dibx000_common.c

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#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/module.h>

#include "dibx000_common.h"

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "turn on debugging (default: 0)");

#define dprintk(args...) do { if (debug) { printk(KERN_DEBUG "DiBX000: "); printk(args); printk("\n"); } } while (0)

static int dibx000_write_word(struct dibx000_i2c_master *mst, u16 reg, u16 val)
{
    int ret;

    if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
        dprintk("could not acquire lock");
        return -EINVAL;
    }

    mst->i2c_write_buffer[0] = (reg >> 8) & 0xff;
    mst->i2c_write_buffer[1] = reg & 0xff;
    mst->i2c_write_buffer[2] = (val >> 8) & 0xff;
    mst->i2c_write_buffer[3] = val & 0xff;

    memset(mst->msg, 0, sizeof(struct i2c_msg));
    mst->msg[0].addr = mst->i2c_addr;
    mst->msg[0].flags = 0;
    mst->msg[0].buf = mst->i2c_write_buffer;
    mst->msg[0].len = 4;

    ret = i2c_transfer(mst->i2c_adap, mst->msg, 1) != 1 ? -EREMOTEIO : 0;
    mutex_unlock(&mst->i2c_buffer_lock);

    return ret;
}

static u16 dibx000_read_word(struct dibx000_i2c_master *mst, u16 reg)
{
    u16 ret;

    if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
        dprintk("could not acquire lock");
        return 0;
    }

    mst->i2c_write_buffer[0] = reg >> 8;
    mst->i2c_write_buffer[1] = reg & 0xff;

    memset(mst->msg, 0, 2 * sizeof(struct i2c_msg));
    mst->msg[0].addr = mst->i2c_addr;
    mst->msg[0].flags = 0;
    mst->msg[0].buf = mst->i2c_write_buffer;
    mst->msg[0].len = 2;
    mst->msg[1].addr = mst->i2c_addr;
    mst->msg[1].flags = I2C_M_RD;
    mst->msg[1].buf = mst->i2c_read_buffer;
    mst->msg[1].len = 2;

    if (i2c_transfer(mst->i2c_adap, mst->msg, 2) != 2)
        dprintk("i2c read error on %d", reg);

    ret = (mst->i2c_read_buffer[0] << 8) | mst->i2c_read_buffer[1];
    mutex_unlock(&mst->i2c_buffer_lock);

    return ret;
}

static int dibx000_is_i2c_done(struct dibx000_i2c_master *mst)
{
    int i = 100;
    u16 status;

    while (((status = dibx000_read_word(mst, mst->base_reg + 2)) & 0x0100) == 0 && --i > 0)
        ;

    /* i2c timed out */
    if (i == 0)
        return -EREMOTEIO;

    /* no acknowledge */
    if ((status & 0x0080) == 0)
        return -EREMOTEIO;

    return 0;
}

static int dibx000_master_i2c_write(struct dibx000_i2c_master *mst, struct i2c_msg *msg, u8 stop)
{
    u16 data;
    u16 da;
    u16 i;
    u16 txlen = msg->len, len;
    const u8 *b = msg->buf;

    while (txlen) {
        dibx000_read_word(mst, mst->base_reg + 2);

        len = txlen > 8 ? 8 : txlen;
        for (i = 0; i < len; i += 2) {
            data = *b++ << 8;
            if (i+1 < len)
                data |= *b++;
            dibx000_write_word(mst, mst->base_reg, data);
        }
        da = (((u8) (msg->addr))  << 9) |
            (1           << 8) |
            (1           << 7) |
            (0           << 6) |
            (0           << 5) |
            ((len & 0x7) << 2) |
            (0           << 1) |
            (0           << 0);

        if (txlen == msg->len)
            da |= 1 << 5; /* start */

        if (txlen-len == 0 && stop)
            da |= 1 << 6; /* stop */

        dibx000_write_word(mst, mst->base_reg+1, da);

        if (dibx000_is_i2c_done(mst) != 0)
            return -EREMOTEIO;
        txlen -= len;
    }

    return 0;
}

static int dibx000_master_i2c_read(struct dibx000_i2c_master *mst, struct i2c_msg *msg)
{
    u16 da;
    u8 *b = msg->buf;
    u16 rxlen = msg->len, len;

    while (rxlen) {
        len = rxlen > 8 ? 8 : rxlen;
        da = (((u8) (msg->addr)) << 9) |
            (1           << 8) |
            (1           << 7) |
            (0           << 6) |
            (0           << 5) |
            ((len & 0x7) << 2) |
            (1           << 1) |
            (0           << 0);

        if (rxlen == msg->len)
            da |= 1 << 5; /* start */

        if (rxlen-len == 0)
            da |= 1 << 6; /* stop */
        dibx000_write_word(mst, mst->base_reg+1, da);

        if (dibx000_is_i2c_done(mst) != 0)
            return -EREMOTEIO;

        rxlen -= len;

        while (len) {
            da = dibx000_read_word(mst, mst->base_reg);
            *b++ = (da >> 8) & 0xff;
            len--;
            if (len >= 1) {
                *b++ =  da   & 0xff;
                len--;
            }
        }
    }

    return 0;
}

int dibx000_i2c_set_speed(struct i2c_adapter *i2c_adap, u16 speed)
{
    struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);

    if (mst->device_rev < DIB7000MC && speed < 235)
        speed = 235;
    return dibx000_write_word(mst, mst->base_reg + 3, (u16)(60000 / speed));

}
EXPORT_SYMBOL(dibx000_i2c_set_speed);

static u32 dibx000_i2c_func(struct i2c_adapter *adapter)
{
    return I2C_FUNC_I2C;
}

static int dibx000_i2c_select_interface(struct dibx000_i2c_master *mst,
                    enum dibx000_i2c_interface intf)
{
    if (mst->device_rev > DIB3000MC && mst->selected_interface != intf) {
        dprintk("selecting interface: %d", intf);
        mst->selected_interface = intf;
        return dibx000_write_word(mst, mst->base_reg + 4, intf);
    }
    return 0;
}

static int dibx000_i2c_master_xfer_gpio12(struct i2c_adapter *i2c_adap, struct i2c_msg msg[], int num)
{
    struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
    int msg_index;
    int ret = 0;

    dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_GPIO_1_2);
    for (msg_index = 0; msg_index < num; msg_index++) {
        if (msg[msg_index].flags & I2C_M_RD) {
            ret = dibx000_master_i2c_read(mst, &msg[msg_index]);
            if (ret != 0)
                return 0;
        } else {
            ret = dibx000_master_i2c_write(mst, &msg[msg_index], 1);
            if (ret != 0)
                return 0;
        }
    }

    return num;
}

static int dibx000_i2c_master_xfer_gpio34(struct i2c_adapter *i2c_adap, struct i2c_msg msg[], int num)
{
    struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
    int msg_index;
    int ret = 0;

    dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_GPIO_3_4);
    for (msg_index = 0; msg_index < num; msg_index++) {
        if (msg[msg_index].flags & I2C_M_RD) {
            ret = dibx000_master_i2c_read(mst, &msg[msg_index]);
            if (ret != 0)
                return 0;
        } else {
            ret = dibx000_master_i2c_write(mst, &msg[msg_index], 1);
            if (ret != 0)
                return 0;
        }
    }

    return num;
}

static struct i2c_algorithm dibx000_i2c_master_gpio12_xfer_algo = {
    .master_xfer = dibx000_i2c_master_xfer_gpio12,
    .functionality = dibx000_i2c_func,
};

static struct i2c_algorithm dibx000_i2c_master_gpio34_xfer_algo = {
    .master_xfer = dibx000_i2c_master_xfer_gpio34,
    .functionality = dibx000_i2c_func,
};

static int dibx000_i2c_gate_ctrl(struct dibx000_i2c_master *mst, u8 tx[4],
                 u8 addr, int onoff)
{
    u16 val;


    if (onoff)
        val = addr << 8;    // bit 7 = use master or not, if 0, the gate is open
    else
        val = 1 << 7;

    if (mst->device_rev > DIB7000)
        val <<= 1;

    tx[0] = (((mst->base_reg + 1) >> 8) & 0xff);
    tx[1] = ((mst->base_reg + 1) & 0xff);
    tx[2] = val >> 8;
    tx[3] = val & 0xff;

    return 0;
}

static int dibx000_i2c_gated_gpio67_xfer(struct i2c_adapter *i2c_adap,
                    struct i2c_msg msg[], int num)
{
    struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
    int ret;

    if (num > 32) {
        dprintk("%s: too much I2C message to be transmitted (%i).\
                Maximum is 32", __func__, num);
        return -ENOMEM;
    }

    dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_GPIO_6_7);

    if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
        dprintk("could not acquire lock");
        return -EINVAL;
    }

    memset(mst->msg, 0, sizeof(struct i2c_msg) * (2 + num));

    /* open the gate */
    dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[0], msg[0].addr, 1);
    mst->msg[0].addr = mst->i2c_addr;
    mst->msg[0].buf = &mst->i2c_write_buffer[0];
    mst->msg[0].len = 4;

    memcpy(&mst->msg[1], msg, sizeof(struct i2c_msg) * num);

    /* close the gate */
    dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[4], 0, 0);
    mst->msg[num + 1].addr = mst->i2c_addr;
    mst->msg[num + 1].buf = &mst->i2c_write_buffer[4];
    mst->msg[num + 1].len = 4;

    ret = (i2c_transfer(mst->i2c_adap, mst->msg, 2 + num) == 2 + num ?
            num : -EIO);

    mutex_unlock(&mst->i2c_buffer_lock);
    return ret;
}

static struct i2c_algorithm dibx000_i2c_gated_gpio67_algo = {
    .master_xfer = dibx000_i2c_gated_gpio67_xfer,
    .functionality = dibx000_i2c_func,
};

static int dibx000_i2c_gated_tuner_xfer(struct i2c_adapter *i2c_adap,
                    struct i2c_msg msg[], int num)
{
    struct dibx000_i2c_master *mst = i2c_get_adapdata(i2c_adap);
    int ret;

    if (num > 32) {
        dprintk("%s: too much I2C message to be transmitted (%i).\
                Maximum is 32", __func__, num);
        return -ENOMEM;
    }

    dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_TUNER);

    if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
        dprintk("could not acquire lock");
        return -EINVAL;
    }
    memset(mst->msg, 0, sizeof(struct i2c_msg) * (2 + num));

    /* open the gate */
    dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[0], msg[0].addr, 1);
    mst->msg[0].addr = mst->i2c_addr;
    mst->msg[0].buf = &mst->i2c_write_buffer[0];
    mst->msg[0].len = 4;

    memcpy(&mst->msg[1], msg, sizeof(struct i2c_msg) * num);

    /* close the gate */
    dibx000_i2c_gate_ctrl(mst, &mst->i2c_write_buffer[4], 0, 0);
    mst->msg[num + 1].addr = mst->i2c_addr;
    mst->msg[num + 1].buf = &mst->i2c_write_buffer[4];
    mst->msg[num + 1].len = 4;

    ret = (i2c_transfer(mst->i2c_adap, mst->msg, 2 + num) == 2 + num ?
            num : -EIO);
    mutex_unlock(&mst->i2c_buffer_lock);
    return ret;
}

static struct i2c_algorithm dibx000_i2c_gated_tuner_algo = {
    .master_xfer = dibx000_i2c_gated_tuner_xfer,
    .functionality = dibx000_i2c_func,
};

struct i2c_adapter *dibx000_get_i2c_adapter(struct dibx000_i2c_master *mst,
                        enum dibx000_i2c_interface intf,
                        int gating)
{
    struct i2c_adapter *i2c = NULL;

    switch (intf) {
    case DIBX000_I2C_INTERFACE_TUNER:
        if (gating)
            i2c = &mst->gated_tuner_i2c_adap;
        break;
    case DIBX000_I2C_INTERFACE_GPIO_1_2:
        if (!gating)
            i2c = &mst->master_i2c_adap_gpio12;
        break;
    case DIBX000_I2C_INTERFACE_GPIO_3_4:
        if (!gating)
            i2c = &mst->master_i2c_adap_gpio34;
        break;
    case DIBX000_I2C_INTERFACE_GPIO_6_7:
        if (gating)
            i2c = &mst->master_i2c_adap_gpio67;
        break;
    default:
        printk(KERN_ERR "DiBX000: incorrect I2C interface selected\n");
        break;
    }

    return i2c;
}

EXPORT_SYMBOL(dibx000_get_i2c_adapter);

void dibx000_reset_i2c_master(struct dibx000_i2c_master *mst)
{
    /* initialize the i2c-master by closing the gate */
    u8 tx[4];
    struct i2c_msg m = {.addr = mst->i2c_addr,.buf = tx,.len = 4 };

    dibx000_i2c_gate_ctrl(mst, tx, 0, 0);
    i2c_transfer(mst->i2c_adap, &m, 1);
    mst->selected_interface = 0xff; // the first time force a select of the I2C
    dibx000_i2c_select_interface(mst, DIBX000_I2C_INTERFACE_TUNER);
}

EXPORT_SYMBOL(dibx000_reset_i2c_master);

static int i2c_adapter_init(struct i2c_adapter *i2c_adap,
                struct i2c_algorithm *algo, const char *name,
                struct dibx000_i2c_master *mst)
{
    strncpy(i2c_adap->name, name, sizeof(i2c_adap->name));
    i2c_adap->algo = algo;
    i2c_adap->algo_data = NULL;
    i2c_set_adapdata(i2c_adap, mst);
    if (i2c_add_adapter(i2c_adap) < 0)
        return -ENODEV;
    return 0;
}

int dibx000_init_i2c_master(struct dibx000_i2c_master *mst, u16 device_rev,
                struct i2c_adapter *i2c_adap, u8 i2c_addr)
{
    int ret;

    mutex_init(&mst->i2c_buffer_lock);
    if (mutex_lock_interruptible(&mst->i2c_buffer_lock) < 0) {
        dprintk("could not acquire lock");
        return -EINVAL;
    }
    memset(mst->msg, 0, sizeof(struct i2c_msg));
    mst->msg[0].addr = i2c_addr >> 1;
    mst->msg[0].flags = 0;
    mst->msg[0].buf = mst->i2c_write_buffer;
    mst->msg[0].len = 4;

    mst->device_rev = device_rev;
    mst->i2c_adap = i2c_adap;
    mst->i2c_addr = i2c_addr >> 1;

    if (device_rev == DIB7000P || device_rev == DIB8000)
        mst->base_reg = 1024;
    else
        mst->base_reg = 768;

    mst->gated_tuner_i2c_adap.dev.parent = mst->i2c_adap->dev.parent;
    if (i2c_adapter_init
            (&mst->gated_tuner_i2c_adap, &dibx000_i2c_gated_tuner_algo,
             "DiBX000 tuner I2C bus", mst) != 0)
        printk(KERN_ERR
                "DiBX000: could not initialize the tuner i2c_adapter\n");

    mst->master_i2c_adap_gpio12.dev.parent = mst->i2c_adap->dev.parent;
    if (i2c_adapter_init
            (&mst->master_i2c_adap_gpio12, &dibx000_i2c_master_gpio12_xfer_algo,
             "DiBX000 master GPIO12 I2C bus", mst) != 0)
        printk(KERN_ERR
                "DiBX000: could not initialize the master i2c_adapter\n");

    mst->master_i2c_adap_gpio34.dev.parent = mst->i2c_adap->dev.parent;
    if (i2c_adapter_init
            (&mst->master_i2c_adap_gpio34, &dibx000_i2c_master_gpio34_xfer_algo,
             "DiBX000 master GPIO34 I2C bus", mst) != 0)
        printk(KERN_ERR
                "DiBX000: could not initialize the master i2c_adapter\n");

    mst->master_i2c_adap_gpio67.dev.parent = mst->i2c_adap->dev.parent;
    if (i2c_adapter_init
            (&mst->master_i2c_adap_gpio67, &dibx000_i2c_gated_gpio67_algo,
             "DiBX000 master GPIO67 I2C bus", mst) != 0)
        printk(KERN_ERR
                "DiBX000: could not initialize the master i2c_adapter\n");

    /* initialize the i2c-master by closing the gate */
    dibx000_i2c_gate_ctrl(mst, mst->i2c_write_buffer, 0, 0);

    ret = (i2c_transfer(i2c_adap, mst->msg, 1) == 1);
    mutex_unlock(&mst->i2c_buffer_lock);

    return ret;
}

EXPORT_SYMBOL(dibx000_init_i2c_master);

void dibx000_exit_i2c_master(struct dibx000_i2c_master *mst)
{
    i2c_del_adapter(&mst->gated_tuner_i2c_adap);
    i2c_del_adapter(&mst->master_i2c_adap_gpio12);
    i2c_del_adapter(&mst->master_i2c_adap_gpio34);
    i2c_del_adapter(&mst->master_i2c_adap_gpio67);
}
EXPORT_SYMBOL(dibx000_exit_i2c_master);


u32 systime(void)
{
    struct timespec t;

    t = current_kernel_time();
    return (t.tv_sec * 10000) + (t.tv_nsec / 100000);
}
EXPORT_SYMBOL(systime);

MODULE_AUTHOR("Patrick Boettcher <[email protected]>");
MODULE_DESCRIPTION("Common function the DiBcom demodulator family");
MODULE_LICENSE("GPL");