From: Pawel Moll <pawel.moll@arm.com>
Date: Thu, 15 Dec 2011 10:44:25 +0000 (+0000)
Subject: ARM: versatile: Map local timers using Device Tree when possible
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=53491593bb5600e64299eb08794837754baca97d;p=people%2Fsstabellini%2Flinux-pvhvm-deprecated.git

ARM: versatile: Map local timers using Device Tree when possible

Try to map TWD registers basing on a "arm,smp-twd" Device Tree
node (compatible value as used in Highbank's DT). This overrides
existing twd_base value.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---

diff --git a/arch/arm/plat-versatile/localtimer.c b/arch/arm/plat-versatile/localtimer.c
index 0fb3961999b..fa09cb48f3e 100644
--- a/arch/arm/plat-versatile/localtimer.c
+++ b/arch/arm/plat-versatile/localtimer.c
@@ -11,6 +11,8 @@
 #include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/clockchips.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
 #include <asm/smp_twd.h>
 #include <asm/localtimer.h>
@@ -21,6 +23,23 @@
  */
 int __cpuinit local_timer_setup(struct clock_event_device *evt)
 {
+#if defined(CONFIG_OF)
+	static int dt_node_probed;
+
+	/* Look for TWD node only once */
+	if (!dt_node_probed) {
+		struct device_node *node = of_find_compatible_node(NULL,
+				NULL, "arm,smp-twd");
+
+		if (node)
+			twd_base = of_iomap(node, 0);
+
+		dt_node_probed = 1;
+	}
+#endif
+	if (!twd_base)
+		return -ENXIO;
+
 	evt->irq = IRQ_LOCALTIMER;
 	twd_timer_setup(evt);
 	return 0;