powerpc/pseries: Use of_irq_get helper() in request_event_sources_irqs()

Instead of calling both of_irq_parse_one() and
irq_create_of_mapping(), call of_irq_get() instead which does
essentially the same thing. of_irq_get() also calls irq_find_host()
for deferred probe support, but this should be fine as
irq_create_of_mapping() also calls that internally. This gets us
closer to making the former 2 functions static.

In the process of simplifying request_event_sources_irqs(), combine
the the pr_err() and WARN_ON() calls to just a WARN().
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/pseries/event_sources.c

@@ -16,7 +16,8 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
-#include <asm/prom.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
 
 #include "pseries.h"
 
@@ -24,34 +25,19 @@ void request_event_sources_irqs(struct device_node *np,
 				irq_handler_t handler,
 				const char *name)
 {
-	int i, index, count = 0;
-	struct of_phandle_args oirq;
-	unsigned int virqs[16];
+	int i, virq, rc;
 
-	/* First try to do a proper OF tree parsing */
-	for (index = 0; of_irq_parse_one(np, index, &oirq) == 0;
-	     index++) {
-		if (count > 15)
-			break;
-		virqs[count] = irq_create_of_mapping(&oirq);
-		if (!virqs[count]) {
-			pr_err("event-sources: Unable to allocate "
-			       "interrupt number for %pOF\n",
-			       np);
-			WARN_ON(1);
-		} else {
-			count++;
-		}
-	}
+	for (i = 0; i < 16; i++) {
+		virq = of_irq_get(np, i);
+		if (virq < 0)
+			return;
+		if (WARN(!virq, "event-sources: Unable to allocate "
+			        "interrupt number for %pOF\n", np))
+			continue;
 
-	/* Now request them */
-	for (i = 0; i < count; i++) {
-		if (request_irq(virqs[i], handler, 0, name, NULL)) {
-			pr_err("event-sources: Unable to request interrupt "
-			       "%d for %pOF\n", virqs[i], np);
-			WARN_ON(1);
+		rc = request_irq(virq, handler, 0, name, NULL);
+		if (WARN(rc, "event-sources: Unable to request interrupt %d for %pOF\n",
+		    virq, np))
 			return;
 	}
-	}
 }
-