LXR linux/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
  19#include <mach/hardware.h>
  20#include <mach/regs-gpio.h>
  21#include <mach/leds-gpio.h>
  22
  23/* our context */
  24
  25struct s3c24xx_gpio_led {
  26        struct led_classdev              cdev;
  27        struct s3c24xx_led_platdata     *pdata;
  28};
  29
  30static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  31{
  32        return platform_get_drvdata(dev);
  33}
  34
  35static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  36{
  37        return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  38}
  39
  40static void s3c24xx_led_set(struct led_classdev *led_cdev,
  41                            enum led_brightness value)
  42{
  43        struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  44        struct s3c24xx_led_platdata *pd = led->pdata;
  45
  46        /* there will be a short delay between setting the output and
  47         * going from output to input when using tristate. */
  48
  49        s3c2410_gpio_setpin(pd->gpio, (value ? 1 : 0) ^
  50                            (pd->flags & S3C24XX_LEDF_ACTLOW));
  51
  52        if (pd->flags & S3C24XX_LEDF_TRISTATE)
  53                s3c2410_gpio_cfgpin(pd->gpio,
  54                        value ? S3C2410_GPIO_OUTPUT : S3C2410_GPIO_INPUT);
  55
  56}
  57
  58static int s3c24xx_led_remove(struct platform_device *dev)
  59{
  60        struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
  61
  62        led_classdev_unregister(&led->cdev);
  63        kfree(led);
  64
  65        return 0;
  66}
  67
  68static int s3c24xx_led_probe(struct platform_device *dev)
  69{
  70        struct s3c24xx_led_platdata *pdata = dev->dev.platform_data;
  71        struct s3c24xx_gpio_led *led;
  72        int ret;
  73
  74        led = kzalloc(sizeof(struct s3c24xx_gpio_led), GFP_KERNEL);
  75        if (led == NULL) {
  76                dev_err(&dev->dev, "No memory for device\n");
  77                return -ENOMEM;
  78        }
  79
  80        platform_set_drvdata(dev, led);
  81
  82        led->cdev.brightness_set = s3c24xx_led_set;
  83        led->cdev.default_trigger = pdata->def_trigger;
  84        led->cdev.name = pdata->name;
  85        led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  86
  87        led->pdata = pdata;
  88
  89        /* no point in having a pull-up if we are always driving */
  90
  91        if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
  92                s3c2410_gpio_setpin(pdata->gpio, 0);
  93                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
  94        } else {
  95                s3c2410_gpio_pullup(pdata->gpio, 0);
  96                s3c2410_gpio_setpin(pdata->gpio, 0);
  97                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
  98        }
  99
 100        /* register our new led device */
 101
 102        ret = led_classdev_register(&dev->dev, &led->cdev);
 103        if (ret < 0) {
 104                dev_err(&dev->dev, "led_classdev_register failed\n");
 105                kfree(led);
 106                return ret;
 107        }
 108
 109        return 0;
 110}
 111
 112static struct platform_driver s3c24xx_led_driver = {
 113        .probe          = s3c24xx_led_probe,
 114        .remove         = s3c24xx_led_remove,
 115        .driver         = {
 116                .name           = "s3c24xx_led",
 117                .owner          = THIS_MODULE,
 118        },
 119};
 120
 121static int __init s3c24xx_led_init(void)
 122{
 123        return platform_driver_register(&s3c24xx_led_driver);
 124}
 125
 126static void __exit s3c24xx_led_exit(void)
 127{
 128        platform_driver_unregister(&s3c24xx_led_driver);
 129}
 130
 131module_init(s3c24xx_led_init);
 132module_exit(s3c24xx_led_exit);
 133
 134MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 135MODULE_DESCRIPTION("S3C24XX LED driver");
 136MODULE_LICENSE("GPL");
 137MODULE_ALIAS("platform:s3c24xx_led");
 138