[PATCH v6 1/7] ARM: S5PV210: Allow to probe EVT revision number.

[MyungJoo Ham]

Early products of S5PV210, EVT0, had several errata that require
kernel to avoid using some parts/instructions of the CPU or to
add protection instructions. There are products with such early
production CPUs; thus, we want to distinguish them in kernel.
This patch is to distinguish such products.

Include <mach/hardware.h> and call s5pv210_revision().

For example,

	if (s5pv210_revision(EVT0)) {
		... execute code targeted only to EVT0 ...
	} else {
		... execute normal code ...
	}

Call set_s5pv210_revision(EVTx) when the EVT revision number can be
identified. We have EVT0, EVT1, and EVT1-Fused avaialble right now and
only EVT1-Fused has the unique revision number at chipid (PRO_ID
register). A function, get_s5pv210_revision_chipid(), returns EVT
revision number if the revision is identified by the chipid; otherwise,
the function returns EVT_UNKNOWN. When EVT cannot be identified with
chipid, it can be identified at board support file
(arch/arm/mach-s5pv210/mach-*.c), not at the cpu file
(arch/arm/mach-s5pv210/cpu.c).

For Aquila machine. (mach-aquila.c)

Part of Aquila machines have the early production CPUs that require
to address errata issues. Note that we don't do this for GONI machines
because they have never used early production CPUs with errata. Besides,
please note that there are other boards that use such early produces
other than Aquila. However, those boards/machines are not registered at
the /linux/arch/arm/tools/mach-types, yet; thus, we have omitted them
in this patch.

For Goni machine. (mach-goni.c)

It's either EVT1 or EVT1-Fused; thus, it can be identified by
get_s5pv210_revision_chipid() function.

Signed-off-by: MyungJoo Ham <myungjoo.ham at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
--
v5 updates:
	- rename revision check function.
	- revise revision check functions so that it does not access
	  board-related information.
	- chipid is used to identify EVT revision.
	- added "s5pv210_revision_or_later()" function
v6 updates:
	- removed consideration for EVT1-FUSED

---
 arch/arm/mach-s5pv210/cpu.c                   |   13 +++++++++++++
 arch/arm/mach-s5pv210/include/mach/hardware.h |   12 +++++++++++-
 arch/arm/mach-s5pv210/mach-aquila.c           |    9 +++++++++
 arch/arm/mach-s5pv210/mach-goni.c             |    3 +++
 4 files changed, 36 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-s5pv210/cpu.c b/arch/arm/mach-s5pv210/cpu.c
index 94c632b..74d4c08 100644
--- a/arch/arm/mach-s5pv210/cpu.c
+++ b/arch/arm/mach-s5pv210/cpu.c
@@ -27,6 +27,7 @@
 #include <asm/proc-fns.h>
 #include <mach/map.h>
 #include <mach/regs-clock.h>
+#include <mach/hardware.h>
 
 #include <plat/cpu.h>
 #include <plat/devs.h>
@@ -128,6 +129,18 @@ static struct sys_device s5pv210_sysdev = {
 	.cls	= &s5pv210_sysclass,
 };
 
+static bool s5pv210_evt0;
+
+bool s5pv210_revision_evt0(void)
+{
+	return s5pv210_evt0 == true;
+}
+
+void set_s5pv210_revision_evt0(bool evt0)
+{
+	s5pv210_evt0 = evt0;
+}
+
 static int __init s5pv210_core_init(void)
 {
 	return sysdev_class_register(&s5pv210_sysclass);
diff --git a/arch/arm/mach-s5pv210/include/mach/hardware.h b/arch/arm/mach-s5pv210/include/mach/hardware.h
index fada7a3..fa50868 100644
--- a/arch/arm/mach-s5pv210/include/mach/hardware.h
+++ b/arch/arm/mach-s5pv210/include/mach/hardware.h
@@ -13,6 +13,16 @@
 #ifndef __ASM_ARCH_HARDWARE_H
 #define __ASM_ARCH_HARDWARE_H __FILE__
 
-/* currently nothing here, placeholder */
+extern bool s5pv210_revision_evt0(void);
+extern void set_s5pv210_revision_evt0(bool);
+
+/*
+ * get_s5pv210_revision_chipid returns s5pv210_revision if the
+ * EVT revision can be determined by the chipid(PRO_ID) register.
+ * However, note that only EVT1-FUSED can be identified from it and
+ * it cannot distinguish between EVT0 and EVT1. In such case, it
+ * returns EVT_UNKNOWN. In such case use set_s5pv210_revision() to
+ * set the revision number manually.
+ */
 
 #endif /* __ASM_ARCH_HARDWARE_H */
diff --git a/arch/arm/mach-s5pv210/mach-aquila.c b/arch/arm/mach-s5pv210/mach-aquila.c
index 46d5c7e..6a8deaa 100644
--- a/arch/arm/mach-s5pv210/mach-aquila.c
+++ b/arch/arm/mach-s5pv210/mach-aquila.c
@@ -30,6 +30,7 @@
 #include <mach/regs-clock.h>
 #include <mach/regs-fb.h>
 #include <mach/gpio.h>
+#include <mach/hardware.h>
 
 #include <plat/gpio-cfg.h>
 #include <plat/regs-serial.h>
@@ -536,6 +537,14 @@ static void __init aquila_map_io(void)
 
 static void __init aquila_machine_init(void)
 {
+	/* CPU Revision (EVTx) */
+	set_s5pv210_revision_evt0(false);
+	if (system_rev & 0x0800) {
+		if ((system_rev & 0xF) < 8)
+			set_s5pv210_revision_evt0(true);
+	} else if (system_rev & 0x2000)
+		set_s5pv210_revision_evt0(true);
+
 	/* PMIC */
 	aquila_pmic_init();
 	i2c_register_board_info(AP_I2C_GPIO_PMIC_BUS_4, i2c_gpio_pmic_devs,
diff --git a/arch/arm/mach-s5pv210/mach-goni.c b/arch/arm/mach-s5pv210/mach-goni.c
index 380d2ae..08ee3f6 100644
--- a/arch/arm/mach-s5pv210/mach-goni.c
+++ b/arch/arm/mach-s5pv210/mach-goni.c
@@ -32,6 +32,7 @@
 #include <mach/regs-clock.h>
 #include <mach/regs-fb.h>
 #include <mach/gpio.h>
+#include <mach/hardware.h>
 
 #include <plat/gpio-cfg.h>
 #include <plat/regs-serial.h>
@@ -520,6 +521,8 @@ static void __init goni_map_io(void)
 
 static void __init goni_machine_init(void)
 {
+	set_s5pv210_revision_evt0(false);
+
 	/* PMIC */
 	goni_pmic_init();
 	i2c_register_board_info(AP_I2C_GPIO_PMIC_BUS_4, i2c_gpio_pmic_devs,
-- 
1.6.3.3