summaryrefslogtreecommitdiff
path: root/arch/arm
diff options
context:
space:
mode:
authorMagnus Damm <magnus.damm@gmail.com>2010-07-29 14:03:04 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-07-29 22:32:28 +0100
commit5da3e714e30d40145f4dd37d79de6bbbcb9e6137 (patch)
tree791495aeb84cda5559229d6c310446236bbbe1c2 /arch/arm
parent58c7d9d2e6116ec694a5af5b8a0aca1467673899 (diff)
ARM: 6277/1: mach-shmobile: Allow users to select HZ, default to 128
Introduce SHMOBILE_TIMER_HZ for SH-Mobile. Allow users to select HZ on their system to minimize potential timer drift. Use 128 Hz as default to work well with the 32768 Hz RCLK. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/Kconfig1
-rw-r--r--arch/arm/mach-shmobile/Kconfig12
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 98922f7d2d12..db4f2ee3a750 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1189,6 +1189,7 @@ config HZ
default 200 if ARCH_EBSA110 || ARCH_S3C2410 || ARCH_S5P6440 || ARCH_S5P6442 || ARCH_S5PV210
default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
default AT91_TIMER_HZ if ARCH_AT91
+ default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE
default 100
config THUMB2_KERNEL
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index f2b88c5fe142..4c704b4e8b34 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -70,6 +70,18 @@ endmenu
menu "Timer and clock configuration"
+config SHMOBILE_TIMER_HZ
+ int "Kernel HZ (jiffies per second)"
+ range 32 1024
+ default "128"
+ help
+ Allows the configuration of the timer frequency. It is customary
+ to have the timer interrupt run at 1000 Hz or 100 Hz, but in the
+ case of low timer frequencies other values may be more suitable.
+ SH-Mobile systems using a 32768 Hz RCLK for clock events may want
+ to select a HZ value such as 128 that can evenly divide RCLK.
+ A HZ value that does not divide evenly may cause timer drift.
+
config SH_TIMER_CMT
bool "CMT timer driver"
default y