On Sat, Jun 30, 2018 at 4:33 PM, Manivannan Sadhasivam
[off-list ref] 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