target/linux/rb1xx-2.6/files/drivers/char/adm5120_gpio.c

   1 /*
   2  *      ADM5120 LED (GPIO) driver
   3  *
   4  *      Copyright (C) Jeroen Vreeken (pe1rxq@amsat.org), 2005
   5  */
   6
   7 #include <linux/autoconf.h>
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/miscdevice.h>
  11 #include <linux/fs.h>
  12
  13 #define LED_MINOR 151
  14 #define GPIO_IO        ((unsigned long *)0xb20000b8)
  15
  16 static ssize_t adm5120_led_write(struct file *file, const char __user *data,
  17         size_t len, loff_t *ppos)
  18 {
  19         unsigned char val;
  20
  21         if (!len || get_user(val, data))
  22                 return -EFAULT;
  23         *GPIO_IO=(*GPIO_IO & 0x00ffffff) | (val<<24);
  24         return 1;
  25 }
  26
  27 static struct file_operations adm5120_led_fops = {
  28         .owner  = THIS_MODULE,
  29         .write  = adm5120_led_write,
  30 };
  31
  32 static struct miscdevice adm5120_led_device = {
  33         LED_MINOR,
  34         "led",
  35         &adm5120_led_fops,
  36 };
  37
  38 static int __init adm5120_led_init(void)
  39 {
  40         printk(KERN_INFO "ADM5120 LED & GPIO driver\n");
  41         if (misc_register(&adm5120_led_device)) {
  42                 printk(KERN_WARNING "Couldn't register device %d\n", LED_MINOR);
  43                 return -EBUSY;
  44         }
  45         return 0;
  46 }
  47
  48 static void __exit adm5120_led_exit(void)
  49 {
  50         misc_deregister(&adm5120_led_device);
  51 }
  52
  53 module_init(adm5120_led_init);
  54 module_exit(adm5120_led_exit);
  55
  56 MODULE_DESCRIPTION("ADM5120 LED and GPIO driver");
  57 MODULE_AUTHOR("Jeroen Vreeken");
  58 MODULE_LICENSE("GPL");