1 #include <linux/kernel.h> 2 #include <linux/module.h> 3 #include <linux/init.h> 4 #include <linux/proc_fs.h> 5 #include <linux/seq_file.h> 6 #include <linux/slab.h> 7 #include <linux/string.h> 8 #include <linux/jiffies.h> 9 #include <linux/timer.h> 10 #include <linux/uaccess.h> 11 #include <linux/sched/loadavg.h> 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 static unsigned long led_blink_timer_timeout; 35 36 static void led_blink(struct timer_list *unused) 37 { 38 unsigned long timeout = led_blink_timer_timeout; 39 40 led_toggle(); 41 42 /* reschedule */ 43 if (!timeout) { /* blink according to load */ 44 led_blink_timer.expires = jiffies + 45 ((1 + (avenrun[0] >> FSHIFT)) * HZ); 46 } else { /* blink at user specified interval */ 47 led_blink_timer.expires = jiffies + (timeout * HZ); 48 } 49 add_timer(&led_blink_timer); 50 } 51 52 static int led_proc_show(struct seq_file *m, void *v) 53 { 54 if (get_auxio() & AUXIO_LED) 55 seq_puts(m, "on\n"); 56 else 57 seq_puts(m, "off\n"); 58 return 0; 59 } 60 61 static int led_proc_open(struct inode *inode, struct file *file) 62 { 63 return single_open(file, led_proc_show, NULL); 64 } 65 66 static ssize_t led_proc_write(struct file *file, const char __user *buffer, 67 size_t count, loff_t *ppos) 68 { 69 char *buf = NULL; 70 71 if (count > LED_MAX_LENGTH) 72 count = LED_MAX_LENGTH; 73 74 buf = memdup_user_nul(buffer, count); 75 if (IS_ERR(buf)) 76 return PTR_ERR(buf); 77 78 /* work around \n when echo'ing into proc */ 79 if (buf[count - 1] == '\n') 80 buf[count - 1] = '\0'; 81 82 /* before we change anything we want to stop any running timers, 83 * otherwise calls such as on will have no persistent effect 84 */ 85 del_timer_sync(&led_blink_timer); 86 87 if (!strcmp(buf, "on")) { 88 auxio_set_led(AUXIO_LED_ON); 89 } else if (!strcmp(buf, "toggle")) { 90 led_toggle(); 91 } else if ((*buf > '0') && (*buf <= '9')) { 92 led_blink_timer_timeout = simple_strtoul(buf, NULL, 10); 93 led_blink(&led_blink_timer); 94 } else if (!strcmp(buf, "load")) { 95 led_blink_timer_timeout = 0; 96 led_blink(&led_blink_timer); 97 } else { 98 auxio_set_led(AUXIO_LED_OFF); 99 } 100 101 kfree(buf); 102 103 return count; 104 } 105 106 static const struct file_operations led_proc_fops = { 107 .owner = THIS_MODULE, 108 .open = led_proc_open, 109 .read = seq_read, 110 .llseek = seq_lseek, 111 .release = single_release, 112 .write = led_proc_write, 113 }; 114 115 static struct proc_dir_entry *led; 116 117 #define LED_VERSION "0.1" 118 119 static int __init led_init(void) 120 { 121 timer_setup(&led_blink_timer, led_blink, 0); 122 123 led = proc_create("led", 0, NULL, &led_proc_fops); 124 if (!led) 125 return -ENOMEM; 126 127 printk(KERN_INFO 128 "led: version %s, Lars Kotthoff <metalhead@metalhead.ws>\n", 129 LED_VERSION); 130 131 return 0; 132 } 133 134 static void __exit led_exit(void) 135 { 136 remove_proc_entry("led", NULL); 137 del_timer_sync(&led_blink_timer); 138 } 139 140 module_init(led_init); 141 module_exit(led_exit); 142 143 MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>"); 144 MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems."); 145 MODULE_LICENSE("GPL"); 146 MODULE_VERSION(LED_VERSION); 147