linuxdebug/arch/sparc/kernel/led.c

147 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/uaccess.h>
#include <linux/sched/loadavg.h>
#include <asm/auxio.h>
#define LED_MAX_LENGTH 8 /* maximum chars written to proc file */
static inline void led_toggle(void)
{
unsigned char val = get_auxio();
unsigned char on, off;
if (val & AUXIO_LED) {
on = 0;
off = AUXIO_LED;
} else {
on = AUXIO_LED;
off = 0;
}
set_auxio(on, off);
}
static struct timer_list led_blink_timer;
static unsigned long led_blink_timer_timeout;
static void led_blink(struct timer_list *unused)
{
unsigned long timeout = led_blink_timer_timeout;
led_toggle();
/* reschedule */
if (!timeout) { /* blink according to load */
led_blink_timer.expires = jiffies +
((1 + (avenrun[0] >> FSHIFT)) * HZ);
} else { /* blink at user specified interval */
led_blink_timer.expires = jiffies + (timeout * HZ);
}
add_timer(&led_blink_timer);
}
#ifdef CONFIG_PROC_FS
static int led_proc_show(struct seq_file *m, void *v)
{
if (get_auxio() & AUXIO_LED)
seq_puts(m, "on\n");
else
seq_puts(m, "off\n");
return 0;
}
static int led_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, led_proc_show, NULL);
}
static ssize_t led_proc_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
char *buf = NULL;
if (count > LED_MAX_LENGTH)
count = LED_MAX_LENGTH;
buf = memdup_user_nul(buffer, count);
if (IS_ERR(buf))
return PTR_ERR(buf);
/* work around \n when echo'ing into proc */
if (buf[count - 1] == '\n')
buf[count - 1] = '\0';
/* before we change anything we want to stop any running timers,
* otherwise calls such as on will have no persistent effect
*/
del_timer_sync(&led_blink_timer);
if (!strcmp(buf, "on")) {
auxio_set_led(AUXIO_LED_ON);
} else if (!strcmp(buf, "toggle")) {
led_toggle();
} else if ((*buf > '0') && (*buf <= '9')) {
led_blink_timer_timeout = simple_strtoul(buf, NULL, 10);
led_blink(&led_blink_timer);
} else if (!strcmp(buf, "load")) {
led_blink_timer_timeout = 0;
led_blink(&led_blink_timer);
} else {
auxio_set_led(AUXIO_LED_OFF);
}
kfree(buf);
return count;
}
static const struct proc_ops led_proc_ops = {
.proc_open = led_proc_open,
.proc_read = seq_read,
.proc_lseek = seq_lseek,
.proc_release = single_release,
.proc_write = led_proc_write,
};
#endif
#define LED_VERSION "0.1"
static int __init led_init(void)
{
timer_setup(&led_blink_timer, led_blink, 0);
#ifdef CONFIG_PROC_FS
if (!proc_create("led", 0, NULL, &led_proc_ops))
return -ENOMEM;
#endif
printk(KERN_INFO
"led: version %s, Lars Kotthoff <metalhead@metalhead.ws>\n",
LED_VERSION);
return 0;
}
static void __exit led_exit(void)
{
remove_proc_entry("led", NULL);
del_timer_sync(&led_blink_timer);
}
module_init(led_init);
module_exit(led_exit);
MODULE_AUTHOR("Lars Kotthoff <metalhead@metalhead.ws>");
MODULE_DESCRIPTION("Provides control of the front LED on SPARC systems.");
MODULE_LICENSE("GPL");
MODULE_VERSION(LED_VERSION);