[PATCH V3] i2c: add bcm2835 driver

On 02/11/2013 03:52 PM, Wolfram Sang wrote:

Hi Stephen,

On Fri, Feb 08, 2013 at 08:52:58PM -0700, Stephen Warren wrote:

quoted

This implements a very basic I2C host driver for the BCM2835 SoC. Missing
features so far are:

* 10-bit addressing.
* DMA.

...

quoted

+	ret = wait_for_completion_timeout(&i2c_dev->completion,
+					  BCM2835_I2C_TIMEOUT);
+	bcm2835_i2c_writel(i2c_dev, BCM2835_I2C_C, BCM2835_I2C_C_CLEAR);
+	if (WARN_ON(ret == 0)) {
+		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
+		return -ETIMEDOUT;
+	}

I'd suggest to skip the WARN_ON. Timeout is the expected case when you
want to read from an EEPROM which is just in the process of
erasing/writing data from the previous command.

I copied that from Tegra. Should that driver be changed too?

quoted

+	adap = &i2c_dev->adapter;
+	i2c_set_adapdata(adap, i2c_dev);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_HWMON;

Do you really need the class?

If I grep for I2C_CLASS_HWMON, I see a ton of hits. I think I'll keep it
unless you strongly object, since it seems typical.

I'll fix up the other points you mentioned.