On 08/05/13 15:38, Arnd Bergmann wrote: > On Wednesday 08 May 2013, Srinivas KANDAGATLA wrote: >> From: Stuart Menefy <stuart.menefy@xxxxxx> >> >> This is a simple driver for the global timer module found in the Cortex >> A9-MP cores from revision r1p0 onwards. This should be able to perform >> the functions of the system timer and the local timer in an SMP system. >> >> The global timer has the following features: >> The global timer is a 64-bit incrementing counter with an >> auto-incrementing feature. It continues incrementing after sending >> interrupts. The global timer is memory mapped in the private memory >> region. >> The global timer is accessible to all Cortex-A9 processors in the >> cluster. Each Cortex-A9 processor has a private 64-bit comparator that >> is used to assert a private interrupt when the global timer has reached >> the comparator value. All the Cortex-A9 processors in a design use the >> banked ID, ID27, for this interrupt. ID27 is sent to the Interrupt >> Controller as a Private Peripheral Interrupt. The global timer is >> clocked by PERIPHCLK. >> >> Signed-off-by: Stuart Menefy <stuart.menefy@xxxxxx> >> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx> >> > > Are you sure we don't already have a driver for this? It sounds unlikely > that you are the first one to do this when the hardware is so common. Yes, in mainline we do not have support to this. > >> Documentation/devicetree/bindings/arm/gt.txt | 21 ++ >> arch/arm/Kconfig | 6 + >> arch/arm/include/asm/global_timer.h | 12 + >> arch/arm/kernel/Makefile | 1 + >> arch/arm/kernel/global_timer.c | 325 ++++++++++++++++++++++++++ >> 5 files changed, 365 insertions(+), 0 deletions(-) >> create mode 100644 Documentation/devicetree/bindings/arm/gt.txt >> create mode 100644 arch/arm/include/asm/global_timer.h >> create mode 100644 arch/arm/kernel/global_timer.c > > Move it into drivers/clocksource? Sure, I will move this in the next version. > >> diff --git a/arch/arm/include/asm/global_timer.h b/arch/arm/include/asm/global_timer.h >> new file mode 100644 >> index 0000000..46f9188 >> --- /dev/null >> +++ b/arch/arm/include/asm/global_timer.h >> @@ -0,0 +1,12 @@ >> +int __init global_timer_init(void __iomem *base, unsigned int timer_irq); > > I don't see a need to call this from platform code for non-DT platforms, it > can easily be used with CLOCKSOURCE_OF_DECLARE() all the time I think. sorry Am confused here. How would this work for non-DT? Looking at the code in clocksource_of_init it just goes through the of_device_id table, which is not used in case of non-DT. > > Arnd > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
