/*
 * Copyright (c) 2001 Jean-Fredric Clere, Nikolas Zimmermann, Georg Acher
 *		      Mark Cave-Ayland, Carlo E Prelz, Dick Streefland
 * Copyright (c) 2002, 2003 Tuukka Toivonen
 * Copyright (c) 2008 Erik Andrén
 *
 * 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
 *
 * P/N 861037:      Sensor HDCS1000        ASIC STV0600
 * P/N 861050-0010: Sensor HDCS1000        ASIC STV0600
 * P/N 861050-0020: Sensor Photobit PB100  ASIC STV0600-1 - QuickCam Express
 * P/N 861055:      Sensor ST VV6410       ASIC STV0610   - LEGO cam
 * P/N 861075-0040: Sensor HDCS1000        ASIC
 * P/N 961179-0700: Sensor ST VV6410       ASIC STV0602   - Dexxa WebCam USB
 * P/N 861040-0000: Sensor ST VV6410       ASIC STV0610   - QuickCam Web
 */

#include "stv06xx_sensor.h"

MODULE_AUTHOR("Erik Andrén");
MODULE_DESCRIPTION("STV06XX USB Camera Driver");
MODULE_LICENSE("GPL");

static int dump_bridge;
static int dump_sensor;

int stv06xx_write_bridge(struct sd *sd, u16 address, u16 i2c_data)
{
	int err;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;
	u8 len = (i2c_data > 0xff) ? 2 : 1;

	buf[0] = i2c_data & 0xff;
	buf[1] = (i2c_data >> 8) & 0xff;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			      0x04, 0x40, address, 0, buf, len,
			      STV06XX_URB_MSG_TIMEOUT);


	PDEBUG(D_CONF, "Written 0x%x to address 0x%x, status: %d",
	       i2c_data, address, err);

	return (err < 0) ? err : 0;
}

int stv06xx_read_bridge(struct sd *sd, u16 address, u8 *i2c_data)
{
	int err;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
			      0x04, 0xc0, address, 0, buf, 1,
			      STV06XX_URB_MSG_TIMEOUT);

	*i2c_data = buf[0];

	PDEBUG(D_CONF, "Read 0x%x from address 0x%x, status %d",
	       *i2c_data, address, err);

	return (err < 0) ? err : 0;
}

/* Wraps the normal write sensor bytes / words functions for writing a
   single value */
int stv06xx_write_sensor(struct sd *sd, u8 address, u16 value)
{
	if (sd->sensor->i2c_len == 2) {
		u16 data[2] = { address, value };
		return stv06xx_write_sensor_words(sd, data, 1);
	} else {
		u8 data[2] = { address, value };
		return stv06xx_write_sensor_bytes(sd, data, 1);
	}
}

static int stv06xx_write_sensor_finish(struct sd *sd)
{
	int err = 0;

	if (IS_850(sd)) {
		struct usb_device *udev = sd->gspca_dev.dev;
		__u8 *buf = sd->gspca_dev.usb_buf;

		/* Quickam Web needs an extra packet */
		buf[0] = 0;
		err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				      0x04, 0x40, 0x1704, 0, buf, 1,
				      STV06XX_URB_MSG_TIMEOUT);
	}

	return (err < 0) ? err : 0;
}

int stv06xx_write_sensor_bytes(struct sd *sd, const u8 *data, u8 len)
{
	int err, i, j;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	PDEBUG(D_USBO, "I2C: Command buffer contains %d entries", len);
	for (i = 0; i < len;) {
		/* Build the command buffer */
		memset(buf, 0, I2C_BUFFER_LENGTH);
		for (j = 0; j < I2C_MAX_BYTES && i < len; j++, i++) {
			buf[j] = data[2*i];
			buf[0x10 + j] = data[2*i+1];
			PDEBUG(D_USBO, "I2C: Writing 0x%02x to reg 0x%02x",
			data[2*i+1], data[2*i]);
		}
		buf[0x20] = sd->sensor->i2c_addr;
		buf[0x21] = j - 1; /* Number of commands to send - 1 */
		buf[0x22] = I2C_WRITE_CMD;
		err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				      0x04, 0x40, 0x0400, 0, buf,
				      I2C_BUFFER_LENGTH,
				      STV06XX_URB_MSG_TIMEOUT);
				      if (err < 0)
					return err;
       }
       return stv06xx_write_sensor_finish(sd);
}

int stv06xx_write_sensor_words(struct sd *sd, const u16 *data, u8 len)
{
	int err, i, j;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	PDEBUG(D_USBO, "I2C: Command buffer contains %d entries", len);

	for (i = 0; i < len;) {
		/* Build the command buffer */
		memset(buf, 0, I2C_BUFFER_LENGTH);
		for (j = 0; j < I2C_MAX_WORDS && i < len; j++, i++) {
			buf[j] = data[2*i];
			buf[0x10 + j * 2] = data[2*i+1];
			buf[0x10 + j * 2 + 1] = data[2*i+1] >> 8;
			PDEBUG(D_USBO, "I2C: Writing 0x%04x to reg 0x%02x",
				data[2*i+1], data[2*i]);
		}
		buf[0x20] = sd->sensor->i2c_addr;
		buf[0x21] = j - 1; /* Number of commands to send - 1 */
		buf[0x22] = I2C_WRITE_CMD;
		err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
				0x04, 0x40, 0x0400, 0, buf,
				I2C_BUFFER_LENGTH,
				STV06XX_URB_MSG_TIMEOUT);
		if (err < 0)
			return err;
	}
	return stv06xx_write_sensor_finish(sd);
}

int stv06xx_read_sensor(struct sd *sd, const u8 address, u16 *value)
{
	int err;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	err = stv06xx_write_bridge(sd, STV_I2C_FLUSH, sd->sensor->i2c_flush);
	if (err < 0)
		return err;

	/* Clear mem */
	memset(buf, 0, I2C_BUFFER_LENGTH);

	buf[0] = address;
	buf[0x20] = sd->sensor->i2c_addr;
	buf[0x21] = 0;

	/* Read I2C register */
	buf[0x22] = I2C_READ_CMD;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			      0x04, 0x40, 0x1400, 0, buf, I2C_BUFFER_LENGTH,
			      STV06XX_URB_MSG_TIMEOUT);
	if (err < 0) {
		PDEBUG(D_ERR, "I2C Read: error writing address: %d", err);
		return err;
	}

	err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
			      0x04, 0xc0, 0x1410, 0, buf, sd->sensor->i2c_len,
			      STV06XX_URB_MSG_TIMEOUT);
	if (sd->sensor->i2c_len == 2)
		*value = buf[0] | (buf[1] << 8);
	else
		*value = buf[0];

	PDEBUG(D_USBO, "I2C: Read 0x%x from address 0x%x, status: %d",
	       *value, address, err);

	return (err < 0) ? err : 0;
}

/* Dumps all bridge registers */
static void stv06xx_dump_bridge(struct sd *sd)
{
	int i;
	u8 data, buf;

	info("Dumping all stv06xx bridge registers");
	for (i = 0x1400; i < 0x160f; i++) {
		stv06xx_read_bridge(sd, i, &data);

		info("Read 0x%x from address 0x%x", data, i);
	}

	for (i = 0x1400; i < 0x160f; i++) {
		stv06xx_read_bridge(sd, i, &data);
		buf = data;

		stv06xx_write_bridge(sd, i, 0xff);
		stv06xx_read_bridge(sd, i, &data);
		if (data == 0xff)
			info("Register 0x%x is read/write", i);
		else if (data != buf)
			info("Register 0x%x is read/write,"
			     "but only partially", i);
		else
			info("Register 0x%x is read-only", i);

		stv06xx_write_bridge(sd, i, buf);
	}
}

/* this function is called at probe and resume time */
static int stv06xx_init(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;
	int err;

	PDEBUG(D_PROBE, "Initializing camera");

	/* Let the usb init settle for a bit
	   before performing the initialization */
	msleep(250);

	err = sd->sensor->init(sd);

	if (dump_sensor)
		sd->sensor->dump(sd);

	return (err < 0) ? err : 0;
}

/* Start the camera */
static int stv06xx_start(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;
	int err;

	/* Prepare the sensor for start */
	err = sd->sensor->start(sd);
	if (err < 0)
		goto out;

	/* Start isochronous streaming */
	err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 1);

out:
	if (err < 0)
		PDEBUG(D_STREAM, "Starting stream failed");
	else
		PDEBUG(D_STREAM, "Started streaming");

	return (err < 0) ? err : 0;
}

static void stv06xx_stopN(struct gspca_dev *gspca_dev)
{
	int err;
	struct sd *sd = (struct sd *) gspca_dev;

	/* stop ISO-streaming */
	err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 0);
	if (err < 0)
		goto out;

	err = sd->sensor->stop(sd);
	if (err < 0)
		goto out;

out:
	if (err < 0)
		PDEBUG(D_STREAM, "Failed to stop stream");
	else
		PDEBUG(D_STREAM, "Stopped streaming");
}

/*
 * Analyse an USB packet of the data stream and store it appropriately.
 * Each packet contains an integral number of chunks. Each chunk has
 * 2-bytes identification, followed by 2-bytes that describe the chunk
 * length. Known/guessed chunk identifications are:
 * 8001/8005/C001/C005 - Begin new frame
 * 8002/8006/C002/C006 - End frame
 * 0200/4200           - Contains actual image data, bayer or compressed
 * 0005                - 11 bytes of unknown data
 * 0100                - 2 bytes of unknown data
 * The 0005 and 0100 chunks seem to appear only in compressed stream.
 */
static void stv06xx_pkt_scan(struct gspca_dev *gspca_dev,
			struct gspca_frame *frame,	/* target */
			__u8 *data,			/* isoc packet */
			int len)			/* iso packet length */
{
	PDEBUG(D_PACK, "Packet of length %d arrived", len);

	/* A packet may contain several frames
	   loop until the whole packet is reached */
	while (len) {
		int id, chunk_len;

		if (len < 4) {
			PDEBUG(D_PACK, "Packet is smaller than 4 bytes");
			return;
		}

		/* Capture the id */
		id = (data[0] << 8) | data[1];

		/* Capture the chunk length */
		chunk_len = (data[2] << 8) | data[3];
		PDEBUG(D_PACK, "Chunk id: %x, length: %d", id, chunk_len);

		data += 4;
		len -= 4;

		if (len < chunk_len) {
			PDEBUG(D_ERR, "URB packet length is smaller"
				" than the specified chunk length");
			return;
		}

		switch (id) {
		case 0x0200:
		case 0x4200:
			PDEBUG(D_PACK, "Frame data packet detected");

			gspca_frame_add(gspca_dev, INTER_PACKET, frame,
					data, chunk_len);
			break;

		case 0x8001:
		case 0x8005:
		case 0xc001:
		case 0xc005:
			PDEBUG(D_PACK, "Starting new frame");

			/* Create a new frame, chunk length should be zero */
			gspca_frame_add(gspca_dev, FIRST_PACKET,
					frame, data, 0);

			if (chunk_len)
				PDEBUG(D_ERR, "Chunk length is "
					      "non-zero on a SOF");
			break;

		case 0x8002:
		case 0x8006:
		case 0xc002:
			PDEBUG(D_PACK, "End of frame detected");

			/* Complete the last frame (if any) */
			gspca_frame_add(gspca_dev, LAST_PACKET, frame, data, 0);

			if (chunk_len)
				PDEBUG(D_ERR, "Chunk length is "
					      "non-zero on a EOF");
			break;

		case 0x0005:
			PDEBUG(D_PACK, "Chunk 0x005 detected");
			/* Unknown chunk with 11 bytes of data,
			   occurs just before end of each frame
			   in compressed mode */
			break;

		case 0x0100:
			PDEBUG(D_PACK, "Chunk 0x0100 detected");
			/* Unknown chunk with 2 bytes of data,
			   occurs 2-3 times per USB interrupt */
			break;
		default:
			PDEBUG(D_PACK, "Unknown chunk %d detected", id);
			/* Unknown chunk */
		}
		data    += chunk_len;
		len     -= chunk_len;
	}
}

static int stv06xx_config(struct gspca_dev *gspca_dev,
			  const struct usb_device_id *id);

/* sub-driver description */
static const struct sd_desc sd_desc = {
	.name = MODULE_NAME,
	.config = stv06xx_config,
	.init = stv06xx_init,
	.start = stv06xx_start,
	.stopN = stv06xx_stopN,
	.pkt_scan = stv06xx_pkt_scan
};

/* This function is called at probe time */
static int stv06xx_config(struct gspca_dev *gspca_dev,
			  const struct usb_device_id *id)
{
	struct sd *sd = (struct sd *) gspca_dev;
	struct cam *cam;

	PDEBUG(D_PROBE, "Configuring camera");

	cam = &gspca_dev->cam;
	cam->epaddr = STV_ISOC_ENDPOINT_ADDR;
	sd->desc = sd_desc;
	gspca_dev->sd_desc = &sd->desc;

	if (dump_bridge)
		stv06xx_dump_bridge(sd);

	sd->sensor = &stv06xx_sensor_vv6410;
	if (!sd->sensor->probe(sd))
		return 0;

	sd->sensor = &stv06xx_sensor_hdcs1x00;
	if (!sd->sensor->probe(sd))
		return 0;

	sd->sensor = &stv06xx_sensor_hdcs1020;
	if (!sd->sensor->probe(sd))
		return 0;

	sd->sensor = &stv06xx_sensor_pb0100;
	if (!sd->sensor->probe(sd))
		return 0;

	sd->sensor = NULL;
	return -ENODEV;
}


/* -- module initialisation -- */
static const __devinitdata struct usb_device_id device_table[] = {
	{USB_DEVICE(0x046d, 0x0840)}, /* QuickCam Express */
	{USB_DEVICE(0x046d, 0x0850)}, /* LEGO cam / QuickCam Web */
	{USB_DEVICE(0x046d, 0x0870)}, /* Dexxa WebCam USB */
	{}
};
MODULE_DEVICE_TABLE(usb, device_table);

/* -- device connect -- */
static int sd_probe(struct usb_interface *intf,
			const struct usb_device_id *id)
{
	PDEBUG(D_PROBE, "Probing for a stv06xx device");
	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
			       THIS_MODULE);
}

static void sd_disconnect(struct usb_interface *intf)
{
	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
	struct sd *sd = (struct sd *) gspca_dev;
	PDEBUG(D_PROBE, "Disconnecting the stv06xx device");

	if (sd->sensor->disconnect)
		sd->sensor->disconnect(sd);
	gspca_disconnect(intf);
}

static struct usb_driver sd_driver = {
	.name = MODULE_NAME,
	.id_table = device_table,
	.probe = sd_probe,
	.disconnect = sd_disconnect,
#ifdef CONFIG_PM
	.suspend = gspca_suspend,
	.resume = gspca_resume,
#endif
};

/* -- 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);

module_param(dump_bridge, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dump_bridge, "Dumps all usb bridge registers at startup");

module_param(dump_sensor, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dump_sensor, "Dumps all sensor registers at startup");