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
led_toggle(void)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
led_blink(struct timer_list * unused)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
led_proc_show(struct seq_file * m,void * v)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
led_proc_open(struct inode * inode,struct file * file)61 static int led_proc_open(struct inode *inode, struct file *file)
62 {
63 return single_open(file, led_proc_show, NULL);
64 }
65
led_proc_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)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
led_init(void)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
led_exit(void)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
