[v2 5/9] clocksource: tegra: Enable ARM arch_timer with TSC

Marc Zyngier marc.zyngier at arm.com
Thu Jan 10 10:10:31 EST 2013


On 10/01/13 15:03, Hiroshi Doyu wrote:
> Hi Mark,
> 
> Marc Zyngier <marc.zyngier at arm.com> wrote @ Wed, 9 Jan 2013 10:01:05 +0100:
> 
>> Almost. I already proposed this in the past, but because the source clock
>> is variable in the Tegra case, this is not flexible enough.
>>
>> What I was suggesting was to do the following:
>>
>> timer {
>>         compatible = "arm,armv7-timer";
>>         [...]
>>         clocks = <&tsc>;
>> }
>>
>> tsc: tsc {
>>         compatible = "nvidia,tegra114-tsc";
>>         reg = <0x700f0000 0x20000>;
>>         freq-range = <... ...>;
>>         clock-output-names = "tsc";
>> }
>>
>> In the arch_timer code, start searching for the "clocks" property, and use
>> that if there is one. Otherwise, fall back to "clock-frequency", and
>> ultimately to reading CNTFRQ.
>>
>> This requires some changes (converting the tsc code to be a clock), but
>> this is at least a proper description of the hardware, and should give you
>> the required flexibility.
> 
> The above seems ok to me. I'll drop this original patch from this
> series for now until T114 clock comes to implement correctly.

Thanks Hiroshi. Please Cc me when you have a patch implementing this
functionality.

	M.
-- 
Jazz is not dead. It just smells funny...




More information about the linux-arm-kernel mailing list