[PATCH] IRQ type flags

Some ARM platforms have the ability to program the interrupt controller to
detect various interrupt edges and/or levels.  For some platforms, this is
critical to setup correctly, particularly those which the setting is dependent
on the device.

Currently, ARM drivers do (eg) the following:

	err = request_irq(irq, ...);

	set_irq_type(irq, IRQT_RISING);

However, if the interrupt has previously been programmed to be level sensitive
(for whatever reason) then this will cause an interrupt storm.

Hence, if we combine set_irq_type() with request_irq(), we can then safely set
the type prior to unmasking the interrupt.  The unfortunate problem is that in
order to support this, these flags need to be visible outside of the ARM
architecture - drivers such as smc91x need these flags and they're
cross-architecture.

Finally, the SA_TRIGGER_* flag passed to request_irq() should reflect the
property that the device would like.  The IRQ controller code should do its
best to select the most appropriate supported mode.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

6 files changed, 25 insertions, 19 deletions

diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 869c466..b5645c4 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -684,8 +684,12 @@ int setup_irq(unsigned int irq, struct irqaction *new)
 	spin_lock_irqsave(&irq_controller_lock, flags);
 	p = &desc->action;
 	if ((old = *p) != NULL) {
-		/* Can't share interrupts unless both agree to */
-		if (!(old->flags & new->flags & SA_SHIRQ)) {
+		/*
+		 * Can't share interrupts unless both agree to and are
+		 * the same type.
+		 */
+		if (!(old->flags & new->flags & SA_SHIRQ) ||
+		    (~old->flags & new->flags) & SA_TRIGGER_MASK) {
 			spin_unlock_irqrestore(&irq_controller_lock, flags);
 			return -EBUSY;
 		}
@@ -705,6 +709,12 @@ int setup_irq(unsigned int irq, struct irqaction *new)
 		desc->running = 0;
 		desc->pending = 0;
 		desc->disable_depth = 1;
+
+		if (new->flags & SA_TRIGGER_MASK) {
+			unsigned int type = new->flags & SA_TRIGGER_MASK;
+			desc->chip->set_type(irq, type);
+		}
+
 		if (!desc->noautoenable) {
 			desc->disable_depth = 0;
 			desc->chip->unmask(irq);
diff --git a/arch/arm/mach-omap1/serial.c b/arch/arm/mach-omap1/serial.c
index fcfb81d..7a68f09 100644
--- a/arch/arm/mach-omap1/serial.c
+++ b/arch/arm/mach-omap1/serial.c
@@ -252,9 +252,8 @@ static void __init omap_serial_set_port_wakeup(int gpio_nr)
 		return;
 	}
 	omap_set_gpio_direction(gpio_nr, 1);
-	set_irq_type(OMAP_GPIO_IRQ(gpio_nr), IRQT_RISING);
 	ret = request_irq(OMAP_GPIO_IRQ(gpio_nr), &omap_serial_wake_interrupt,
-			  0, "serial wakeup", NULL);
+			  SA_TRIGGER_RISING, "serial wakeup", NULL);
 	if (ret) {
 		omap_free_gpio(gpio_nr);
 		printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",
diff --git a/arch/arm/mach-pxa/corgi.c b/arch/arm/mach-pxa/corgi.c
index 100fb31..5a7b873 100644
--- a/arch/arm/mach-pxa/corgi.c
+++ b/arch/arm/mach-pxa/corgi.c
@@ -213,15 +213,14 @@ static int corgi_mci_init(struct device *dev, irqreturn_t (*corgi_detect_int)(in
 
 	corgi_mci_platform_data.detect_delay = msecs_to_jiffies(250);
 
-	err = request_irq(CORGI_IRQ_GPIO_nSD_DETECT, corgi_detect_int, SA_INTERRUPT,
-			     "MMC card detect", data);
+	err = request_irq(CORGI_IRQ_GPIO_nSD_DETECT, corgi_detect_int,
+			  SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+			  "MMC card detect", data);
 	if (err) {
 		printk(KERN_ERR "corgi_mci_init: MMC/SD: can't request MMC card detect IRQ\n");
 		return -1;
 	}
 
-	set_irq_type(CORGI_IRQ_GPIO_nSD_DETECT, IRQT_BOTHEDGE);
-
 	return 0;
 }
 
diff --git a/arch/arm/mach-pxa/poodle.c b/arch/arm/mach-pxa/poodle.c
index eef3de2..663c950 100644
--- a/arch/arm/mach-pxa/poodle.c
+++ b/arch/arm/mach-pxa/poodle.c
@@ -146,15 +146,14 @@ static int poodle_mci_init(struct device *dev, irqreturn_t (*poodle_detect_int)(
 
 	poodle_mci_platform_data.detect_delay = msecs_to_jiffies(250);
 
-	err = request_irq(POODLE_IRQ_GPIO_nSD_DETECT, poodle_detect_int, SA_INTERRUPT,
-			     "MMC card detect", data);
+	err = request_irq(POODLE_IRQ_GPIO_nSD_DETECT, poodle_detect_int,
+			  SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+			  "MMC card detect", data);
 	if (err) {
 		printk(KERN_ERR "poodle_mci_init: MMC/SD: can't request MMC card detect IRQ\n");
 		return -1;
 	}
 
-	set_irq_type(POODLE_IRQ_GPIO_nSD_DETECT, IRQT_BOTHEDGE);
-
 	return 0;
 }
 
diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index f2007db..a9eacc0 100644
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -296,15 +296,14 @@ static int spitz_mci_init(struct device *dev, irqreturn_t (*spitz_detect_int)(in
 
 	spitz_mci_platform_data.detect_delay = msecs_to_jiffies(250);
 
-	err = request_irq(SPITZ_IRQ_GPIO_nSD_DETECT, spitz_detect_int, SA_INTERRUPT,
-			     "MMC card detect", data);
+	err = request_irq(SPITZ_IRQ_GPIO_nSD_DETECT, spitz_detect_int,
+			  SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+			  "MMC card detect", data);
 	if (err) {
 		printk(KERN_ERR "spitz_mci_init: MMC/SD: can't request MMC card detect IRQ\n");
 		return -1;
 	}
 
-	set_irq_type(SPITZ_IRQ_GPIO_nSD_DETECT, IRQT_BOTHEDGE);
-
 	return 0;
 }
 
diff --git a/arch/arm/mach-s3c2410/usb-simtec.c b/arch/arm/mach-s3c2410/usb-simtec.c
index 5098b50..495f8c6 100644
--- a/arch/arm/mach-s3c2410/usb-simtec.c
+++ b/arch/arm/mach-s3c2410/usb-simtec.c
@@ -84,13 +84,13 @@ static void usb_simtec_enableoc(struct s3c2410_hcd_info *info, int on)
 	int ret;
 
 	if (on) {
-		ret = request_irq(IRQ_USBOC, usb_simtec_ocirq, SA_INTERRUPT,
+		ret = request_irq(IRQ_USBOC, usb_simtec_ocirq,
+				  SA_INTERRUPT | SA_TRIGGER_RISING |
+				   SA_TRIGGER_FALLING,
 				  "USB Over-current", info);
 		if (ret != 0) {
 			printk(KERN_ERR "failed to request usb oc irq\n");
 		}
-
-		set_irq_type(IRQ_USBOC, IRQT_BOTHEDGE);
 	} else {
 		free_irq(IRQ_USBOC, info);
 	}