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#include <linux/gpio.h>
  19
  20#include <mach/hardware.h>
  21#include <mach/regs-gpio.h>
  22#include <mach/leds-gpio.h>
  23
  24/* our context */
  25
  26struct s3c24xx_gpio_led {
  27        struct led_classdev              cdev;
  28        struct s3c24xx_led_platdata     *pdata;
  29};
  30
  31static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  32{
  33        return platform_get_drvdata(dev);
  34}
  35
  36static inline struct s3c24xx_gpio_led *to_gpio(struct led_classdev *led_cdev)
  37{
  38        return container_of(led_cdev, struct s3c24xx_gpio_led, cdev);
  39}
  40
  41static void s3c24xx_led_set(struct led_classdev *led_cdev,
  42                            enum led_brightness value)
  43{
  44        struct s3c24xx_gpio_led *led = to_gpio(led_cdev);
  45        struct s3c24xx_led_platdata *pd = led->pdata;
  46
  47        /* there will be a short delay between setting the output and
  48         * going from output to input when using tristate. */
  49
  50        s3c2410_gpio_setpin(pd->gpio, (value ? 1 : 0) ^
  51                            (pd->flags & S3C24XX_LEDF_ACTLOW));
  52
  53        if (pd->flags & S3C24XX_LEDF_TRISTATE)
  54                s3c2410_gpio_cfgpin(pd->gpio,
  55                        value ? S3C2410_GPIO_OUTPUT : S3C2410_GPIO_INPUT);
  56
  57}
  58
  59static int s3c24xx_led_remove(struct platform_device *dev)
  60{
  61        struct s3c24xx_gpio_led *led = pdev_to_gpio(dev);
  62
  63        led_classdev_unregister(&led->cdev);
  64        kfree(led);
  65
  66        return 0;
  67}
  68
  69static int s3c24xx_led_probe(struct platform_device *dev)
  70{
  71        struct s3c24xx_led_platdata *pdata = dev->dev.platform_data;
  72        struct s3c24xx_gpio_led *led;
  73        int ret;
  74
  75        led = kzalloc(sizeof(struct s3c24xx_gpio_led), GFP_KERNEL);
  76        if (led == NULL) {
  77                dev_err(&dev->dev, "No memory for device\n");
  78                return -ENOMEM;
  79        }
  80
  81        platform_set_drvdata(dev, led);
  82
  83        led->cdev.brightness_set = s3c24xx_led_set;
  84        led->cdev.default_trigger = pdata->def_trigger;
  85        led->cdev.name = pdata->name;
  86        led->cdev.flags |= LED_CORE_SUSPENDRESUME;
  87
  88        led->pdata = pdata;
  89
  90        /* no point in having a pull-up if we are always driving */
  91
  92        if (pdata->flags & S3C24XX_LEDF_TRISTATE) {
  93                s3c2410_gpio_setpin(pdata->gpio, 0);
  94                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_INPUT);
  95        } else {
  96                s3c2410_gpio_pullup(pdata->gpio, 0);
  97                s3c2410_gpio_setpin(pdata->gpio, 0);
  98                s3c2410_gpio_cfgpin(pdata->gpio, S3C2410_GPIO_OUTPUT);
  99        }
 100
 101        /* register our new led device */
 102
 103        ret = led_classdev_register(&dev->dev, &led->cdev);
 104        if (ret < 0) {
 105                dev_err(&dev->dev, "led_classdev_register failed\n");
 106                kfree(led);
 107                return ret;
 108        }
 109
 110        return 0;
 111}
 112
 113static struct platform_driver s3c24xx_led_driver = {
 114        .probe          = s3c24xx_led_probe,
 115        .remove         = s3c24xx_led_remove,
 116        .driver         = {
 117                .name           = "s3c24xx_led",
 118                .owner          = THIS_MODULE,
 119        },
 120};
 121
 122static int __init s3c24xx_led_init(void)
 123{
 124        return platform_driver_register(&s3c24xx_led_driver);
 125}
 126
 127static void __exit s3c24xx_led_exit(void)
 128{
 129        platform_driver_unregister(&s3c24xx_led_driver);
 130}
 131
 132module_init(s3c24xx_led_init);
 133module_exit(s3c24xx_led_exit);
 134
 135MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 136MODULE_DESCRIPTION("S3C24XX LED driver");
 137MODULE_LICENSE("GPL");
 138MODULE_ALIAS("platform:s3c24xx_led");
 139