Messages in this thread | | | Date | Wed, 05 Feb 2014 13:17:09 -0700 | From | Stephen Warren <> | Subject | Re: [PATCH v2 1/3] clocksource: tegra: Add nvidia,tegra30-timer compat |
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On 02/05/2014 01:06 PM, Andrew Chew wrote: >> On 02/03/2014 05:17 PM, Andrew Chew wrote: >>> There are some differences between tegra20's timer registers and >>> tegra30's (and later). For example, tegra30 has more timers. In >>> addition, watchdogs are not present in tegra20. >>> >>> Add this compatibility string in order to be able to distinguish >>> whether the additional timers and watchdogs are there or not. >> >>> diff --git a/drivers/clocksource/tegra20_timer.c >>> b/drivers/clocksource/tegra20_timer.c >> >>> CLOCKSOURCE_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", >>> tegra20_init_timer); >>> +CLOCKSOURCE_OF_DECLARE(tegra30_timer, "nvidia,tegra30-timer", >>> +tegra20_init_timer); >> >> Thinking about this more, nothing in this driver actually cares about >> Tegra20 vs. Tegra30+, since the timer that's used is present in all chips. >> Hence, this patch isn't needed. > > Don't I need to add nvidia,tegra30-timer so that the tegra WDT driver > can match against it? It would be weird to have the tegra WDT driver > bind against nvidia,tegra20-timer when the tegra WDT driver as it is won't > work at all on tegra20.
The DT files need to contain all of:
* The specific SoC (this is already present) * nvidia,tegra30-timer for SoCs >= Tegra30 (this is missing) * nvidia,tegra20-timer for all SoCs (this is already present)
However, since all DTs will contain nvidia,tegra20-timer, since all HW is backwards-compatible IIUC, any code that only cares about the parts that have existed since Tegra20 only need match against the Tegra20 compatible value.
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