[ARM] 4768/2: ixp4xx: Button and LED updates for the nas100d board

 * Convert GPIO and IRQ handling to use the <asm/gpio.h> api.
 * Perform the reset only after the power button has been held down
   for at least two seconds.  Do the reset on the release of the power
   button, so that NAS devices which have been set to auto-power-on (by
   solder bridging the power button) do not continuously power cycle.
 * Remove all superflous constants from nas100d.h
 * Add LED constants to nas100d.h while we're there.
 * Update the board LED setup code to use those constants.
Signed-off-by: Rod Whitby <rod@whitby.id.au>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-ixp4xx/nas100d-power.c

@@ -21,15 +21,59 @@
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/reboot.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
 
+#include <asm/gpio.h>
 #include <asm/mach-types.h>
 
-static irqreturn_t nas100d_reset_handler(int irq, void *dev_id)
+/* This is used to make sure the power-button pusher is serious.  The button
+ * must be held until the value of this counter reaches zero.
+ */
+static int power_button_countdown;
+
+/* Must hold the button down for at least this many counts to be processed */
+#define PBUTTON_HOLDDOWN_COUNT 4 /* 2 secs */
+
+static void nas100d_power_handler(unsigned long data);
+static DEFINE_TIMER(nas100d_power_timer, nas100d_power_handler, 0, 0);
+
+static void nas100d_power_handler(unsigned long data)
 {
-	/* Signal init to do the ctrlaltdel action, this will bypass init if
-	 * it hasn't started and do a kernel_restart.
+	/* This routine is called twice per second to check the
+	 * state of the power button.
 	 */
-	ctrl_alt_del();
+
+	if (gpio_get_value(NAS100D_PB_GPIO)) {
+
+		/* IO Pin is 1 (button pushed) */
+		if (power_button_countdown > 0)
+			power_button_countdown--;
+
+	} else {
+
+		/* Done on button release, to allow for auto-power-on mods. */
+		if (power_button_countdown == 0) {
+			/* Signal init to do the ctrlaltdel action,
+			 * this will bypass init if it hasn't started
+			 * and do a kernel_restart.
+			 */
+			ctrl_alt_del();
+
+			/* Change the state of the power LED to "blink" */
+			gpio_line_set(NAS100D_LED_PWR_GPIO, IXP4XX_GPIO_LOW);
+		} else {
+			power_button_countdown = PBUTTON_HOLDDOWN_COUNT;
+		}
+	}
+
+	mod_timer(&nas100d_power_timer, jiffies + msecs_to_jiffies(500));
+}
+
+static irqreturn_t nas100d_reset_handler(int irq, void *dev_id)
+{
+	/* This is the paper-clip reset, it shuts the machine down directly. */
+	machine_power_off();
 
 	return IRQ_HANDLED;
 }
@@ -39,17 +83,30 @@ static int __init nas100d_power_init(void)
 	if (!(machine_is_nas100d()))
 		return 0;
 
-	set_irq_type(NAS100D_RB_IRQ, IRQT_LOW);
+	set_irq_type(gpio_to_irq(NAS100D_RB_GPIO), IRQT_LOW);
 
-	if (request_irq(NAS100D_RB_IRQ, &nas100d_reset_handler,
+	if (request_irq(gpio_to_irq(NAS100D_RB_GPIO), &nas100d_reset_handler,
 		IRQF_DISABLED, "NAS100D reset button", NULL) < 0) {
 
 		printk(KERN_DEBUG "Reset Button IRQ %d not available\n",
-			NAS100D_RB_IRQ);
+			gpio_to_irq(NAS100D_RB_GPIO));
 
 		return -EIO;
 	}
 
+	/* The power button on the Iomega NAS100d is on GPIO 14, but
+	 * it cannot handle interrupts on that GPIO line.  So we'll
+	 * have to poll it with a kernel timer.
+	 */
+
+	/* Make sure that the power button GPIO is set up as an input */
+	gpio_line_config(NAS100D_PB_GPIO, IXP4XX_GPIO_IN);
+
+	/* Set the initial value for the power button IRQ handler */
+	power_button_countdown = PBUTTON_HOLDDOWN_COUNT;
+
+	mod_timer(&nas100d_power_timer, jiffies + msecs_to_jiffies(500));
+
 	return 0;
 }
 
@@ -58,7 +115,9 @@ static void __exit nas100d_power_exit(void)
 	if (!(machine_is_nas100d()))
 		return;
 
-	free_irq(NAS100D_RB_IRQ, NULL);
+	del_timer_sync(&nas100d_power_timer);
+
+	free_irq(gpio_to_irq(NAS100D_RB_GPIO), NULL);
 }
 
 module_init(nas100d_power_init);

arch/arm/mach-ixp4xx/nas100d-setup.c

@@ -43,20 +43,20 @@ static struct platform_device nas100d_flash = {
 static struct resource nas100d_led_resources[] = {
 	{
 		.name		= "wlan",   /* green led */
-		.start		= 0,
-		.end		= 0,
+		.start		= NAS100D_LED_WLAN_GPIO,
+		.end		= NAS100D_LED_WLAN_GPIO,
 		.flags		= IXP4XX_GPIO_LOW,
 	},
 	{
-		.name		= "ready",  /* blue power led (off is flashing!) */
-		.start		= 15,
-		.end		= 15,
+		.name		= "power",  /* blue power led (off=flashing) */
+		.start		= NAS100D_LED_PWR_GPIO,
+		.end		= NAS100D_LED_PWR_GPIO,
 		.flags		= IXP4XX_GPIO_LOW,
 	},
 	{
 		.name		= "disk",   /* yellow led */
-		.start		= 3,
-		.end		= 3,
+		.start		= NAS100D_LED_DISK_GPIO,
+		.end		= NAS100D_LED_DISK_GPIO,
 		.flags		= IXP4XX_GPIO_LOW,
 	},
 };

include/asm-arm/arch-ixp4xx/nas100d.h

@@ -38,15 +38,15 @@
 
 /* Buttons */
 
-#define NAS100D_PB_GPIO         14
-#define NAS100D_RB_GPIO         4
+#define NAS100D_PB_GPIO         14   /* power button */
+#define NAS100D_RB_GPIO         4    /* reset button */
+
+/* Power control */
+
 #define NAS100D_PO_GPIO         12   /* power off */
 
-#define NAS100D_PB_IRQ          IRQ_IXP4XX_GPIO14
-#define NAS100D_RB_IRQ          IRQ_IXP4XX_GPIO4
+/* LEDs */
 
-/*
-#define NAS100D_PB_BM           (1L << NAS100D_PB_GPIO)
-#define NAS100D_PO_BM           (1L << NAS100D_PO_GPIO)
-#define NAS100D_RB_BM           (1L << NAS100D_RB_GPIO)
-*/
+#define NAS100D_LED_WLAN_GPIO	0
+#define NAS100D_LED_DISK_GPIO	3
+#define NAS100D_LED_PWR_GPIO	15