Re: [PATCH] [v2] surface pro 3: Add support driver for Surface Pro 3 buttons

[Joe Perches <joe@perches.com>]

On Fri, 2015-08-07 at 15:57 +0800, Chen Yu wrote:
> Since Surface Pro 3 does not follow the specs of "Windows ACPI Design
> Guide for SoC Platform", code in drivers/input/misc/soc_array.c can
> not detect these buttons on it.

The comments below are all just style trivia
and can be ignored entirely.

> diff --git a/drivers/platform/x86/surfacepro3_button.c b/drivers/platform/x86/surfacepro3_button.c
[]
> +#define handle_surface_button_notify(type, code)		\
> +({								\
> +	int ret = 0;						\
> +	if (SURFACE_BUTTON_NOTIFY_PRESS_##type == event)	\
> +		pressed = true;					\
> +	if (pressed ||						\
> +		 (SURFACE_BUTTON_NOTIFY_RELEASE_##type == event)) {	\
> +		key_code = code;				\
> +		ret = 1;					\
> +	} else							\
> +		ret = 0;					\
> +	ret;							\
> +})

This seems a bit complicated.

The else ret = 0 isn't necessary as it's initialized to 0.
bool might be better than int.

> +static void surface_button_notify(struct acpi_device *device, u32 event)
> +{
> +	struct surface_button *button = acpi_driver_data(device);
> +	struct input_dev *input;
> +	int key_code = KEY_RESERVED;
> +	bool pressed = false;
> +
> +	if (!handle_surface_button_notify(POWER, KEY_POWER) &&
> +		!handle_surface_button_notify(HOME, KEY_LEFTMETA) &&
> +		!handle_surface_button_notify(VOLUME_UP, KEY_VOLUMEUP) &&
> +		!handle_surface_button_notify(VOLUME_DOWN, KEY_VOLUMEDOWN))
> +		dev_info_ratelimited(&device->dev,
> +			"Unsupported event [0x%x]\n", event);

Some might prefer alignment to the open parenthesis:

	if (!handle_surface_button_notify(POWER, KEY_POWER) &&
	    !handle_surface_button_notify(HOME, KEY_LEFTMETA) &&
	    !handle_surface_button_notify(VOLUME_UP, KEY_VOLUMEUP) &&
	    !handle_surface_button_notify(VOLUME_DOWN, KEY_VOLUMEDOWN))

I think the older switch/case was easier to understand.