drivers/media/platform/omap3isp/isphist.c - arm/linux-arm64-legacy - Git at Google

 /*
  * isphist.c
  *
  * TI OMAP3 ISP - Histogram module
  *
  * Copyright (C) 2010 Nokia Corporation
  * Copyright (C) 2009 Texas Instruments, Inc.
  *
  * Contacts: David Cohen <dacohen@gmail.com>
  *	     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  *	     Sakari Ailus <sakari.ailus@iki.fi>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA
  */

 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/device.h>

 #include "isp.h"
 #include "ispreg.h"
 #include "isphist.h"

 #define OMAP24XX_DMA_NO_DEVICE		0

 #define HIST_CONFIG_DMA	1

 #define HIST_USING_DMA(hist) ((hist)->dma_ch >= 0)

 /*
  * hist_reset_mem - clear Histogram memory before start stats engine.
  */
 static void hist_reset_mem(struct ispstat *hist)
 {
 	struct isp_device *isp = hist->isp;
 	struct omap3isp_hist_config *conf = hist->priv;
 	unsigned int i;

 	isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);

 	/*
 	 * By setting it, the histogram internal buffer is being cleared at the
 	 * same time it's being read. This bit must be cleared afterwards.
 	 */
 	isp_reg_set(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

 	/*
 	 * We'll clear 4 words at each iteration for optimization. It avoids
 	 * 3/4 of the jumps. We also know HIST_MEM_SIZE is divisible by 4.
 	 */
 	for (i = OMAP3ISP_HIST_MEM_SIZE / 4; i > 0; i--) {
 		isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 		isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 		isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 		isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 	}
 	isp_reg_clr(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

 	hist->wait_acc_frames = conf->num_acc_frames;
 }

 static void hist_dma_config(struct ispstat *hist)
 {
 	struct isp_device *isp = hist->isp;

 	hist->dma_config.data_type = OMAP_DMA_DATA_TYPE_S32;
 	hist->dma_config.sync_mode = OMAP_DMA_SYNC_ELEMENT;
 	hist->dma_config.frame_count = 1;
 	hist->dma_config.src_amode = OMAP_DMA_AMODE_CONSTANT;
 	hist->dma_config.src_start = isp->mmio_base_phys[OMAP3_ISP_IOMEM_HIST]
 				   + ISPHIST_DATA;
 	hist->dma_config.dst_amode = OMAP_DMA_AMODE_POST_INC;
 	hist->dma_config.src_or_dst_synch = OMAP_DMA_SRC_SYNC;
 }

 /*
  * hist_setup_regs - Helper function to update Histogram registers.
  */
 static void hist_setup_regs(struct ispstat *hist, void *priv)
 {
 	struct isp_device *isp = hist->isp;
 	struct omap3isp_hist_config *conf = priv;
 	int c;
 	u32 cnt;
 	u32 wb_gain;
 	u32 reg_hor[OMAP3ISP_HIST_MAX_REGIONS];
 	u32 reg_ver[OMAP3ISP_HIST_MAX_REGIONS];

 	if (!hist->update || hist->state == ISPSTAT_DISABLED ||
 	    hist->state == ISPSTAT_DISABLING)
 		return;

 	cnt = conf->cfa << ISPHIST_CNT_CFA_SHIFT;

 	wb_gain = conf->wg[0] << ISPHIST_WB_GAIN_WG00_SHIFT;
 	wb_gain |= conf->wg[1] << ISPHIST_WB_GAIN_WG01_SHIFT;
 	wb_gain |= conf->wg[2] << ISPHIST_WB_GAIN_WG02_SHIFT;
 	if (conf->cfa == OMAP3ISP_HIST_CFA_BAYER)
 		wb_gain |= conf->wg[3] << ISPHIST_WB_GAIN_WG03_SHIFT;

 	/* Regions size and position */
 	for (c = 0; c < OMAP3ISP_HIST_MAX_REGIONS; c++) {
 		if (c < conf->num_regions) {
 			reg_hor[c] = (conf->region[c].h_start <<
 				     ISPHIST_REG_START_SHIFT)
 				   | (conf->region[c].h_end <<
 				     ISPHIST_REG_END_SHIFT);
 			reg_ver[c] = (conf->region[c].v_start <<
 				     ISPHIST_REG_START_SHIFT)
 				   | (conf->region[c].v_end <<
 				     ISPHIST_REG_END_SHIFT);
 		} else {
 			reg_hor[c] = 0;
 			reg_ver[c] = 0;
 		}
 	}

 	cnt |= conf->hist_bins << ISPHIST_CNT_BINS_SHIFT;
 	switch (conf->hist_bins) {
 	case OMAP3ISP_HIST_BINS_256:
 		cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 8) <<
 			ISPHIST_CNT_SHIFT_SHIFT;
 		break;
 	case OMAP3ISP_HIST_BINS_128:
 		cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 7) <<
 			ISPHIST_CNT_SHIFT_SHIFT;
 		break;
 	case OMAP3ISP_HIST_BINS_64:
 		cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 6) <<
 			ISPHIST_CNT_SHIFT_SHIFT;
 		break;
 	default: /* OMAP3ISP_HIST_BINS_32 */
 		cnt |= (ISPHIST_IN_BIT_WIDTH_CCDC - 5) <<
 			ISPHIST_CNT_SHIFT_SHIFT;
 		break;
 	}

 	hist_reset_mem(hist);

 	isp_reg_writel(isp, cnt, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT);
 	isp_reg_writel(isp, wb_gain,  OMAP3_ISP_IOMEM_HIST, ISPHIST_WB_GAIN);
 	isp_reg_writel(isp, reg_hor[0], OMAP3_ISP_IOMEM_HIST, ISPHIST_R0_HORZ);
 	isp_reg_writel(isp, reg_ver[0], OMAP3_ISP_IOMEM_HIST, ISPHIST_R0_VERT);
 	isp_reg_writel(isp, reg_hor[1], OMAP3_ISP_IOMEM_HIST, ISPHIST_R1_HORZ);
 	isp_reg_writel(isp, reg_ver[1], OMAP3_ISP_IOMEM_HIST, ISPHIST_R1_VERT);
 	isp_reg_writel(isp, reg_hor[2], OMAP3_ISP_IOMEM_HIST, ISPHIST_R2_HORZ);
 	isp_reg_writel(isp, reg_ver[2], OMAP3_ISP_IOMEM_HIST, ISPHIST_R2_VERT);
 	isp_reg_writel(isp, reg_hor[3], OMAP3_ISP_IOMEM_HIST, ISPHIST_R3_HORZ);
 	isp_reg_writel(isp, reg_ver[3], OMAP3_ISP_IOMEM_HIST, ISPHIST_R3_VERT);

 	hist->update = 0;
 	hist->config_counter += hist->inc_config;
 	hist->inc_config = 0;
 	hist->buf_size = conf->buf_size;
 }

 static void hist_enable(struct ispstat *hist, int enable)
 {
 	if (enable) {
 		isp_reg_set(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR,
 			    ISPHIST_PCR_ENABLE);
 		omap3isp_subclk_enable(hist->isp, OMAP3_ISP_SUBCLK_HIST);
 	} else {
 		isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR,
 			    ISPHIST_PCR_ENABLE);
 		omap3isp_subclk_disable(hist->isp, OMAP3_ISP_SUBCLK_HIST);
 	}
 }

 static int hist_busy(struct ispstat *hist)
 {
 	return isp_reg_readl(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR)
 						& ISPHIST_PCR_BUSY;
 }

 static void hist_dma_cb(int lch, u16 ch_status, void *data)
 {
 	struct ispstat *hist = data;

 	if (ch_status & ~OMAP_DMA_BLOCK_IRQ) {
 		dev_dbg(hist->isp->dev, "hist: DMA error. status = 0x%04x\n",
 			ch_status);
 		omap_stop_dma(lch);
 		hist_reset_mem(hist);
 		atomic_set(&hist->buf_err, 1);
 	}
 	isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
 		    ISPHIST_CNT_CLEAR);

 	omap3isp_stat_dma_isr(hist);
 	if (hist->state != ISPSTAT_DISABLED)
 		omap3isp_hist_dma_done(hist->isp);
 }

 static int hist_buf_dma(struct ispstat *hist)
 {
 	dma_addr_t dma_addr = hist->active_buf->dma_addr;

 	if (unlikely(!dma_addr)) {
 		dev_dbg(hist->isp->dev, "hist: invalid DMA buffer address\n");
 		hist_reset_mem(hist);
 		return STAT_NO_BUF;
 	}

 	isp_reg_writel(hist->isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);
 	isp_reg_set(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
 		    ISPHIST_CNT_CLEAR);
 	omap3isp_flush(hist->isp);
 	hist->dma_config.dst_start = dma_addr;
 	hist->dma_config.elem_count = hist->buf_size / sizeof(u32);
 	omap_set_dma_params(hist->dma_ch, &hist->dma_config);

 	omap_start_dma(hist->dma_ch);

 	return STAT_BUF_WAITING_DMA;
 }

 static int hist_buf_pio(struct ispstat *hist)
 {
 	struct isp_device *isp = hist->isp;
 	u32 *buf = hist->active_buf->virt_addr;
 	unsigned int i;

 	if (!buf) {
 		dev_dbg(isp->dev, "hist: invalid PIO buffer address\n");
 		hist_reset_mem(hist);
 		return STAT_NO_BUF;
 	}

 	isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);

 	/*
 	 * By setting it, the histogram internal buffer is being cleared at the
 	 * same time it's being read. This bit must be cleared just after all
 	 * data is acquired.
 	 */
 	isp_reg_set(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

 	/*
 	 * We'll read 4 times a 4-bytes-word at each iteration for
 	 * optimization. It avoids 3/4 of the jumps. We also know buf_size is
 	 * divisible by 16.
 	 */
 	for (i = hist->buf_size / 16; i > 0; i--) {
 		*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 		*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 		*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 		*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
 	}
 	isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
 		    ISPHIST_CNT_CLEAR);

 	return STAT_BUF_DONE;
 }

 /*
  * hist_buf_process - Callback from ISP driver for HIST interrupt.
  */
 static int hist_buf_process(struct ispstat *hist)
 {
 	struct omap3isp_hist_config *user_cfg = hist->priv;
 	int ret;

 	if (atomic_read(&hist->buf_err) || hist->state != ISPSTAT_ENABLED) {
 		hist_reset_mem(hist);
 		return STAT_NO_BUF;
 	}

 	if (--(hist->wait_acc_frames))
 		return STAT_NO_BUF;

 	if (HIST_USING_DMA(hist))
 		ret = hist_buf_dma(hist);
 	else
 		ret = hist_buf_pio(hist);

 	hist->wait_acc_frames = user_cfg->num_acc_frames;

 	return ret;
 }

 static u32 hist_get_buf_size(struct omap3isp_hist_config *conf)
 {
 	return OMAP3ISP_HIST_MEM_SIZE_BINS(conf->hist_bins) * conf->num_regions;
 }

 /*
  * hist_validate_params - Helper function to check user given params.
  * @new_conf: Pointer to user configuration structure.
  *
  * Returns 0 on success configuration.
  */
 static int hist_validate_params(struct ispstat *hist, void *new_conf)
 {
 	struct omap3isp_hist_config *user_cfg = new_conf;
 	int c;
 	u32 buf_size;

 	if (user_cfg->cfa > OMAP3ISP_HIST_CFA_FOVEONX3)
 		return -EINVAL;

 	/* Regions size and position */

 	if ((user_cfg->num_regions < OMAP3ISP_HIST_MIN_REGIONS) ||
 	    (user_cfg->num_regions > OMAP3ISP_HIST_MAX_REGIONS))
 		return -EINVAL;

 	/* Regions */
 	for (c = 0; c < user_cfg->num_regions; c++) {
 		if (user_cfg->region[c].h_start & ~ISPHIST_REG_START_END_MASK)
 			return -EINVAL;
 		if (user_cfg->region[c].h_end & ~ISPHIST_REG_START_END_MASK)
 			return -EINVAL;
 		if (user_cfg->region[c].v_start & ~ISPHIST_REG_START_END_MASK)
 			return -EINVAL;
 		if (user_cfg->region[c].v_end & ~ISPHIST_REG_START_END_MASK)
 			return -EINVAL;
 		if (user_cfg->region[c].h_start > user_cfg->region[c].h_end)
 			return -EINVAL;
 		if (user_cfg->region[c].v_start > user_cfg->region[c].v_end)
 			return -EINVAL;
 	}

 	switch (user_cfg->num_regions) {
 	case 1:
 		if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_256)
 			return -EINVAL;
 		break;
 	case 2:
 		if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_128)
 			return -EINVAL;
 		break;
 	default: /* 3 or 4 */
 		if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_64)
 			return -EINVAL;
 		break;
 	}

 	buf_size = hist_get_buf_size(user_cfg);
 	if (buf_size > user_cfg->buf_size)
 		/* User's buf_size request wasn't enough */
 		user_cfg->buf_size = buf_size;
 	else if (user_cfg->buf_size > OMAP3ISP_HIST_MAX_BUF_SIZE)
 		user_cfg->buf_size = OMAP3ISP_HIST_MAX_BUF_SIZE;

 	return 0;
 }

 static int hist_comp_params(struct ispstat *hist,
 			    struct omap3isp_hist_config *user_cfg)
 {
 	struct omap3isp_hist_config *cur_cfg = hist->priv;
 	int c;

 	if (cur_cfg->cfa != user_cfg->cfa)
 		return 1;

 	if (cur_cfg->num_acc_frames != user_cfg->num_acc_frames)
 		return 1;

 	if (cur_cfg->hist_bins != user_cfg->hist_bins)
 		return 1;

 	for (c = 0; c < OMAP3ISP_HIST_MAX_WG; c++) {
 		if (c == 3 && user_cfg->cfa == OMAP3ISP_HIST_CFA_FOVEONX3)
 			break;
 		else if (cur_cfg->wg[c] != user_cfg->wg[c])
 			return 1;
 	}

 	if (cur_cfg->num_regions != user_cfg->num_regions)
 		return 1;

 	/* Regions */
 	for (c = 0; c < user_cfg->num_regions; c++) {
 		if (cur_cfg->region[c].h_start != user_cfg->region[c].h_start)
 			return 1;
 		if (cur_cfg->region[c].h_end != user_cfg->region[c].h_end)
 			return 1;
 		if (cur_cfg->region[c].v_start != user_cfg->region[c].v_start)
 			return 1;
 		if (cur_cfg->region[c].v_end != user_cfg->region[c].v_end)
 			return 1;
 	}

 	return 0;
 }

 /*
  * hist_update_params - Helper function to check and store user given params.
  * @new_conf: Pointer to user configuration structure.
  */
 static void hist_set_params(struct ispstat *hist, void *new_conf)
 {
 	struct omap3isp_hist_config *user_cfg = new_conf;
 	struct omap3isp_hist_config *cur_cfg = hist->priv;

 	if (!hist->configured || hist_comp_params(hist, user_cfg)) {
 		memcpy(cur_cfg, user_cfg, sizeof(*user_cfg));
 		if (user_cfg->num_acc_frames == 0)
 			user_cfg->num_acc_frames = 1;
 		hist->inc_config++;
 		hist->update = 1;
 		/*
 		 * User might be asked for a bigger buffer than necessary for
 		 * this configuration. In order to return the right amount of
 		 * data during buffer request, let's calculate the size here
 		 * instead of stick with user_cfg->buf_size.
 		 */
 		cur_cfg->buf_size = hist_get_buf_size(cur_cfg);

 	}
 }

 static long hist_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
 {
 	struct ispstat *stat = v4l2_get_subdevdata(sd);

 	switch (cmd) {
 	case VIDIOC_OMAP3ISP_HIST_CFG:
 		return omap3isp_stat_config(stat, arg);
 	case VIDIOC_OMAP3ISP_STAT_REQ:
 		return omap3isp_stat_request_statistics(stat, arg);
 	case VIDIOC_OMAP3ISP_STAT_EN: {
 		int *en = arg;
 		return omap3isp_stat_enable(stat, !!*en);
 	}
 	}

 	return -ENOIOCTLCMD;

 }

 static const struct ispstat_ops hist_ops = {
 	.validate_params	= hist_validate_params,
 	.set_params		= hist_set_params,
 	.setup_regs		= hist_setup_regs,
 	.enable			= hist_enable,
 	.busy			= hist_busy,
 	.buf_process		= hist_buf_process,
 };

 static const struct v4l2_subdev_core_ops hist_subdev_core_ops = {
 	.ioctl = hist_ioctl,
 	.subscribe_event = omap3isp_stat_subscribe_event,
 	.unsubscribe_event = omap3isp_stat_unsubscribe_event,
 };

 static const struct v4l2_subdev_video_ops hist_subdev_video_ops = {
 	.s_stream = omap3isp_stat_s_stream,
 };

 static const struct v4l2_subdev_ops hist_subdev_ops = {
 	.core = &hist_subdev_core_ops,
 	.video = &hist_subdev_video_ops,
 };

 /*
  * omap3isp_hist_init - Module Initialization.
  */
 int omap3isp_hist_init(struct isp_device *isp)
 {
 	struct ispstat *hist = &isp->isp_hist;
 	struct omap3isp_hist_config *hist_cfg;
 	int ret = -1;

 	hist_cfg = devm_kzalloc(isp->dev, sizeof(*hist_cfg), GFP_KERNEL);
 	if (hist_cfg == NULL)
 		return -ENOMEM;

 	hist->isp = isp;

 	if (HIST_CONFIG_DMA)
 		ret = omap_request_dma(OMAP24XX_DMA_NO_DEVICE, "DMA_ISP_HIST",
 				       hist_dma_cb, hist, &hist->dma_ch);
 	if (ret) {
 		if (HIST_CONFIG_DMA)
 			dev_warn(isp->dev, "hist: DMA request channel failed. "
 					   "Using PIO only.\n");
 		hist->dma_ch = -1;
 	} else {
 		dev_dbg(isp->dev, "hist: DMA channel = %d\n", hist->dma_ch);
 		hist_dma_config(hist);
 		omap_enable_dma_irq(hist->dma_ch, OMAP_DMA_BLOCK_IRQ);
 	}

 	hist->ops = &hist_ops;
 	hist->priv = hist_cfg;
 	hist->event_type = V4L2_EVENT_OMAP3ISP_HIST;

 	ret = omap3isp_stat_init(hist, "histogram", &hist_subdev_ops);
 	if (ret) {
 		if (HIST_USING_DMA(hist))
 			omap_free_dma(hist->dma_ch);
 	}

 	return ret;
 }

 /*
  * omap3isp_hist_cleanup - Module cleanup.
  */
 void omap3isp_hist_cleanup(struct isp_device *isp)
 {
 	if (HIST_USING_DMA(&isp->isp_hist))
 		omap_free_dma(isp->isp_hist.dma_ch);
 	omap3isp_stat_cleanup(&isp->isp_hist);
 }
	/*
	* isphist.c
	*
	* TI OMAP3 ISP - Histogram module
	*
	* Copyright (C) 2010 Nokia Corporation
	* Copyright (C) 2009 Texas Instruments, Inc.
	*
	* Contacts: David Cohen <dacohen@gmail.com>
	* Laurent Pinchart <laurent.pinchart@ideasonboard.com>
	* Sakari Ailus <sakari.ailus@iki.fi>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	* 02110-1301 USA
	*/

	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>
	#include <linux/device.h>

	#include "isp.h"
	#include "ispreg.h"
	#include "isphist.h"

	#define OMAP24XX_DMA_NO_DEVICE 0

	#define HIST_CONFIG_DMA 1

	#define HIST_USING_DMA(hist) ((hist)->dma_ch >= 0)

	/*
	* hist_reset_mem - clear Histogram memory before start stats engine.
	*/
	static void hist_reset_mem(struct ispstat *hist)
	{
	struct isp_device *isp = hist->isp;
	struct omap3isp_hist_config *conf = hist->priv;
	unsigned int i;

	isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);

	/*
	* By setting it, the histogram internal buffer is being cleared at the
	* same time it's being read. This bit must be cleared afterwards.
	*/
	isp_reg_set(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

	/*
	* We'll clear 4 words at each iteration for optimization. It avoids
	* 3/4 of the jumps. We also know HIST_MEM_SIZE is divisible by 4.
	*/
	for (i = OMAP3ISP_HIST_MEM_SIZE / 4; i > 0; i--) {
	isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	}
	isp_reg_clr(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

	hist->wait_acc_frames = conf->num_acc_frames;
	}

	static void hist_dma_config(struct ispstat *hist)
	{
	struct isp_device *isp = hist->isp;

	hist->dma_config.data_type = OMAP_DMA_DATA_TYPE_S32;
	hist->dma_config.sync_mode = OMAP_DMA_SYNC_ELEMENT;
	hist->dma_config.frame_count = 1;
	hist->dma_config.src_amode = OMAP_DMA_AMODE_CONSTANT;
	hist->dma_config.src_start = isp->mmio_base_phys[OMAP3_ISP_IOMEM_HIST]
	+ ISPHIST_DATA;
	hist->dma_config.dst_amode = OMAP_DMA_AMODE_POST_INC;
	hist->dma_config.src_or_dst_synch = OMAP_DMA_SRC_SYNC;
	}

	/*
	* hist_setup_regs - Helper function to update Histogram registers.
	*/
	static void hist_setup_regs(struct ispstat hist, void priv)
	{
	struct isp_device *isp = hist->isp;
	struct omap3isp_hist_config *conf = priv;
	int c;
	u32 cnt;
	u32 wb_gain;
	u32 reg_hor[OMAP3ISP_HIST_MAX_REGIONS];
	u32 reg_ver[OMAP3ISP_HIST_MAX_REGIONS];

	if (!hist->update \|\| hist->state == ISPSTAT_DISABLED \|\|
	hist->state == ISPSTAT_DISABLING)
	return;

	cnt = conf->cfa << ISPHIST_CNT_CFA_SHIFT;

	wb_gain = conf->wg[0] << ISPHIST_WB_GAIN_WG00_SHIFT;
	wb_gain \|= conf->wg[1] << ISPHIST_WB_GAIN_WG01_SHIFT;
	wb_gain \|= conf->wg[2] << ISPHIST_WB_GAIN_WG02_SHIFT;
	if (conf->cfa == OMAP3ISP_HIST_CFA_BAYER)
	wb_gain \|= conf->wg[3] << ISPHIST_WB_GAIN_WG03_SHIFT;

	/* Regions size and position */
	for (c = 0; c < OMAP3ISP_HIST_MAX_REGIONS; c++) {
	if (c < conf->num_regions) {
	reg_hor[c] = (conf->region[c].h_start <<
	ISPHIST_REG_START_SHIFT)
	\| (conf->region[c].h_end <<
	ISPHIST_REG_END_SHIFT);
	reg_ver[c] = (conf->region[c].v_start <<
	ISPHIST_REG_START_SHIFT)
	\| (conf->region[c].v_end <<
	ISPHIST_REG_END_SHIFT);
	} else {
	reg_hor[c] = 0;
	reg_ver[c] = 0;
	}
	}

	cnt \|= conf->hist_bins << ISPHIST_CNT_BINS_SHIFT;
	switch (conf->hist_bins) {
	case OMAP3ISP_HIST_BINS_256:
	cnt \|= (ISPHIST_IN_BIT_WIDTH_CCDC - 8) <<
	ISPHIST_CNT_SHIFT_SHIFT;
	break;
	case OMAP3ISP_HIST_BINS_128:
	cnt \|= (ISPHIST_IN_BIT_WIDTH_CCDC - 7) <<
	ISPHIST_CNT_SHIFT_SHIFT;
	break;
	case OMAP3ISP_HIST_BINS_64:
	cnt \|= (ISPHIST_IN_BIT_WIDTH_CCDC - 6) <<
	ISPHIST_CNT_SHIFT_SHIFT;
	break;
	default: /* OMAP3ISP_HIST_BINS_32 */
	cnt \|= (ISPHIST_IN_BIT_WIDTH_CCDC - 5) <<
	ISPHIST_CNT_SHIFT_SHIFT;
	break;
	}

	hist_reset_mem(hist);

	isp_reg_writel(isp, cnt, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT);
	isp_reg_writel(isp, wb_gain, OMAP3_ISP_IOMEM_HIST, ISPHIST_WB_GAIN);
	isp_reg_writel(isp, reg_hor[0], OMAP3_ISP_IOMEM_HIST, ISPHIST_R0_HORZ);
	isp_reg_writel(isp, reg_ver[0], OMAP3_ISP_IOMEM_HIST, ISPHIST_R0_VERT);
	isp_reg_writel(isp, reg_hor[1], OMAP3_ISP_IOMEM_HIST, ISPHIST_R1_HORZ);
	isp_reg_writel(isp, reg_ver[1], OMAP3_ISP_IOMEM_HIST, ISPHIST_R1_VERT);
	isp_reg_writel(isp, reg_hor[2], OMAP3_ISP_IOMEM_HIST, ISPHIST_R2_HORZ);
	isp_reg_writel(isp, reg_ver[2], OMAP3_ISP_IOMEM_HIST, ISPHIST_R2_VERT);
	isp_reg_writel(isp, reg_hor[3], OMAP3_ISP_IOMEM_HIST, ISPHIST_R3_HORZ);
	isp_reg_writel(isp, reg_ver[3], OMAP3_ISP_IOMEM_HIST, ISPHIST_R3_VERT);

	hist->update = 0;
	hist->config_counter += hist->inc_config;
	hist->inc_config = 0;
	hist->buf_size = conf->buf_size;
	}

	static void hist_enable(struct ispstat *hist, int enable)
	{
	if (enable) {
	isp_reg_set(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR,
	ISPHIST_PCR_ENABLE);
	omap3isp_subclk_enable(hist->isp, OMAP3_ISP_SUBCLK_HIST);
	} else {
	isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR,
	ISPHIST_PCR_ENABLE);
	omap3isp_subclk_disable(hist->isp, OMAP3_ISP_SUBCLK_HIST);
	}
	}

	static int hist_busy(struct ispstat *hist)
	{
	return isp_reg_readl(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_PCR)
	& ISPHIST_PCR_BUSY;
	}

	static void hist_dma_cb(int lch, u16 ch_status, void *data)
	{
	struct ispstat *hist = data;

	if (ch_status & ~OMAP_DMA_BLOCK_IRQ) {
	dev_dbg(hist->isp->dev, "hist: DMA error. status = 0x%04x\n",
	ch_status);
	omap_stop_dma(lch);
	hist_reset_mem(hist);
	atomic_set(&hist->buf_err, 1);
	}
	isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
	ISPHIST_CNT_CLEAR);

	omap3isp_stat_dma_isr(hist);
	if (hist->state != ISPSTAT_DISABLED)
	omap3isp_hist_dma_done(hist->isp);
	}

	static int hist_buf_dma(struct ispstat *hist)
	{
	dma_addr_t dma_addr = hist->active_buf->dma_addr;

	if (unlikely(!dma_addr)) {
	dev_dbg(hist->isp->dev, "hist: invalid DMA buffer address\n");
	hist_reset_mem(hist);
	return STAT_NO_BUF;
	}

	isp_reg_writel(hist->isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);
	isp_reg_set(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
	ISPHIST_CNT_CLEAR);
	omap3isp_flush(hist->isp);
	hist->dma_config.dst_start = dma_addr;
	hist->dma_config.elem_count = hist->buf_size / sizeof(u32);
	omap_set_dma_params(hist->dma_ch, &hist->dma_config);

	omap_start_dma(hist->dma_ch);

	return STAT_BUF_WAITING_DMA;
	}

	static int hist_buf_pio(struct ispstat *hist)
	{
	struct isp_device *isp = hist->isp;
	u32 *buf = hist->active_buf->virt_addr;
	unsigned int i;

	if (!buf) {
	dev_dbg(isp->dev, "hist: invalid PIO buffer address\n");
	hist_reset_mem(hist);
	return STAT_NO_BUF;
	}

	isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_HIST, ISPHIST_ADDR);

	/*
	* By setting it, the histogram internal buffer is being cleared at the
	* same time it's being read. This bit must be cleared just after all
	* data is acquired.
	*/
	isp_reg_set(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT, ISPHIST_CNT_CLEAR);

	/*
	* We'll read 4 times a 4-bytes-word at each iteration for
	* optimization. It avoids 3/4 of the jumps. We also know buf_size is
	* divisible by 16.
	*/
	for (i = hist->buf_size / 16; i > 0; i--) {
	*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	*buf++ = isp_reg_readl(isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_DATA);
	}
	isp_reg_clr(hist->isp, OMAP3_ISP_IOMEM_HIST, ISPHIST_CNT,
	ISPHIST_CNT_CLEAR);

	return STAT_BUF_DONE;
	}

	/*
	* hist_buf_process - Callback from ISP driver for HIST interrupt.
	*/
	static int hist_buf_process(struct ispstat *hist)
	{
	struct omap3isp_hist_config *user_cfg = hist->priv;
	int ret;

	if (atomic_read(&hist->buf_err) \|\| hist->state != ISPSTAT_ENABLED) {
	hist_reset_mem(hist);
	return STAT_NO_BUF;
	}

	if (--(hist->wait_acc_frames))
	return STAT_NO_BUF;

	if (HIST_USING_DMA(hist))
	ret = hist_buf_dma(hist);
	else
	ret = hist_buf_pio(hist);

	hist->wait_acc_frames = user_cfg->num_acc_frames;

	return ret;
	}

	static u32 hist_get_buf_size(struct omap3isp_hist_config *conf)
	{
	return OMAP3ISP_HIST_MEM_SIZE_BINS(conf->hist_bins) * conf->num_regions;
	}

	/*
	* hist_validate_params - Helper function to check user given params.
	* @new_conf: Pointer to user configuration structure.
	*
	* Returns 0 on success configuration.
	*/
	static int hist_validate_params(struct ispstat hist, void new_conf)
	{
	struct omap3isp_hist_config *user_cfg = new_conf;
	int c;
	u32 buf_size;

	if (user_cfg->cfa > OMAP3ISP_HIST_CFA_FOVEONX3)
	return -EINVAL;

	/* Regions size and position */

	if ((user_cfg->num_regions < OMAP3ISP_HIST_MIN_REGIONS) \|\|
	(user_cfg->num_regions > OMAP3ISP_HIST_MAX_REGIONS))
	return -EINVAL;

	/* Regions */
	for (c = 0; c < user_cfg->num_regions; c++) {
	if (user_cfg->region[c].h_start & ~ISPHIST_REG_START_END_MASK)
	return -EINVAL;
	if (user_cfg->region[c].h_end & ~ISPHIST_REG_START_END_MASK)
	return -EINVAL;
	if (user_cfg->region[c].v_start & ~ISPHIST_REG_START_END_MASK)
	return -EINVAL;
	if (user_cfg->region[c].v_end & ~ISPHIST_REG_START_END_MASK)
	return -EINVAL;
	if (user_cfg->region[c].h_start > user_cfg->region[c].h_end)
	return -EINVAL;
	if (user_cfg->region[c].v_start > user_cfg->region[c].v_end)
	return -EINVAL;
	}

	switch (user_cfg->num_regions) {
	case 1:
	if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_256)
	return -EINVAL;
	break;
	case 2:
	if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_128)
	return -EINVAL;
	break;
	default: /* 3 or 4 */
	if (user_cfg->hist_bins > OMAP3ISP_HIST_BINS_64)
	return -EINVAL;
	break;
	}

	buf_size = hist_get_buf_size(user_cfg);
	if (buf_size > user_cfg->buf_size)
	/* User's buf_size request wasn't enough */
	user_cfg->buf_size = buf_size;
	else if (user_cfg->buf_size > OMAP3ISP_HIST_MAX_BUF_SIZE)
	user_cfg->buf_size = OMAP3ISP_HIST_MAX_BUF_SIZE;

	return 0;
	}

	static int hist_comp_params(struct ispstat *hist,
	struct omap3isp_hist_config *user_cfg)
	{
	struct omap3isp_hist_config *cur_cfg = hist->priv;
	int c;

	if (cur_cfg->cfa != user_cfg->cfa)
	return 1;

	if (cur_cfg->num_acc_frames != user_cfg->num_acc_frames)
	return 1;

	if (cur_cfg->hist_bins != user_cfg->hist_bins)
	return 1;

	for (c = 0; c < OMAP3ISP_HIST_MAX_WG; c++) {
	if (c == 3 && user_cfg->cfa == OMAP3ISP_HIST_CFA_FOVEONX3)
	break;
	else if (cur_cfg->wg[c] != user_cfg->wg[c])
	return 1;
	}

	if (cur_cfg->num_regions != user_cfg->num_regions)
	return 1;

	/* Regions */
	for (c = 0; c < user_cfg->num_regions; c++) {
	if (cur_cfg->region[c].h_start != user_cfg->region[c].h_start)
	return 1;
	if (cur_cfg->region[c].h_end != user_cfg->region[c].h_end)
	return 1;
	if (cur_cfg->region[c].v_start != user_cfg->region[c].v_start)
	return 1;
	if (cur_cfg->region[c].v_end != user_cfg->region[c].v_end)
	return 1;
	}

	return 0;
	}

	/*
	* hist_update_params - Helper function to check and store user given params.
	* @new_conf: Pointer to user configuration structure.
	*/
	static void hist_set_params(struct ispstat hist, void new_conf)
	{
	struct omap3isp_hist_config *user_cfg = new_conf;
	struct omap3isp_hist_config *cur_cfg = hist->priv;

	if (!hist->configured \|\| hist_comp_params(hist, user_cfg)) {
	memcpy(cur_cfg, user_cfg, sizeof(*user_cfg));
	if (user_cfg->num_acc_frames == 0)
	user_cfg->num_acc_frames = 1;
	hist->inc_config++;
	hist->update = 1;
	/*
	* User might be asked for a bigger buffer than necessary for
	* this configuration. In order to return the right amount of
	* data during buffer request, let's calculate the size here
	* instead of stick with user_cfg->buf_size.
	*/
	cur_cfg->buf_size = hist_get_buf_size(cur_cfg);

	}
	}

	static long hist_ioctl(struct v4l2_subdev sd, unsigned int cmd, void arg)
	{
	struct ispstat *stat = v4l2_get_subdevdata(sd);

	switch (cmd) {
	case VIDIOC_OMAP3ISP_HIST_CFG:
	return omap3isp_stat_config(stat, arg);
	case VIDIOC_OMAP3ISP_STAT_REQ:
	return omap3isp_stat_request_statistics(stat, arg);
	case VIDIOC_OMAP3ISP_STAT_EN: {
	int *en = arg;
	return omap3isp_stat_enable(stat, !!*en);
	}
	}

	return -ENOIOCTLCMD;

	}

	static const struct ispstat_ops hist_ops = {
	.validate_params = hist_validate_params,
	.set_params = hist_set_params,
	.setup_regs = hist_setup_regs,
	.enable = hist_enable,
	.busy = hist_busy,
	.buf_process = hist_buf_process,
	};

	static const struct v4l2_subdev_core_ops hist_subdev_core_ops = {
	.ioctl = hist_ioctl,
	.subscribe_event = omap3isp_stat_subscribe_event,
	.unsubscribe_event = omap3isp_stat_unsubscribe_event,
	};

	static const struct v4l2_subdev_video_ops hist_subdev_video_ops = {
	.s_stream = omap3isp_stat_s_stream,
	};

	static const struct v4l2_subdev_ops hist_subdev_ops = {
	.core = &hist_subdev_core_ops,
	.video = &hist_subdev_video_ops,
	};

	/*
	* omap3isp_hist_init - Module Initialization.
	*/
	int omap3isp_hist_init(struct isp_device *isp)
	{
	struct ispstat *hist = &isp->isp_hist;
	struct omap3isp_hist_config *hist_cfg;
	int ret = -1;

	hist_cfg = devm_kzalloc(isp->dev, sizeof(*hist_cfg), GFP_KERNEL);
	if (hist_cfg == NULL)
	return -ENOMEM;

	hist->isp = isp;

	if (HIST_CONFIG_DMA)
	ret = omap_request_dma(OMAP24XX_DMA_NO_DEVICE, "DMA_ISP_HIST",
	hist_dma_cb, hist, &hist->dma_ch);
	if (ret) {
	if (HIST_CONFIG_DMA)
	dev_warn(isp->dev, "hist: DMA request channel failed. "
	"Using PIO only.\n");
	hist->dma_ch = -1;
	} else {
	dev_dbg(isp->dev, "hist: DMA channel = %d\n", hist->dma_ch);
	hist_dma_config(hist);
	omap_enable_dma_irq(hist->dma_ch, OMAP_DMA_BLOCK_IRQ);
	}

	hist->ops = &hist_ops;
	hist->priv = hist_cfg;
	hist->event_type = V4L2_EVENT_OMAP3ISP_HIST;

	ret = omap3isp_stat_init(hist, "histogram", &hist_subdev_ops);
	if (ret) {
	if (HIST_USING_DMA(hist))
	omap_free_dma(hist->dma_ch);
	}

	return ret;
	}

	/*
	* omap3isp_hist_cleanup - Module cleanup.
	*/
	void omap3isp_hist_cleanup(struct isp_device *isp)
	{
	if (HIST_USING_DMA(&isp->isp_hist))
	omap_free_dma(isp->isp_hist.dma_ch);
	omap3isp_stat_cleanup(&isp->isp_hist);
	}