drivers/leds/leds-s3c24xx.c

   1 /* drivers/leds/leds-s3c24xx.c
   2  *
   3  * (c) 2006 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * S3C24XX - LEDs GPIO driver
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12 */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/leds.h>
  17 #include <linux/gpio.h>
  18 #include <linux/slab.h>
  19 #include <linux/module.h>
  20 #include <linux/platform_data/leds-s3c24xx.h>
  21
  22 #include <mach/regs-gpio.h>
  23 #include <plat/gpio-cfg.h>
  24
  25 /* our context */
  26
  27 struct s3c24xx_gpio_led {
  28         struct led_classdev              cdev;
  29         struct s3c24xx_led_platdata     *pdata;
  30 };
  31
  32 static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  33 {
  34         return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  35 }
  36
  37 static void s3c24xx_led_set(struct led_classdev *led_cdev,
  38                             enum led_brightness value)
  39 {
  40         struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  41         struct s3c24xx_led_platdata *pd = led->pdata;
  42         int state = (value ? 1 : 0) ^ (pd->flags & S3C24XX_LEDF_ACTLOW);
  43
  44         /* there will be a short delay between setting the output and
  45          * going from output to input when using tristate. */
  46
  47         gpio_set_value(pd->gpio, state);
  48
  49         if (pd->flags & S3C24XX_LEDF_TRISTATE) {
  50                 if (value)
  51                         gpio_direction_output(pd->gpio, state);
  52                 else
  53                         gpio_direction_input(pd->gpio);
  54         }
  55 }
  56
  57 static int s3c24xx_led_probe(struct platform_device *dev)
  58 {
  59         struct s3c24xx_led_platdata *pdata = dev_get_platdata(&dev->dev);
  60         struct s3c24xx_gpio_led *led;
  61         int ret;
  62
  63         led = devm_kzalloc(&dev->dev, sizeof(struct s3c24xx_gpio_led),
  64                            GFP_KERNEL);
  65         if (!led)
  66                 return -ENOMEM;
  67
  68         led->cdev.brightness_set = s3c24xx_led_set;
  69         led->cdev.default_trigger = pdata->def_trigger;
  70         led->cdev.name = pdata->name;
  71         led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  72
  73         led->pdata = pdata;
  74
  75         ret = devm_gpio_request(&dev->dev, pdata->gpio, "S3C24XX_LED");
  76         if (ret < 0)
  77                 return ret;
  78
  79         /* no point in having a pull-up if we are always driving */
  80
  81         s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);
  82
  83         if (pdata->flags & S3C24XX_LEDF_TRISTATE)
  84                 gpio_direction_input(pdata->gpio);
  85         else
  86                 gpio_direction_output(pdata->gpio,
  87                         pdata->flags & S3C24XX_LEDF_ACTLOW ? 1 : 0);
  88
  89         /* register our new led device */
  90
  91         ret = devm_led_classdev_register(&dev->dev, &led->cdev);
  92         if (ret < 0)
  93                 dev_err(&dev->dev, "led_classdev_register failed\n");
  94
  95         return ret;
  96 }
  97
  98 static struct platform_driver s3c24xx_led_driver = {
  99         .probe          = s3c24xx_led_probe,
 100         .driver         = {
 101                 .name           = "s3c24xx_led",
 102         },
 103 };
 104
 105 module_platform_driver(s3c24xx_led_driver);
 106
 107 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 108 MODULE_DESCRIPTION("S3C24XX LED driver");
 109 MODULE_LICENSE("GPL");
 110 MODULE_ALIAS("platform:s3c24xx_led");