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 0fb3961999b51861c352fae14635cfa9f8e6c422..fa09cb48f3e522a61b4060cf4da8b60da237d944 100644 (file)
--- 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;