ARM: EXYNOS: Add support for mapping PMU base address via DT

Add support for mapping Samsung Power Management Unit (PMU)
base address from device tree.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
index 269526b..80cbbc7 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c
@@ -19,6 +19,7 @@
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/pm_domain.h>
+#include <linux/irqchip.h>
 
 #include <asm/cacheflush.h>
 #include <asm/hardware/cache-l2x0.h>
@@ -31,6 +32,8 @@
 #include "regs-pmu.h"
 #include "regs-sys.h"
 
+void __iomem *pmu_base_addr;
+
 static struct map_desc exynos4_iodesc[] __initdata = {
 	{
 		.virtual	= (unsigned long)S3C_VA_SYS,
@@ -264,6 +267,39 @@
 	exynos_map_io();
 }
 
+static const struct of_device_id exynos_dt_pmu_match[] = {
+	{ .compatible = "samsung,exynos3250-pmu" },
+	{ .compatible = "samsung,exynos4210-pmu" },
+	{ .compatible = "samsung,exynos4212-pmu" },
+	{ .compatible = "samsung,exynos4412-pmu" },
+	{ .compatible = "samsung,exynos5250-pmu" },
+	{ .compatible = "samsung,exynos5420-pmu" },
+	{ /*sentinel*/ },
+};
+
+static void exynos_map_pmu(void)
+{
+	struct device_node *np;
+
+	np = of_find_matching_node(NULL, exynos_dt_pmu_match);
+	if (np)
+		pmu_base_addr = of_iomap(np, 0);
+
+	if (!pmu_base_addr)
+		panic("failed to find exynos pmu register\n");
+}
+
+static void __init exynos_init_irq(void)
+{
+	irqchip_init();
+	/*
+	 * Since platsmp.c needs pmu base address by the time
+	 * DT is not unflatten so we can't use DT APIs before
+	 * init_irq
+	 */
+	exynos_map_pmu();
+}
+
 static void __init exynos_dt_machine_init(void)
 {
 	struct device_node *i2c_np;
@@ -344,6 +380,7 @@
 	.smp		= smp_ops(exynos_smp_ops),
 	.map_io		= exynos_init_io,
 	.init_early	= exynos_firmware_init,
+	.init_irq	= exynos_init_irq,
 	.init_machine	= exynos_dt_machine_init,
 	.init_late	= exynos_init_late,
 	.dt_compat	= exynos_dt_compat,