[PATCH] ARM: 2744/1: ixp2000 gpio irq support

Patch from Lennert Buytenhek

This patch cleans up the ixp2000 gpio irq code and implements the
set_irq_type method for gpio irqs so that users can select for which
events (falling edge/rising edge/level low/level high) on the gpio
pin they want the corresponding gpio irq to be triggered.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 67 insertions, 18 deletions

diff --git a/arch/arm/mach-ixp2000/core.c b/arch/arm/mach-ixp2000/core.c
index fc0555596d6..0ee34acb8d7 100644
--- a/arch/arm/mach-ixp2000/core.c
+++ b/arch/arm/mach-ixp2000/core.c
@@ -40,6 +40,8 @@
 #include <asm/mach/time.h>
 #include <asm/mach/irq.h>
 
+#include <asm/arch/gpio.h>
+
 static DEFINE_SPINLOCK(ixp2000_slowport_lock);
 static unsigned long ixp2000_slowport_irq_flags;
 
@@ -179,7 +181,7 @@ static int ixp2000_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 
 	/* clear timer 1 */
 	ixp2000_reg_write(IXP2000_T1_CLR, 1);
-	
+
 	while ((next_jiffy_time - *missing_jiffy_timer_csr) > ticks_per_jiffy) {
 		timer_tick(regs);
 		next_jiffy_time -= ticks_per_jiffy;
@@ -238,35 +240,40 @@ void __init ixp2000_init_time(unsigned long tick_rate)
 /*************************************************************************
  * GPIO helpers
  *************************************************************************/
-static unsigned long GPIO_IRQ_rising_edge;
 static unsigned long GPIO_IRQ_falling_edge;
+static unsigned long GPIO_IRQ_rising_edge;
 static unsigned long GPIO_IRQ_level_low;
 static unsigned long GPIO_IRQ_level_high;
 
-void gpio_line_config(int line, int style)
+static void update_gpio_int_csrs(void)
+{
+	ixp2000_reg_write(IXP2000_GPIO_FEDR, GPIO_IRQ_falling_edge);
+	ixp2000_reg_write(IXP2000_GPIO_REDR, GPIO_IRQ_rising_edge);
+	ixp2000_reg_write(IXP2000_GPIO_LSLR, GPIO_IRQ_level_low);
+	ixp2000_reg_write(IXP2000_GPIO_LSHR, GPIO_IRQ_level_high);
+}
+
+void gpio_line_config(int line, int direction)
 {
 	unsigned long flags;
 
 	local_irq_save(flags);
+	if (direction == GPIO_OUT) {
+		irq_desc[line + IRQ_IXP2000_GPIO0].valid = 0;
 
-	if(style == GPIO_OUT) {
 		/* if it's an output, it ain't an interrupt anymore */
-		ixp2000_reg_write(IXP2000_GPIO_PDSR, (1 << line));
 		GPIO_IRQ_falling_edge &= ~(1 << line);
 		GPIO_IRQ_rising_edge &= ~(1 << line);
 		GPIO_IRQ_level_low &= ~(1 << line);
 		GPIO_IRQ_level_high &= ~(1 << line);
-		ixp2000_reg_write(IXP2000_GPIO_FEDR, GPIO_IRQ_falling_edge);
-		ixp2000_reg_write(IXP2000_GPIO_REDR, GPIO_IRQ_rising_edge);
-		ixp2000_reg_write(IXP2000_GPIO_LSHR, GPIO_IRQ_level_high);
-		ixp2000_reg_write(IXP2000_GPIO_LSLR, GPIO_IRQ_level_low);
-		irq_desc[line+IRQ_IXP2000_GPIO0].valid = 0;
-	} else if(style == GPIO_IN) {
-		ixp2000_reg_write(IXP2000_GPIO_PDCR, (1 << line));
+		update_gpio_int_csrs();
+
+		ixp2000_reg_write(IXP2000_GPIO_PDSR, 1 << line);
+	} else if (direction == GPIO_IN) {
+		ixp2000_reg_write(IXP2000_GPIO_PDCR, 1 << line);
 	}
-		
 	local_irq_restore(flags);
-}	
+}
 
 
 /*************************************************************************
@@ -285,9 +292,50 @@ static void ixp2000_GPIO_irq_handler(unsigned int irq, struct irqdesc *desc, str
 	}
 }
 
+static int ixp2000_GPIO_irq_type(unsigned int irq, unsigned int type)
+{
+	int line = irq - IRQ_IXP2000_GPIO0;
+
+	/*
+	 * First, configure this GPIO line as an input.
+	 */
+	ixp2000_reg_write(IXP2000_GPIO_PDCR, 1 << line);
+
+	/*
+	 * Then, set the proper trigger type.
+	 */
+	if (type & IRQT_FALLING)
+		GPIO_IRQ_falling_edge |= 1 << line;
+	else
+		GPIO_IRQ_falling_edge &= ~(1 << line);
+	if (type & IRQT_RISING)
+		GPIO_IRQ_rising_edge |= 1 << line;
+	else
+		GPIO_IRQ_rising_edge &= ~(1 << line);
+	if (type & IRQT_LOW)
+		GPIO_IRQ_level_low |= 1 << line;
+	else
+		GPIO_IRQ_level_low &= ~(1 << line);
+	if (type & IRQT_HIGH)
+		GPIO_IRQ_level_high |= 1 << line;
+	else
+		GPIO_IRQ_level_high &= ~(1 << line);
+	update_gpio_int_csrs();
+
+	/*
+	 * Finally, mark the corresponding IRQ as valid.
+	 */
+	irq_desc[irq].valid = 1;
+
+	return 0;
+}
+
 static void ixp2000_GPIO_irq_mask_ack(unsigned int irq)
 {
 	ixp2000_reg_write(IXP2000_GPIO_INCR, (1 << (irq - IRQ_IXP2000_GPIO0)));
+
+	ixp2000_reg_write(IXP2000_GPIO_EDSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
+	ixp2000_reg_write(IXP2000_GPIO_LDSR, (1 << (irq - IRQ_IXP2000_GPIO0)));
 	ixp2000_reg_write(IXP2000_GPIO_INST, (1 << (irq - IRQ_IXP2000_GPIO0)));
 }
 
@@ -302,6 +350,7 @@ static void ixp2000_GPIO_irq_unmask(unsigned int irq)
 }
 
 static struct irqchip ixp2000_GPIO_irq_chip = {
+	.type	= ixp2000_GPIO_irq_type,
 	.ack	= ixp2000_GPIO_irq_mask_ack,
 	.mask	= ixp2000_GPIO_irq_mask,
 	.unmask	= ixp2000_GPIO_irq_unmask
@@ -338,7 +387,7 @@ static void ixp2000_irq_mask(unsigned int irq)
 
 static void ixp2000_irq_unmask(unsigned int irq)
 {
-	ixp2000_reg_write(IXP2000_IRQ_ENABLE_SET,  (1 << irq));
+	ixp2000_reg_write(IXP2000_IRQ_ENABLE_SET, (1 << irq));
 }
 
 static struct irqchip ixp2000_irq_chip = {
@@ -375,16 +424,16 @@ void __init ixp2000_init_irq(void)
 	 * our mask/unmask code much simpler.
 	 */
 	for (irq = IRQ_IXP2000_SOFT_INT; irq <= IRQ_IXP2000_THDB3; irq++) {
-		if((1 << irq) & IXP2000_VALID_IRQ_MASK) {
+		if ((1 << irq) & IXP2000_VALID_IRQ_MASK) {
 			set_irq_chip(irq, &ixp2000_irq_chip);
 			set_irq_handler(irq, do_level_IRQ);
 			set_irq_flags(irq, IRQF_VALID);
 		} else set_irq_flags(irq, 0);
 	}
-	
+
 	/*
 	 * GPIO IRQs are invalid until someone sets the interrupt mode
-	 * by calling gpio_line_set();
+	 * by calling set_irq_type().
 	 */
 	for (irq = IRQ_IXP2000_GPIO0; irq <= IRQ_IXP2000_GPIO7; irq++) {
 		set_irq_chip(irq, &ixp2000_GPIO_irq_chip);