// 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_FSstatic 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 (count > 0 && 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	 */	timer_delete_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);	timer_delete_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);