linux/arch/sparc/kernel/led.c

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#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/string.h>
#include <asm/auxio.h>
#define LED_MAX_LENGTH 8 /* maximum chars written to proc file */
static inline void led_toggle(void)
{
unsigned char val = get_auxio();
unsigned char on, off;
if (val & AUXIO_LED) {
on = 0;
off = AUXIO_LED;
} else {
on = AUXIO_LED;
off = 0;
}
set_auxio(on, off);
}
static struct timer_list led_blink_timer;
static void led_blink(unsigned long timeout)
{
led_toggle();
/* reschedule */
if (!timeout) { /* blink according to load */
led_blink_timer.expires = jiffies +
((1 + (avenrun[0] >> FSHIFT)) * HZ);
led_blink_timer.data = 0;
} else { /* blink at user specified interval */
led_blink_timer.expires = jiffies + (timeout * HZ);
led_blink_timer.data = timeout;
}
add_timer(&led_blink_timer);
}
static int led_read_proc(char *buf, char **start, off_t offset, int count,
int *eof, void *data)
{
int len = 0;
if (get_auxio() & AUXIO_LED)
len = sprintf(buf, "on\n");
else
len = sprintf(buf, "off\n");
return len;
}
static int led_write_proc(struct file *file, const char __user *buffer,
unsigned long count, void *data)
{
char *buf = NULL;
if (count > LED_MAX_LENGTH)
count = LED_MAX_LENGTH;
buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
if (!buf)
return -ENOMEM;
if (copy_from_user(buf, buffer, count)) {
kfree(buf);
return -EFAULT;
}
buf[count] = '\0';
/* work around \n when echo'ing into proc */
if (buf[count - 1] == '\n')
buf[count - 1] = '\0';
/* before we change anything we want to stop any running timers,
* otherwise calls such as on will have no persistent effect
*/
del_timer_sync(&led_blink_timer);
if (!strcmp(buf, "on")) {
auxio_set_led(AUXIO_LED_ON);
} else if (!strcmp(buf, "toggle")) {
led_toggle();
} else if ((*buf > '0') && (*buf <= '9')) {
led_blink(simple_strtoul(buf, NULL, 10));
} else if (!strcmp(buf, "load")) {
led_blink(0);
} else {
auxio_set_led(AUXIO_LED_OFF);
}
kfree(buf);
return count;
}
static struct proc_dir_entry *led;
#define LED_VERSION "0.1"
static int __init led_init(void)
{
init_timer(&led_blink_timer);
led_blink_timer.function = led_blink;
led = create_proc_entry("led", 0, NULL);
if (!led)
return -ENOMEM;
led->read_proc = led_read_proc; /* reader function */
led->write_proc = led_write_proc; /* writer function */
led->owner = THIS_MODULE;
printk(KERN_INFO
"led: version %s, Lars Kotthoff <metalhead@metalhead.ws>\n",
LED_VERSION);
return 0;
}
static void __exit led_exit(void)
{
remove_proc_entry("led", NULL);
del_timer_sync(&led_blink_timer);
}
module_init(led_init);
module_exit(led_exit);
MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>");
MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems.");
MODULE_LICENSE("GPL");
MODULE_VERSION(LED_VERSION);