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Commit 3c9a071d authored by Herbert Valerio Riedel's avatar Herbert Valerio Riedel Committed by Russell King
Browse files

[ARM] 4670/1: ep93xx: implement IRQT_BOTHEDGE gpio irq sense type 



Having a both-edge sensitive irq trigger type is required for the
generic gpio-keys input driver; alas the ep93xx does not support
both-edge gpio triggers in hardware, so this patch implements them by
switching edge polarity on each triggered interrupt.  This is the same
approach as taken by the Orion SoC both-edge gpio irq support
implementation.

Signed-off-by: default avatarHerbert Valerio Riedel <hvr@gnu.org>
Acked-by: default avatarLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 7ca72253

arch/arm/mach-ep93xx/core.c

+53 −11
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * Core routines for Cirrus EP93xx chips.

 *

 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>

 * Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org>

 *

 * Thanks go to Michael Burian and Ray Lehtiniemi for their key

 * role in the ep93xx linux community.
@@ -315,12 +316,29 @@ static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc) 
	desc_handle_irq(gpio_irq, irq_desc + gpio_irq);

}



static void ep93xx_gpio_irq_ack(unsigned int irq)

{

	int line = irq_to_gpio(irq);

	int port = line >> 3;

	int port_mask = 1 << (line & 7);



	if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) {

		gpio_int_type2[port] ^= port_mask; /* switch edge direction */

		update_gpio_int_params(port);

	}



	__raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));

}



static void ep93xx_gpio_irq_mask_ack(unsigned int irq)

{

	int line = irq_to_gpio(irq);

	int port = line >> 3;

	int port_mask = 1 << (line & 7);



	if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE)

		gpio_int_type2[port] ^= port_mask; /* switch edge direction */



	gpio_int_unmasked[port] &= ~port_mask;

	update_gpio_int_params(port);
@@ -353,31 +371,54 @@ static void ep93xx_gpio_irq_unmask(unsigned int irq) 
 */

static int ep93xx_gpio_irq_type(unsigned int irq, unsigned int type)

{

	struct irq_desc *desc = irq_desc + irq;

	const int gpio = irq_to_gpio(irq);

	const int port = gpio >> 3;

	const int port_mask = 1 << (gpio & 7);



	ep93xx_gpio_set_direction(gpio, GPIO_IN);



	if (type & IRQT_RISING) {

		gpio_int_enabled[port] |= port_mask;

	switch (type) {

	case IRQT_RISING:

		gpio_int_type1[port] |= port_mask;

		gpio_int_type2[port] |= port_mask;

	} else if (type & IRQT_FALLING) {

		gpio_int_enabled[port] |= port_mask;

		desc->handle_irq = handle_edge_irq;

		break;

	case IRQT_FALLING:

		gpio_int_type1[port] |= port_mask;

		gpio_int_type2[port] &= ~port_mask;

	} else if (type & IRQT_HIGH) {

		gpio_int_enabled[port] |= port_mask;

		desc->handle_irq = handle_edge_irq;

		break;

	case IRQT_HIGH:

		gpio_int_type1[port] &= ~port_mask;

		gpio_int_type2[port] |= port_mask;

	} else if (type & IRQT_LOW) {

		gpio_int_enabled[port] |= port_mask;

		desc->handle_irq = handle_level_irq;

		break;

	case IRQT_LOW:

		gpio_int_type1[port] &= ~port_mask;

		gpio_int_type2[port] &= ~port_mask;

	} else {

		gpio_int_enabled[port] &= ~port_mask;

		desc->handle_irq = handle_level_irq;

		break;

	case IRQT_BOTHEDGE:

		gpio_int_type1[port] |= port_mask;

		/* set initial polarity based on current input level */

		if (gpio_get_value(gpio))

			gpio_int_type2[port] &= ~port_mask; /* falling */

		else

			gpio_int_type2[port] |= port_mask; /* rising */

		desc->handle_irq = handle_edge_irq;

		break;

	default:

		pr_err("ep93xx: failed to set irq type %d for gpio %d\n",

		       type, gpio);

		return -EINVAL;

	}



	gpio_int_enabled[port] |= port_mask;



	desc->status &= ~IRQ_TYPE_SENSE_MASK;

	desc->status |= type & IRQ_TYPE_SENSE_MASK;



	update_gpio_int_params(port);



	return 0;
@@ -385,7 +426,8 @@ static int ep93xx_gpio_irq_type(unsigned int irq, unsigned int type) 


static struct irq_chip ep93xx_gpio_irq_chip = {

	.name		= "GPIO",

	.ack		= ep93xx_gpio_irq_mask_ack,

	.ack		= ep93xx_gpio_irq_ack,

	.mask_ack	= ep93xx_gpio_irq_mask_ack,

	.mask		= ep93xx_gpio_irq_mask,

	.unmask		= ep93xx_gpio_irq_unmask,

	.set_type	= ep93xx_gpio_irq_type,