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
  21#include <mach/hardware.h>
  22#include <mach/regs-gpio.h>
  23#include <mach/leds-gpio.h>
  24
  25/* our context */
  26
  27struct s3c24xx_gpio_led {
  28        struct led_classdev              cdev;
  29        struct s3c24xx_led_platdata     *pdata;
  30};
  31
  32static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  33{
  34        return platform_get_drvdata(dev);
  35}
  36
  37static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  38{
  39        return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  40}
  41
  42static void s3c24xx_led_set(struct led_classdev *led_cdev,
  43                            enum led_brightness value)
  44{
  45        struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  46        struct s3c24xx_led_platdata *pd = led->pdata;
  47
  48        /* there will be a short delay between setting the output and
  49         * going from output to input when using tristate. */
  50
  51        s3c2410_gpio_setpin(pd->gpio, (value ? 1 : 0) ^
  52                            (pd->flags & S3C24XX_LEDF_ACTLOW));
  53
  54        if (pd->flags & S3C24XX_LEDF_TRISTATE)
  55                s3c2410_gpio_cfgpin(pd->gpio,
  56                        value ? S3C2410_GPIO_OUTPUT : S3C2410_GPIO_INPUT);
  57
  58}
  59
  60static int s3c24xx_led_remove(struct platform_device *dev)
  61{
  62        struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
  63
  64        led_classdev_unregister(&led->cdev);
  65        kfree(led);
  66
  67        return 0;
  68}
  69
  70static int s3c24xx_led_probe(struct platform_device *dev)
  71{
  72        struct s3c24xx_led_platdata *pdata = dev->dev.platform_data;
  73        struct s3c24xx_gpio_led *led;
  74        int ret;
  75
  76        led = kzalloc(sizeof(struct s3c24xx_gpio_led), GFP_KERNEL);
  77        if (led == NULL) {
  78                dev_err(&dev->dev, "No memory for device\n");
  79                return -ENOMEM;
  80        }
  81
  82        platform_set_drvdata(dev, led);
  83
  84        led->cdev.brightness_set = s3c24xx_led_set;
  85        led->cdev.default_trigger = pdata->def_trigger;
  86        led->cdev.name = pdata->name;
  87        led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  88
  89        led->pdata = pdata;
  90
  91        /* no point in having a pull-up if we are always driving */
  92
  93        if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
  94                s3c2410_gpio_setpin(pdata->gpio, 0);
  95                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
  96        } else {
  97                s3c2410_gpio_pullup(pdata->gpio, 0);
  98                s3c2410_gpio_setpin(pdata->gpio, 0);
  99                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
 100        }
 101
 102        /* register our new led device */
 103
 104        ret = led_classdev_register(&dev->dev, &led->cdev);
 105        if (ret < 0) {
 106                dev_err(&dev->dev, "led_classdev_register failed\n");
 107                kfree(led);
 108                return ret;
 109        }
 110
 111        return 0;
 112}
 113
 114static struct platform_driver s3c24xx_led_driver = {
 115        .probe          = s3c24xx_led_probe,
 116        .remove         = s3c24xx_led_remove,
 117        .driver         = {
 118                .name           = "s3c24xx_led",
 119                .owner          = THIS_MODULE,
 120        },
 121};
 122
 123static int __init s3c24xx_led_init(void)
 124{
 125        return platform_driver_register(&s3c24xx_led_driver);
 126}
 127
 128static void __exit s3c24xx_led_exit(void)
 129{
 130        platform_driver_unregister(&s3c24xx_led_driver);
 131}
 132
 133module_init(s3c24xx_led_init);
 134module_exit(s3c24xx_led_exit);
 135
 136MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 137MODULE_DESCRIPTION("S3C24XX LED driver");
 138MODULE_LICENSE("GPL");
 139MODULE_ALIAS("platform:s3c24xx_led");
 140