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/init.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/leds.h>
  18 #include <linux/gpio.h>
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21 #include <linux/platform_data/leds-s3c24xx.h>
  22
  23 #include <mach/regs-gpio.h>
  24 #include <plat/gpio-cfg.h>
  25
  26 /* our context */
  27
  28 struct s3c24xx_gpio_led {
  29         struct led_classdev              cdev;
  30         struct s3c24xx_led_platdata     *pdata;
  31 };
  32
  33 static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  34 {
  35         return platform_get_drvdata(dev);
  36 }
  37
  38 static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  39 {
  40         return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  41 }
  42
  43 static void s3c24xx_led_set(struct led_classdev *led_cdev,
  44                             enum led_brightness value)
  45 {
  46         struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  47         struct s3c24xx_led_platdata *pd = led->pdata;
  48         int state = (value ? 1 : 0) ^ (pd->flags & S3C24XX_LEDF_ACTLOW);
  49
  50         /* there will be a short delay between setting the output and
  51          * going from output to input when using tristate. */
  52
  53         gpio_set_value(pd->gpio, state);
  54
  55         if (pd->flags & S3C24XX_LEDF_TRISTATE) {
  56                 if (value)
  57                         gpio_direction_output(pd->gpio, state);
  58                 else
  59                         gpio_direction_input(pd->gpio);
  60         }
  61 }
  62
  63 static int s3c24xx_led_remove(struct platform_device *dev)
  64 {
  65         struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
  66
  67         led_classdev_unregister(&led->cdev);
  68
  69         return 0;
  70 }
  71
  72 static int s3c24xx_led_probe(struct platform_device *dev)
  73 {
  74         struct s3c24xx_led_platdata *pdata = dev_get_platdata(&dev->dev);
  75         struct s3c24xx_gpio_led *led;
  76         int ret;
  77
  78         led = devm_kzalloc(&dev->dev, sizeof(struct s3c24xx_gpio_led),
  79                            GFP_KERNEL);
  80         if (led == NULL) {
  81                 dev_err(&dev->dev, "No memory for device\n");
  82                 return -ENOMEM;
  83         }
  84
  85         platform_set_drvdata(dev, led);
  86
  87         led->cdev.brightness_set = s3c24xx_led_set;
  88         led->cdev.default_trigger = pdata->def_trigger;
  89         led->cdev.name = pdata->name;
  90         led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  91
  92         led->pdata = pdata;
  93
  94         ret = devm_gpio_request(&dev->dev, pdata->gpio, "S3C24XX_LED");
  95         if (ret < 0)
  96                 return ret;
  97
  98         /* no point in having a pull-up if we are always driving */
  99
 100         s3c_gpio_setpull(pdata->gpio, S3C_GPIO_PULL_NONE);
 101
 102         if (pdata->flags & S3C24XX_LEDF_TRISTATE)
 103                 gpio_direction_input(pdata->gpio);
 104         else
 105                 gpio_direction_output(pdata->gpio,
 106                         pdata->flags & S3C24XX_LEDF_ACTLOW ? 1 : 0);
 107
 108         /* register our new led device */
 109
 110         ret = led_classdev_register(&dev->dev, &led->cdev);
 111         if (ret < 0)
 112                 dev_err(&dev->dev, "led_classdev_register failed\n");
 113
 114         return ret;
 115 }
 116
 117 static struct platform_driver s3c24xx_led_driver = {
 118         .probe          = s3c24xx_led_probe,
 119         .remove         = s3c24xx_led_remove,
 120         .driver         = {
 121                 .name           = "s3c24xx_led",
 122                 .owner          = THIS_MODULE,
 123         },
 124 };
 125
 126 module_platform_driver(s3c24xx_led_driver);
 127
 128 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 129 MODULE_DESCRIPTION("S3C24XX LED driver");
 130 MODULE_LICENSE("GPL");
 131 MODULE_ALIAS("platform:s3c24xx_led");