[ARM] Add system device for LEDs.

This allows us to make the suspend/resume handling local to the LEDs
code itself, rather than being scattered in several files.

arch/arm/kernel/pm.c

@@ -15,7 +15,6 @@
 #include <linux/errno.h>
 #include <linux/sched.h>
 
-#include <asm/leds.h>
 #include <asm/system.h>
 
 /*
@@ -42,15 +41,11 @@ int suspend(void)
 		goto resume_legacy;
 
 	local_irq_disable();
-	leds_event(led_stop);
-
 	sysdev_suspend(3);
 
 	ret = pm_do_suspend();
 
 	sysdev_resume();
-
-	leds_event(led_start);
 	local_irq_enable();
 
 	device_resume();

arch/arm/kernel/process.c

@@ -117,12 +117,10 @@ __setup("reboot=", reboot_setup);
 
 void machine_halt(void)
 {
-	leds_event(led_halted);
 }
 
 void machine_power_off(void)
 {
-	leds_event(led_halted);
 	if (pm_power_off)
 		pm_power_off();
 }

arch/arm/kernel/time.c

@@ -26,6 +26,7 @@
 #include <linux/timex.h>
 #include <linux/errno.h>
 #include <linux/profile.h>
+#include <linux/sysdev.h>
 
 #include <asm/hardware.h>
 #include <asm/io.h>
@@ -72,8 +73,6 @@ unsigned long (*gettimeoffset)(void) = dummy_gettimeoffset;
  */
 unsigned long long sched_clock(void)
 {
-	unsigned long long this_offset;
-
 	return (unsigned long long)jiffies * (1000000000 / HZ);
 }
 
@@ -137,6 +136,47 @@ static void dummy_leds_event(led_event_t evt)
 
 void (*leds_event)(led_event_t) = dummy_leds_event;
 
+static int leds_suspend(struct sys_device *dev, u32 state)
+{
+	leds_event(led_stop);
+	return 0;
+}
+
+static int leds_resume(struct sys_device *dev)
+{
+	leds_event(led_start);
+	return 0;
+}
+
+static int leds_shutdown(struct sys_device *dev)
+{
+	leds_event(led_halted);
+	return 0;
+}
+
+static struct sysdev_class leds_sysclass = {
+	set_kset_name("leds"),
+	.shutdown	= leds_shutdown,
+	.suspend	= leds_suspend,
+	.resume		= leds_resume,
+};
+
+static struct sys_device leds_device = {
+	.id		= 0,
+	.cls		= &leds_sysclass,
+};
+
+static int __init leds_init(void)
+{
+	int ret;
+	ret = sysdev_class_register(&leds_sysclass);
+	if (ret == 0)
+		ret = sys_device_register(&leds_device);
+	return ret;
+}
+
+device_initcall(leds_init);
+
 EXPORT_SYMBOL(leds_event);
 #endif