/* DVB USB compliant linux driver for Nebula Electronics µDigiTV DVB-T USB2.0
 * receiver
 *
 * Copyright (C) 2005 Patrick Boettcher (patrick.boettcher@desy.de) and
 *                    Allan Third (allan.third@cs.man.ac.uk)
 *
 * partly based on the SDK published by Nebula Electronics (TODO do we want this line ?)
 *
 *	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, version 2.
 *
 * see Documentation/dvb/README.dvb-usb for more information
 */
#include "dvb-usb.h"

#include "mt352.h"

/* protocol: this is what I read of the USB log:
 *
 * Always 7 bytes control message(s),
 *
 * First byte at describes the command. Reads are 2 consecutive transfer (as always).
 *
 * I2C address is stored somewhere inside the device.
 *
 * 0x02 i2c reading (2 messages)
 *  1st msg <reg> <len>
 *  2nd msg <reg> <len> <value>
 *
 * 0x05 i2c writing
 *      <reg> <len> <value>
 *   len = 1 for the mt352
 *
 * Others:
 *
 * 0x03 remote control query (read 4 bytes)
 *  1st msg: 0x00 0x04
 *  2nd msg: 0x00 0x04 4 bytes key (probably NEC protocol)
 *
 * 0x08 stream control ?
 *    0x00 0x04 0x01
 *
 * 0x07 unkown (maybe pid filter?)
 */


/* I2C */
static int digitv_i2c_msg(struct dvb_usb_device *d,u8 *wbuf, u16 wlen, u8 *rbuf, u16 rlen)
{
	u8 sndbuf[7],rcvbuf[7]; /* <cmd> <reg> <len> <val[4]> */
	int wo = (rbuf == NULL || rlen == 0); /* write-only */

	memset(sndbuf,0,7); memset(rcvbuf,0,7);

	sndbuf[0] = wo ? 0x05 : 0x03;
	sndbuf[1] = wbuf[0]; /* register */
	sndbuf[2] = wo ? wlen-1 : rlen;

	if (wo)
		memcpy(&sndbuf[3],&wbuf[1],wlen-1);

	dvb_usb_generic_rw(d,sndbuf,7,rcvbuf,7);

	if (!wo)
		memcpy(rbuf,&rcvbuf[3],rlen);

	return 0;
}

static int digitv_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num)
{
	struct dvb_usb_device *d = i2c_get_adapdata(adap);
	int i;

	if (down_interruptible(&d->i2c_sem) < 0)
		return -EAGAIN;

	if (num > 2)
		warn("more than 2 i2c messages at a time is not handled yet. TODO.");

	for (i = 0; i < num; i++) {
		/* write/read request */
		if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) {
			if (digitv_i2c_msg(d, msg[i].buf, msg[i].len,
						msg[i+1].buf,msg[i+1].len) < 0)
				break;
			i++;
		} else
			if (digitv_i2c_msg(d, msg[i].buf,msg[i].len,NULL,0) < 0)
				break;
	}

	up(&d->i2c_sem);
	return i;
}

static u32 digitv_i2c_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_I2C;
}

static struct i2c_algorithm digitv_i2c_algo = {
	.name          = "Nebula DigiTV USB I2C algorithm",
	.id            = I2C_ALGO_BIT,
	.master_xfer   = digitv_i2c_xfer,
	.functionality = digitv_i2c_func,
};

/* Callbacks for DVB USB */
static int probe_count;
static int digitv_identify_state (struct usb_device *udev, struct
		dvb_usb_properties *props, struct dvb_usb_device_description **desc,
		int *cold)
{

	/* here we have to determine if the device is in cold state (pre firmware
	 * load) or in warm state therefore compare the 'lsusb -v' of each state.
	 * Most likely the number of endpoints or interfaces can be used to figure
	 * the real state out.
	 * For now we assume each odd call of this function (when the device is
	 * plugged in or virtually plugged in after the firmware load) is warm
	 * state and each even call is cold probe_count is set to 0 at module load.
	 */

	*cold = (probe_count % 2) == 0;
	probe_count++;
	return 0;
}

static int digitv_frontend_attach(struct dvb_usb_device *d)
{
	struct mt352_config digitv_config;

	memset(&digitv_config,0,sizeof(struct mt352_config));
	digitv_config.demod_init = NULL; /* TODO maybe */
	digitv_config.demod_address = 0x0; /* ignore by the digitv anyway */
	digitv_config.pll_set = NULL; /* TODO */

	d->fe = mt352_attach(&digitv_config, &d->i2c_adap);
	return 0;
}


/* DVB USB Driver stuff */
static struct dvb_usb_properties digitv_properties;

static int digitv_probe(struct usb_interface *intf,
		const struct usb_device_id *id)
{
	return dvb_usb_device_init(intf,&digitv_properties,THIS_MODULE);
}

static struct usb_device_id digitv_table [] = {
		{ USB_DEVICE(USB_VID_ANCHOR, USB_PID_NEBULA_DIGITV) },
		{ }		/* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, digitv_table);

static struct dvb_usb_properties digitv_properties = {
	.caps = DVB_USB_IS_AN_I2C_ADAPTER,
	.usb_ctrl = CYPRESS_FX2,

	.firmware = "dvb-usb-digitv-01.fw",

	.size_of_priv     = 0,

	.streaming_ctrl   = NULL, // digitv_streaming_ctrl,
	.pid_filter       = NULL,
	.pid_filter_ctrl  = NULL,
	.power_ctrl       = NULL, // digitv_power_ctrl,
	.frontend_attach  = digitv_frontend_attach,
	.tuner_attach     = NULL, // digitv_tuner_attach,
	.read_mac_address = NULL,

	.rc_interval      = 0, // 150,
	.init_rc          = NULL, // digitv_rc_init,
	.query_rc         = NULL, // digitv_rc_query,

	.identify_state   = digitv_identify_state,

	.i2c_algo         = &digitv_i2c_algo,

	.generic_bulk_ctrl_endpoint = 0x01,
	/* parameter for the MPEG2-data transfer */
	.urb = {
		.type = DVB_USB_BULK,
		.count = 7,
		.endpoint = 0x02,
		.u {
			.bulk = {
				.buffersize = 4096,
			}
		}
	},

	.num_device_descs = 2,
	.devices = {
		{   "Nebula Electronics µDigiTV DVB-T USB2.0)",
			{ &digitv_table[0], NULL },
			{ NULL },
		},
	}
};

static struct usb_driver digitv_driver = {
	.owner		= THIS_MODULE,
	.name		= "Nebula Electronics µDigiTV DVB-T USB2.0 device",
	.probe		= digitv_probe,
	.disconnect = dvb_usb_device_exit,
	.id_table	= digitv_table,
};

/* module stuff */
static int __init digitv_module_init(void)
{
	int result;
	if ((result = usb_register(&digitv_driver))) {
		err("usb_register failed. Error number %d",result);
		return result;
	}

	return 0;
}

static void __exit digitv_module_exit(void)
{
	/* deregister this driver from the USB subsystem */
	usb_deregister(&digitv_driver);
}

module_init (digitv_module_init);
module_exit (digitv_module_exit);

MODULE_AUTHOR("Patrick Boettcher <patrick.boettcher@desy.de>");
MODULE_DESCRIPTION("Driver for Nebula Electronics µDigiTV DVB-T USB2.0");
MODULE_VERSION("1.0-alpha");
MODULE_LICENSE("GPL");