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Commit 799a0600 authored by Hartley Sweeten's avatar Hartley Sweeten Committed by Russell King
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[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: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent d52a26a9

arch/arm/mach-ep93xx/core.c

+18 −0
Original line number Diff line number Diff line
@@ -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

 *************************************************************************/

arch/arm/mach-ep93xx/include/mach/gpio.h

+2 −0
Original line number Diff line number Diff line
@@ -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>