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Date: Wed, 21 Dec 2011 15:46:37 +0900
From: Kukjin Kim <kgene.kim@...sung.com>
To: 'Denis Kuzmenko' <linux@...onet.org.ua>,
linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-samsung-soc@...r.kernel.org,
'Grant Likely' <grant.likely@...retlab.ca>,
'Linus Walleij' <linus.walleij@...aro.org>,
'Richard Purdie' <rpurdie@...ys.net>,
'Joe Perches' <joe@...ches.com>
Subject: RE: [PATCH v4] s3c/s3c24xx: arm: leds: Make s3c24xx LEDS driver use
gpiolib. Fix error disabling pull during probe.
Denis Kuzmenko wrote:
>
> Make s3c24xx LEDS driver use gpiolib. Fix error disabling pull during
> probe.
>
> Signed-off-by: Denis Kuzmenko <linux@...onet.org.ua>
Acked-by: Kukjin Kim <kgene.kim@...sung.com>
Richard, I think, this should be handled in your tree.
Thanks.
Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@...sung.com>, 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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