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
  21 #include <mach/hardware.h>
  22 #include <mach/regs-gpio.h>
  23 #include <mach/leds-gpio.h>
  24
  25 /* our context */
  26
  27 struct s3c24xx_gpio_led {
  28         struct led_classdev              cdev;
  29         struct s3c24xx_led_platdata     *pdata;
  30 };
  31
  32 static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  33 {
  34         return platform_get_drvdata(dev);
  35 }
  36
  37 static 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
  42 static 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
  60 static 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
  70 static 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
 114 static 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
 123 static int __init s3c24xx_led_init(void)
 124 {
 125         return platform_driver_register(&s3c24xx_led_driver);
 126 }
 127
 128 static void __exit s3c24xx_led_exit(void)
 129 {
 130         platform_driver_unregister(&s3c24xx_led_driver);
 131 }
 132
 133 module_init(s3c24xx_led_init);
 134 module_exit(s3c24xx_led_exit);
 135
 136 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 137 MODULE_DESCRIPTION("S3C24XX LED driver");
 138 MODULE_LICENSE("GPL");
 139 MODULE_ALIAS("platform:s3c24xx_led");