cx23885-i2c.c

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/*
 *  Driver for the Conexant CX23885 PCIe bridge
 *
 *  Copyright (c) 2006 Steven Toth <[email protected]>
 *
 *  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/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <asm/io.h>

#include "cx23885.h"

#include <media/v4l2-common.h>

static unsigned int i2c_debug;
module_param(i2c_debug, int, 0644);
MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");

static unsigned int i2c_scan;
module_param(i2c_scan, int, 0444);
MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");

#define dprintk(level, fmt, arg...)\
    do { if (i2c_debug >= level)\
        printk(KERN_DEBUG "%s/0: " fmt, dev->name, ## arg);\
    } while (0)

#define I2C_WAIT_DELAY 32
#define I2C_WAIT_RETRY 64

#define I2C_EXTEND  (1 << 3)
#define I2C_NOSTOP  (1 << 4)

static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
{
    struct cx23885_i2c *bus = i2c_adap->algo_data;
    struct cx23885_dev *dev = bus->dev;
    return cx_read(bus->reg_stat) & 0x01;
}

static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
{
    struct cx23885_i2c *bus = i2c_adap->algo_data;
    struct cx23885_dev *dev = bus->dev;
    return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
}

static int i2c_wait_done(struct i2c_adapter *i2c_adap)
{
    int count;

    for (count = 0; count < I2C_WAIT_RETRY; count++) {
        if (!i2c_is_busy(i2c_adap))
            break;
        udelay(I2C_WAIT_DELAY);
    }

    if (I2C_WAIT_RETRY == count)
        return 0;

    return 1;
}

static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
             const struct i2c_msg *msg, int joined_rlen)
{
    struct cx23885_i2c *bus = i2c_adap->algo_data;
    struct cx23885_dev *dev = bus->dev;
    u32 wdata, addr, ctrl;
    int retval, cnt;

    if (joined_rlen)
        dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
            msg->len, joined_rlen);
    else
        dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

    /* Deal with i2c probe functions with zero payload */
    if (msg->len == 0) {
        cx_write(bus->reg_addr, msg->addr << 25);
        cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
        if (!i2c_wait_done(i2c_adap))
            return -EIO;
        if (!i2c_slave_did_ack(i2c_adap))
            return -ENXIO;

        dprintk(1, "%s() returns 0\n", __func__);
        return 0;
    }


    /* dev, reg + first byte */
    addr = (msg->addr << 25) | msg->buf[0];
    wdata = msg->buf[0];
    ctrl = bus->i2c_period | (1 << 12) | (1 << 2);

    if (msg->len > 1)
        ctrl |= I2C_NOSTOP | I2C_EXTEND;
    else if (joined_rlen)
        ctrl |= I2C_NOSTOP;

    cx_write(bus->reg_addr, addr);
    cx_write(bus->reg_wdata, wdata);
    cx_write(bus->reg_ctrl, ctrl);

    if (!i2c_wait_done(i2c_adap))
        goto eio;
    if (i2c_debug) {
        printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
        if (!(ctrl & I2C_NOSTOP))
            printk(" >\n");
    }

    for (cnt = 1; cnt < msg->len; cnt++) {
        /* following bytes */
        wdata = msg->buf[cnt];
        ctrl = bus->i2c_period | (1 << 12) | (1 << 2);

        if (cnt < msg->len - 1)
            ctrl |= I2C_NOSTOP | I2C_EXTEND;
        else if (joined_rlen)
            ctrl |= I2C_NOSTOP;

        cx_write(bus->reg_addr, addr);
        cx_write(bus->reg_wdata, wdata);
        cx_write(bus->reg_ctrl, ctrl);

        if (!i2c_wait_done(i2c_adap))
            goto eio;
        if (i2c_debug) {
            dprintk(1, " %02x", msg->buf[cnt]);
            if (!(ctrl & I2C_NOSTOP))
                dprintk(1, " >\n");
        }
    }
    return msg->len;

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

static int i2c_readbytes(struct i2c_adapter *i2c_adap,
             const struct i2c_msg *msg, int joined)
{
    struct cx23885_i2c *bus = i2c_adap->algo_data;
    struct cx23885_dev *dev = bus->dev;
    u32 ctrl, cnt;
    int retval;


    if (i2c_debug && !joined)
        dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);

    /* Deal with i2c probe functions with zero payload */
    if (msg->len == 0) {
        cx_write(bus->reg_addr, msg->addr << 25);
        cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
        if (!i2c_wait_done(i2c_adap))
            return -EIO;
        if (!i2c_slave_did_ack(i2c_adap))
            return -ENXIO;


        dprintk(1, "%s() returns 0\n", __func__);
        return 0;
    }

    if (i2c_debug) {
        if (joined)
            dprintk(1, " R");
        else
            dprintk(1, " <R %02x", (msg->addr << 1) + 1);
    }

    for (cnt = 0; cnt < msg->len; cnt++) {

        ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;

        if (cnt < msg->len - 1)
            ctrl |= I2C_NOSTOP | I2C_EXTEND;

        cx_write(bus->reg_addr, msg->addr << 25);
        cx_write(bus->reg_ctrl, ctrl);

        if (!i2c_wait_done(i2c_adap))
            goto eio;
        msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
        if (i2c_debug) {
            dprintk(1, " %02x", msg->buf[cnt]);
            if (!(ctrl & I2C_NOSTOP))
                dprintk(1, " >\n");
        }
    }
    return msg->len;

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

static int i2c_xfer(struct i2c_adapter *i2c_adap,
            struct i2c_msg *msgs, int num)
{
    struct cx23885_i2c *bus = i2c_adap->algo_data;
    struct cx23885_dev *dev = bus->dev;
    int i, retval = 0;

    dprintk(1, "%s(num = %d)\n", __func__, num);

    for (i = 0 ; i < num; i++) {
        dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
            __func__, num, msgs[i].addr, msgs[i].len);
        if (msgs[i].flags & I2C_M_RD) {
            /* read */
            retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
        } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
               msgs[i].addr == msgs[i + 1].addr) {
            /* write then read from same address */
            retval = i2c_sendbytes(i2c_adap, &msgs[i],
                           msgs[i + 1].len);
            if (retval < 0)
                goto err;
            i++;
            retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
        } else {
            /* write */
            retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
        }
        if (retval < 0)
            goto err;
    }
    return num;

 err:
    return retval;
}

static u32 cx23885_functionality(struct i2c_adapter *adap)
{
    return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
}

static struct i2c_algorithm cx23885_i2c_algo_template = {
    .master_xfer    = i2c_xfer,
    .functionality  = cx23885_functionality,
};

/* ----------------------------------------------------------------------- */

static struct i2c_adapter cx23885_i2c_adap_template = {
    .name              = "cx23885",
    .owner             = THIS_MODULE,
    .algo              = &cx23885_i2c_algo_template,
};

static struct i2c_client cx23885_i2c_client_template = {
    .name   = "cx23885 internal",
};

static char *i2c_devs[128] = {
    [0x10 >> 1] = "tda10048",
    [0x12 >> 1] = "dib7000pc",
    [0x1c >> 1] = "lgdt3303",
    [0x86 >> 1] = "tda9887",
    [0x32 >> 1] = "cx24227",
    [0x88 >> 1] = "cx25837",
    [0x84 >> 1] = "tda8295",
    [0x98 >> 1] = "flatiron",
    [0xa0 >> 1] = "eeprom",
    [0xc0 >> 1] = "tuner/mt2131/tda8275",
    [0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
    [0xc8 >> 1] = "tuner/xc3028L",
};

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

    for (i = 0; i < 128; i++) {
        c->addr = i;
        rc = i2c_master_recv(c, &buf, 0);
        if (rc < 0)
            continue;
        printk(KERN_INFO "%s: i2c scan: found device @ 0x%x  [%s]\n",
               name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
    }
}

/* init + register i2c adapter */
int cx23885_i2c_register(struct cx23885_i2c *bus)
{
    struct cx23885_dev *dev = bus->dev;

    dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);

    bus->i2c_adap = cx23885_i2c_adap_template;
    bus->i2c_client = cx23885_i2c_client_template;
    bus->i2c_adap.dev.parent = &dev->pci->dev;

    strlcpy(bus->i2c_adap.name, bus->dev->name,
        sizeof(bus->i2c_adap.name));

    bus->i2c_adap.algo_data = bus;
    i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
    i2c_add_adapter(&bus->i2c_adap);

    bus->i2c_client.adapter = &bus->i2c_adap;

    if (0 == bus->i2c_rc) {
        dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
        if (i2c_scan) {
            printk(KERN_INFO "%s: scan bus %d:\n",
                    dev->name, bus->nr);
            do_i2c_scan(dev->name, &bus->i2c_client);
        }
    } else
        printk(KERN_WARNING "%s: i2c bus %d register FAILED\n",
            dev->name, bus->nr);

    /* Instantiate the IR receiver device, if present */
    if (0 == bus->i2c_rc) {
        struct i2c_board_info info;
        const unsigned short addr_list[] = {
            0x6b, I2C_CLIENT_END
        };

        memset(&info, 0, sizeof(struct i2c_board_info));
        strlcpy(info.type, "ir_video", I2C_NAME_SIZE);
        /* Use quick read command for probe, some IR chips don't
         * support writes */
        i2c_new_probed_device(&bus->i2c_adap, &info, addr_list,
                      i2c_probe_func_quick_read);
    }

    return bus->i2c_rc;
}

int cx23885_i2c_unregister(struct cx23885_i2c *bus)
{
    i2c_del_adapter(&bus->i2c_adap);
    return 0;
}

void cx23885_av_clk(struct cx23885_dev *dev, int enable)
{
    /* write 0 to bus 2 addr 0x144 via i2x_xfer() */
    char buffer[3];
    struct i2c_msg msg;
    dprintk(1, "%s(enabled = %d)\n", __func__, enable);

    /* Register 0x144 */
    buffer[0] = 0x01;
    buffer[1] = 0x44;
    if (enable == 1)
        buffer[2] = 0x05;
    else
        buffer[2] = 0x00;

    msg.addr = 0x44;
    msg.flags = I2C_M_TEN;
    msg.len = 3;
    msg.buf = buffer;

    i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
}

/* ----------------------------------------------------------------------- */

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