[PATCH] ep93xx: implement gpiolib set_debounce for built-in GPIOs

GPIO Ports A, B, and F on the ep93xx provide interrupt capability.  It is
possible to debounce the input signal on these ports when interrupts are
enabled.

Support for this debounce capability was provided with an ep93xx internal
function.  Now that gpiolib knows about gpio debounce, use the gpiolib
method and do not export the internal function.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <redacted>

---

diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c
index bec34b8..a889fa7 100644
--- a/arch/arm/mach-ep93xx/gpio.c
+++ b/arch/arm/mach-ep93xx/gpio.c

@@ -61,7 +61,7 @@ static inline 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)
+static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
 {
 	int line = irq_to_gpio(irq);
 	int port = line >> 3;

@@ -75,7 +75,6 @@ void ep93xx_gpio_int_debounce(unsigned int irq, int enable)
 	__raw_writeb(gpio_int_debounce[port],
 		EP93XX_GPIO_REG(int_debounce_register_offset[port]));
 }
-EXPORT_SYMBOL(ep93xx_gpio_int_debounce);
 
 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
 {

@@ -335,6 +334,20 @@ static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 	local_irq_restore(flags);
 }
 
+static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
+				    unsigned offset, unsigned debounce)
+{
+	int gpio = chip->base + offset;
+	int irq = gpio_to_irq(gpio);
+
+	if (irq < 0)
+		return -EINVAL;
+
+	ep93xx_gpio_int_debounce(irq, debounce ? true : false);
+
+	return 0;
+}
+
 static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 {
 	struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);

@@ -434,6 +447,18 @@ void __init ep93xx_gpio_init(void)
 				 EP93XX_SYSCON_DEVCFG_GONIDE |
 				 EP93XX_SYSCON_DEVCFG_HONIDE);
 
-	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
-		gpiochip_add(&ep93xx_gpio_banks[i].chip);
+	for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
+		struct gpio_chip *chip = &ep93xx_gpio_banks[i].chip;
+
+		/*
+		 * Ports A, B, and F support input debouncing when
+		 * used as interrupts.
+		 */
+		if (!strcmp(chip->label, "A") ||
+		    !strcmp(chip->label, "B") ||
+		    !strcmp(chip->label, "F"))
+			chip->set_debounce = ep93xx_gpio_set_debounce;
+
+		gpiochip_add(chip);
+	}
 }

diff --git a/arch/arm/mach-ep93xx/include/mach/gpio.h b/arch/arm/mach-ep93xx/include/mach/gpio.h
index c991b14..c57152c 100644
--- a/arch/arm/mach-ep93xx/include/mach/gpio.h
+++ b/arch/arm/mach-ep93xx/include/mach/gpio.h

@@ -99,8 +99,6 @@
 /* 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>

On 01/27/2011 12:22 PM, H Hartley Sweeten wrote:

We should just move the code from ep93xx_gpio_int_debounce here. Why
have two functions to do one thing?

This could just be if *chip->label == 'A'. I don't really mind either way.

There don't appear to be any users of ep93xx_gpio_int_debounce anyway.
But with the above mentioned changes:

Acked-by: Ryan Mallon <redacted>

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

Ryan Mallon         		5 Amuri Park, 404 Barbadoes St
ryan at bluewatersys.com         	PO Box 13 889, Christchurch 8013
http://www.bluewatersys.com	New Zealand
Phone: +64 3 3779127		Freecall: Australia 1800 148 751
Fax:   +64 3 3779135			  USA 1800 261 2934

On Wednesday, January 26, 2011 4:48 PM, Ryan Mallon wrote:

On 01/27/2011 12:22 PM, H Hartley Sweeten wrote:

quoted

GPIO Ports A, B, and F on the ep93xx provide interrupt capability.  It is
possible to debounce the input signal on these ports when interrupts are
enabled.

Support for this debounce capability was provided with an ep93xx internal
function.  Now that gpiolib knows about gpio debounce, use the gpiolib
method and do not export the internal function.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <redacted>

---

diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c
index bec34b8..a889fa7 100644
--- a/arch/arm/mach-ep93xx/gpio.c
+++ b/arch/arm/mach-ep93xx/gpio.c

@@ -61,7 +61,7 @@ static inline 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)
+static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
 {
 	int line = irq_to_gpio(irq);
 	int port = line >> 3;

@@ -75,7 +75,6 @@ void ep93xx_gpio_int_debounce(unsigned int irq, int enable)
 	__raw_writeb(gpio_int_debounce[port],
 		EP93XX_GPIO_REG(int_debounce_register_offset[port]));
 }
-EXPORT_SYMBOL(ep93xx_gpio_int_debounce);
 
 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
 {

@@ -335,6 +334,20 @@ static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 	local_irq_restore(flags);
 }
 
+static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
+				    unsigned offset, unsigned debounce)
+{
+	int gpio = chip->base + offset;
+	int irq = gpio_to_irq(gpio);
+
+	if (irq < 0)
+		return -EINVAL;
+
+	ep93xx_gpio_int_debounce(irq, debounce ? true : false);

We should just move the code from ep93xx_gpio_int_debounce here. Why
have two functions to do one thing?

The reason I left the original function it that it messes with the cached gpio_int_debounce
values.  Also, the 'debounce' feature is interrupt specific.  If the gpio pin is no enabled
as an interrupt the debounce has no effect.  As such I figured it was cleaner to leave it
in place.

Would you still like me to combine the functions?

Regards,
Hartley

On 01/27/2011 12:59 PM, H Hartley Sweeten wrote:

On Wednesday, January 26, 2011 4:48 PM, Ryan Mallon wrote:

quoted

On 01/27/2011 12:22 PM, H Hartley Sweeten wrote:

quoted

GPIO Ports A, B, and F on the ep93xx provide interrupt capability.  It is
possible to debounce the input signal on these ports when interrupts are
enabled.

Support for this debounce capability was provided with an ep93xx internal
function.  Now that gpiolib knows about gpio debounce, use the gpiolib
method and do not export the internal function.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <redacted>

---

diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c
index bec34b8..a889fa7 100644
--- a/arch/arm/mach-ep93xx/gpio.c
+++ b/arch/arm/mach-ep93xx/gpio.c

@@ -61,7 +61,7 @@ static inline 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)
+static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
 {
 	int line = irq_to_gpio(irq);
 	int port = line >> 3;

@@ -75,7 +75,6 @@ void ep93xx_gpio_int_debounce(unsigned int irq, int enable)
 	__raw_writeb(gpio_int_debounce[port],
 		EP93XX_GPIO_REG(int_debounce_register_offset[port]));
 }
-EXPORT_SYMBOL(ep93xx_gpio_int_debounce);
 
 static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
 {

@@ -335,6 +334,20 @@ static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 	local_irq_restore(flags);
 }
 
+static int ep93xx_gpio_set_debounce(struct gpio_chip *chip,
+				    unsigned offset, unsigned debounce)
+{
+	int gpio = chip->base + offset;
+	int irq = gpio_to_irq(gpio);
+
+	if (irq < 0)
+		return -EINVAL;
+
+	ep93xx_gpio_int_debounce(irq, debounce ? true : false);

We should just move the code from ep93xx_gpio_int_debounce here. Why
have two functions to do one thing?

The reason I left the original function it that it messes with the cached gpio_int_debounce
values.  Also, the 'debounce' feature is interrupt specific.  If the gpio pin is no enabled
as an interrupt the debounce has no effect.  As such I figured it was cleaner to leave it
in place.

That's a valid reason. It is fine as is.

~Ryan

-- 
Bluewater Systems Ltd - ARM Technology Solution Centre

Ryan Mallon         		5 Amuri Park, 404 Barbadoes St
ryan at bluewatersys.com         	PO Box 13 889, Christchurch 8013
http://www.bluewatersys.com	New Zealand
Phone: +64 3 3779127		Freecall: Australia 1800 148 751
Fax:   +64 3 3779135			  USA 1800 261 2934