[U-Boot] [PATCH 1/2] omap3: Identify the CPU in arch_cpu_init()

[Sanjeev Premi <premi@ti.com>]

The function get_cpu_rev() is called multiple times
during execution resulting in probe into the IDCODE
register to extract the revision information.

This patch does the following:
- Moves the steps to identify static cpu information
  into arch_cpu_init().
- Updates configs for all omap3 boards to define
  CONFIG_ARCH_CPU_INIT.
- Updates get_cpu_rev() to return value calculated in
  arch_cpu_init().
- Since revision isn't expected to be longer than 8bits,
  get_cpu_rev() return a u8 value instead of u32.

Signed-off-by: Sanjeev Premi <premi@ti.com>
---
 cpu/arm_cortexa8/omap3/sys_info.c      |   60 +++++++++++++++++++------------
 include/asm-arm/arch-omap3/sys_proto.h |    2 +-
 include/configs/omap3_beagle.h         |    2 +
 include/configs/omap3_evm.h            |    2 +
 include/configs/omap3_overo.h          |    2 +
 include/configs/omap3_pandora.h        |    2 +
 include/configs/omap3_zoom1.h          |    2 +
 include/configs/omap3_zoom2.h          |    2 +
 8 files changed, 50 insertions(+), 24 deletions(-)

diff --git a/cpu/arm_cortexa8/omap3/sys_info.c b/cpu/arm_cortexa8/omap3/sys_info.c
index 31b2003..40866ae 100644
--- a/cpu/arm_cortexa8/omap3/sys_info.c
+++ b/cpu/arm_cortexa8/omap3/sys_info.c
@@ -41,6 +41,41 @@ static char *rev_s[CPU_3XX_MAX_REV] = {
 				"3.0",
 				"3.1"};
 
+static u8 cpu_revision;
+
+/**
+ * Perform architecture specific initialization.
+ *
+ * Currently, it identifies the cpu revision.
+ */
+int arch_cpu_init (void)
+{
+	u32 cpuid = 0;
+	struct ctrl_id *id_base;
+
+	/*
+	 * On ES1.0 the IDCODE register is not exposed on L4
+	 * so using CPU ID to differentiate between ES1.0 and > ES1.0.
+	 */
+	__asm__ __volatile__("mrc p15, 0, %0, c0, c0, 0":"=r"(cpuid));
+	if ((cpuid & 0xf) == 0x0) {
+		cpu_revision = CPU_3XX_ES10;
+	} else {
+		/* Decode the IDs on > ES1.0 */
+		id_base = (struct ctrl_id *) OMAP34XX_ID_L4_IO_BASE;
+
+		cpuid = readl(&id_base->idcode);
+
+		cpu_revision = (cpuid >> CPU_3XX_ID_SHIFT) & 0xf;
+
+		/* Some early ES2.0 seem to report rev 0, fix this */
+		if(cpu_revision == 0)
+			cpu_revision = CPU_3XX_ES20;
+	}
+
+	return 0;
+}
+
 /*****************************************************************
  * dieid_num_r(void) - read and set die ID
  *****************************************************************/
@@ -78,30 +113,9 @@ u32 get_cpu_type(void)
 /******************************************
  * get_cpu_rev(void) - extract version info
  ******************************************/
-u32 get_cpu_rev(void)
+u8 get_cpu_rev(void)
 {
-	u32 cpuid = 0;
-	struct ctrl_id *id_base;
-
-	/*
-	 * On ES1.0 the IDCODE register is not exposed on L4
-	 * so using CPU ID to differentiate between ES1.0 and > ES1.0.
-	 */
-	__asm__ __volatile__("mrc p15, 0, %0, c0, c0, 0":"=r"(cpuid));
-	if ((cpuid & 0xf) == 0x0)
-		return CPU_3XX_ES10;
-	else {
-		/* Decode the IDs on > ES1.0 */
-		id_base = (struct ctrl_id *) OMAP34XX_ID_L4_IO_BASE;
-
-		cpuid = (readl(&id_base->idcode) >> CPU_3XX_ID_SHIFT) & 0xf;
-
-		/* Some early ES2.0 seem to report ID 0, fix this */
-		if(cpuid == 0)
-			cpuid = CPU_3XX_ES20;
-
-		return cpuid;
-	}
+	return cpu_revision;
 }
 
 /****************************************************
diff --git a/include/asm-arm/arch-omap3/sys_proto.h b/include/asm-arm/arch-omap3/sys_proto.h
index 34bd515..1c99c45 100644
--- a/include/asm-arm/arch-omap3/sys_proto.h
+++ b/include/asm-arm/arch-omap3/sys_proto.h
@@ -40,7 +40,7 @@ void enable_gpmc_cs_config(const u32 *gpmc_config, struct gpmc_cs *cs, u32 base,
 void watchdog_init(void);
 void set_muxconf_regs(void);
 
-u32 get_cpu_rev(void);
+u8 get_cpu_rev(void);
 u32 get_mem_type(void);
 u32 get_sysboot_value(void);
 u32 is_gpmc_muxed(void);
diff --git a/include/configs/omap3_beagle.h b/include/configs/omap3_beagle.h
index 19a5ec9..640562c 100644
--- a/include/configs/omap3_beagle.h
+++ b/include/configs/omap3_beagle.h
@@ -28,6 +28,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define CONFIG_ARCH_CPU_INIT	1
+
 /*
  * High Level Configuration Options
  */
diff --git a/include/configs/omap3_evm.h b/include/configs/omap3_evm.h
index a5514ae..0e85393 100644
--- a/include/configs/omap3_evm.h
+++ b/include/configs/omap3_evm.h
@@ -33,6 +33,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define CONFIG_ARCH_CPU_INIT	1
+
 /*
  * High Level Configuration Options
  */
diff --git a/include/configs/omap3_overo.h b/include/configs/omap3_overo.h
index ffb515d..4ff06a3 100644
--- a/include/configs/omap3_overo.h
+++ b/include/configs/omap3_overo.h
@@ -20,6 +20,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define CONFIG_ARCH_CPU_INIT	1
+
 /*
  * High Level Configuration Options
  */
diff --git a/include/configs/omap3_pandora.h b/include/configs/omap3_pandora.h
index 6f21af3..fee592f 100644
--- a/include/configs/omap3_pandora.h
+++ b/include/configs/omap3_pandora.h
@@ -23,6 +23,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define CONFIG_ARCH_CPU_INIT	1
+
 /*
  * High Level Configuration Options
  */
diff --git a/include/configs/omap3_zoom1.h b/include/configs/omap3_zoom1.h
index da4b677..8866cda 100644
--- a/include/configs/omap3_zoom1.h
+++ b/include/configs/omap3_zoom1.h
@@ -29,6 +29,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define CONFIG_ARCH_CPU_INIT	1
+
 /*
  * High Level Configuration Options
  */
diff --git a/include/configs/omap3_zoom2.h b/include/configs/omap3_zoom2.h
index 32cd6fd..5381aa9 100644
--- a/include/configs/omap3_zoom2.h
+++ b/include/configs/omap3_zoom2.h
@@ -30,6 +30,8 @@
 #ifndef __CONFIG_H
 #define __CONFIG_H
 
+#define CONFIG_ARCH_CPU_INIT	1
+
 /*
  * High Level Configuration Options
  */
-- 
1.6.2.2