[PATCH 4/4] ARM: tegra: Set SCU base address dynamically from DT

Hiroshi Doyu hdoyu at nvidia.com
Mon Dec 17 17:18:04 EST 2012


Set Snoop Control Unit(SCU) register base address dynamically from DT.

Signed-off-by: Hiroshi Doyu <hdoyu at nvidia.com>
---
 arch/arm/mach-tegra/platsmp.c |   23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
index 1b926df..45c0b79 100644
--- a/arch/arm/mach-tegra/platsmp.c
+++ b/arch/arm/mach-tegra/platsmp.c
@@ -18,6 +18,8 @@
 #include <linux/jiffies.h>
 #include <linux/smp.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
 
 #include <asm/cacheflush.h>
 #include <asm/hardware/gic.h>
@@ -36,7 +38,7 @@
 
 extern void tegra_secondary_startup(void);
 
-static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
+static void __iomem *scu_base;
 
 #define EVP_CPU_RESET_VECTOR \
 	(IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)
@@ -143,14 +145,28 @@ done:
 	return status;
 }
 
+static const struct of_device_id cortex_a9_scu_match[] __initconst = {
+	{ .compatible = "arm,cortex-a9-scu", },
+	{}
+};
+
 /*
  * Initialise the CPU possible map early - this describes the CPUs
  * which may be present or become present in the system.
  */
 static void __init tegra_smp_init_cpus(void)
 {
-	unsigned int i, ncores = scu_get_core_count(scu_base);
+	struct device_node *np;
+	unsigned int i, ncores = 1;
+
+	np = of_find_matching_node(NULL, cortex_a9_scu_match);
+	if (!np)
+		return;
+	scu_base = of_iomap(np, 0);
+	if (!scu_base)
+		return;
 
+	ncores = scu_get_core_count(scu_base);
 	if (ncores > nr_cpu_ids) {
 		pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
 			ncores, nr_cpu_ids);
@@ -166,7 +182,8 @@ static void __init tegra_smp_init_cpus(void)
 static void __init tegra_smp_prepare_cpus(unsigned int max_cpus)
 {
 	tegra_cpu_reset_handler_init();
-	scu_enable(scu_base);
+	if (scu_base)
+		scu_enable(scu_base);
 }
 
 struct smp_operations tegra_smp_ops __initdata = {
-- 
1.7.9.5



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