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Date: Fri, 18 Nov 2011 23:44:53 +0200
From: Denis Kuzmenko <linux@...onet.org.ua>
To: Stephen Warren <swarren@...dia.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Grant Likely <grant.likely@...retlab.ca>,
Linus Walleij <linus.walleij@...aro.org>,
Richard Purdie <rpurdie@...ys.net>,
Wolfram Sang <w.sang@...gutronix.de>
Subject: Re: [PATCH] s3c/s3c24xx: arm: leds: Make s3c24xx LEDS driver use
gpiolib
On 11/18/2011 11:00 PM, Denis Kuzmenko wrote:
> On 11/18/2011 07:08 PM, Stephen Warren wrote:
>> Denis Kuzmenko wrote at Thursday, November 17, 2011 1:47 PM:
>>> Make s3c24xx LEDS driver use gpiolib.
>>
>> I made some slightly nit-picky
>> comments below.
How's that? (some comments are taken to account and problem with pull-resistor fixed)
---
Make s3c24xx LEDS driver use gpiolib. Disable using pull-resistor when not
using S3C24XX_LEDF_TRISTATE and enble it when in opposite case.
Signed-off-by: Denis Kuzmenko <linux@...onet.org.ua>
---
Patch is against 3.0.9
Tested on Mini2440 board which implements most complex case where both
S3C24XX_LEDF_ACTLOW and S3C24XX_LEDF_TRISTATE are set
diff --git a/drivers/leds/leds-s3c24xx.c b/drivers/leds/leds-s3c24xx.c
index a77771d..02bd6a8 100644
--- a/drivers/leds/leds-s3c24xx.c
+++ b/drivers/leds/leds-s3c24xx.c
@@ -45,23 +45,35 @@ 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);
+ /*
+ * ensure value is 0 or 1 to use it with bitwise XOR (^)
+ * (only 100% brightness is supported)
+ */
+ value = value ? 1 : 0;
+
+ if (pd->flags & S3C24XX_LEDF_TRISTATE) {
+ if (value) {
+ /* invert value if S3C24XX_LEDF_ACTLOW is set */
+ value = (pd->flags & S3C24XX_LEDF_ACTLOW) ^ value;
+ gpio_direction_output(pd->gpio, value);
+ } else {
+ gpio_direction_input(pd->gpio);
+ }
+ } else {
+ /* invert value if S3C24XX_LEDF_ACTLOW is set */
+ value = (pd->flags & S3C24XX_LEDF_ACTLOW) ^ value;
+ gpio_set_value(pd->gpio, value);
+ }
}
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;
@@ -76,7 +88,8 @@ 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);
@@ -88,15 +101,34 @@ 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;
+ }
if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
- s3c2410_gpio_setpin(pdata->gpio, 0);
- s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
+ /*
+ * pull is needed here to protect pin from being left
+ * floating
+ */
+ ret = s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_UP);
+ if (ret)
+ s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_DOWN);
+ /* initially turn off led */
+ 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_request_one(pdata->gpio, GPIOF_OUT_INIT_LOW,
+ pdata->name);
+ /* initially turn off led */
+ 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 */
@@ -104,11 +136,18 @@ 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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