linux/drivers/leds/leds-s3c24xx.c
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   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
  22#include <mach/hardware.h>
  23#include <mach/regs-gpio.h>
  24#include <mach/leds-gpio.h>
  25
  26/* our context */
  27
  28struct s3c24xx_gpio_led {
  29        struct led_classdev              cdev;
  30        struct s3c24xx_led_platdata     *pdata;
  31};
  32
  33static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  34{
  35        return platform_get_drvdata(dev);
  36}
  37
  38static 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
  43static 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
  49        /* there will be a short delay between setting the output and
  50         * going from output to input when using tristate. */
  51
  52        s3c2410_gpio_setpin(pd->gpio, (value ? 1 : 0) ^
  53                            (pd->flags & S3C24XX_LEDF_ACTLOW));
  54
  55        if (pd->flags & S3C24XX_LEDF_TRISTATE)
  56                s3c2410_gpio_cfgpin(pd->gpio,
  57                        value ? S3C2410_GPIO_OUTPUT : S3C2410_GPIO_INPUT);
  58
  59}
  60
  61static int s3c24xx_led_remove(struct platform_device *dev)
  62{
  63        struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
  64
  65        led_classdev_unregister(&led->cdev);
  66        kfree(led);
  67
  68        return 0;
  69}
  70
  71static int s3c24xx_led_probe(struct platform_device *dev)
  72{
  73        struct s3c24xx_led_platdata *pdata = dev->dev.platform_data;
  74        struct s3c24xx_gpio_led *led;
  75        int ret;
  76
  77        led = kzalloc(sizeof(struct s3c24xx_gpio_led), GFP_KERNEL);
  78        if (led == NULL) {
  79                dev_err(&dev->dev, "No memory for device\n");
  80                return -ENOMEM;
  81        }
  82
  83        platform_set_drvdata(dev, led);
  84
  85        led->cdev.brightness_set = s3c24xx_led_set;
  86        led->cdev.default_trigger = pdata->def_trigger;
  87        led->cdev.name = pdata->name;
  88        led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  89
  90        led->pdata = pdata;
  91
  92        /* no point in having a pull-up if we are always driving */
  93
  94        if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
  95                s3c2410_gpio_setpin(pdata->gpio, 0);
  96                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
  97        } else {
  98                s3c2410_gpio_pullup(pdata->gpio, 0);
  99                s3c2410_gpio_setpin(pdata->gpio, 0);
 100                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
 101        }
 102
 103        /* register our new led device */
 104
 105        ret = led_classdev_register(&dev->dev, &led->cdev);
 106        if (ret < 0) {
 107                dev_err(&dev->dev, "led_classdev_register failed\n");
 108                kfree(led);
 109                return ret;
 110        }
 111
 112        return 0;
 113}
 114
 115static struct platform_driver s3c24xx_led_driver = {
 116        .probe          = s3c24xx_led_probe,
 117        .remove         = s3c24xx_led_remove,
 118        .driver         = {
 119                .name           = "s3c24xx_led",
 120                .owner          = THIS_MODULE,
 121        },
 122};
 123
 124module_platform_driver(s3c24xx_led_driver);
 125
 126MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 127MODULE_DESCRIPTION("S3C24XX LED driver");
 128MODULE_LICENSE("GPL");
 129MODULE_ALIAS("platform:s3c24xx_led");
 130