[patch 1/3] xtensa: fix wrong extern declaration renamed in code using it

[patch 1/3] xtensa: fix wrong extern declaration renamed in code using it

[Oskar Schirmer]

The variable ccount_nsec has been renamed to nsec_per_ccount
in arch/xtensa/kernel/time.c in 2b8aea74 (2007-08-05),
but the fix failed to rename the variable in
arch/xtensa/include/asm/timex.h as well.

Signed-off-by: Oskar Schirmer <os@emlix.com>
---
 arch/xtensa/include/asm/timex.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/include/asm/timex.h b/arch/xtensa/include/asm/timex.h
index b83a818..053bc42 100644
--- a/arch/xtensa/include/asm/timex.h
+++ b/arch/xtensa/include/asm/timex.h
@@ -39,9 +39,9 @@
 
 #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
 extern unsigned long ccount_per_jiffy;
-extern unsigned long ccount_nsec;
+extern unsigned long nsec_per_ccount;
 #define CCOUNT_PER_JIFFY ccount_per_jiffy
-#define NSEC_PER_CCOUNT  ccount_nsec
+#define NSEC_PER_CCOUNT  nsec_per_ccount
 #else
 #define CCOUNT_PER_JIFFY (CONFIG_XTENSA_CPU_CLOCK*(1000000UL/HZ))
 #define NSEC_PER_CCOUNT (1000UL / CONFIG_XTENSA_CPU_CLOCK)
-- 
1.6.2.107.ge47ee

[patch 2/3] xtensa: implement ccount calibration for s6000

[Oskar Schirmer]

Calculate core frequency from timers at boot time
instead of assuming a fixed frequency. This is
useful as the true frequency is set up by the
boot loader, thus variable.

Signed-off-by: Oskar Schirmer <os@emlix.com>
---
 arch/xtensa/Kconfig                 |    1 +
 arch/xtensa/variants/s6000/Makefile |    1 +
 arch/xtensa/variants/s6000/delay.c  |   27 +++++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 0 deletions(-)
 create mode 100644 arch/xtensa/variants/s6000/delay.c

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index fa6dc4d..ac02f3c 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -80,6 +80,7 @@ config XTENSA_VARIANT_S6000
 	bool "s6000 - Stretch software configurable processor"
 	select VARIANT_IRQ_SWITCH
 	select ARCH_REQUIRE_GPIOLIB
+	select XTENSA_CALIBRATE_CCOUNT
 endchoice
 
 config XTENSA_UNALIGNED_USER
diff --git a/arch/xtensa/variants/s6000/Makefile b/arch/xtensa/variants/s6000/Makefile
index 408c4fe..16645a0 100644
--- a/arch/xtensa/variants/s6000/Makefile
+++ b/arch/xtensa/variants/s6000/Makefile
@@ -1,3 +1,4 @@
 # s6000 Makefile
 
 obj-y		+= irq.o gpio.o dmac.o isef.o uncached-mapping.o
+obj-$(CONFIG_XTENSA_CALIBRATE_CCOUNT)	+= delay.o
diff --git a/arch/xtensa/variants/s6000/delay.c b/arch/xtensa/variants/s6000/delay.c
new file mode 100644
index 0000000..54b2b57
--- /dev/null
+++ b/arch/xtensa/variants/s6000/delay.c
@@ -0,0 +1,27 @@
+#include <asm/delay.h>
+#include <asm/timex.h>
+#include <asm/io.h>
+#include <variant/hardware.h>
+
+#define LOOPS 10
+void platform_calibrate_ccount(void)
+{
+	u32 uninitialized_var(a);
+	u32 uninitialized_var(u);
+	u32 b;
+	u32 tstamp = S6_REG_GREG1 + S6_GREG1_GLOBAL_TIMER;
+	int i = LOOPS+1;
+	do {
+		u32 t = u;
+		asm volatile(
+		"1:	l32i %0, %2, 0 ;"
+		"	beq %0, %1, 1b ;"
+		: "=&a"(u) : "a"(t), "a"(tstamp));
+		b = xtensa_get_ccount();
+		if (i == LOOPS)
+			a = b;
+	} while (--i >= 0);
+	b -= a;
+	nsec_per_ccount = (LOOPS * 10000) / b;
+	ccount_per_jiffy = b * (100000UL / (LOOPS * HZ));
+}
-- 
1.6.2.107.ge47ee

[patch 3/3] xtensa: update s6105_defconfig for ccount calibration

[Oskar Schirmer]

The previous patch enabled ccount calibration for the s6000 variant.
This patch updates the defconfig for the s6105 platform to reflect this
change.

Signed-off-by: Oskar Schirmer <os@emlix.com>
---
 arch/xtensa/configs/s6105_defconfig |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/configs/s6105_defconfig b/arch/xtensa/configs/s6105_defconfig
index 6ced233..8eec578 100644
--- a/arch/xtensa/configs/s6105_defconfig
+++ b/arch/xtensa/configs/s6105_defconfig
@@ -115,7 +115,7 @@ CONFIG_XTENSA_VARIANT_S6000=y
 CONFIG_PREEMPT=y
 # CONFIG_MATH_EMULATION is not set
 # CONFIG_HIGHMEM is not set
-# CONFIG_XTENSA_CALIBRATE_CCOUNT is not set
+CONFIG_XTENSA_CALIBRATE_CCOUNT=y
 CONFIG_SERIAL_CONSOLE=y
 # CONFIG_XTENSA_ISS_NETWORK is not set
 
@@ -131,7 +131,6 @@ CONFIG_SERIAL_CONSOLE=y
 # CONFIG_XTENSA_PLATFORM_ISS is not set
 # CONFIG_XTENSA_PLATFORM_XT2000 is not set
 CONFIG_XTENSA_PLATFORM_S6105=y
-CONFIG_XTENSA_CPU_CLOCK=300
 CONFIG_GENERIC_CALIBRATE_DELAY=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE="console=ttyS1,38400 debug bootmem_debug loglevel=7"
-- 
1.6.2.107.ge47ee