Implement GPIO interrupt debouncing on ep93xx.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>

Index: linux-2.6.22/arch/arm/mach-ep93xx/core.c
===================================================================
--- linux-2.6.22.orig/arch/arm/mach-ep93xx/core.c
+++ linux-2.6.22/arch/arm/mach-ep93xx/core.c
@@ -154,6 +154,7 @@ struct sys_timer ep93xx_timer = {
  *************************************************************************/
 static unsigned char gpio_int_unmasked[3];
 static unsigned char gpio_int_enabled[3];
+static unsigned char gpio_int_debounce[3];
 static unsigned char gpio_int_type1[3];
 static unsigned char gpio_int_type2[3];
 
@@ -161,16 +162,19 @@ static void update_gpio_int_params(int a
 {
 	if (abf == 0) {
 		__raw_writeb(0, EP93XX_GPIO_A_INT_ENABLE);
+		__raw_writeb(gpio_int_debounce[0], EP93XX_GPIO_A_INT_DEBOUNCE);
 		__raw_writeb(gpio_int_type2[0], EP93XX_GPIO_A_INT_TYPE2);
 		__raw_writeb(gpio_int_type1[0], EP93XX_GPIO_A_INT_TYPE1);
 		__raw_writeb(gpio_int_unmasked[0] & gpio_int_enabled[0], EP93XX_GPIO_A_INT_ENABLE);
 	} else if (abf == 1) {
 		__raw_writeb(0, EP93XX_GPIO_B_INT_ENABLE);
+		__raw_writeb(gpio_int_debounce[1], EP93XX_GPIO_B_INT_DEBOUNCE);
 		__raw_writeb(gpio_int_type2[1], EP93XX_GPIO_B_INT_TYPE2);
 		__raw_writeb(gpio_int_type1[1], EP93XX_GPIO_B_INT_TYPE1);
 		__raw_writeb(gpio_int_unmasked[1] & gpio_int_enabled[1], EP93XX_GPIO_B_INT_ENABLE);
 	} else if (abf == 2) {
 		__raw_writeb(0, EP93XX_GPIO_F_INT_ENABLE);
+		__raw_writeb(gpio_int_debounce[2], EP93XX_GPIO_F_INT_DEBOUNCE);
 		__raw_writeb(gpio_int_type2[2], EP93XX_GPIO_F_INT_TYPE2);
 		__raw_writeb(gpio_int_type1[2], EP93XX_GPIO_F_INT_TYPE1);
 		__raw_writeb(gpio_int_unmasked[2] & gpio_int_enabled[2], EP93XX_GPIO_F_INT_ENABLE);
@@ -361,6 +365,13 @@ static int ep93xx_gpio_irq_type(unsigned
 	} else {
 		gpio_int_enabled[port] &= ~(1 << line);
 	}
+
+	if (type & IRQ_TYPE_DEBOUNCE) {
+		gpio_int_debounce[port] |= 1 << line;
+	} else {
+		gpio_int_debounce[port] &= ~(1 << line);
+	}
+
 	update_gpio_int_params(port);
 
 	return 0;
Index: linux-2.6.22/include/asm-arm/arch-ep93xx/ep93xx-regs.h
===================================================================
--- linux-2.6.22.orig/include/asm-arm/arch-ep93xx/ep93xx-regs.h
+++ linux-2.6.22/include/asm-arm/arch-ep93xx/ep93xx-regs.h
@@ -78,16 +78,19 @@
 #define EP93XX_GPIO_F_INT_ACK		EP93XX_GPIO_REG(0x54)
 #define EP93XX_GPIO_F_INT_ENABLE	EP93XX_GPIO_REG(0x58)
 #define EP93XX_GPIO_F_INT_STATUS	EP93XX_GPIO_REG(0x5c)
+#define EP93XX_GPIO_F_INT_DEBOUNCE	EP93XX_GPIO_REG(0x64)
 #define EP93XX_GPIO_A_INT_TYPE1		EP93XX_GPIO_REG(0x90)
 #define EP93XX_GPIO_A_INT_TYPE2		EP93XX_GPIO_REG(0x94)
 #define EP93XX_GPIO_A_INT_ACK		EP93XX_GPIO_REG(0x98)
 #define EP93XX_GPIO_A_INT_ENABLE	EP93XX_GPIO_REG(0x9c)
 #define EP93XX_GPIO_A_INT_STATUS	EP93XX_GPIO_REG(0xa0)
+#define EP93XX_GPIO_A_INT_DEBOUNCE	EP93XX_GPIO_REG(0xa8)
 #define EP93XX_GPIO_B_INT_TYPE1		EP93XX_GPIO_REG(0xac)
 #define EP93XX_GPIO_B_INT_TYPE2		EP93XX_GPIO_REG(0xb0)
 #define EP93XX_GPIO_B_INT_ACK		EP93XX_GPIO_REG(0xb4)
 #define EP93XX_GPIO_B_INT_ENABLE	EP93XX_GPIO_REG(0xb8)
 #define EP93XX_GPIO_B_INT_STATUS	EP93XX_GPIO_REG(0xbc)
+#define EP93XX_GPIO_B_INT_DEBOUNCE	EP93XX_GPIO_REG(0xc4)
 
 #define EP93XX_AAC_BASE			(EP93XX_APB_VIRT_BASE + 0x00080000)
 
Index: linux-2.6.22/include/linux/irq.h
===================================================================
--- linux-2.6.22.orig/include/linux/irq.h
+++ linux-2.6.22/include/linux/irq.h
@@ -44,6 +44,7 @@ typedef	void fastcall (*irq_flow_handler
 #define IRQ_TYPE_LEVEL_LOW	0x00000008	/* Level low type */
 #define IRQ_TYPE_SENSE_MASK	0x0000000f	/* Mask of the above */
 #define IRQ_TYPE_PROBE		0x00000010	/* Probing in progress */
+#define IRQ_TYPE_DEBOUNCE	0x00000020	/* Enable HW debounce */
 
 /* Internal flags */
 #define IRQ_INPROGRESS		0x00000100	/* IRQ handler active - do not enter! */