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
16static 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
32static struct timer_list led_blink_timer;
33
34static 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
50static 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
59static int led_proc_open(struct inode *inode, struct file *file)
60{
61	return single_open(file, led_proc_show, NULL);
62}
63
64static 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
109static 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
118static struct proc_dir_entry *led;
119
120#define LED_VERSION	"0.1"
121
122static 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
138static void __exit led_exit(void)
139{
140	remove_proc_entry("led", NULL);
141	del_timer_sync(&led_blink_timer);
142}
143
144module_init(led_init);
145module_exit(led_exit);
146
147MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>");
148MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems.");
149MODULE_LICENSE("GPL");
150MODULE_VERSION(LED_VERSION);
151