omap4: add OMAP4430 revision check

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/arch/arm/cpu/armv7/omap4/board.c b/arch/arm/cpu/armv7/omap4/board.c
index 3fd6f84..09861a9 100644
--- a/arch/arm/cpu/armv7/omap4/board.c
+++ b/arch/arm/cpu/armv7/omap4/board.c
@@ -28,6 +28,7 @@
  * MA 02111-1307 USA
  */
 #include <common.h>
+#include <asm/armv7.h>
 #include <asm/arch/cpu.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/sizes.h>
@@ -35,6 +36,8 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+u32 *const omap4_revision = (u32 *)OMAP4_SRAM_SCRATCH_OMAP4_REV;
+
 void do_set_mux(u32 base, struct pad_conf_entry const *array, int size)
 {
 	int i;
@@ -72,6 +75,66 @@
 	}
 }
 
+static u32 cortex_a9_rev(void)
+{
+
+	unsigned int rev;
+
+	/* Read Main ID Register (MIDR) */
+	asm ("mrc p15, 0, %0, c0, c0, 0" : "=r" (rev));
+
+	return rev;
+}
+
+static void init_omap4_revision(void)
+{
+	/*
+	 * For some of the ES2/ES1 boards ID_CODE is not reliable:
+	 * Also, ES1 and ES2 have different ARM revisions
+	 * So use ARM revision for identification
+	 */
+	unsigned int arm_rev = cortex_a9_rev();
+
+	switch (arm_rev) {
+	case MIDR_CORTEX_A9_R0P1:
+		*omap4_revision = OMAP4430_ES1_0;
+		break;
+	case MIDR_CORTEX_A9_R1P2:
+		switch (readl(CONTROL_ID_CODE)) {
+		case OMAP4_CONTROL_ID_CODE_ES2_0:
+			*omap4_revision = OMAP4430_ES2_0;
+			break;
+		case OMAP4_CONTROL_ID_CODE_ES2_1:
+			*omap4_revision = OMAP4430_ES2_1;
+			break;
+		case OMAP4_CONTROL_ID_CODE_ES2_2:
+			*omap4_revision = OMAP4430_ES2_2;
+			break;
+		default:
+			*omap4_revision = OMAP4430_ES2_0;
+			break;
+		}
+		break;
+	case MIDR_CORTEX_A9_R1P3:
+		*omap4_revision = OMAP4430_ES2_3;
+		break;
+	default:
+		*omap4_revision = OMAP4430_SILICON_ID_INVALID;
+		break;
+	}
+}
+
+void omap_rev_string(char *omap4_rev_string)
+{
+	u32 omap4_rev = omap_revision();
+	u32 omap4_variant = (omap4_rev & 0xFFFF0000) >> 16;
+	u32 major_rev = (omap4_rev & 0x00000F00) >> 8;
+	u32 minor_rev = (omap4_rev & 0x000000F0) >> 4;
+
+	sprintf(omap4_rev_string, "OMAP%x ES%x.%x", omap4_variant, major_rev,
+		minor_rev);
+}
+
 /*
  * Routine: s_init
  * Description: Does early system init of watchdog, muxing,  andclocks
@@ -88,6 +151,7 @@
  */
 void s_init(void)
 {
+	init_omap4_revision();
 	watchdog_init();
 	set_mux_conf_regs();
 }
diff --git a/arch/arm/include/asm/arch-omap4/omap4.h b/arch/arm/include/asm/arch-omap4/omap4.h
index a30bb33..76b06c2 100644
--- a/arch/arm/include/asm/arch-omap4/omap4.h
+++ b/arch/arm/include/asm/arch-omap4/omap4.h
@@ -51,6 +51,15 @@
 #define CONTROL_PADCONF_CORE	(OMAP44XX_L4_CORE_BASE + 0x100000)
 #define CONTROL_PADCONF_WKUP	(OMAP44XX_L4_CORE_BASE + 0x31E000)
 
+/* CONTROL_ID_CODE */
+#define CONTROL_ID_CODE		0x4A002204
+
+#define OMAP4_CONTROL_ID_CODE_ES1_0	0x0B85202F
+#define OMAP4_CONTROL_ID_CODE_ES2_0	0x1B85202F
+#define OMAP4_CONTROL_ID_CODE_ES2_1	0x3B95C02F
+#define OMAP4_CONTROL_ID_CODE_ES2_2	0x4B95C02F
+#define OMAP4_CONTROL_ID_CODE_ES2_3	0x6B95C02F
+
 /* UART */
 #define UART1_BASE		(OMAP44XX_L4_PER_BASE + 0x6a000)
 #define UART2_BASE		(OMAP44XX_L4_PER_BASE + 0x6c000)
@@ -119,13 +128,17 @@
 /* base address for indirect vectors (internal boot mode) */
 #define SRAM_ROM_VECT_BASE	0x4030D000
 /* Temporary SRAM stack used while low level init is done */
-#define LOW_LEVEL_SRAM_STACK	NON_SECURE_SRAM_END
+#define LOW_LEVEL_SRAM_STACK		NON_SECURE_SRAM_END
+#define SRAM_SCRATCH_SPACE_ADDR		NON_SECURE_SRAM_START
+/* SRAM scratch space entries */
+#define OMAP4_SRAM_SCRATCH_OMAP4_REV	SRAM_SCRATCH_SPACE_ADDR
 
-/*
- * OMAP4 real hardware:
- * TODO: Change this to the IDCODE in the hw regsiter
- */
-#define CPU_OMAP4430_ES10	1
-#define CPU_OMAP4430_ES20	2
+/* Silicon revisions */
+#define OMAP4430_SILICON_ID_INVALID	0xFFFFFFFF
+#define OMAP4430_ES1_0	0x44300100
+#define OMAP4430_ES2_0	0x44300200
+#define OMAP4430_ES2_1	0x44300210
+#define OMAP4430_ES2_2	0x44300220
+#define OMAP4430_ES2_3	0x44300230
 
 #endif
diff --git a/arch/arm/include/asm/arch-omap4/sys_proto.h b/arch/arm/include/asm/arch-omap4/sys_proto.h
index 3624378..c10fa18 100644
--- a/arch/arm/include/asm/arch-omap4/sys_proto.h
+++ b/arch/arm/include/asm/arch-omap4/sys_proto.h
@@ -40,6 +40,7 @@
 u32 wait_on_value(u32, u32, void *, u32);
 void sdelay(unsigned long);
 void set_pl310_ctrl_reg(u32 val);
+void omap_rev_string(char *omap4_rev_string);
 
 static inline u32 running_from_sdram(void)
 {
@@ -88,4 +89,10 @@
 #endif
 }
 
+static inline u32 omap_revision(void)
+{
+	extern u32 *const omap4_revision;
+	return *omap4_revision;
+}
+
 #endif
diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h
index 88b9c62..b5784d8 100644
--- a/arch/arm/include/asm/armv7.h
+++ b/arch/arm/include/asm/armv7.h
@@ -25,6 +25,11 @@
 #define ARMV7_H
 #include <linux/types.h>
 
+/* Cortex-A9 revisions */
+#define MIDR_CORTEX_A9_R0P1	0x410FC091
+#define MIDR_CORTEX_A9_R1P2	0x411FC092
+#define MIDR_CORTEX_A9_R1P3	0x411FC093
+
 /* CCSIDR */
 #define CCSIDR_LINE_SIZE_OFFSET		0
 #define CCSIDR_LINE_SIZE_MASK		0x7