Re: [PATCH v3 4/5] platform/chrome: cros_kbd_led_backlight: support OF match

[Matthias Kaehlcke <mka@chromium.org>]

On Mon, Mar 21, 2022 at 04:55:46PM +0800, Tzung-Bi Shih wrote:
> For letting device tree based machines to use the driver, support OF match.
> 
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
> ---
> Changes from v2:
> - Add commit message.
> - Add R-b tag.
> 
> Changes from v1:
> (https://patchwork.kernel.org/project/chrome-platform/patch/20220214053646.3088298-5-tzungbi@google.com/)
> - Update email address accordingly.
> - Use device_get_match_data() per review comment in v1.
> 
>  drivers/platform/chrome/cros_kbd_led_backlight.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
> index 05b4f274086b..5cbe27cb4610 100644
> --- a/drivers/platform/chrome/cros_kbd_led_backlight.c
> +++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
> @@ -10,7 +10,9 @@
>  #include <linux/kernel.h>
>  #include <linux/leds.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  #include <linux/platform_device.h>
> +#include <linux/property.h>
>  #include <linux/slab.h>
>  
>  /**
> @@ -127,7 +129,7 @@ static int keyboard_led_probe(struct platform_device *pdev)
>  	const struct keyboard_led_drvdata *drvdata;
>  	int error;
>  
> -	drvdata = acpi_device_get_match_data(&pdev->dev);
> +	drvdata = device_get_match_data(&pdev->dev);
>  	if (!drvdata)
>  		return -EINVAL;
>  
> @@ -163,10 +165,21 @@ static const struct acpi_device_id keyboard_led_acpi_match[] = {
>  MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
>  #endif
>  
> +#ifdef CONFIG_OF
> +static const struct of_device_id keyboard_led_of_match[] = {
> +	{
> +		.compatible = "google,cros-kbd-led-backlight",
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, keyboard_led_of_match);
> +#endif
> +
>  static struct platform_driver keyboard_led_driver = {
>  	.driver		= {
>  		.name	= "chromeos-keyboard-leds",
>  		.acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),
> +		.of_match_table = of_match_ptr(keyboard_led_of_match),

In patch "[5/5] platform/chrome: cros_kbd_led_backlight: support EC PWM
backend" [1] you create the 'stubs' keyboard_led_init_ec_pwm_null() and
keyboard_led_drvdata_ec_pwm when CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM
isn't set, only to have something to assign to keyboard_led_of_match.data.
Instead you could assign .of_match_table only if CONFIG_CROS_KBD_LED_BACKLIGHT_EC_PWM
is set.

[1] https://patchwork.kernel.org/project/chrome-platform/patch/20220321085547.1162312-6-tzungbi@kernel.org/