linux——I2C驱动

HKA_S32 ISPWriteI2CData(HKA_U8 u8I2cDev, HKA_U8 u8DevAddr, HKA_U32 u32RegAddr,
                        HKA_U32 u32RegAddrByteNum, HKA_U32 u32Data, HKA_U32 u32DataByteNum)
{
    int ret = 0;
    struct i2c_adapter *padap = NULL;
    struct i2c_msg msg;
    char buf[8];
    int count = 0;

    padap = i2c_get_adapter(u8I2cDev);
    if (!padap)
    {
        pr_err("I2C adapter[%d] get error\n", u8I2cDev);
        return -ENODEV;
    }

    switch (u32RegAddrByteNum)
    {
    case 1:
        buf[count++] = u32RegAddr & 0xFF;
        break;
    case 2:
        buf[count++] = (u32RegAddr >> 8) & 0xFF;
        buf[count++] = u32RegAddr & 0xFF;
        break;
    default:
        pr_err("I2C addr bytenum error\n");
        ret = -EINVAL;
        goto err;
    }

    switch (u32DataByteNum)
    {
    case 1:
        buf[count++] = u32Data & 0xFF;
        break;
    case 2:
        buf[count++] = (u32Data >> 8) & 0xFF;
        buf[count++] = u32Data & 0xFF;
        break;
    default:
        pr_err("I2C addr bytenum error\n");
        ret = -EINVAL;
        goto err;
    }

    msg.addr = u8DevAddr;
    msg.flags = 0;
    msg.len = count;
    msg.buf = (char *)buf;
    ret = i2c_transfer(padap, &msg, 1);
    if (ret < 0)
    {
        pr_err("I2c: count:%d, addrsize:%d, datasize:%d\n", count, u32RegAddrByteNum, u32DataByteNum);
        pr_err("I2C write error, dev:%#x, reg:%#x,data:%#x, ret=%d\n", u8DevAddr, u32RegAddr, u32Data, ret);
        ret = -EIO;
        goto err;
    }
//    else
//    {

      pr_debug("[SDK_ISP_DRV]old I2C write OK,reg:%#x,data:%#x \n", u32RegAddr, u32Data);
//    }
    i2c_put_adapter(padap);
    return 0;
err:
    i2c_put_adapter(padap);
    return ret;
}