arch/sparc/kernel/led.c

   1 #include <linux/kernel.h>
   2 #include <linux/module.h>
   3 #include <linux/init.h>
   4 #include <linux/proc_fs.h>
   5 #include <linux/string.h>
   6 <<<<<<< HEAD:arch/sparc/kernel/led.c
   7 =======
   8 #include <linux/jiffies.h>
   9 #include <linux/timer.h>
  10 #include <linux/uaccess.h>
  11 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:arch/sparc/kernel/led.c
  12
  13 #include <asm/auxio.h>
  14
  15 #define LED_MAX_LENGTH 8 /* maximum chars written to proc file */
  16
  17 static inline void led_toggle(void)
  18 {
  19         unsigned char val = get_auxio();
  20         unsigned char on, off;
  21
  22         if (val & AUXIO_LED) {
  23                 on = 0;
  24                 off = AUXIO_LED;
  25         } else {
  26                 on = AUXIO_LED;
  27                 off = 0;
  28         }
  29
  30         set_auxio(on, off);
  31 }
  32
  33 static struct timer_list led_blink_timer;
  34
  35 static void led_blink(unsigned long timeout)
  36 {
  37         led_toggle();
  38
  39         /* reschedule */
  40         if (!timeout) { /* blink according to load */
  41                 led_blink_timer.expires = jiffies +
  42                         ((1 + (avenrun[0] >> FSHIFT)) * HZ);
  43                 led_blink_timer.data = 0;
  44         } else { /* blink at user specified interval */
  45                 led_blink_timer.expires = jiffies + (timeout * HZ);
  46                 led_blink_timer.data = timeout;
  47         }
  48         add_timer(&led_blink_timer);
  49 }
  50
  51 static int led_read_proc(char *buf, char **start, off_t offset, int count,
  52                          int *eof, void *data)
  53 {
  54         int len = 0;
  55
  56         if (get_auxio() & AUXIO_LED)
  57                 len = sprintf(buf, "on\n");
  58         else
  59                 len = sprintf(buf, "off\n");
  60
  61         return len;
  62 }
  63
  64 static int led_write_proc(struct file *file, const char __user *buffer,
  65                           unsigned long count, void *data)
  66 {
  67         char *buf = NULL;
  68
  69         if (count > LED_MAX_LENGTH)
  70                 count = LED_MAX_LENGTH;
  71
  72         buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
  73         if (!buf)
  74                 return -ENOMEM;
  75
  76         if (copy_from_user(buf, buffer, count)) {
  77                 kfree(buf);
  78                 return -EFAULT;
  79         }
  80
  81         buf[count] = '\0';
  82
  83         /* work around \n when echo'ing into proc */
  84         if (buf[count - 1] == '\n')
  85                 buf[count - 1] = '\0';
  86
  87         /* before we change anything we want to stop any running timers,
  88          * otherwise calls such as on will have no persistent effect
  89          */
  90         del_timer_sync(&led_blink_timer);
  91
  92         if (!strcmp(buf, "on")) {
  93                 auxio_set_led(AUXIO_LED_ON);
  94         } else if (!strcmp(buf, "toggle")) {
  95                 led_toggle();
  96         } else if ((*buf > '0') && (*buf <= '9')) {
  97                 led_blink(simple_strtoul(buf, NULL, 10));
  98         } else if (!strcmp(buf, "load")) {
  99                 led_blink(0);
 100         } else {
 101                 auxio_set_led(AUXIO_LED_OFF);
 102         }
 103
 104         kfree(buf);
 105
 106         return count;
 107 }
 108
 109 static struct proc_dir_entry *led;
 110
 111 #define LED_VERSION     "0.1"
 112
 113 static int __init led_init(void)
 114 {
 115         init_timer(&led_blink_timer);
 116         led_blink_timer.function = led_blink;
 117
 118         led = create_proc_entry("led", 0, NULL);
 119         if (!led)
 120                 return -ENOMEM;
 121
 122         led->read_proc = led_read_proc; /* reader function */
 123         led->write_proc = led_write_proc; /* writer function */
 124         led->owner = THIS_MODULE;
 125
 126         printk(KERN_INFO
 127                "led: version %s, Lars Kotthoff <metalhead@metalhead.ws>\n",
 128                LED_VERSION);
 129
 130         return 0;
 131 }
 132
 133 static void __exit led_exit(void)
 134 {
 135         remove_proc_entry("led", NULL);
 136         del_timer_sync(&led_blink_timer);
 137 }
 138
 139 module_init(led_init);
 140 module_exit(led_exit);
 141
 142 MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>");
 143 MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems.");
 144 MODULE_LICENSE("GPL");
 145 MODULE_VERSION(LED_VERSION);