arch/arm/mach-ebsa110/leds.c

   1 /*
   2  * Driver for the LED found on the EBSA110 machine
   3  * Based on Versatile and RealView machine LED code
   4  *
   5  * License terms: GNU General Public License (GPL) version 2
   6  * Author: Bryan Wu <bryan.wu@canonical.com>
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/io.h>
  11 #include <linux/slab.h>
  12 #include <linux/leds.h>
  13
  14 #include <asm/mach-types.h>
  15
  16 #include "core.h"
  17
  18 #if defined(CONFIG_NEW_LEDS) && defined(CONFIG_LEDS_CLASS)
  19 static void ebsa110_led_set(struct led_classdev *cdev,
  20                               enum led_brightness b)
  21 {
  22         u8 reg = __raw_readb(SOFT_BASE);
  23
  24         if (b != LED_OFF)
  25                 reg |= 0x80;
  26         else
  27                 reg &= ~0x80;
  28
  29         __raw_writeb(reg, SOFT_BASE);
  30 }
  31
  32 static enum led_brightness ebsa110_led_get(struct led_classdev *cdev)
  33 {
  34         u8 reg = __raw_readb(SOFT_BASE);
  35
  36         return (reg & 0x80) ? LED_FULL : LED_OFF;
  37 }
  38
  39 static int __init ebsa110_leds_init(void)
  40 {
  41
  42         struct led_classdev *cdev;
  43         int ret;
  44
  45         if (!machine_is_ebsa110())
  46                 return -ENODEV;
  47
  48         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
  49         if (!cdev)
  50                 return -ENOMEM;
  51
  52         cdev->name = "ebsa110:0";
  53         cdev->brightness_set = ebsa110_led_set;
  54         cdev->brightness_get = ebsa110_led_get;
  55         cdev->default_trigger = "heartbeat";
  56
  57         ret = led_classdev_register(NULL, cdev);
  58         if (ret < 0) {
  59                 kfree(cdev);
  60                 return ret;
  61         }
  62
  63         return 0;
  64 }
  65
  66 /*
  67  * Since we may have triggers on any subsystem, defer registration
  68  * until after subsystem_init.
  69  */
  70 fs_initcall(ebsa110_leds_init);
  71 #endif