/*
 * OMAP3 image quality tuning
 *
 * Copyright (C) 2010-2012 Ideas on board SPRL
 *
 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * 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 <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "isp/omap3isp.h"
#include "isp/stats.h"
#include "isp/tools.h"

#include "iq.h"

struct iq_tuning {
	struct omap3_isp_device *isp;

	unsigned int frame_count;
	unsigned int pix_max;
	float mean_level;

	unsigned int exposure;
	unsigned int exposure_min;
	unsigned int exposure_max;

	unsigned int gain;
	unsigned int gain_min;
	unsigned int gain_max;

	unsigned int black_level;
};

void iq_aewb_process(struct iq_tuning *iq,
		     const struct omap3_isp_aewb_stats *stats)
{
	unsigned int i;
	float gains[4];
	double factor;
	double gain;
	double mean;

	/* Automatic White Balance */
	mean = stats->accum[0] + stats->accum[3]
	     + (stats->accum[1] + stats->accum[2]) / 2;
	mean /= 3;

	for (i = 0; i < 4; ++i)
		gains[i] = mean / stats->accum[i];

	omap3_isp_preview_set_white_balance(iq->isp, gains);

	/* Automatic Exposure */
	if ((iq->frame_count++ % 2) == 0)
		return;

	mean = stats->accum[0] + stats->accum[1]
	     + stats->accum[2] + stats->accum[3];
	mean /= 4 * stats->npix;

	factor = (iq->pix_max * iq->mean_level) / mean;

	gain = factor * iq->exposure * iq->gain / iq->gain_min;
	iq->exposure = clamp((unsigned int)gain,
			    iq->exposure_min, iq->exposure_max);

	gain = gain / iq->exposure * iq->gain_min;
	iq->gain = clamp((unsigned int)gain,
			iq->gain_min, iq->gain_max);

	printf("AE: factor %.4f exposure %u sensor gain %u\n",
		factor, iq->exposure, iq->gain);

	omap3_isp_sensor_set_exposure(iq->isp, iq->exposure);
	omap3_isp_sensor_set_gain(iq->isp, iq->gain);
}

struct iq_tuning *iq_init(struct omap3_isp_device *isp)
{
	struct v4l2_mbus_framefmt format;
	struct v4l2_rect window;
	struct iq_tuning *iq;

	iq = malloc(sizeof *iq);
	if (iq == NULL)
		return NULL;

	iq->isp = isp;
	iq->frame_count = 0;
	iq->pix_max = (1 << 10) - 1;
	iq->mean_level = 0.15;
	iq->exposure = 1000;
	iq->exposure_min = 10;
	iq->exposure_max = 2000;
	iq->gain = 8;
	iq->gain_min = 8;
	iq->gain_max = 1024;
	iq->black_level = 64;

	omap3_isp_sensor_set_gain(isp, iq->gain);
	omap3_isp_sensor_set_exposure(isp, iq->exposure);
	omap3_isp_ccdc_set_black_level(isp, iq->black_level);

	omap3_isp_stats_get_format(isp, &format);
	window.left = 0;
	window.top = 0;
	window.width = format.width;
	window.height = format.height;

	omap3_isp_aewb_configure(isp, &window, iq->pix_max - iq->black_level - 1);
	omap3_isp_stats_enable(isp, true);

	return iq;
}

void iq_cleanup(struct iq_tuning *iq)
{
	free(iq);
}