ARM: mx50: Add support to get the silicon revision

For MX50, the HW_ADADIG_DIGPROG register in the ANATOP module will
have the correct silicon revision:

Major       Minor   Description
0x50        0x0     TO1.0
0x50        0x1     TO1.1

Signed-off-by: Dinh Nguyen <Dinh.Nguyen@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 39 insertions, 0 deletions

diff --git a/arch/arm/mach-mx5/cpu.c b/arch/arm/mach-mx5/cpu.c
index 3b4c30743052..472bdfab2e55 100644
--- a/arch/arm/mach-mx5/cpu.c
+++ b/arch/arm/mach-mx5/cpu.c
@@ -21,6 +21,7 @@
 static int cpu_silicon_rev = -1;
 
 #define IIM_SREV 0x24
+#define MX50_HW_ADADIG_DIGPROG  0xB0
 
 static int get_mx51_srev(void)
 {
@@ -127,6 +128,44 @@ int mx53_revision(void)
 }
 EXPORT_SYMBOL(mx53_revision);
 
+static int get_mx50_srev(void)
+{
+        void __iomem *anatop = ioremap(MX50_ANATOP_BASE_ADDR, SZ_8K);
+        u32 rev;
+
+        if (!anatop) {
+                cpu_silicon_rev = -EINVAL;
+                return 0;
+        }
+
+        rev = readl(anatop + MX50_HW_ADADIG_DIGPROG);
+        rev &= 0xff;
+
+        iounmap(anatop);
+        if (rev == 0x0)
+                return IMX_CHIP_REVISION_1_0;
+        else if (rev == 0x1)
+                return IMX_CHIP_REVISION_1_1;
+        return 0;
+}
+
+/*
+ * Returns:
+ *      the silicon revision of the cpu
+ *      -EINVAL - not a mx50
+ */
+int mx50_revision(void)
+{
+        if (!cpu_is_mx50())
+                return -EINVAL;
+
+        if (cpu_silicon_rev == -1)
+                cpu_silicon_rev = get_mx50_srev();
+
+        return cpu_silicon_rev;
+}
+EXPORT_SYMBOL(mx50_revision);
+
 static int __init post_cpu_init(void)
 {
         unsigned int reg;