1 files changed, 146 insertions, 0 deletions
diff --git a/arch/sparc/kernel/led.c b/arch/sparc/kernel/led.c
new file mode 100644
index 000000000..ab657b359
--- /dev/null
+++ b/arch/sparc/kernel/led.c
@@ -0,0 +1,146 @@
+// 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);