static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg)
{
if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
dev_err(pd->dev, "Unsupported zero length i2c read\n");
return -EIO;
}
/* Initialize channel registers */
iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd));
/* Enable channel and configure rx ack */
iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd));
/* Set the clock */
iowrite8(pd->iccl, ICCL(pd));
iowrite8(pd->icch, ICCH(pd));
pd->msg = usr_msg;
pd->pos = -1;
pd->sr = 0;
/* Enable all interrupts to begin with */
iowrite8(ICIC_WAITE | ICIC_ALE | ICIC_TACKE | ICIC_DTEE, ICIC(pd));
return 0;
}
static void activate_ch(struct sh_mobile_i2c_data *pd)
{
/* Make sure the clock is enabled */
clk_enable(pd->clk);
/* Enable channel and configure rx ack */
iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd));
/* Mask all interrupts */
iowrite8(0, ICIC(pd));
/* Set the clock */
iowrite8(pd->iccl, ICCL(pd));
iowrite8(pd->icch, ICCH(pd));
}
static void activate_ch(struct sh_mobile_i2c_data *pd)
{
unsigned long i2c_clk;
u_int32_t num;
u_int32_t denom;
u_int32_t tmp;
/* Wake up device and enable clock */
pm_runtime_get_sync(pd->dev);
clk_enable(pd->clk);
/* Get clock rate after clock is enabled */
i2c_clk = clk_get_rate(pd->clk);
/* Calculate the value for iccl. From the data sheet:
* iccl = (p clock / transfer rate) * (L / (L + H))
* where L and H are the SCL low/high ratio (5/4 in this case).
* We also round off the result.
*/
num = i2c_clk * 5;
denom = NORMAL_SPEED * 9;
tmp = num * 10 / denom;
if (tmp % 10 >= 5)
pd->iccl = (u_int8_t)((num/denom) + 1);
else
pd->iccl = (u_int8_t)(num/denom);
/* Calculate the value for icch. From the data sheet:
icch = (p clock / transfer rate) * (H / (L + H)) */
num = i2c_clk * 4;
tmp = num * 10 / denom;
if (tmp % 10 >= 5)
pd->icch = (u_int8_t)((num/denom) + 1);
else
pd->icch = (u_int8_t)(num/denom);
/* Enable channel and configure rx ack */
iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd));
/* Mask all interrupts */
iowrite8(0, ICIC(pd));
/* Set the clock */
iowrite8(pd->iccl, ICCL(pd));
iowrite8(pd->icch, ICCH(pd));
}
