macintosh/via-pmu-led: make disk activity usage a parameter.

Whether to use the LED as a disk activity is a user preference.
Some like this usage while others find the LED too bright. So it
might be a good idea to make this choice a runtime parameter rather
than compile-time config.

The default is set to disabled as OS X does not use the LED as a
disk activity indicator.

Signed-off-by: Hill Ma <maahiuzeon@gmail.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -250,6 +250,12 @@
 			Use timer override. For some broken Nvidia NF5 boards
 			that require a timer override, but don't have HPET
 
+	adb_pmu_led_disk [PPC]
+			Use front LED as disk LED by default. Only applies to
+			PowerBook, iBook, PowerMac 7,2/7,3.
+			Format: <bool>  (1/Y/y=enable, 0/N/n=disable)
+			Default: disabled
+
 	add_efi_memmap	[EFI; X86] Include EFI memory map in
 			kernel's map of available physical RAM.
 

drivers/macintosh/Kconfig

@@ -78,16 +78,6 @@ config ADB_PMU_LED
 	  behaviour of the old CONFIG_BLK_DEV_IDE_PMAC_BLINK, select this
 	  and the disk LED trigger and configure appropriately through sysfs.
 
-config ADB_PMU_LED_DISK
-	bool "Use front LED as DISK LED by default"
-	depends on ADB_PMU_LED
-	depends on LEDS_CLASS
-	select LEDS_TRIGGERS
-	select LEDS_TRIGGER_DISK
-	help
-	  This option makes the front LED default to the disk trigger
-	  so that it blinks on disk activity.
-
 config PMAC_SMU
 	bool "Support for SMU  based PowerMacs"
 	depends on PPC_PMAC64

drivers/macintosh/via-pmu-led.c

@@ -25,6 +25,7 @@
 #include <linux/leds.h>
 #include <linux/adb.h>
 #include <linux/pmu.h>
+#include <linux/moduleparam.h>
 #include <asm/prom.h>
 
 static spinlock_t pmu_blink_lock;
@@ -71,11 +72,10 @@ static void pmu_led_set(struct led_classdev *led_cdev,
  	spin_unlock_irqrestore(&pmu_blink_lock, flags);
 }
 
+int adb_pmu_led_disk;
+
 static struct led_classdev pmu_led = {
 	.name = "pmu-led::front",
-#ifdef CONFIG_ADB_PMU_LED_DISK
-	.default_trigger = "disk-activity",
-#endif
 	.brightness_set = pmu_led_set,
 };
 
@@ -106,6 +106,9 @@ static int __init via_pmu_led_init(void)
 	}
 	of_node_put(dt);
 
+	if (adb_pmu_led_disk)
+		pmu_led.default_trigger = "disk-activity";
+
 	spin_lock_init(&pmu_blink_lock);
 	/* no outstanding req */
 	pmu_blink_req.complete = 1;
@@ -114,4 +117,6 @@ static int __init via_pmu_led_init(void)
 	return led_classdev_register(NULL, &pmu_led);
 }
 
+core_param(adb_pmu_led_disk, adb_pmu_led_disk, bool, 0644);
+
 late_initcall(via_pmu_led_init);