/*

    bttv-i2c.c  --  all the i2c code is here

    bttv - Bt848 frame grabber driver

    Copyright (C) 1996,97,98 Ralph  Metzler (rjkm@thp.uni-koeln.de)
			   & Marcus Metzler (mocm@thp.uni-koeln.de)
    (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>

    (c) 2005 Mauro Carvalho Chehab <mchehab@infradead.org>
	- Multituner support and i2c address binding

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>

#include "bttvp.h"
#include <media/v4l2-common.h>
#include <linux/jiffies.h>
#include <asm/io.h>

static int i2c_debug;
static int i2c_hw;
static int i2c_scan;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
module_param(i2c_hw,    int, 0444);
MODULE_PARM_DESC(i2c_hw,"force use of hardware i2c support, "
			"instead of software bitbang");
module_param(i2c_scan,  int, 0444);
MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");

static unsigned int i2c_udelay = 5;
module_param(i2c_udelay, int, 0444);
MODULE_PARM_DESC(i2c_udelay,"soft i2c delay at insmod time, in usecs "
		"(should be 5 or higher). Lower value means higher bus speed.");

/* ----------------------------------------------------------------------- */
/* I2C functions - bitbanging adapter (software i2c)                       */

static void bttv_bit_setscl(void *data, int state)
{
	struct bttv *btv = (struct bttv*)data;

	if (state)
		btv->i2c_state |= 0x02;
	else
		btv->i2c_state &= ~0x02;
	btwrite(btv->i2c_state, BT848_I2C);
	btread(BT848_I2C);
}

static void bttv_bit_setsda(void *data, int state)
{
	struct bttv *btv = (struct bttv*)data;

	if (state)
		btv->i2c_state |= 0x01;
	else
		btv->i2c_state &= ~0x01;
	btwrite(btv->i2c_state, BT848_I2C);
	btread(BT848_I2C);
}

static int bttv_bit_getscl(void *data)
{
	struct bttv *btv = (struct bttv*)data;
	int state;

	state = btread(BT848_I2C) & 0x02 ? 1 : 0;
	return state;
}

static int bttv_bit_getsda(void *data)
{
	struct bttv *btv = (struct bttv*)data;
	int state;

	state = btread(BT848_I2C) & 0x01;
	return state;
}

static struct i2c_algo_bit_data __devinitdata bttv_i2c_algo_bit_template = {
	.setsda  = bttv_bit_setsda,
	.setscl  = bttv_bit_setscl,
	.getsda  = bttv_bit_getsda,
	.getscl  = bttv_bit_getscl,
	.udelay  = 16,
	.timeout = 200,
};

/* ----------------------------------------------------------------------- */
/* I2C functions - hardware i2c                                            */

static u32 functionality(struct i2c_adapter *adap)
{
	return I2C_FUNC_SMBUS_EMUL;
}

static int
bttv_i2c_wait_done(struct bttv *btv)
{
	int rc = 0;

	/* timeout */
	if (wait_event_interruptible_timeout(btv->i2c_queue,
		btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)

	rc = -EIO;

	if (btv->i2c_done & BT848_INT_RACK)
		rc = 1;
	btv->i2c_done = 0;
	return rc;
}

#define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
		BT848_I2C_SCL | BT848_I2C_SDA)

static int
bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
{
	u32 xmit;
	int retval,cnt;

	/* sanity checks */
	if (0 == msg->len)
		return -EINVAL;

	/* start, address + first byte */
	xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
	if (msg->len > 1 || !last)
		xmit |= BT878_I2C_NOSTOP;
	btwrite(xmit, BT848_I2C);
	retval = bttv_i2c_wait_done(btv);
	if (retval < 0)
		goto err;
	if (retval == 0)
		goto eio;
	if (i2c_debug) {
		printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
		if (!(xmit & BT878_I2C_NOSTOP))
			printk(" >\n");
	}

	for (cnt = 1; cnt < msg->len; cnt++ ) {
		/* following bytes */
		xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
		if (cnt < msg->len-1 || !last)
			xmit |= BT878_I2C_NOSTOP;
		btwrite(xmit, BT848_I2C);
		retval = bttv_i2c_wait_done(btv);
		if (retval < 0)
			goto err;
		if (retval == 0)
			goto eio;
		if (i2c_debug) {
			printk(" %02x", msg->buf[cnt]);
			if (!(xmit & BT878_I2C_NOSTOP))
				printk(" >\n");
		}
	}
	return msg->len;

 eio:
	retval = -EIO;
 err:
	if (i2c_debug)
		printk(" ERR: %d\n",retval);
	return retval;
}

static int
bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
{
	u32 xmit;
	u32 cnt;
	int retval;

	for(cnt = 0; cnt < msg->len; cnt++) {
		xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
		if (cnt < msg->len-1)
			xmit |= BT848_I2C_W3B;
		if (cnt < msg->len-1 || !last)
			xmit |= BT878_I2C_NOSTOP;
		if (cnt)
			xmit |= BT878_I2C_NOSTART;
		btwrite(xmit, BT848_I2C);
		retval = bttv_i2c_wait_done(btv);
		if (retval < 0)
			goto err;
		if (retval == 0)
			goto eio;
		msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
		if (i2c_debug) {
			if (!(xmit & BT878_I2C_NOSTART))
				printk(" <R %02x", (msg->addr << 1) +1);
			printk(" =%02x", msg->buf[cnt]);
			if (!(xmit & BT878_I2C_NOSTOP))
				printk(" >\n");
		}
	}
	return msg->len;

 eio:
	retval = -EIO;
 err:
	if (i2c_debug)
		printk(" ERR: %d\n",retval);
	return retval;
}

static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
	struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
	struct bttv *btv = to_bttv(v4l2_dev);
	int retval = 0;
	int i;

	if (i2c_debug)
		printk("bt-i2c:");
	btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
	for (i = 0 ; i < num; i++) {
		if (msgs[i].flags & I2C_M_RD) {
			/* read */
			retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
			if (retval < 0)
				goto err;
		} else {
			/* write */
			retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
			if (retval < 0)
				goto err;
		}
	}
	return num;

 err:
	return retval;
}

static const struct i2c_algorithm bttv_algo = {
	.master_xfer   = bttv_i2c_xfer,
	.functionality = functionality,
};

/* ----------------------------------------------------------------------- */
/* I2C functions - common stuff                                            */

/* read I2C */
int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
{
	unsigned char buffer = 0;

	if (0 != btv->i2c_rc)
		return -1;
	if (bttv_verbose && NULL != probe_for)
		printk(KERN_INFO "bttv%d: i2c: checking for %s @ 0x%02x... ",
		       btv->c.nr,probe_for,addr);
	btv->i2c_client.addr = addr >> 1;
	if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
		if (NULL != probe_for) {
			if (bttv_verbose)
				printk("not found\n");
		} else
			printk(KERN_WARNING "bttv%d: i2c read 0x%x: error\n",
			       btv->c.nr,addr);
		return -1;
	}
	if (bttv_verbose && NULL != probe_for)
		printk("found\n");
	return buffer;
}

/* write I2C */
int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
		    unsigned char b2, int both)
{
	unsigned char buffer[2];
	int bytes = both ? 2 : 1;

	if (0 != btv->i2c_rc)
		return -1;
	btv->i2c_client.addr = addr >> 1;
	buffer[0] = b1;
	buffer[1] = b2;
	if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
		return -1;
	return 0;
}

/* read EEPROM content */
void __devinit bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
{
	memset(eedata, 0, 256);
	if (0 != btv->i2c_rc)
		return;
	btv->i2c_client.addr = addr >> 1;
	tveeprom_read(&btv->i2c_client, eedata, 256);
}

static char *i2c_devs[128] = {
	[ 0x1c >> 1 ] = "lgdt330x",
	[ 0x30 >> 1 ] = "IR (hauppauge)",
	[ 0x80 >> 1 ] = "msp34xx",
	[ 0x86 >> 1 ] = "tda9887",
	[ 0xa0 >> 1 ] = "eeprom",
	[ 0xc0 >> 1 ] = "tuner (analog)",
	[ 0xc2 >> 1 ] = "tuner (analog)",
};

static void do_i2c_scan(char *name, struct i2c_client *c)
{
	unsigned char buf;
	int i,rc;

	for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
		c->addr = i;
		rc = i2c_master_recv(c,&buf,0);
		if (rc < 0)
			continue;
		printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
		       name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
	}
}

/* init + register i2c algo-bit adapter */
int __devinit init_bttv_i2c(struct bttv *btv)
{
	strlcpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);

	if (i2c_hw)
		btv->use_i2c_hw = 1;
	if (btv->use_i2c_hw) {
		/* bt878 */
		strlcpy(btv->c.i2c_adap.name, "bt878",
			sizeof(btv->c.i2c_adap.name));
		btv->c.i2c_adap.algo = &bttv_algo;
	} else {
		/* bt848 */
	/* Prevents usage of invalid delay values */
		if (i2c_udelay<5)
			i2c_udelay=5;

		strlcpy(btv->c.i2c_adap.name, "bttv",
			sizeof(btv->c.i2c_adap.name));
		memcpy(&btv->i2c_algo, &bttv_i2c_algo_bit_template,
		       sizeof(bttv_i2c_algo_bit_template));
		btv->i2c_algo.udelay = i2c_udelay;
		btv->i2c_algo.data = btv;
		btv->c.i2c_adap.algo_data = &btv->i2c_algo;
	}
	btv->c.i2c_adap.owner = THIS_MODULE;

	btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
	snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
		 "bt%d #%d [%s]", btv->id, btv->c.nr,
		 btv->use_i2c_hw ? "hw" : "sw");

	i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
	btv->i2c_client.adapter = &btv->c.i2c_adap;


	if (btv->use_i2c_hw) {
		btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
	} else {
		bttv_bit_setscl(btv,1);
		bttv_bit_setsda(btv,1);
		btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
	}
	if (0 == btv->i2c_rc && i2c_scan)
		do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);

	return btv->i2c_rc;
}

/* Instantiate the I2C IR receiver device, if present */
void __devinit init_bttv_i2c_ir(struct bttv *btv)
{
	if (0 == btv->i2c_rc) {
		struct i2c_board_info info;
		/* The external IR receiver is at i2c address 0x34 (0x35 for
		   reads).  Future Hauppauge cards will have an internal
		   receiver at 0x30 (0x31 for reads).  In theory, both can be
		   fitted, and Hauppauge suggest an external overrides an
		   internal.

		   That's why we probe 0x1a (~0x34) first. CB
		*/
		const unsigned short addr_list[] = {
			0x1a, 0x18, 0x4b, 0x64, 0x30, 0x71,
			I2C_CLIENT_END
		};

		memset(&info, 0, sizeof(struct i2c_board_info));
		strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
		i2c_new_probed_device(&btv->c.i2c_adap, &info, addr_list);
	}
}

int __devexit fini_bttv_i2c(struct bttv *btv)
{
	if (0 != btv->i2c_rc)
		return 0;

	return i2c_del_adapter(&btv->c.i2c_adap);
}

/*
 * Local variables:
 * c-basic-offset: 8
 * End:
 */
