1040	v4l2_subdev_init(subdev, sd_ops);
1041	snprintf(subdev->name, V4L2_SUBDEV_NAME_SIZE, "OMAP3 ISP %s", name);
1042	subdev->grp_id = BIT(16);	/* group ID for isp subdevs */
1043	subdev->flags |= V4L2_SUBDEV_FL_HAS_EVENTS | V4L2_SUBDEV_FL_HAS_DEVNODE;
1044	v4l2_set_subdevdata(subdev, stat);
1045
1046	stat->pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;
1047	me->ops = NULL;
1048
1049	return media_entity_pads_init(me, 1, &stat->pad);
1050}
1051
1052int omap3isp_stat_init(struct ispstat *stat, const char *name,
1053		       const struct v4l2_subdev_ops *sd_ops)
1054{
1055	int ret;
1056
1057	stat->buf = kcalloc(STAT_MAX_BUFS, sizeof(*stat->buf), GFP_KERNEL);
1058	if (!stat->buf)
1059		return -ENOMEM;
1060
1061	isp_stat_buf_clear(stat);
1062	mutex_init(&stat->ioctl_lock);
1063	atomic_set(&stat->buf_err, 0);
1064
1065	ret = isp_stat_init_entities(stat, name, sd_ops);
1066	if (ret < 0) {
1067		mutex_destroy(&stat->ioctl_lock);
1068		kfree(stat->buf);
1069	}
1070
1071	return ret;
1072}
1073
1074void omap3isp_stat_cleanup(struct ispstat *stat)
1075{
1076	media_entity_cleanup(&stat->subdev.entity);
1077	mutex_destroy(&stat->ioctl_lock);
1078	isp_stat_bufs_free(stat);
1079	kfree(stat->buf);
1080	kfree(stat->priv);
1081	kfree(stat->recover_priv);
1082}
1083