Re: [PATCH v2 2/3] leds: upboard: Add LED support

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Fri, Oct 19, 2018 at 8:27 PM Dan O'Donovan <dan@xxxxxxxxxx> wrote:
>
> From: Javier Arteaga <javier@xxxxxxxxxx>
>
> Allow userspace to use the on-board LEDs as "upboard:<color>:".



> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/mfd/upboard.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/acpi.h>

For better maintenance keep this ordered.

> +       adev = ACPI_COMPANION(dev);
> +       if (!adev || strcmp(acpi_device_hid(adev), "AANT0F01"))
> +               return -ENODEV;

Why do you need this part?

> +       if (led_index >= ARRAY_SIZE(upboard_led_names))
> +               return -EINVAL;

> +       if (!dev->parent)
> +               return -EINVAL;

...I think this check will cover cases when driver is being probed standalone.
Otherwise it's caller's responsibility not to instantiate it if
platform doesn't have this LED feature.

> +       regmap = dev_get_regmap(dev->parent, NULL);
> +       if (!regmap)
> +               return -EINVAL;

-- 
With Best Regards,
Andy Shevchenko