leds: convert IDE trigger to common disk trigger

This patch converts the IDE specific LED trigger to a generic disk
activity LED trigger. The libata core is now a trigger source just
like before the IDE disk driver. It's merely a replacement of the
string ide by disk.

The patch is taken from http://dev.gentoo.org/~josejx/ata.patch and is
widely used by any ibook/powerbook owners with great satisfaction.
Likewise, it is very often used successfully on different ARM platforms.

Unlike the original patch, the existing 'ide-disk' trigger is still
available for backward compatibility. That reduce the amount of patches
in affected device trees out of the mainline kernel. For further
development, the new name 'disk-activity' should be used.

Cc: Joseph Jezak <[e-mail]>
Cc: Jörg Sommer <[e-mail]>
Cc: Richard Purdie <[e-mail]>
Signed-off-by: Stephan Linz <[e-mail]>
Signed-off-by: Jacek Anaszewski <[e-mail]>

drivers/ata/libata-core.c

···
 #include <asm/unaligned.h>
 #include <linux/cdrom.h>
 #include <linux/ratelimit.h>
+#include <linux/leds.h>
 #include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 
···
 void ata_qc_complete(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;
+
+	/* Trigger the LED (if available) */
+	ledtrig_disk_activity();
 
 	/* XXX: New EH and old EH use different mechanisms to
 	 * synchronize EH with regular execution path.

drivers/ide/ide-disk.c

···
 	BUG_ON(drive->dev_flags & IDE_DFLAG_BLOCKED);
 	BUG_ON(rq->cmd_type != REQ_TYPE_FS);
 
-	ledtrig_ide_activity();
+	ledtrig_disk_activity();
 
 	pr_debug("%s: %sing: block=%llu, sectors=%u\n",
 		 drive->name, rq_data_dir(rq) == READ ? "read" : "writ",

drivers/leds/leds-hp6xx.c

···
 
 static struct led_classdev hp6xx_green_led = {
 	.name			= "hp6xx:green",
-	.default_trigger	= "ide-disk",
+	.default_trigger	= "disk-activity",
 	.brightness_set		= hp6xxled_green_set,
 	.flags			= LED_CORE_SUSPENDRESUME,
 };

drivers/leds/trigger/Kconfig

···
 
 	  If unsure, say Y.
 
-config LEDS_TRIGGER_IDE_DISK
-	bool "LED IDE Disk Trigger"
-	depends on IDE_GD_ATA
+config LEDS_TRIGGER_DISK
+	bool "LED Disk Trigger"
+	depends on IDE_GD_ATA || ATA
 	depends on LEDS_TRIGGERS
 	help
-	  This allows LEDs to be controlled by IDE disk activity.
+	  This allows LEDs to be controlled by disk activity.
 	  If unsure, say Y.
 
 config LEDS_TRIGGER_MTD

drivers/leds/trigger/Makefile

···
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o
 obj-$(CONFIG_LEDS_TRIGGER_ONESHOT)	+= ledtrig-oneshot.o
-obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)	+= ledtrig-ide-disk.o
+obj-$(CONFIG_LEDS_TRIGGER_DISK)		+= ledtrig-disk.o
 obj-$(CONFIG_LEDS_TRIGGER_MTD)		+= ledtrig-mtd.o
 obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT)	+= ledtrig-heartbeat.o
 obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT)	+= ledtrig-backlight.o

drivers/leds/trigger/ledtrig-ide-disk.c drivers/leds/trigger/ledtrig-disk.c

···
 /*
- * LED IDE-Disk Activity Trigger
+ * LED Disk Activity Trigger
  *
  * Copyright 2006 Openedhand Ltd.
  *
···
 
 #define BLINK_DELAY 30
 
+DEFINE_LED_TRIGGER(ledtrig_disk);
 DEFINE_LED_TRIGGER(ledtrig_ide);
 
-void ledtrig_ide_activity(void)
+void ledtrig_disk_activity(void)
 {
-	unsigned long ide_blink_delay = BLINK_DELAY;
+	unsigned long blink_delay = BLINK_DELAY;
 
+	led_trigger_blink_oneshot(ledtrig_disk,
+				  &blink_delay, &blink_delay, 0);
 	led_trigger_blink_oneshot(ledtrig_ide,
-				  &ide_blink_delay, &ide_blink_delay, 0);
+				  &blink_delay, &blink_delay, 0);
 }
-EXPORT_SYMBOL(ledtrig_ide_activity);
+EXPORT_SYMBOL(ledtrig_disk_activity);
 
-static int __init ledtrig_ide_init(void)
+static int __init ledtrig_disk_init(void)
 {
+	led_trigger_register_simple("disk-activity", &ledtrig_disk);
 	led_trigger_register_simple("ide-disk", &ledtrig_ide);
+
 	return 0;
 }
-device_initcall(ledtrig_ide_init);
+device_initcall(ledtrig_disk_init);

include/linux/leds.h

···
 #endif /* CONFIG_LEDS_TRIGGERS */
 
 /* Trigger specific functions */
-#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
-extern void ledtrig_ide_activity(void);
+#ifdef CONFIG_LEDS_TRIGGER_DISK
+extern void ledtrig_disk_activity(void);
 #else
-static inline void ledtrig_ide_activity(void) {}
+static inline void ledtrig_disk_activity(void) {}
 #endif
 
 #ifdef CONFIG_LEDS_TRIGGER_MTD