RE: [PATCH v4] s3c/s3c24xx: arm: leds: Make s3c24xx LEDS driver usegpiolib. Fix error disabling pull during probe.

[Kukjin Kim]

Denis Kuzmenko wrote:
> 
> Make s3c24xx LEDS driver use gpiolib. Fix error disabling pull during
> probe.
> 
> Signed-off-by: Denis Kuzmenko <linux@xxxxxxxxxxxxxx>

Acked-by: Kukjin Kim <kgene.kim@xxxxxxxxxxx>

Richard, I think, this should be handled in your tree.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.

> ---
> 
> There is a comment "no point in having a pull-up if we are always driving"
> but code was actually enabled pull-resistor for that case probably because
> of
> function parameter misunderstanding (1 - disables, 0 - enables). So this
> was
> changed to another function which takes alphabetically defined constant as
> parameter.
> Tested on Mini2440 board which implements most complex case where both
> S3C24XX_LEDF_ACTLOW and S3C24XX_LEDF_TRISTATE are set.
> 
> Changes v1->v2
>         Fix typo's and style problems.
> Changes v2->v3
>         Remove pull-resistor enabling code for case of
S3C24XX_LEDF_TRISTATE
> flag is set
> Changes v3->v4
> 	!! approach for XOR operation with (pd->flags & S3C24XX_LEDF_ACTLOW)
> (otherwise code will became buggy when S3C24XX_LEDF_ACTLOW valu will be
> changed)
> 
> See https://lkml.org/lkml/2011/11/22/42 and
> https://lkml.org/lkml/2011/12/13/338
> previous for discussions.
> 
> diff --git a/drivers/leds/leds-s3c24xx.c b/drivers/leds/leds-s3c24xx.c
> index 29f8b0f..8062664 100644
> --- a/drivers/leds/leds-s3c24xx.c
> +++ b/drivers/leds/leds-s3c24xx.c
> @@ -46,23 +46,29 @@ static void s3c24xx_led_set(struct led_classdev
> *led_cdev,
>  	struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
>  	struct s3c24xx_led_platdata *pd = led->pdata;
> 
> -	/* there will be a short delay between setting the output and
> -	 * going from output to input when using tristate. */
> -
> -	s3c2410_gpio_setpin(pd->gpio, (value ? 1 : 0) ^
> -			    (pd->flags & S3C24XX_LEDF_ACTLOW));
> -
> -	if (pd->flags & S3C24XX_LEDF_TRISTATE)
> -		s3c2410_gpio_cfgpin(pd->gpio,
> -			value ? S3C2410_GPIO_OUTPUT : S3C2410_GPIO_INPUT);
> +	if (pd->flags & S3C24XX_LEDF_TRISTATE) {
> +		if (value) {
> +			/* invert value if S3C24XX_LEDF_ACTLOW is set */
> +			gpio_direction_output(pd->gpio,
> +				!!value ^ !!(pd->flags &
S3C24XX_LEDF_ACTLOW));
> +		} else {
> +			gpio_direction_input(pd->gpio);
> +		}
> +	} else {
> +		/* invert value if S3C24XX_LEDF_ACTLOW is set */
> +		gpio_direction_output(pd->gpio,
> +			!!value ^ !!(pd->flags & S3C24XX_LEDF_ACTLOW));
> +	}
> 
>  }
> 
>  static int s3c24xx_led_remove(struct platform_device *dev)
>  {
> +	struct s3c24xx_led_platdata *pdata = dev->dev.platform_data;
>  	struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
> 
>  	led_classdev_unregister(&led->cdev);
> +	gpio_free(pdata->gpio);
>  	kfree(led);
> 
>  	return 0;
> @@ -77,7 +83,8 @@ static int s3c24xx_led_probe(struct platform_device
*dev)
>  	led = kzalloc(sizeof(struct s3c24xx_gpio_led), GFP_KERNEL);
>  	if (led == NULL) {
>  		dev_err(&dev->dev, "No memory for device\n");
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto err_kzalloc;
>  	}
> 
>  	platform_set_drvdata(dev, led);
> @@ -89,15 +96,24 @@ static int s3c24xx_led_probe(struct platform_device
> *dev)
> 
>  	led->pdata = pdata;
> 
> -	/* no point in having a pull-up if we are always driving */
> +	ret = gpio_request(pdata->gpio, pdata->name);
> +	if (ret < 0) {
> +		dev_err(&dev->dev, "gpio_request failed\n");
> +		goto err_gpio_request;
> +	}
> 
> +	/* apply GPIO settings and initially turn off the LED */
>  	if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
> -		s3c2410_gpio_setpin(pdata->gpio, 0);
> -		s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
> +		ret = gpio_direction_input(pdata->gpio);
>  	} else {
> -		s3c2410_gpio_pullup(pdata->gpio, 0);
> -		s3c2410_gpio_setpin(pdata->gpio, 0);
> -		s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
> +		/* no point in having a pull-up as we are always driving */
> +		s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);
> +		ret = gpio_direction_output(pdata->gpio,
> +				!!(pdata->flags & S3C24XX_LEDF_ACTLOW));
> +	}
> +	if (ret < 0) {
> +		dev_err(&dev->dev, "can't set gpio direction\n");
> +		goto err_gpio_set_direction;
>  	}
> 
>  	/* register our new led device */
> @@ -105,11 +121,18 @@ static int s3c24xx_led_probe(struct platform_device
> *dev)
>  	ret = led_classdev_register(&dev->dev, &led->cdev);
>  	if (ret < 0) {
>  		dev_err(&dev->dev, "led_classdev_register failed\n");
> -		kfree(led);
> -		return ret;
> +		goto err_led_classdev_register;
>  	}
> 
>  	return 0;
> +
> +err_led_classdev_register:
> +err_gpio_set_direction:
> +		gpio_free(pdata->gpio);
> +err_gpio_request:
> +		kfree(led);
> +err_kzalloc:
> +		return ret;
>  }
> 
>  static struct platform_driver s3c24xx_led_driver = {

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