bttv-i2c.c

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/*

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

    bttv - Bt848 frame grabber driver

    Copyright (C) 1996,97,98 Ralph  Metzler ([email protected])
               & Marcus Metzler ([email protected])
    (c) 1999-2003 Gerd Knorr <[email protected]>

    (c) 2005 Mauro Carvalho Chehab <[email protected]>
    - 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.

*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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) {
        pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
    }

    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)
            pr_cont(" %02x", msg->buf[cnt]);
    }
    if (!(xmit & BT878_I2C_NOSTOP))
        pr_cont(">\n");
    return msg->len;

 eio:
    retval = -EIO;
 err:
    if (i2c_debug)
        pr_cont(" 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;

        if (i2c_debug) {
            if (!(xmit & BT878_I2C_NOSTART))
                pr_cont(" <R %02x", (msg->addr << 1) +1);
        }

        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) {
            pr_cont(" =%02x", msg->buf[cnt]);
        }
        if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
            pr_cont(" >\n");
    }


    return msg->len;

 eio:
    retval = -EIO;
 err:
    if (i2c_debug)
        pr_cont(" 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)
        pr_debug("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)
        pr_info("%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)
                pr_cont("not found\n");
        } else
            pr_warn("%d: i2c read 0x%x: error\n",
                btv->c.nr, addr);
        return -1;
    }
    if (bttv_verbose && NULL != probe_for)
        pr_cont("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;
        pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
            name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
    }
}

/* init + register i2c 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;
}