# Re: \[PATCH v2 04/18\] clocksource: Add ARM System timer driver

- From: Uwe Kleine-König \<hidden\>
- Date: 2015-02-20 19:55:27 
- List: linux-devicetree
- Page: https://ratatoskr.run/linux-devicetree/2015/02/4434835
- Thread: https://ratatoskr.run/linux-arm-kernel/2015/02/4434727/t.md

```text
Hello,

On Fri, Feb 20, 2015 at 07:01:03PM +0100, Maxime Coquelin wrote:
> This patch adds clocksource support for ARMv7-M's System timer,
> also known as SysTick.
> 
> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> ---
>  drivers/clocksource/Kconfig          |  7 ++++
>  drivers/clocksource/Makefile         |  1 +
>  drivers/clocksource/armv7m_systick.c | 78 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 86 insertions(+)
>  create mode 100644 drivers/clocksource/armv7m_systick.c
> 
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index fc01ec2..fb6011e 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -124,6 +124,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
>  	help
>  	 Use ARM global timer clock source as sched_clock
>  
> +config ARMV7M_SYSTICK
> +	bool
I assume this symbol is enabled later in the series. Would it make sense
to allow enabing the symbol for compile test coverage?

> +	select CLKSRC_OF if OF
What happens if ARMV7M_SYSTICK=y but OF=n? Doesn't the driver fail to
compile?

> +	select CLKSRC_MMIO
> +	help
> +	  This options enables support for the ARMv7M system timer unit
the right spelling is ARMv7-M.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
```