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
  26 struct s3c24xx_gpio_led {
  27         struct led_classdev              cdev;
  28         struct s3c24xx_led_platdata     *pdata;
  29 };
  30
  31 static inline struct s3c24xx_gpio_led *pdev_to_gpio(struct platform_device *dev)
  32 {
  33         return platform_get_drvdata(dev);
  34 }
  35
  36 static 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
  41 static 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
  59 static 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
  69 static 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         led->cdev.brightness = pdata->flags & S3C24XX_LEDF_STARTON ? 1 : 0;
  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                 /* backlight led needs to be turned on early on */
  99                 s3c2410_gpio_setpin(pdata->gpio, led->cdev.brightness);
 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
 115 static 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
 124 static int __init s3c24xx_led_init(void)
 125 {
 126         return platform_driver_register(&s3c24xx_led_driver);
 127 }
 128
 129 static void __exit s3c24xx_led_exit(void)
 130 {
 131         platform_driver_unregister(&s3c24xx_led_driver);
 132 }
 133
 134 module_init(s3c24xx_led_init);
 135 module_exit(s3c24xx_led_exit);
 136
 137 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 138 MODULE_DESCRIPTION("S3C24XX LED driver");
 139 MODULE_LICENSE("GPL");
 140 MODULE_ALIAS("platform:s3c24xx_led");