From 9ded96f24c3a5fcbef954e88c443385a1af37eb9 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 8 Jan 2006 01:02:07 -0800 Subject: [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/kernel/irq.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 869c466e625..b5645c4462c 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); -- cgit v1.2.3-18-g5258