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SubjectRe: [PATCH v3 5/6] i2c: Add Actions Semiconductor Owl family S900 I2C driver
On Sat, Jun 30, 2018 at 4:33 PM, Manivannan Sadhasivam
<manivannan.sadhasivam@linaro.org> wrote:
> Add Actions Semiconductor Owl family S900 I2C driver.

Thanks for an update. Few left comments and it would LGTM.

> +static int owl_i2c_reset(struct owl_i2c_dev *i2c_dev)
> +{

> + mdelay(1);

But now, since it's not used in atomic context, we may switch to
usleep_range() / msleep() instead.

> + owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
> + OWL_I2C_CTL_EN, true);
> +

> + /* Wait 50ms for FIFO reset complete */
> + do {

> + mdelay(1);

Especially in this case it's very important.

> + } while (timeout++ < OWL_I2C_MAX_RETRIES);

> +}

> + val = (i2c_dev->clk_rate + i2c_dev->bus_freq * 16 - 1) /
> + (i2c_dev->bus_freq * 16);

This is effectively DIV_ROUND_UP(->clk_rate, ->bus_freq * 16).

> + /*
> + * By default, 0 will be returned if interrupt occurred but no
> + * read or write happened. Else if msg_ptr equals to message length,
> + * message count will be returned.
> + */

> + if (i2c_dev->msg_ptr == msg->len)
> + ret = num;

I dunno if

ret = ->msg_ptr == len ? num : 0;

would be slightly more explicit (yes, I aware about ret == 0).

Up to you to choose.

> + /* We support only frequencies of 100k and 400k for now */
> + if (i2c_dev->bus_freq != OWL_I2C_DEF_SPEED_HZ &&
> + i2c_dev->bus_freq > OWL_I2C_MAX_SPEED_HZ) {

I think it should be != in the second case as well.

> + dev_err(dev, "invalid clock-frequency %d\n", i2c_dev->bus_freq);
> + return -EINVAL;
> + }

--
With Best Regards,
Andy Shevchenko

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