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
12 #include <asm/auxio.h>
13
14 #define LED_MAX_LENGTH 8 /* maximum chars written to proc file */
15
led_toggle(void)16 static inline void led_toggle(void)
17 {
18 unsigned char val = get_auxio();
19 unsigned char on, off;
20
21 if (val & AUXIO_LED) {
22 on = 0;
23 off = AUXIO_LED;
24 } else {
25 on = AUXIO_LED;
26 off = 0;
27 }
28
29 set_auxio(on, off);
30 }
31
32 static struct timer_list led_blink_timer;
33
led_blink(unsigned long timeout)34 static void led_blink(unsigned long timeout)
35 {
36 led_toggle();
37
38 /* reschedule */
39 if (!timeout) { /* blink according to load */
40 led_blink_timer.expires = jiffies +
41 ((1 + (avenrun[0] >> FSHIFT)) * HZ);
42 led_blink_timer.data = 0;
43 } else { /* blink at user specified interval */
44 led_blink_timer.expires = jiffies + (timeout * HZ);
45 led_blink_timer.data = timeout;
46 }
47 add_timer(&led_blink_timer);
48 }
49
led_proc_show(struct seq_file * m,void * v)50 static int led_proc_show(struct seq_file *m, void *v)
51 {
52 if (get_auxio() & AUXIO_LED)
53 seq_puts(m, "on\n");
54 else
55 seq_puts(m, "off\n");
56 return 0;
57 }
58
led_proc_open(struct inode * inode,struct file * file)59 static int led_proc_open(struct inode *inode, struct file *file)
60 {
61 return single_open(file, led_proc_show, NULL);
62 }
63
led_proc_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)64 static ssize_t led_proc_write(struct file *file, const char __user *buffer,
65 size_t count, loff_t *ppos)
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 const struct file_operations led_proc_fops = {
110 .owner = THIS_MODULE,
111 .open = led_proc_open,
112 .read = seq_read,
113 .llseek = seq_lseek,
114 .release = single_release,
115 .write = led_proc_write,
116 };
117
118 static struct proc_dir_entry *led;
119
120 #define LED_VERSION "0.1"
121
led_init(void)122 static int __init led_init(void)
123 {
124 init_timer(&led_blink_timer);
125 led_blink_timer.function = led_blink;
126
127 led = proc_create("led", 0, NULL, &led_proc_fops);
128 if (!led)
129 return -ENOMEM;
130
131 printk(KERN_INFO
132 "led: version %s, Lars Kotthoff <metalhead@metalhead.ws>\n",
133 LED_VERSION);
134
135 return 0;
136 }
137
led_exit(void)138 static void __exit led_exit(void)
139 {
140 remove_proc_entry("led", NULL);
141 del_timer_sync(&led_blink_timer);
142 }
143
144 module_init(led_init);
145 module_exit(led_exit);
146
147 MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>");
148 MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems.");
149 MODULE_LICENSE("GPL");
150 MODULE_VERSION(LED_VERSION);
151