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authorHartley Sweeten <hartleys@visionengravers.com>2008-10-28 17:55:30 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-12-01 17:22:09 +0000
commit799a0600ac49b03c1a6244847c2725c0082ba775 (patch)
tree971e5b3529b09228b095feedc9eeb9e0734fa568 /arch/arm/mach-ep93xx
parentd52a26a956d3925c6eaf8770e95e4d5f13740696 (diff)
[ARM] 5324/2: ep93xx: support gpio interrupt debounce
Add debounce support for ep93xx gpio interrupts. On the EP93xx, GPIO ports A, B, and F can be used to generate interrupts. For each port, if interrupts are enabled, it is possible to debouce the input signal. Debouncing is implemented by passing the input signal through a 2-bit shift register clocked by a 128Hz clock. This patch adds a platform specific way to enable the debouce feature for these input ports. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-ep93xx')
-rw-r--r--arch/arm/mach-ep93xx/core.c18
-rw-r--r--arch/arm/mach-ep93xx/include/mach/gpio.h2
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index 61da67f31ce..4781f323703 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -155,12 +155,14 @@ static unsigned char gpio_int_unmasked[3];
static unsigned char gpio_int_enabled[3];
static unsigned char gpio_int_type1[3];
static unsigned char gpio_int_type2[3];
+static unsigned char gpio_int_debouce[3];
/* Port ordering is: A B F */
static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
+static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
void ep93xx_gpio_update_int_params(unsigned port)
{
@@ -183,6 +185,22 @@ void ep93xx_gpio_int_mask(unsigned line)
gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
}
+void ep93xx_gpio_int_debounce(unsigned int irq, int enable)
+{
+ int line = irq_to_gpio(irq);
+ int port = line >> 3;
+ int port_mask = 1 << (line & 7);
+
+ if (enable)
+ gpio_int_debouce[port] |= port_mask;
+ else
+ gpio_int_debouce[port] &= ~port_mask;
+
+ __raw_writeb(gpio_int_debouce[port],
+ EP93XX_GPIO_REG(int_debounce_register_offset[port]));
+}
+EXPORT_SYMBOL(ep93xx_gpio_int_debounce);
+
/*************************************************************************
* EP93xx IRQ handling
*************************************************************************/
diff --git a/arch/arm/mach-ep93xx/include/mach/gpio.h b/arch/arm/mach-ep93xx/include/mach/gpio.h
index f7020414c5d..0a1498ae899 100644
--- a/arch/arm/mach-ep93xx/include/mach/gpio.h
+++ b/arch/arm/mach-ep93xx/include/mach/gpio.h
@@ -99,6 +99,8 @@
/* maximum value for irq capable line identifiers */
#define EP93XX_GPIO_LINE_MAX_IRQ EP93XX_GPIO_LINE_F(7)
+extern void ep93xx_gpio_int_debounce(unsigned int irq, int enable);
+
/* new generic GPIO API - see Documentation/gpio.txt */
#include <asm-generic/gpio.h>