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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ispstat.c4 *5 * TI OMAP3 ISP - Statistics core6 *7 * Copyright (C) 2010 Nokia Corporation8 * Copyright (C) 2009 Texas Instruments, Inc9 *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 of26 * AEWB_PACKET_SIZE and AF_PAXEL_SIZE.27 */28#define MAGIC_SIZE		1629#define MAGIC_NUM		0x5530 31/* HACK: AF module seems to be writing one more paxel data than it should. */32#define AF_EXTRA_DATA		OMAP3ISP_AF_PAXEL_SIZE33 34/*35 * HACK: H3A modules go to an invalid state after have a SBL overflow. It makes36 * the next buffer to start to be written in the same point where the overflow37 * occurred instead of the configured address. The only known way to make it to38 * go back to a valid state is having a valid buffer processing. Of course it39 * requires at least a doubled buffer size to avoid an access to invalid memory40 * region. But it does not fix everything. It may happen more than one41 * consecutive SBL overflows. In that case, it might be unpredictable how many42 * buffers the allocated memory should fit. For that case, a recover43 * configuration was created. It produces the minimum buffer size for each H3A44 * module and decrease the change for more SBL overflows. This recover state45 * will be enabled every time a SBL overflow occur. As the output buffer size46 * isn't big, it's possible to have an extra size able to fit many recover47 * buffers making it extreamily unlikely to have an access to invalid memory48 * region.49 */50#define NUM_H3A_RECOVER_BUFS	1051 52/*53 * HACK: Because of HW issues the generic layer sometimes need to have54 * 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 the148	 * right buf_size for the current configuration is pointed by149	 * 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 to197		 * 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	else263		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 uses389 * ISP DMA, external DMA or PIO to transfer data.390 *391 * The first case (for the AEWB and AF engines) passes the ISP device, resulting392 * 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 driver396 * passes NULL instead, resulting in the buffers being mapped directly as397 * physical pages.398 *399 * The third case (for the histogram engine) doesn't require any mapping. The400 * buffers could be allocated with kmalloc/vmalloc, but we still use401 * 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	data->buf = (uintptr_t)data64.buf;525	memcpy(&data->frame, &data64.frame, sizeof(data->frame));526 527	return 0;528}529 530/*531 * omap3isp_stat_config - Receives new statistic engine configuration.532 * @new_conf: Pointer to config structure.533 *534 * Returns 0 if successful, -EINVAL if new_conf pointer is NULL, -ENOMEM if535 * was unable to allocate memory for the buffer, or other errors if parameters536 * are invalid.537 */538int omap3isp_stat_config(struct ispstat *stat, void *new_conf)539{540	int ret;541	unsigned long irqflags;542	struct ispstat_generic_config *user_cfg = new_conf;543	u32 buf_size = user_cfg->buf_size;544 545	mutex_lock(&stat->ioctl_lock);546 547	dev_dbg(stat->isp->dev,548		"%s: configuring module with buffer size=0x%08lx\n",549		stat->subdev.name, (unsigned long)buf_size);550 551	ret = stat->ops->validate_params(stat, new_conf);552	if (ret) {553		mutex_unlock(&stat->ioctl_lock);554		dev_dbg(stat->isp->dev, "%s: configuration values are invalid.\n",555			stat->subdev.name);556		return ret;557	}558 559	if (buf_size != user_cfg->buf_size)560		dev_dbg(stat->isp->dev,561			"%s: driver has corrected buffer size request to 0x%08lx\n",562			stat->subdev.name,563			(unsigned long)user_cfg->buf_size);564 565	/*566	 * Hack: H3A modules may need a doubled buffer size to avoid access567	 * to a invalid memory address after a SBL overflow.568	 * The buffer size is always PAGE_ALIGNED.569	 * Hack 2: MAGIC_SIZE is added to buf_size so a magic word can be570	 * inserted at the end to data integrity check purpose.571	 * Hack 3: AF module writes one paxel data more than it should, so572	 * the buffer allocation must consider it to avoid invalid memory573	 * access.574	 * Hack 4: H3A need to allocate extra space for the recover state.575	 */576	if (IS_H3A(stat)) {577		buf_size = user_cfg->buf_size * 2 + MAGIC_SIZE;578		if (IS_H3A_AF(stat))579			/*580			 * Adding one extra paxel data size for each recover581			 * buffer + 2 regular ones.582			 */583			buf_size += AF_EXTRA_DATA * (NUM_H3A_RECOVER_BUFS + 2);584		if (stat->recover_priv) {585			struct ispstat_generic_config *recover_cfg =586				stat->recover_priv;587			buf_size += recover_cfg->buf_size *588				    NUM_H3A_RECOVER_BUFS;589		}590		buf_size = PAGE_ALIGN(buf_size);591	} else { /* Histogram */592		buf_size = PAGE_ALIGN(user_cfg->buf_size + MAGIC_SIZE);593	}594 595	ret = isp_stat_bufs_alloc(stat, buf_size);596	if (ret) {597		mutex_unlock(&stat->ioctl_lock);598		return ret;599	}600 601	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);602	stat->ops->set_params(stat, new_conf);603	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);604 605	/*606	 * Returning the right future config_counter for this setup, so607	 * userspace can *know* when it has been applied.608	 */609	user_cfg->config_counter = stat->config_counter + stat->inc_config;610 611	/* Module has a valid configuration. */612	stat->configured = 1;613	dev_dbg(stat->isp->dev,614		"%s: module has been successfully configured.\n",615		stat->subdev.name);616 617	mutex_unlock(&stat->ioctl_lock);618 619	return 0;620}621 622/*623 * isp_stat_buf_process - Process statistic buffers.624 * @buf_state: points out if buffer is ready to be processed. It's necessary625 *	       because histogram needs to copy the data from internal memory626 *	       before be able to process the buffer.627 */628static int isp_stat_buf_process(struct ispstat *stat, int buf_state)629{630	int ret = STAT_NO_BUF;631 632	if (!atomic_add_unless(&stat->buf_err, -1, 0) &&633	    buf_state == STAT_BUF_DONE && stat->state == ISPSTAT_ENABLED) {634		ret = isp_stat_buf_queue(stat);635		isp_stat_buf_next(stat);636	}637 638	return ret;639}640 641int omap3isp_stat_pcr_busy(struct ispstat *stat)642{643	return stat->ops->busy(stat);644}645 646int omap3isp_stat_busy(struct ispstat *stat)647{648	return omap3isp_stat_pcr_busy(stat) | stat->buf_processing |649		(stat->state != ISPSTAT_DISABLED);650}651 652/*653 * isp_stat_pcr_enable - Disables/Enables statistic engines.654 * @pcr_enable: 0/1 - Disables/Enables the engine.655 *656 * Must be called from ISP driver when the module is idle and synchronized657 * with CCDC.658 */659static void isp_stat_pcr_enable(struct ispstat *stat, u8 pcr_enable)660{661	if ((stat->state != ISPSTAT_ENABLING &&662	     stat->state != ISPSTAT_ENABLED) && pcr_enable)663		/* Userspace has disabled the module. Aborting. */664		return;665 666	stat->ops->enable(stat, pcr_enable);667	if (stat->state == ISPSTAT_DISABLING && !pcr_enable)668		stat->state = ISPSTAT_DISABLED;669	else if (stat->state == ISPSTAT_ENABLING && pcr_enable)670		stat->state = ISPSTAT_ENABLED;671}672 673void omap3isp_stat_suspend(struct ispstat *stat)674{675	unsigned long flags;676 677	spin_lock_irqsave(&stat->isp->stat_lock, flags);678 679	if (stat->state != ISPSTAT_DISABLED)680		stat->ops->enable(stat, 0);681	if (stat->state == ISPSTAT_ENABLED)682		stat->state = ISPSTAT_SUSPENDED;683 684	spin_unlock_irqrestore(&stat->isp->stat_lock, flags);685}686 687void omap3isp_stat_resume(struct ispstat *stat)688{689	/* Module will be re-enabled with its pipeline */690	if (stat->state == ISPSTAT_SUSPENDED)691		stat->state = ISPSTAT_ENABLING;692}693 694static void isp_stat_try_enable(struct ispstat *stat)695{696	unsigned long irqflags;697 698	if (stat->priv == NULL)699		/* driver wasn't initialised */700		return;701 702	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);703	if (stat->state == ISPSTAT_ENABLING && !stat->buf_processing &&704	    stat->buf_alloc_size) {705		/*706		 * Userspace's requested to enable the engine but it wasn't yet.707		 * Let's do that now.708		 */709		stat->update = 1;710		isp_stat_buf_next(stat);711		stat->ops->setup_regs(stat, stat->priv);712		isp_stat_buf_insert_magic(stat, stat->active_buf);713 714		/*715		 * H3A module has some hw issues which forces the driver to716		 * ignore next buffers even if it was disabled in the meantime.717		 * On the other hand, Histogram shouldn't ignore buffers anymore718		 * if it's being enabled.719		 */720		if (!IS_H3A(stat))721			atomic_set(&stat->buf_err, 0);722 723		isp_stat_pcr_enable(stat, 1);724		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);725		dev_dbg(stat->isp->dev, "%s: module is enabled.\n",726			stat->subdev.name);727	} else {728		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);729	}730}731 732void omap3isp_stat_isr_frame_sync(struct ispstat *stat)733{734	isp_stat_try_enable(stat);735}736 737void omap3isp_stat_sbl_overflow(struct ispstat *stat)738{739	unsigned long irqflags;740 741	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);742	/*743	 * Due to a H3A hw issue which prevents the next buffer to start from744	 * the correct memory address, 2 buffers must be ignored.745	 */746	atomic_set(&stat->buf_err, 2);747 748	/*749	 * If more than one SBL overflow happen in a row, H3A module may access750	 * invalid memory region.751	 * stat->sbl_ovl_recover is set to tell to the driver to temporarily use752	 * a soft configuration which helps to avoid consecutive overflows.753	 */754	if (stat->recover_priv)755		stat->sbl_ovl_recover = 1;756	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);757}758 759/*760 * omap3isp_stat_enable - Disable/Enable statistic engine as soon as possible761 * @enable: 0/1 - Disables/Enables the engine.762 *763 * Client should configure all the module registers before this.764 * This function can be called from a userspace request.765 */766int omap3isp_stat_enable(struct ispstat *stat, u8 enable)767{768	unsigned long irqflags;769 770	dev_dbg(stat->isp->dev, "%s: user wants to %s module.\n",771		stat->subdev.name, enable ? "enable" : "disable");772 773	/* Prevent enabling while configuring */774	mutex_lock(&stat->ioctl_lock);775 776	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);777 778	if (!stat->configured && enable) {779		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);780		mutex_unlock(&stat->ioctl_lock);781		dev_dbg(stat->isp->dev,782			"%s: cannot enable module as it's never been successfully configured so far.\n",783			stat->subdev.name);784		return -EINVAL;785	}786 787	if (enable) {788		if (stat->state == ISPSTAT_DISABLING)789			/* Previous disabling request wasn't done yet */790			stat->state = ISPSTAT_ENABLED;791		else if (stat->state == ISPSTAT_DISABLED)792			/* Module is now being enabled */793			stat->state = ISPSTAT_ENABLING;794	} else {795		if (stat->state == ISPSTAT_ENABLING) {796			/* Previous enabling request wasn't done yet */797			stat->state = ISPSTAT_DISABLED;798		} else if (stat->state == ISPSTAT_ENABLED) {799			/* Module is now being disabled */800			stat->state = ISPSTAT_DISABLING;801			isp_stat_buf_clear(stat);802		}803	}804 805	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);806	mutex_unlock(&stat->ioctl_lock);807 808	return 0;809}810 811int omap3isp_stat_s_stream(struct v4l2_subdev *subdev, int enable)812{813	struct ispstat *stat = v4l2_get_subdevdata(subdev);814 815	if (enable) {816		/*817		 * Only set enable PCR bit if the module was previously818		 * enabled through ioctl.819		 */820		isp_stat_try_enable(stat);821	} else {822		unsigned long flags;823		/* Disable PCR bit and config enable field */824		omap3isp_stat_enable(stat, 0);825		spin_lock_irqsave(&stat->isp->stat_lock, flags);826		stat->ops->enable(stat, 0);827		spin_unlock_irqrestore(&stat->isp->stat_lock, flags);828 829		/*830		 * If module isn't busy, a new interrupt may come or not to831		 * set the state to DISABLED. As Histogram needs to read its832		 * internal memory to clear it, let interrupt handler833		 * responsible of changing state to DISABLED. If the last834		 * interrupt is coming, it's still safe as the handler will835		 * ignore the second time when state is already set to DISABLED.836		 * It's necessary to synchronize Histogram with streamoff, once837		 * the module may be considered idle before last SDMA transfer838		 * starts if we return here.839		 */840		if (!omap3isp_stat_pcr_busy(stat))841			omap3isp_stat_isr(stat);842 843		dev_dbg(stat->isp->dev, "%s: module is being disabled\n",844			stat->subdev.name);845	}846 847	return 0;848}849 850/*851 * __stat_isr - Interrupt handler for statistic drivers852 */853static void __stat_isr(struct ispstat *stat, int from_dma)854{855	int ret = STAT_BUF_DONE;856	int buf_processing;857	unsigned long irqflags;858	struct isp_pipeline *pipe;859 860	/*861	 * stat->buf_processing must be set before disable module. It's862	 * necessary to not inform too early the buffers aren't busy in case863	 * of SDMA is going to be used.864	 */865	spin_lock_irqsave(&stat->isp->stat_lock, irqflags);866	if (stat->state == ISPSTAT_DISABLED) {867		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);868		return;869	}870	buf_processing = stat->buf_processing;871	stat->buf_processing = 1;872	stat->ops->enable(stat, 0);873 874	if (buf_processing && !from_dma) {875		if (stat->state == ISPSTAT_ENABLED) {876			spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);877			dev_err(stat->isp->dev,878				"%s: interrupt occurred when module was still processing a buffer.\n",879				stat->subdev.name);880			ret = STAT_NO_BUF;881			goto out;882		} else {883			/*884			 * Interrupt handler was called from streamoff when885			 * the module wasn't busy anymore to ensure it is being886			 * disabled after process last buffer. If such buffer887			 * processing has already started, no need to do888			 * anything else.889			 */890			spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);891			return;892		}893	}894	spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);895 896	/* If it's busy we can't process this buffer anymore */897	if (!omap3isp_stat_pcr_busy(stat)) {898		if (!from_dma && stat->ops->buf_process)899			/* Module still need to copy data to buffer. */900			ret = stat->ops->buf_process(stat);901		if (ret == STAT_BUF_WAITING_DMA)902			/* Buffer is not ready yet */903			return;904 905		spin_lock_irqsave(&stat->isp->stat_lock, irqflags);906 907		/*908		 * Histogram needs to read its internal memory to clear it909		 * before be disabled. For that reason, common statistic layer910		 * can return only after call stat's buf_process() operator.911		 */912		if (stat->state == ISPSTAT_DISABLING) {913			stat->state = ISPSTAT_DISABLED;914			spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);915			stat->buf_processing = 0;916			return;917		}918		pipe = to_isp_pipeline(&stat->subdev.entity);919		stat->frame_number = atomic_read(&pipe->frame_number);920 921		/*922		 * Before this point, 'ret' stores the buffer's status if it's923		 * ready to be processed. Afterwards, it holds the status if924		 * it was processed successfully.925		 */926		ret = isp_stat_buf_process(stat, ret);927 928		if (likely(!stat->sbl_ovl_recover)) {929			stat->ops->setup_regs(stat, stat->priv);930		} else {931			/*932			 * Using recover config to increase the chance to have933			 * a good buffer processing and make the H3A module to934			 * go back to a valid state.935			 */936			stat->update = 1;937			stat->ops->setup_regs(stat, stat->recover_priv);938			stat->sbl_ovl_recover = 0;939 940			/*941			 * Set 'update' in case of the module needs to use942			 * regular configuration after next buffer.943			 */944			stat->update = 1;945		}946 947		isp_stat_buf_insert_magic(stat, stat->active_buf);948 949		/*950		 * Hack: H3A modules may access invalid memory address or send951		 * corrupted data to userspace if more than 1 SBL overflow952		 * happens in a row without re-writing its buffer's start memory953		 * address in the meantime. Such situation is avoided if the954		 * module is not immediately re-enabled when the ISR misses the955		 * timing to process the buffer and to setup the registers.956		 * Because of that, pcr_enable(1) was moved to inside this 'if'957		 * block. But the next interruption will still happen as during958		 * pcr_enable(0) the module was busy.959		 */960		isp_stat_pcr_enable(stat, 1);961		spin_unlock_irqrestore(&stat->isp->stat_lock, irqflags);962	} else {963		/*964		 * If a SBL overflow occurs and the H3A driver misses the timing965		 * to process the buffer, stat->buf_err is set and won't be966		 * cleared now. So the next buffer will be correctly ignored.967		 * It's necessary due to a hw issue which makes the next H3A968		 * buffer to start from the memory address where the previous969		 * one stopped, instead of start where it was configured to.970		 * Do not "stat->buf_err = 0" here.971		 */972 973		if (stat->ops->buf_process)974			/*975			 * Driver may need to erase current data prior to976			 * process a new buffer. If it misses the timing, the977			 * next buffer might be wrong. So should be ignored.978			 * It happens only for Histogram.979			 */980			atomic_set(&stat->buf_err, 1);981 982		ret = STAT_NO_BUF;983		dev_dbg(stat->isp->dev,984			"%s: cannot process buffer, device is busy.\n",985			stat->subdev.name);986	}987 988out:989	stat->buf_processing = 0;990	isp_stat_queue_event(stat, ret != STAT_BUF_DONE);991}992 993void omap3isp_stat_isr(struct ispstat *stat)994{995	__stat_isr(stat, 0);996}997 998void omap3isp_stat_dma_isr(struct ispstat *stat)999{1000	__stat_isr(stat, 1);1001}1002 1003int omap3isp_stat_subscribe_event(struct v4l2_subdev *subdev,1004				  struct v4l2_fh *fh,1005				  struct v4l2_event_subscription *sub)1006{1007	struct ispstat *stat = v4l2_get_subdevdata(subdev);1008 1009	if (sub->type != stat->event_type)1010		return -EINVAL;1011 1012	return v4l2_event_subscribe(fh, sub, STAT_NEVENTS, NULL);1013}1014 1015int omap3isp_stat_unsubscribe_event(struct v4l2_subdev *subdev,1016				    struct v4l2_fh *fh,1017				    struct v4l2_event_subscription *sub)1018{1019	return v4l2_event_unsubscribe(fh, sub);1020}1021 1022void omap3isp_stat_unregister_entities(struct ispstat *stat)1023{1024	v4l2_device_unregister_subdev(&stat->subdev);1025}1026 1027int omap3isp_stat_register_entities(struct ispstat *stat,1028				    struct v4l2_device *vdev)1029{1030	stat->subdev.dev = vdev->mdev->dev;1031 1032	return v4l2_device_register_subdev(vdev, &stat->subdev);1033}1034 1035static int isp_stat_init_entities(struct ispstat *stat, const char *name,1036				  const struct v4l2_subdev_ops *sd_ops)1037{1038	struct v4l2_subdev *subdev = &stat->subdev;1039	struct media_entity *me = &subdev->entity;1040 1041	v4l2_subdev_init(subdev, sd_ops);1042	snprintf(subdev->name, sizeof(subdev->name), "OMAP3 ISP %s", name);1043	subdev->grp_id = BIT(16);	/* group ID for isp subdevs */1044	subdev->flags |= V4L2_SUBDEV_FL_HAS_EVENTS | V4L2_SUBDEV_FL_HAS_DEVNODE;1045	v4l2_set_subdevdata(subdev, stat);1046 1047	stat->pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT;1048	me->ops = NULL;1049 1050	return media_entity_pads_init(me, 1, &stat->pad);1051}1052 1053int omap3isp_stat_init(struct ispstat *stat, const char *name,1054		       const struct v4l2_subdev_ops *sd_ops)1055{1056	int ret;1057 1058	stat->buf = kcalloc(STAT_MAX_BUFS, sizeof(*stat->buf), GFP_KERNEL);1059	if (!stat->buf)1060		return -ENOMEM;1061 1062	isp_stat_buf_clear(stat);1063	mutex_init(&stat->ioctl_lock);1064	atomic_set(&stat->buf_err, 0);1065 1066	ret = isp_stat_init_entities(stat, name, sd_ops);1067	if (ret < 0) {1068		mutex_destroy(&stat->ioctl_lock);1069		kfree(stat->buf);1070	}1071 1072	return ret;1073}1074 1075void omap3isp_stat_cleanup(struct ispstat *stat)1076{1077	media_entity_cleanup(&stat->subdev.entity);1078	mutex_destroy(&stat->ioctl_lock);1079	isp_stat_bufs_free(stat);1080	kfree(stat->buf);1081	kfree(stat->priv);1082	kfree(stat->recover_priv);1083}1084