[PATCH 3/7] [POWERPC] QEIC: implement low+high multiplexed IRQ chained handler

[Anton Vorontsov]

For MPC8568E low and high QEIC lines routed to the single MPIC
input, thus low and high sources should be demultiplexed.

Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
---
 arch/powerpc/sysdev/qe_lib/qe_ic.c |   34 ++++++++++++++++++++++++++++------
 1 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/sysdev/qe_lib/qe_ic.c b/arch/powerpc/sysdev/qe_lib/qe_ic.c
index 8e743e0..0ecb614 100644
--- a/arch/powerpc/sysdev/qe_lib/qe_ic.c
+++ b/arch/powerpc/sysdev/qe_lib/qe_ic.c
@@ -345,6 +345,22 @@ void qe_ic_cascade_high(unsigned int irq, struct irq_desc *desc)
 		desc->chip->end(irq);
 }
 
+static void qe_ic_cascade_muxed(unsigned int irq, struct irq_desc *desc)
+{
+	struct qe_ic *qe_ic = desc->handler_data;
+	unsigned int cascade_irq;
+
+	cascade_irq = qe_ic_get_high_irq(qe_ic);
+	if (cascade_irq == NO_IRQ)
+		cascade_irq = qe_ic_get_low_irq(qe_ic);
+
+	if (cascade_irq != NO_IRQ)
+		generic_handle_irq(cascade_irq);
+
+	if (desc->chip->end)
+		desc->chip->end(irq);
+}
+
 void __init qe_ic_init(struct device_node *node, unsigned int flags)
 {
 	struct qe_ic *qe_ic;
@@ -404,12 +420,18 @@ void __init qe_ic_init(struct device_node *node, unsigned int flags)
 
 	qe_ic_write(qe_ic->regs, QEIC_CICR, temp);
 
-	set_irq_data(qe_ic->virq_low, qe_ic);
-	set_irq_chained_handler(qe_ic->virq_low, qe_ic_cascade_low);
-
-	if (qe_ic->virq_high != NO_IRQ) {
-		set_irq_data(qe_ic->virq_high, qe_ic);
-		set_irq_chained_handler(qe_ic->virq_high, qe_ic_cascade_high);
+	if (qe_ic->virq_high == qe_ic->virq_low) {
+		set_irq_data(qe_ic->virq_low, qe_ic);
+		set_irq_chained_handler(qe_ic->virq_low, qe_ic_cascade_muxed);
+	} else {
+		set_irq_data(qe_ic->virq_low, qe_ic);
+		set_irq_chained_handler(qe_ic->virq_low, qe_ic_cascade_low);
+
+		if (qe_ic->virq_high != NO_IRQ) {
+			set_irq_data(qe_ic->virq_high, qe_ic);
+			set_irq_chained_handler(qe_ic->virq_high,
+						qe_ic_cascade_high);
+		}
 	}
 
 	printk("QEIC (%d IRQ sources) at %p\n", NR_QE_IC_INTS, qe_ic->regs);
-- 
1.5.0.6