powerpc/cpm2_pic: Allow correct flow_types for port C interrupts

Port C interrupts can be either falling edge, or either edge.
Other external interrupts are either falling edge or active low.
Tested on a custom 8280 based board.
Signed-off-by: NMark Ware <mware@elphinstone.net>
Acked-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

arch/powerpc/sysdev/cpm2_pic.c

@@ -143,13 +143,23 @@ static int cpm2_set_irq_type(unsigned int virq, unsigned int flow_type)
 	struct irq_desc *desc = irq_to_desc(virq);
 	unsigned int vold, vnew, edibit;
 
-	if (flow_type == IRQ_TYPE_NONE)
-		flow_type = IRQ_TYPE_LEVEL_LOW;
-
-	if (flow_type & IRQ_TYPE_EDGE_RISING) {
-		printk(KERN_ERR "CPM2 PIC: sense type 0x%x not supported\n",
-			flow_type);
-		return -EINVAL;
+	/* Port C interrupts are either IRQ_TYPE_EDGE_FALLING or
+	 * IRQ_TYPE_EDGE_BOTH (default).  All others are IRQ_TYPE_EDGE_FALLING
+	 * or IRQ_TYPE_LEVEL_LOW (default)
+	 */
+	if (src >= CPM2_IRQ_PORTC15 && src <= CPM2_IRQ_PORTC0) {
+		if (flow_type == IRQ_TYPE_NONE)
+			flow_type = IRQ_TYPE_EDGE_BOTH;
+
+		if (flow_type != IRQ_TYPE_EDGE_BOTH &&
+		    flow_type != IRQ_TYPE_EDGE_FALLING)
+			goto err_sense;
+	} else {
+		if (flow_type == IRQ_TYPE_NONE)
+			flow_type = IRQ_TYPE_LEVEL_LOW;
+
+		if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
+			goto err_sense;
 	}
 
 	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
@@ -181,6 +191,10 @@ static int cpm2_set_irq_type(unsigned int virq, unsigned int flow_type)
 	if (vold != vnew)
 		out_be32(&cpm2_intctl->ic_siexr, vnew);
 	return 0;
+
+err_sense:
+	pr_err("CPM2 PIC: sense type 0x%x not supported\n", flow_type);
+	return -EINVAL;
 }
 
 static struct irq_chip cpm2_pic = {