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-rw-r--r--arch/mn10300/kernel/irq.c71
1 files changed, 45 insertions, 26 deletions
diff --git a/arch/mn10300/kernel/irq.c b/arch/mn10300/kernel/irq.c
index 761c434a248..56c64ccc9c2 100644
--- a/arch/mn10300/kernel/irq.c
+++ b/arch/mn10300/kernel/irq.c
@@ -20,22 +20,8 @@ EXPORT_SYMBOL(__mn10300_irq_enabled_epsw);
atomic_t irq_err_count;
/*
- * MN10300 INTC controller operations
+ * MN10300 interrupt controller operations
*/
-static void mn10300_cpupic_disable(unsigned int irq)
-{
- u16 tmp = GxICR(irq);
- GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
- tmp = GxICR(irq);
-}
-
-static void mn10300_cpupic_enable(unsigned int irq)
-{
- u16 tmp = GxICR(irq);
- GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
- tmp = GxICR(irq);
-}
-
static void mn10300_cpupic_ack(unsigned int irq)
{
u16 tmp;
@@ -60,26 +46,54 @@ static void mn10300_cpupic_mask_ack(unsigned int irq)
static void mn10300_cpupic_unmask(unsigned int irq)
{
u16 tmp = GxICR(irq);
- GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
+ GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
tmp = GxICR(irq);
}
-static void mn10300_cpupic_end(unsigned int irq)
+static void mn10300_cpupic_unmask_clear(unsigned int irq)
{
+ /* the MN10300 PIC latches its interrupt request bit, even after the
+ * device has ceased to assert its interrupt line and the interrupt
+ * channel has been disabled in the PIC, so for level-triggered
+ * interrupts we need to clear the request bit when we re-enable */
u16 tmp = GxICR(irq);
- GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
+ GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
tmp = GxICR(irq);
}
-static struct irq_chip mn10300_cpu_pic = {
- .name = "cpu",
- .disable = mn10300_cpupic_disable,
- .enable = mn10300_cpupic_enable,
+/*
+ * MN10300 PIC level-triggered IRQ handling.
+ *
+ * The PIC has no 'ACK' function per se. It is possible to clear individual
+ * channel latches, but each latch relatches whether or not the channel is
+ * masked, so we need to clear the latch when we unmask the channel.
+ *
+ * Also for this reason, we don't supply an ack() op (it's unused anyway if
+ * mask_ack() is provided), and mask_ack() just masks.
+ */
+static struct irq_chip mn10300_cpu_pic_level = {
+ .name = "cpu_l",
+ .disable = mn10300_cpupic_mask,
+ .enable = mn10300_cpupic_unmask_clear,
+ .ack = NULL,
+ .mask = mn10300_cpupic_mask,
+ .mask_ack = mn10300_cpupic_mask,
+ .unmask = mn10300_cpupic_unmask_clear,
+};
+
+/*
+ * MN10300 PIC edge-triggered IRQ handling.
+ *
+ * We use the latch clearing function of the PIC as the 'ACK' function.
+ */
+static struct irq_chip mn10300_cpu_pic_edge = {
+ .name = "cpu_e",
+ .disable = mn10300_cpupic_mask,
+ .enable = mn10300_cpupic_unmask,
.ack = mn10300_cpupic_ack,
.mask = mn10300_cpupic_mask,
.mask_ack = mn10300_cpupic_mask_ack,
.unmask = mn10300_cpupic_unmask,
- .end = mn10300_cpupic_end,
};
/*
@@ -114,7 +128,8 @@ void set_intr_level(int irq, u16 level)
*/
void set_intr_postackable(int irq)
{
- set_irq_handler(irq, handle_level_irq);
+ set_irq_chip_and_handler(irq, &mn10300_cpu_pic_level,
+ handle_level_irq);
}
/*
@@ -126,8 +141,12 @@ void __init init_IRQ(void)
for (irq = 0; irq < NR_IRQS; irq++)
if (irq_desc[irq].chip == &no_irq_type)
- set_irq_chip_and_handler(irq, &mn10300_cpu_pic,
- handle_edge_irq);
+ /* due to the PIC latching interrupt requests, even
+ * when the IRQ is disabled, IRQ_PENDING is superfluous
+ * and we can use handle_level_irq() for edge-triggered
+ * interrupts */
+ set_irq_chip_and_handler(irq, &mn10300_cpu_pic_edge,
+ handle_level_irq);
unit_init_IRQ();
}