1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/kernel.h> |
3 | #include <linux/module.h> |
4 | #include <linux/init.h> |
5 | #include <linux/proc_fs.h> |
6 | #include <linux/seq_file.h> |
7 | #include <linux/slab.h> |
8 | #include <linux/string.h> |
9 | #include <linux/jiffies.h> |
10 | #include <linux/timer.h> |
11 | #include <linux/uaccess.h> |
12 | #include <linux/sched/loadavg.h> |
13 | |
14 | #include <asm/auxio.h> |
15 | |
16 | #define LED_MAX_LENGTH 8 /* maximum chars written to proc file */ |
17 | |
18 | static inline void led_toggle(void) |
19 | { |
20 | unsigned char val = get_auxio(); |
21 | unsigned char on, off; |
22 | |
23 | if (val & AUXIO_LED) { |
24 | on = 0; |
25 | off = AUXIO_LED; |
26 | } else { |
27 | on = AUXIO_LED; |
28 | off = 0; |
29 | } |
30 | |
31 | set_auxio(on, off); |
32 | } |
33 | |
34 | static struct timer_list led_blink_timer; |
35 | static unsigned long led_blink_timer_timeout; |
36 | |
37 | static void led_blink(struct timer_list *unused) |
38 | { |
39 | unsigned long timeout = led_blink_timer_timeout; |
40 | |
41 | led_toggle(); |
42 | |
43 | /* reschedule */ |
44 | if (!timeout) { /* blink according to load */ |
45 | led_blink_timer.expires = jiffies + |
46 | ((1 + (avenrun[0] >> FSHIFT)) * HZ); |
47 | } else { /* blink at user specified interval */ |
48 | led_blink_timer.expires = jiffies + (timeout * HZ); |
49 | } |
50 | add_timer(timer: &led_blink_timer); |
51 | } |
52 | |
53 | #ifdef CONFIG_PROC_FS |
54 | static int led_proc_show(struct seq_file *m, void *v) |
55 | { |
56 | if (get_auxio() & AUXIO_LED) |
57 | seq_puts(m, s: "on\n" ); |
58 | else |
59 | seq_puts(m, s: "off\n" ); |
60 | return 0; |
61 | } |
62 | |
63 | static int led_proc_open(struct inode *inode, struct file *file) |
64 | { |
65 | return single_open(file, led_proc_show, NULL); |
66 | } |
67 | |
68 | static ssize_t led_proc_write(struct file *file, const char __user *buffer, |
69 | size_t count, loff_t *ppos) |
70 | { |
71 | char *buf = NULL; |
72 | |
73 | if (count > LED_MAX_LENGTH) |
74 | count = LED_MAX_LENGTH; |
75 | |
76 | buf = memdup_user_nul(buffer, count); |
77 | if (IS_ERR(ptr: buf)) |
78 | return PTR_ERR(ptr: buf); |
79 | |
80 | /* work around \n when echo'ing into proc */ |
81 | if (buf[count - 1] == '\n') |
82 | buf[count - 1] = '\0'; |
83 | |
84 | /* before we change anything we want to stop any running timers, |
85 | * otherwise calls such as on will have no persistent effect |
86 | */ |
87 | del_timer_sync(timer: &led_blink_timer); |
88 | |
89 | if (!strcmp(buf, "on" )) { |
90 | auxio_set_led(AUXIO_LED_ON); |
91 | } else if (!strcmp(buf, "toggle" )) { |
92 | led_toggle(); |
93 | } else if ((*buf > '0') && (*buf <= '9')) { |
94 | led_blink_timer_timeout = simple_strtoul(buf, NULL, 10); |
95 | led_blink(unused: &led_blink_timer); |
96 | } else if (!strcmp(buf, "load" )) { |
97 | led_blink_timer_timeout = 0; |
98 | led_blink(unused: &led_blink_timer); |
99 | } else { |
100 | auxio_set_led(AUXIO_LED_OFF); |
101 | } |
102 | |
103 | kfree(objp: buf); |
104 | |
105 | return count; |
106 | } |
107 | |
108 | static const struct proc_ops led_proc_ops = { |
109 | .proc_open = led_proc_open, |
110 | .proc_read = seq_read, |
111 | .proc_lseek = seq_lseek, |
112 | .proc_release = single_release, |
113 | .proc_write = led_proc_write, |
114 | }; |
115 | #endif |
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 | #ifdef CONFIG_PROC_FS |
124 | if (!proc_create(name: "led" , mode: 0, NULL, proc_ops: &led_proc_ops)) |
125 | return -ENOMEM; |
126 | #endif |
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(timer: &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 | |