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

    Signed-off-by: Denis Kuzmenko <linux@solonet.org.ua>
    ---

    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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