Re: [PATCH v2 2/2] clocksource/drivers/mtk_systimer: Add support for Mediatek SoCs

From: Stanley Chu
Date: Wed Jun 27 2018 - 05:50:29 EST


On Wed, 2018-06-27 at 11:39 +0200, Daniel Lezcano wrote:
> On 27/06/2018 09:53, Stanley Chu wrote:
> > This patch adds a new clock event for the timer
> > found on the Mediatek SoCs.
> >
> > The Mediatek System Timer has several 32-bit timers.
> > Only one timer is used by this driver as a clock event
> > supporting oneshot events.
> >
> > The System Timer can be run with two clocks. A 13 MHz system
> > clock and the RTC clock running at 32 KHz. This implementation
> > uses the system clock with no clock source divider.
>
> Recent platforms have the arch_arm_timer and it will be always selected.
>
> What is the benefit of adding this timer ?
>
>
Hi Daniel,

To save power as much as possible, our platform enables
"arch_timer_c3stop" in arch_arm_timer, and thus another always-on timer
is required for tick-broadcasting. System Timer is introduced for above
purpose.

Thanks.
Stanley Chu