Re: [PATCH v4 2/6] mfd: axp20x: Split the driver into core and i2c bits

From: Chen-Yu Tsai
Date: Tue Nov 24 2015 - 10:09:40 EST


On Tue, Nov 24, 2015 at 8:35 PM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Tue, Nov 24, 2015 at 1:28 PM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
>> Hi,
>>
>> On Tue, Nov 24, 2015 at 5:37 PM, Andy Shevchenko
>> <andy.shevchenko@xxxxxxxxx> wrote:
>>> On Tue, Nov 24, 2015 at 5:48 AM, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
>>>> The axp20x driver assumes the device is i2c based. This is not the
>>>> case with later chips, which use a proprietary 2 wire serial bus
>>>> by Allwinner called "Reduced Serial Bus".
>>>>
>>>> This patch follows the example of mfd/wm831x and splits it into
>>>> an interface independent core, and an i2c specific glue layer.
>>>> MFD_AXP20X and the new MFD_AXP20X_I2C are changed to tristate
>>>> symbols, allowing the driver to be built as modules.
>>>>
>>>> Included but unused header files are removed as well.
>
> Soâ
>
>>>> + if (dev->of_node) {
>>>
>>> What about
>>>
>>> if (âof_node) {
>>> const struct of_device_id *id;
>>> â
>>> } else if ACPI_COMPANION(â) {
>
> This should be has_acpi_companion().

I don't think the "else if" is necessary. There's only 2 possible ways
the device gets probed, either device tree or ACPI.

>>> const struct acpi_device_id *id;
>>> â
>>> } else {
>>> return -ENODEV;
>>> }
>>
>> I really don't want to change code that I'm just moving around.
>> Same goes for the other comments about this patch. I can do another
>> patch on top of this to fix the style issues if it really bothers
>> people.
>
> Fair enough.
> My comments mostly about unnecessity of second parameter in the functions.
>
> So, you already did some clean up in this patch (above), what about
> to do another? I also prefer separate patch *before* you do a split.

Sure. I'll do a patch or 2 before the split. Would you mind if I add your
Suggested-by tag?


Regards
ChenYu

>>>> + axp20x = devm_kzalloc(&i2c->dev, sizeof(*axp20x), GFP_KERNEL);
>>>> + if (!axp20x)
>>>> + return -ENOMEM;
>>>> +
>>>> + ret = axp20x_i2c_match_device(axp20x, &i2c->dev);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + axp20x->dev = &i2c->dev;
>>>> + axp20x->irq = i2c->irq;
>>>
>>> If you move _match_device() here you will be able to drop away struct
>>> device * parameter.
>
> --
> With Best Regards,
> Andy Shevchenko
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