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