/*
 * Pixart PAC207BCA library
 *
 * Copyright (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl>
 * Copyright (C) 2005 Thomas Kaiser thomas@kaiser-linux.li
 * Copyleft (C) 2005 Michel Xhaard mxhaard@magic.fr
 *
 * V4L2 by Jean-Francois Moine <http://moinejf.free.fr>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#define MODULE_NAME "pac207"

#include "gspca.h"

MODULE_AUTHOR("Hans de Goede <j.w.r.degoede@hhs.nl>");
MODULE_DESCRIPTION("Pixart PAC207");
MODULE_LICENSE("GPL");

#define PAC207_CTRL_TIMEOUT		100  /* ms */

#define PAC207_BRIGHTNESS_MIN		0
#define PAC207_BRIGHTNESS_MAX		255
#define PAC207_BRIGHTNESS_DEFAULT	4 /* power on default: 4 */

/* An exposure value of 4 also works (3 does not) but then we need to lower
   the compression balance setting when in 352x288 mode, otherwise the usb
   bandwidth is not enough and packets get dropped resulting in corrupt
   frames. The problem with this is that when the compression balance gets
   lowered below 0x80, the pac207 starts using a different compression
   algorithm for some lines, these lines get prefixed with a 0x2dd2 prefix
   and currently we do not know how to decompress these lines, so for now
   we use a minimum exposure value of 5 */
#define PAC207_EXPOSURE_MIN		5
#define PAC207_EXPOSURE_MAX		26
#define PAC207_EXPOSURE_DEFAULT		5 /* power on default: 3 ?? */
#define PAC207_EXPOSURE_KNEE		11 /* 4 = 30 fps, 11 = 8, 15 = 6 */

#define PAC207_GAIN_MIN			0
#define PAC207_GAIN_MAX			31
#define PAC207_GAIN_DEFAULT         	9 /* power on default: 9 */
#define PAC207_GAIN_KNEE		20

#define PAC207_AUTOGAIN_DEADZONE	30
/* We calculating the autogain at the end of the transfer of a frame, at this
   moment a frame with the old settings is being transmitted, and a frame is
   being captured with the old settings. So if we adjust the autogain we must
   ignore atleast the 2 next frames for the new settings to come into effect
   before doing any other adjustments */
#define PAC207_AUTOGAIN_IGNORE_FRAMES	3

/* specific webcam descriptor */
struct sd {
	struct gspca_dev gspca_dev;		/* !! must be the first item */

	u8 mode;

	u8 brightness;
	u8 exposure;
	u8 autogain;
	u8 gain;

	u8 sof_read;
	u8 header_read;
	u8 autogain_ignore_frames;

	atomic_t avg_lum;
};

/* V4L2 controls supported by the driver */
static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getbrightness(struct gspca_dev *gspca_dev, __s32 *val);
static int sd_setexposure(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getexposure(struct gspca_dev *gspca_dev, __s32 *val);
static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getautogain(struct gspca_dev *gspca_dev, __s32 *val);
static int sd_setgain(struct gspca_dev *gspca_dev, __s32 val);
static int sd_getgain(struct gspca_dev *gspca_dev, __s32 *val);

static struct ctrl sd_ctrls[] = {
#define SD_BRIGHTNESS 0
	{
	    {
		.id      = V4L2_CID_BRIGHTNESS,
		.type    = V4L2_CTRL_TYPE_INTEGER,
		.name    = "Brightness",
		.minimum = PAC207_BRIGHTNESS_MIN,
		.maximum = PAC207_BRIGHTNESS_MAX,
		.step = 1,
		.default_value = PAC207_BRIGHTNESS_DEFAULT,
		.flags = 0,
	    },
	    .set = sd_setbrightness,
	    .get = sd_getbrightness,
	},
#define SD_EXPOSURE 1
	{
	    {
		.id = V4L2_CID_EXPOSURE,
		.type = V4L2_CTRL_TYPE_INTEGER,
		.name = "exposure",
		.minimum = PAC207_EXPOSURE_MIN,
		.maximum = PAC207_EXPOSURE_MAX,
		.step = 1,
		.default_value = PAC207_EXPOSURE_DEFAULT,
		.flags = 0,
	    },
	    .set = sd_setexposure,
	    .get = sd_getexposure,
	},
#define SD_AUTOGAIN 2
	{
	    {
		.id	  = V4L2_CID_AUTOGAIN,
		.type	= V4L2_CTRL_TYPE_BOOLEAN,
		.name	= "Auto Gain",
		.minimum = 0,
		.maximum = 1,
		.step	= 1,
		.default_value = 1,
		.flags = 0,
	    },
	    .set = sd_setautogain,
	    .get = sd_getautogain,
	},
#define SD_GAIN 3
	{
	    {
		.id = V4L2_CID_GAIN,
		.type = V4L2_CTRL_TYPE_INTEGER,
		.name = "gain",
		.minimum = PAC207_GAIN_MIN,
		.maximum = PAC207_GAIN_MAX,
		.step = 1,
		.default_value = PAC207_GAIN_DEFAULT,
		.flags = 0,
	    },
	    .set = sd_setgain,
	    .get = sd_getgain,
	},
};

static struct v4l2_pix_format sif_mode[] = {
	{176, 144, V4L2_PIX_FMT_PAC207, V4L2_FIELD_NONE,
		.bytesperline = 176,
		.sizeimage = (176 + 2) * 144,
			/* uncompressed, add 2 bytes / line for line header */
		.colorspace = V4L2_COLORSPACE_SRGB,
		.priv = 1},
	{352, 288, V4L2_PIX_FMT_PAC207, V4L2_FIELD_NONE,
		.bytesperline = 352,
			/* compressed, but only when needed (not compressed
			   when the framerate is low) */
		.sizeimage = (352 + 2) * 288,
		.colorspace = V4L2_COLORSPACE_SRGB,
		.priv = 0},
};

static const __u8 pac207_sensor_init[][8] = {
	{0x10, 0x12, 0x0d, 0x12, 0x0c, 0x01, 0x29, 0xf0},
	{0x00, 0x64, 0x64, 0x64, 0x04, 0x10, 0xf0, 0x30},
	{0x00, 0x00, 0x00, 0x70, 0xa0, 0xf8, 0x00, 0x00},
	{0x00, 0x00, 0x32, 0x00, 0x96, 0x00, 0xa2, 0x02},
	{0x32, 0x00, 0x96, 0x00, 0xA2, 0x02, 0xaf, 0x00},
};

			/* 48 reg_72 Rate Control end BalSize_4a =0x36 */
static const __u8 PacReg72[] = { 0x00, 0x00, 0x36, 0x00 };

static const unsigned char pac207_sof_marker[5] =
		{ 0xff, 0xff, 0x00, 0xff, 0x96 };

static int pac207_write_regs(struct gspca_dev *gspca_dev, u16 index,
	const u8 *buffer, u16 length)
{
	struct usb_device *udev = gspca_dev->dev;
	int err;

	memcpy(gspca_dev->usb_buf, buffer, length);

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0x01,
			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
			0x00, index,
			gspca_dev->usb_buf, length, PAC207_CTRL_TIMEOUT);
	if (err < 0)
		PDEBUG(D_ERR,
			"Failed to write registers to index 0x%04X, error %d)",
			index, err);

	return err;
}


static int pac207_write_reg(struct gspca_dev *gspca_dev, u16 index, u16 value)
{
	struct usb_device *udev = gspca_dev->dev;
	int err;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 0x00,
			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
			value, index, NULL, 0, PAC207_CTRL_TIMEOUT);
	if (err)
		PDEBUG(D_ERR, "Failed to write a register (index 0x%04X,"
			" value 0x%02X, error %d)", index, value, err);

	return err;
}

static int pac207_read_reg(struct gspca_dev *gspca_dev, u16 index)
{
	struct usb_device *udev = gspca_dev->dev;
	int res;

	res = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), 0x00,
			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
			0x00, index,
			gspca_dev->usb_buf, 1, PAC207_CTRL_TIMEOUT);
	if (res < 0) {
		PDEBUG(D_ERR,
			"Failed to read a register (index 0x%04X, error %d)",
			index, res);
		return res;
	}

	return gspca_dev->usb_buf[0];
}

/* this function is called at probe time */
static int sd_config(struct gspca_dev *gspca_dev,
			const struct usb_device_id *id)
{
	struct sd *sd = (struct sd *) gspca_dev;
	struct cam *cam;
	u8 idreg[2];

	idreg[0] = pac207_read_reg(gspca_dev, 0x0000);
	idreg[1] = pac207_read_reg(gspca_dev, 0x0001);
	idreg[0] = ((idreg[0] & 0x0F) << 4) | ((idreg[1] & 0xf0) >> 4);
	idreg[1] = idreg[1] & 0x0f;
	PDEBUG(D_PROBE, "Pixart Sensor ID 0x%02X Chips ID 0x%02X",
		idreg[0], idreg[1]);

	if (idreg[0] != 0x27) {
		PDEBUG(D_PROBE, "Error invalid sensor ID!");
		return -ENODEV;
	}

	pac207_write_reg(gspca_dev, 0x41, 0x00);
				/* Bit_0=Image Format,
				 * Bit_1=LED,
				 * Bit_2=Compression test mode enable */
	pac207_write_reg(gspca_dev, 0x0f, 0x00); /* Power Control */
	pac207_write_reg(gspca_dev, 0x11, 0x30); /* Analog Bias */

	PDEBUG(D_PROBE,
		"Pixart PAC207BCA Image Processor and Control Chip detected"
		" (vid/pid 0x%04X:0x%04X)", id->idVendor, id->idProduct);

	cam = &gspca_dev->cam;
	cam->dev_name = (char *) id->driver_info;
	cam->epaddr = 0x05;
	cam->cam_mode = sif_mode;
	cam->nmodes = ARRAY_SIZE(sif_mode);
	sd->brightness = PAC207_BRIGHTNESS_DEFAULT;
	sd->exposure = PAC207_EXPOSURE_DEFAULT;
	sd->gain = PAC207_GAIN_DEFAULT;

	return 0;
}

/* this function is called at open time */
static int sd_open(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;

	sd->autogain = 1;
	return 0;
}

/* -- start the camera -- */
static void sd_start(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;
	__u8 mode;

	pac207_write_reg(gspca_dev, 0x0f, 0x10); /* Power control (Bit 6-0) */
	pac207_write_regs(gspca_dev, 0x0002, pac207_sensor_init[0], 8);
	pac207_write_regs(gspca_dev, 0x000a, pac207_sensor_init[1], 8);
	pac207_write_regs(gspca_dev, 0x0012, pac207_sensor_init[2], 8);
	pac207_write_regs(gspca_dev, 0x0040, pac207_sensor_init[3], 8);
	pac207_write_regs(gspca_dev, 0x0042, pac207_sensor_init[4], 8);
	pac207_write_regs(gspca_dev, 0x0048, PacReg72, 4);

	/* Compression Balance */
	if (gspca_dev->width == 176)
		pac207_write_reg(gspca_dev, 0x4a, 0xff);
	else
		pac207_write_reg(gspca_dev, 0x4a, 0x88);
	pac207_write_reg(gspca_dev, 0x4b, 0x00); /* Sram test value */
	pac207_write_reg(gspca_dev, 0x08, sd->brightness);

	/* PGA global gain (Bit 4-0) */
	pac207_write_reg(gspca_dev, 0x0e, sd->gain);
	pac207_write_reg(gspca_dev, 0x02, sd->exposure); /* PXCK = 12MHz /n */

	mode = 0x02; /* Image Format (Bit 0), LED (1), Compr. test mode (2) */
	if (gspca_dev->width == 176) {	/* 176x144 */
		mode |= 0x01;
		PDEBUG(D_STREAM, "pac207_start mode 176x144");
	} else {				/* 352x288 */
		PDEBUG(D_STREAM, "pac207_start mode 352x288");
	}
	pac207_write_reg(gspca_dev, 0x41, mode);

	pac207_write_reg(gspca_dev, 0x13, 0x01); /* Bit 0, auto clear */
	pac207_write_reg(gspca_dev, 0x1c, 0x01); /* not documented */
	msleep(10);
	pac207_write_reg(gspca_dev, 0x40, 0x01); /* Start ISO pipe */

	sd->sof_read = 0;
	sd->autogain_ignore_frames = 0;
	atomic_set(&sd->avg_lum, -1);
}

static void sd_stopN(struct gspca_dev *gspca_dev)
{
	pac207_write_reg(gspca_dev, 0x40, 0x00); /* Stop ISO pipe */
	pac207_write_reg(gspca_dev, 0x41, 0x00); /* Turn of LED */
	pac207_write_reg(gspca_dev, 0x0f, 0x00); /* Power Control */
}

static void sd_stop0(struct gspca_dev *gspca_dev)
{
}

/* this function is called at close time */
static void sd_close(struct gspca_dev *gspca_dev)
{
}

static void pac207_do_auto_gain(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;
	int avg_lum = atomic_read(&sd->avg_lum);

	if (avg_lum == -1)
		return;

	if (sd->autogain_ignore_frames > 0)
		sd->autogain_ignore_frames--;
	else if (gspca_auto_gain_n_exposure(gspca_dev, avg_lum,
			100 + sd->brightness / 2, PAC207_AUTOGAIN_DEADZONE,
			PAC207_GAIN_KNEE, PAC207_EXPOSURE_KNEE))
		sd->autogain_ignore_frames = PAC207_AUTOGAIN_IGNORE_FRAMES;
}

static unsigned char *pac207_find_sof(struct gspca_dev *gspca_dev,
					unsigned char *m, int len)
{
	struct sd *sd = (struct sd *) gspca_dev;
	int i;

	/* Search for the SOF marker (fixed part) in the header */
	for (i = 0; i < len; i++) {
		if (m[i] == pac207_sof_marker[sd->sof_read]) {
			sd->sof_read++;
			if (sd->sof_read == sizeof(pac207_sof_marker)) {
				PDEBUG(D_STREAM,
					"SOF found, bytes to analyze: %u."
					" Frame starts at byte #%u",
					len, i + 1);
				sd->sof_read = 0;
				return m + i + 1;
			}
		} else {
			sd->sof_read = 0;
		}
	}

	return NULL;
}

static void sd_pkt_scan(struct gspca_dev *gspca_dev,
			struct gspca_frame *frame,
			__u8 *data,
			int len)
{
	struct sd *sd = (struct sd *) gspca_dev;
	unsigned char *sof;

	sof = pac207_find_sof(gspca_dev, data, len);
	if (sof) {
		int n;

		/* finish decoding current frame */
		n = sof - data;
		if (n > sizeof pac207_sof_marker)
			n -= sizeof pac207_sof_marker;
		else
			n = 0;
		frame = gspca_frame_add(gspca_dev, LAST_PACKET, frame,
					data, n);
		sd->header_read = 0;
		gspca_frame_add(gspca_dev, FIRST_PACKET, frame, NULL, 0);
		len -= sof - data;
		data = sof;
	}
	if (sd->header_read < 11) {
		int needed;

		/* get average lumination from frame header (byte 5) */
		if (sd->header_read < 5) {
			needed = 5 - sd->header_read;
			if (len >= needed)
				atomic_set(&sd->avg_lum, data[needed - 1]);
		}
		/* skip the rest of the header */
		needed = 11 - sd->header_read;
		if (len <= needed) {
			sd->header_read += len;
			return;
		}
		data += needed;
		len -= needed;
		sd->header_read = 11;
	}

	gspca_frame_add(gspca_dev, INTER_PACKET, frame, data, len);
}

static void setbrightness(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;

	pac207_write_reg(gspca_dev, 0x08, sd->brightness);
	pac207_write_reg(gspca_dev, 0x13, 0x01);	/* Bit 0, auto clear */
	pac207_write_reg(gspca_dev, 0x1c, 0x01);	/* not documented */
}

static void setexposure(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;

	pac207_write_reg(gspca_dev, 0x02, sd->exposure);
	pac207_write_reg(gspca_dev, 0x13, 0x01);	/* Bit 0, auto clear */
	pac207_write_reg(gspca_dev, 0x1c, 0x01);	/* not documented */
}

static void setgain(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;

	pac207_write_reg(gspca_dev, 0x0e, sd->gain);
	pac207_write_reg(gspca_dev, 0x13, 0x01);	/* Bit 0, auto clear */
	pac207_write_reg(gspca_dev, 0x1c, 0x01);	/* not documented */
}

static int sd_setbrightness(struct gspca_dev *gspca_dev, __s32 val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	sd->brightness = val;
	if (gspca_dev->streaming)
		setbrightness(gspca_dev);
	return 0;
}

static int sd_getbrightness(struct gspca_dev *gspca_dev, __s32 *val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	*val = sd->brightness;
	return 0;
}

static int sd_setexposure(struct gspca_dev *gspca_dev, __s32 val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	sd->exposure = val;
	if (gspca_dev->streaming)
		setexposure(gspca_dev);
	return 0;
}

static int sd_getexposure(struct gspca_dev *gspca_dev, __s32 *val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	*val = sd->exposure;
	return 0;
}

static int sd_setgain(struct gspca_dev *gspca_dev, __s32 val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	sd->gain = val;
	if (gspca_dev->streaming)
		setgain(gspca_dev);
	return 0;
}

static int sd_getgain(struct gspca_dev *gspca_dev, __s32 *val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	*val = sd->gain;
	return 0;
}

static int sd_setautogain(struct gspca_dev *gspca_dev, __s32 val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	sd->autogain = val;
	/* when switching to autogain set defaults to make sure
	   we are on a valid point of the autogain gain /
	   exposure knee graph, and give this change time to
	   take effect before doing autogain. */
	if (sd->autogain) {
		sd->exposure = PAC207_EXPOSURE_DEFAULT;
		sd->gain = PAC207_GAIN_DEFAULT;
		if (gspca_dev->streaming) {
			sd->autogain_ignore_frames =
				PAC207_AUTOGAIN_IGNORE_FRAMES;
			setexposure(gspca_dev);
			setgain(gspca_dev);
		}
	}

	return 0;
}

static int sd_getautogain(struct gspca_dev *gspca_dev, __s32 *val)
{
	struct sd *sd = (struct sd *) gspca_dev;

	*val = sd->autogain;
	return 0;
}

/* sub-driver description */
static const struct sd_desc sd_desc = {
	.name = MODULE_NAME,
	.ctrls = sd_ctrls,
	.nctrls = ARRAY_SIZE(sd_ctrls),
	.config = sd_config,
	.open = sd_open,
	.start = sd_start,
	.stopN = sd_stopN,
	.stop0 = sd_stop0,
	.close = sd_close,
	.dq_callback = pac207_do_auto_gain,
	.pkt_scan = sd_pkt_scan,
};

/* -- module initialisation -- */
static const __devinitdata struct usb_device_id device_table[] = {
	{USB_DEVICE(0x041e, 0x4028)},
	{USB_DEVICE(0x093a, 0x2460)},
	{USB_DEVICE(0x093a, 0x2463)},
	{USB_DEVICE(0x093a, 0x2464)},
	{USB_DEVICE(0x093a, 0x2468)},
	{USB_DEVICE(0x093a, 0x2470)},
	{USB_DEVICE(0x093a, 0x2471)},
	{USB_DEVICE(0x093a, 0x2472)},
	{USB_DEVICE(0x2001, 0xf115)},
	{}
};
MODULE_DEVICE_TABLE(usb, device_table);

/* -- device connect -- */
static int sd_probe(struct usb_interface *intf,
			const struct usb_device_id *id)
{
	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
				THIS_MODULE);
}

static struct usb_driver sd_driver = {
	.name = MODULE_NAME,
	.id_table = device_table,
	.probe = sd_probe,
	.disconnect = gspca_disconnect,
};

/* -- module insert / remove -- */
static int __init sd_mod_init(void)
{
	if (usb_register(&sd_driver) < 0)
		return -1;
	PDEBUG(D_PROBE, "registered");
	return 0;
}
static void __exit sd_mod_exit(void)
{
	usb_deregister(&sd_driver);
	PDEBUG(D_PROBE, "deregistered");
}

module_init(sd_mod_init);
module_exit(sd_mod_exit);