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 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_proc_show(struct seq_file *m, void *v) 52 { 53 if (get_auxio() & AUXIO_LED) 54 seq_puts(m, "on\n"); 55 else 56 seq_puts(m, "off\n"); 57 return 0; 58 } 59 60 static int led_proc_open(struct inode *inode, struct file *file) 61 { 62 return single_open(file, led_proc_show, NULL); 63 } 64 65 static ssize_t led_proc_write(struct file *file, const char __user *buffer, 66 size_t count, loff_t *ppos) 67 { 68 char *buf = NULL; 69 70 if (count > LED_MAX_LENGTH) 71 count = LED_MAX_LENGTH; 72 73 buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL); 74 if (!buf) 75 return -ENOMEM; 76 77 if (copy_from_user(buf, buffer, count)) { 78 kfree(buf); 79 return -EFAULT; 80 } 81 82 buf[count] = '\0'; 83 84 /* work around \n when echo'ing into proc */ 85 if (buf[count - 1] == '\n') 86 buf[count - 1] = '\0'; 87 88 /* before we change anything we want to stop any running timers, 89 * otherwise calls such as on will have no persistent effect 90 */ 91 del_timer_sync(&led_blink_timer); 92 93 if (!strcmp(buf, "on")) { 94 auxio_set_led(AUXIO_LED_ON); 95 } else if (!strcmp(buf, "toggle")) { 96 led_toggle(); 97 } else if ((*buf > '0') && (*buf <= '9')) { 98 led_blink(simple_strtoul(buf, NULL, 10)); 99 } else if (!strcmp(buf, "load")) { 100 led_blink(0); 101 } else { 102 auxio_set_led(AUXIO_LED_OFF); 103 } 104 105 kfree(buf); 106 107 return count; 108 } 109 110 static const struct file_operations led_proc_fops = { 111 .owner = THIS_MODULE, 112 .open = led_proc_open, 113 .read = seq_read, 114 .llseek = seq_lseek, 115 .release = single_release, 116 .write = led_proc_write, 117 }; 118 119 static struct proc_dir_entry *led; 120 121 #define LED_VERSION "0.1" 122 123 static int __init led_init(void) 124 { 125 init_timer(&led_blink_timer); 126 led_blink_timer.function = led_blink; 127 128 led = proc_create("led", 0, NULL, &led_proc_fops); 129 if (!led) 130 return -ENOMEM; 131 132 printk(KERN_INFO 133 "led: version %s, Lars Kotthoff <metalhead@metalhead.ws>\n", 134 LED_VERSION); 135 136 return 0; 137 } 138 139 static void __exit led_exit(void) 140 { 141 remove_proc_entry("led", NULL); 142 del_timer_sync(&led_blink_timer); 143 } 144 145 module_init(led_init); 146 module_exit(led_exit); 147 148 MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>"); 149 MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems."); 150 MODULE_LICENSE("GPL"); 151 MODULE_VERSION(LED_VERSION); 152