Re: [PATCH] i2c: core: helper function to detect slave mode

From: Andy Shevchenko
Date: Fri Jan 06 2017 - 11:29:58 EST


On Thu, Jan 5, 2017 at 7:24 PM, Luis Oliveira
<Luis.Oliveira@xxxxxxxxxxxx> wrote:
> This function has the purpose of mode detection by checking the
> device nodes for a reg matching with the I2C_OWN_SLAVE_ADDREESS flag.
> Currently only checks using OF functions (ACPI slave not supported yet).

The code looks good, one important comment below, after addressing it:

Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

P.S. Btw, we have Suggested-by tag for giving credit for suggestion.
Please use it.

> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -3691,6 +3691,25 @@ int i2c_slave_unregister(struct i2c_client *client)

Please, add kernel doc description here, important thing is to explain
return codes in Return: section of it.

> +int i2c_slave_mode_detect(struct device *dev)
> +{

> + struct device_node *child;
> + u32 reg;

I would consider them as private to the OF branch. But it's really
minor and up to you (I don't remember if we have such style examples
in i2c core code).

> +
> + if (IS_BUILTIN(CONFIG_OF) && dev->of_node) {
> + for_each_child_of_node(dev->of_node, child) {
> + of_property_read_u32(child, "reg", &reg);
> + if (reg & I2C_OWN_SLAVE_ADDRESS)
> + return 1;
> + }
> + } else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) {
> + dev_dbg(dev, "ACPI slave is not supported yet\n");
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(i2c_slave_mode_detect);

--
With Best Regards,
Andy Shevchenko