Messages in this thread | | | Subject | Re: [PATCH V5 2/7] clocksource: tegra: add Tegra210 timer support | From | Joseph Lo <> | Date | Fri, 1 Feb 2019 23:37:04 +0800 |
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On 2/1/19 11:13 PM, Dmitry Osipenko wrote: > 01.02.2019 17:13, Joseph Lo пишет: >> On 2/1/19 9:54 PM, Jon Hunter wrote: >>> >>> On 01/02/2019 13:11, Dmitry Osipenko wrote: >>>> 01.02.2019 16:06, Dmitry Osipenko пишет: >>>>> 01.02.2019 6:36, Joseph Lo пишет: >>>>>> Add support for the Tegra210 timer that runs at oscillator clock >>>>>> (TMR10-TMR13). We need these timers to work as clock event device and to >>>>>> replace the ARMv8 architected timer due to it can't survive across the >>>>>> power cycle of the CPU core or CPUPORESET signal. So it can't be a wake-up >>>>>> source when CPU suspends in power down state. >>>>>> >>>>>> Also convert the original driver to use timer-of API. >>>>>> >>>>>> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> >>>>>> Cc: Thomas Gleixner <tglx@linutronix.de> >>>>>> Cc: linux-kernel@vger.kernel.org >>>>>> Signed-off-by: Joseph Lo <josephl@nvidia.com> >>>>>> Acked-by: Thierry Reding <treding@nvidia.com> >>>>>> --- snip. >>>>>> +} >>>>>> +TIMER_OF_DECLARE(tegra210_timer, "nvidia,tegra210-timer", tegra210_timer_init); >>>>>> +#else /* CONFIG_ARM */ >>>>>> +static int __init tegra20_init_timer(struct device_node *np) >>>>>> +{ >>>>> What about T132? Isn't it ARM64 which uses tegra20-timer IP? At least T132 DT suggests so and seems this change will break it. >>>>> >>>>> [snip] >>>>> >>>> >>>> Ah, noticed the "depends on ARM" in Kconfig.. Seems okay then. >>>> >>> >>> >>> This is a good point, because even though we had 'depends on ARM', this >>> still means that the Tegra132 DT is incorrect. >>> >>> Joseph, can you take a quick look at Tegra132? >> >> Hi Jon and Dmitry, >> >> No worry about T132, T132 uses arch timer (v7). The tegra20 timer driver has never been used. We should fix the dtsi file later. > > Hi Joseph, > > So is T132 HW actually incompatible with the tegra20-timer? If it's compatible, then I think the driver's code should be made more universal to support T132. >
From HW point of view, the TIMER1 ~ TIMER4 is compatible with "nvidia,tegra20-timer". But Tegra132 actually has 10 timers which are exactly the same as Tegra30. So it should backward compatible with "nvidia,tegra30-timer", which is tegra_wdt driver now. And Tegra132 should never use this driver.
The Tegra timer driver should only be used on Tegra20/30/210, three platforms only. Others use arch timer driver for system timer driver.
So we don't really need to take care the usage on other Tegra platforms.
Thanks, Joseph
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