[PATCH] genirq: add SA_TRIGGER support

Enable drivers to request an IRQ with a given irq-flow (trigger/polarity)
setting.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 3ed7aee..627d401 100644 (file)
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -225,8 +225,14 @@ int setup_irq(unsigned int irq, struct irqaction *new)
        p = &desc->action;
        old = *p;
        if (old) {
-               /* 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 (level, edge, polarity). So both flag
+                * fields must have SA_SHIRQ set and the bits which
+                * set the trigger type must match.
+                */
+               if (!((old->flags & new->flags) & SA_SHIRQ) ||
+                   ((old->flags ^ new->flags) & SA_TRIGGER_MASK))
                        goto mismatch;
 
 #if defined(CONFIG_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
@@ -250,7 +256,22 @@ int setup_irq(unsigned int irq, struct irqaction *new)
 #endif
        if (!shared) {
                irq_chip_set_defaults(desc->chip);
-               compat_irq_chip_set_default_handler(desc);
+
+               /* Setup the type (level, edge polarity) if configured: */
+               if (new->flags & SA_TRIGGER_MASK) {
+                       if (desc->chip && desc->chip->set_type)
+                               desc->chip->set_type(irq,
+                                               new->flags & SA_TRIGGER_MASK);
+                       else
+                               /*
+                                * SA_TRIGGER_* but the PIC does not support
+                                * multiple flow-types?
+                                */
+                               printk(KERN_WARNING "setup_irq(%d) SA_TRIGGER"
+                                      "set. No set_type function available\n",
+                                      irq);
+               } else
+                       compat_irq_chip_set_default_handler(desc);
 
                desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
                                  IRQ_INPROGRESS);
@@ -262,7 +283,9 @@ int setup_irq(unsigned int irq, struct irqaction *new)
                                desc->chip->startup(irq);
                        else
                                desc->chip->enable(irq);
-               }
+               } else
+                       /* Undo nested disables: */
+                       desc->depth = 1;
        }
        spin_unlock_irqrestore(&desc->lock, flags);