cx231xx-i2c.c

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/*
   cx231xx-i2c.c - driver for Conexant Cx23100/101/102 USB video capture devices

   Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
        Based on em28xx driver
        Based on Cx23885 driver

   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/kernel.h>
#include <linux/usb.h>
#include <linux/i2c.h>
#include <media/v4l2-common.h>
#include <media/tuner.h>

#include "cx231xx.h"

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

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

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

#define dprintk1(lvl, fmt, args...)         \
do {                            \
    if (i2c_debug >= lvl) {             \
        printk(fmt, ##args);            \
        }                   \
} while (0)

#define dprintk2(lvl, fmt, args...)         \
do {                            \
    if (i2c_debug >= lvl) {             \
        printk(KERN_DEBUG "%s at %s: " fmt, \
               dev->name, __func__ , ##args);   \
      }                         \
} while (0)

static inline bool is_tuner(struct cx231xx *dev, struct cx231xx_i2c *bus,
            const struct i2c_msg *msg, int tuner_type)
{
    if (bus->nr != dev->board.tuner_i2c_master)
        return false;

    if (msg->addr != dev->board.tuner_addr)
        return false;

    if (dev->tuner_type != tuner_type)
        return false;

    return true;
}

/*
 * cx231xx_i2c_send_bytes()
 */
int cx231xx_i2c_send_bytes(struct i2c_adapter *i2c_adap,
               const struct i2c_msg *msg)
{
    struct cx231xx_i2c *bus = i2c_adap->algo_data;
    struct cx231xx *dev = bus->dev;
    struct cx231xx_i2c_xfer_data req_data;
    int status = 0;
    u16 size = 0;
    u8 loop = 0;
    u8 saddr_len = 1;
    u8 *buf_ptr = NULL;
    u16 saddr = 0;
    u8 need_gpio = 0;

    if (is_tuner(dev, bus, msg, TUNER_XC5000)) {
        size = msg->len;

        if (size == 2) {    /* register write sub addr */
            /* Just writing sub address will cause problem
            * to XC5000. So ignore the request */
            return 0;
        } else if (size == 4) { /* register write with sub addr */
            if (msg->len >= 2)
                saddr = msg->buf[0] << 8 | msg->buf[1];
            else if (msg->len == 1)
                saddr = msg->buf[0];

            switch (saddr) {
            case 0x0000:    /* start tuner calibration mode */
                need_gpio = 1;
                /* FW Loading is done */
                dev->xc_fw_load_done = 1;
                break;
            case 0x000D:    /* Set signal source */
            case 0x0001:    /* Set TV standard - Video */
            case 0x0002:    /* Set TV standard - Audio */
            case 0x0003:    /* Set RF Frequency */
                need_gpio = 1;
                break;
            default:
                if (dev->xc_fw_load_done)
                    need_gpio = 1;
                break;
            }

            if (need_gpio) {
                dprintk1(1,
                "GPIO WRITE: addr 0x%x, len %d, saddr 0x%x\n",
                msg->addr, msg->len, saddr);

                return dev->cx231xx_gpio_i2c_write(dev,
                                   msg->addr,
                                   msg->buf,
                                   msg->len);
            }
        }

        /* special case for Xc5000 tuner case */
        saddr_len = 1;

        /* adjust the length to correct length */
        size -= saddr_len;
        buf_ptr = (u8 *) (msg->buf + 1);

        do {
            /* prepare xfer_data struct */
            req_data.dev_addr = msg->addr;
            req_data.direction = msg->flags;
            req_data.saddr_len = saddr_len;
            req_data.saddr_dat = msg->buf[0];
            req_data.buf_size = size > 16 ? 16 : size;
            req_data.p_buffer = (u8 *) (buf_ptr + loop * 16);

            bus->i2c_nostop = (size > 16) ? 1 : 0;
            bus->i2c_reserve = (loop == 0) ? 0 : 1;

            /* usb send command */
            status = dev->cx231xx_send_usb_command(bus, &req_data);
            loop++;

            if (size >= 16)
                size -= 16;
            else
                size = 0;

        } while (size > 0);

        bus->i2c_nostop = 0;
        bus->i2c_reserve = 0;

    } else {        /* regular case */

        /* prepare xfer_data struct */
        req_data.dev_addr = msg->addr;
        req_data.direction = msg->flags;
        req_data.saddr_len = 0;
        req_data.saddr_dat = 0;
        req_data.buf_size = msg->len;
        req_data.p_buffer = msg->buf;

        /* usb send command */
        status = dev->cx231xx_send_usb_command(bus, &req_data);
    }

    return status < 0 ? status : 0;
}

/*
 * cx231xx_i2c_recv_bytes()
 * read a byte from the i2c device
 */
static int cx231xx_i2c_recv_bytes(struct i2c_adapter *i2c_adap,
                  const struct i2c_msg *msg)
{
    struct cx231xx_i2c *bus = i2c_adap->algo_data;
    struct cx231xx *dev = bus->dev;
    struct cx231xx_i2c_xfer_data req_data;
    int status = 0;
    u16 saddr = 0;
    u8 need_gpio = 0;

    if (is_tuner(dev, bus, msg, TUNER_XC5000)) {
        if (msg->len == 2)
            saddr = msg->buf[0] << 8 | msg->buf[1];
        else if (msg->len == 1)
            saddr = msg->buf[0];

        if (dev->xc_fw_load_done) {

            switch (saddr) {
            case 0x0009:    /* BUSY check */
                dprintk1(1,
                "GPIO R E A D: Special case BUSY check \n");
                /*Try read BUSY register, just set it to zero*/
                msg->buf[0] = 0;
                if (msg->len == 2)
                    msg->buf[1] = 0;
                return 0;
            case 0x0004:    /* read Lock status */
                need_gpio = 1;
                break;

            }

            if (need_gpio) {
                /* this is a special case to handle Xceive tuner
                clock stretch issue with gpio based I2C */

                dprintk1(1,
                "GPIO R E A D: addr 0x%x, len %d, saddr 0x%x\n",
                msg->addr, msg->len,
                msg->buf[0] << 8 | msg->buf[1]);

                status =
                    dev->cx231xx_gpio_i2c_write(dev, msg->addr,
                                msg->buf,
                                msg->len);
                status =
                    dev->cx231xx_gpio_i2c_read(dev, msg->addr,
                                   msg->buf,
                                   msg->len);
                return status;
            }
        }

        /* prepare xfer_data struct */
        req_data.dev_addr = msg->addr;
        req_data.direction = msg->flags;
        req_data.saddr_len = msg->len;
        req_data.saddr_dat = msg->buf[0] << 8 | msg->buf[1];
        req_data.buf_size = msg->len;
        req_data.p_buffer = msg->buf;

        /* usb send command */
        status = dev->cx231xx_send_usb_command(bus, &req_data);

    } else {

        /* prepare xfer_data struct */
        req_data.dev_addr = msg->addr;
        req_data.direction = msg->flags;
        req_data.saddr_len = 0;
        req_data.saddr_dat = 0;
        req_data.buf_size = msg->len;
        req_data.p_buffer = msg->buf;

        /* usb send command */
        status = dev->cx231xx_send_usb_command(bus, &req_data);
    }

    return status < 0 ? status : 0;
}

/*
 * cx231xx_i2c_recv_bytes_with_saddr()
 * read a byte from the i2c device
 */
static int cx231xx_i2c_recv_bytes_with_saddr(struct i2c_adapter *i2c_adap,
                         const struct i2c_msg *msg1,
                         const struct i2c_msg *msg2)
{
    struct cx231xx_i2c *bus = i2c_adap->algo_data;
    struct cx231xx *dev = bus->dev;
    struct cx231xx_i2c_xfer_data req_data;
    int status = 0;
    u16 saddr = 0;
    u8 need_gpio = 0;

    if (msg1->len == 2)
        saddr = msg1->buf[0] << 8 | msg1->buf[1];
    else if (msg1->len == 1)
        saddr = msg1->buf[0];

    if (is_tuner(dev, bus, msg2, TUNER_XC5000)) {
        if ((msg2->len < 16)) {

            dprintk1(1,
            "i2c_read: addr 0x%x, len %d, saddr 0x%x, len %d\n",
            msg2->addr, msg2->len, saddr, msg1->len);

            switch (saddr) {
            case 0x0008:    /* read FW load status */
                need_gpio = 1;
                break;
            case 0x0004:    /* read Lock status */
                need_gpio = 1;
                break;
            }

            if (need_gpio) {
                status =
                    dev->cx231xx_gpio_i2c_write(dev, msg1->addr,
                                msg1->buf,
                                msg1->len);
                status =
                    dev->cx231xx_gpio_i2c_read(dev, msg2->addr,
                                   msg2->buf,
                                   msg2->len);
                return status;
            }
        }
    }

    /* prepare xfer_data struct */
    req_data.dev_addr = msg2->addr;
    req_data.direction = msg2->flags;
    req_data.saddr_len = msg1->len;
    req_data.saddr_dat = saddr;
    req_data.buf_size = msg2->len;
    req_data.p_buffer = msg2->buf;

    /* usb send command */
    status = dev->cx231xx_send_usb_command(bus, &req_data);

    return status < 0 ? status : 0;
}

/*
 * cx231xx_i2c_check_for_device()
 * check if there is a i2c_device at the supplied address
 */
static int cx231xx_i2c_check_for_device(struct i2c_adapter *i2c_adap,
                    const struct i2c_msg *msg)
{
    struct cx231xx_i2c *bus = i2c_adap->algo_data;
    struct cx231xx *dev = bus->dev;
    struct cx231xx_i2c_xfer_data req_data;
    int status = 0;

    /* prepare xfer_data struct */
    req_data.dev_addr = msg->addr;
    req_data.direction = msg->flags;
    req_data.saddr_len = 0;
    req_data.saddr_dat = 0;
    req_data.buf_size = 0;
    req_data.p_buffer = NULL;

    /* usb send command */
    status = dev->cx231xx_send_usb_command(bus, &req_data);

    return status < 0 ? status : 0;
}

/*
 * cx231xx_i2c_xfer()
 * the main i2c transfer function
 */
static int cx231xx_i2c_xfer(struct i2c_adapter *i2c_adap,
                struct i2c_msg msgs[], int num)
{
    struct cx231xx_i2c *bus = i2c_adap->algo_data;
    struct cx231xx *dev = bus->dev;
    int addr, rc, i, byte;

    if (num <= 0)
        return 0;
    mutex_lock(&dev->i2c_lock);
    for (i = 0; i < num; i++) {

        addr = msgs[i].addr >> 1;

        dprintk2(2, "%s %s addr=%x len=%d:",
             (msgs[i].flags & I2C_M_RD) ? "read" : "write",
             i == num - 1 ? "stop" : "nonstop", addr, msgs[i].len);
        if (!msgs[i].len) {
            /* no len: check only for device presence */
            rc = cx231xx_i2c_check_for_device(i2c_adap, &msgs[i]);
            if (rc < 0) {
                dprintk2(2, " no device\n");
                mutex_unlock(&dev->i2c_lock);
                return rc;
            }

        } else if (msgs[i].flags & I2C_M_RD) {
            /* read bytes */
            rc = cx231xx_i2c_recv_bytes(i2c_adap, &msgs[i]);
            if (i2c_debug >= 2) {
                for (byte = 0; byte < msgs[i].len; byte++)
                    printk(" %02x", msgs[i].buf[byte]);
            }
        } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
               msgs[i].addr == msgs[i + 1].addr
               && (msgs[i].len <= 2) && (bus->nr < 3)) {
            /* read bytes */
            rc = cx231xx_i2c_recv_bytes_with_saddr(i2c_adap,
                                   &msgs[i],
                                   &msgs[i + 1]);
            if (i2c_debug >= 2) {
                for (byte = 0; byte < msgs[i].len; byte++)
                    printk(" %02x", msgs[i].buf[byte]);
            }
            i++;
        } else {
            /* write bytes */
            if (i2c_debug >= 2) {
                for (byte = 0; byte < msgs[i].len; byte++)
                    printk(" %02x", msgs[i].buf[byte]);
            }
            rc = cx231xx_i2c_send_bytes(i2c_adap, &msgs[i]);
        }
        if (rc < 0)
            goto err;
        if (i2c_debug >= 2)
            printk("\n");
    }
    mutex_unlock(&dev->i2c_lock);
    return num;
err:
    dprintk2(2, " ERROR: %i\n", rc);
    mutex_unlock(&dev->i2c_lock);
    return rc;
}

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

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

static struct i2c_algorithm cx231xx_algo = {
    .master_xfer = cx231xx_i2c_xfer,
    .functionality = functionality,
};

static struct i2c_adapter cx231xx_adap_template = {
    .owner = THIS_MODULE,
    .name = "cx231xx",
    .algo = &cx231xx_algo,
};

static struct i2c_client cx231xx_client_template = {
    .name = "cx231xx internal",
};

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

/*
 * i2c_devs
 * incomplete list of known devices
 */
static char *i2c_devs[128] = {
    [0x60 >> 1] = "colibri",
    [0x88 >> 1] = "hammerhead",
    [0x8e >> 1] = "CIR",
    [0x32 >> 1] = "GeminiIII",
    [0x02 >> 1] = "Aquarius",
    [0xa0 >> 1] = "eeprom",
    [0xc0 >> 1] = "tuner",
    [0xc2 >> 1] = "tuner",
};

/*
 * cx231xx_do_i2c_scan()
 * check i2c address range for devices
 */
void cx231xx_do_i2c_scan(struct cx231xx *dev, struct i2c_client *c)
{
    unsigned char buf;
    int i, rc;

    cx231xx_info(": Checking for I2C devices ..\n");
    for (i = 0; i < 128; i++) {
        c->addr = i;
        rc = i2c_master_recv(c, &buf, 0);
        if (rc < 0)
            continue;
        cx231xx_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
                 dev->name, i << 1,
                 i2c_devs[i] ? i2c_devs[i] : "???");
    }
    cx231xx_info(": Completed Checking for I2C devices.\n");
}

/*
 * cx231xx_i2c_register()
 * register i2c bus
 */
int cx231xx_i2c_register(struct cx231xx_i2c *bus)
{
    struct cx231xx *dev = bus->dev;

    BUG_ON(!dev->cx231xx_send_usb_command);

    bus->i2c_adap = cx231xx_adap_template;
    bus->i2c_client = cx231xx_client_template;
    bus->i2c_adap.dev.parent = &dev->udev->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) {
        if (i2c_scan)
            cx231xx_do_i2c_scan(dev, &bus->i2c_client);
    } else
        cx231xx_warn("%s: i2c bus %d register FAILED\n",
                 dev->name, bus->nr);

    return bus->i2c_rc;
}

/*
 * cx231xx_i2c_unregister()
 * unregister i2c_bus
 */
int cx231xx_i2c_unregister(struct cx231xx_i2c *bus)
{
    i2c_del_adapter(&bus->i2c_adap);
    return 0;
}