[PATCH v5 1/7] soc: sunxi: sram: export register 0 for THS on H616

[Daniel Lezcano]

On 23/02/2024 17:02, Andre Przywara wrote:
> On Thu, 22 Feb 2024 19:44:12 +0100
> Daniel Lezcano <daniel.lezcano at linaro.org> wrote:
> 
> Hi Daniel,
> 
>> On 22/02/2024 19:26, Jernej Škrabec wrote:
>>> Dne ponedeljek, 19. februar 2024 ob 16:36:33 CET je Andre Przywara napisal(a):
>>>> The Allwinner H616 SoC contains a mysterious bit at register offset 0x0
>>>> in the SRAM control block. If bit 16 is set (the reset value), the
>>>> temperature readings of the THS are way off, leading to reports about
>>>> 200C, at normal ambient temperatures. Clearing this bits brings the
>>>> reported values down to the expected values.
>>>> The BSP code clears this bit in firmware (U-Boot), and has an explicit
>>>> comment about this, but offers no real explanation.
>>>>
>>>> Experiments in U-Boot show that register 0x0 has no effect on the SRAM C
>>>> visibility: all tested bit settings still allow full read and write
>>>> access by the CPU to the whole of SRAM C. Only bit 24 of the register at
>>>> offset 0x4 makes all of SRAM C inaccessible by the CPU. So modelling
>>>> the THS switch functionality as an SRAM region would not reflect reality.
>>>>
>>>> Since we should not rely on firmware settings, allow other code (the THS
>>>> driver) to access this register, by exporting it through the already
>>>> existing regmap. This mimics what we already do for the LDO control and
>>>> the EMAC register.
>>>>
>>>> To avoid concurrent accesses to the same register at the same time, by
>>>> the SRAM switch code and the regmap code, use the same lock to protect
>>>> the access. The regmap subsystem allows to use an existing lock, so we
>>>> just need to hook in there.
>>>>
>>>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>>>
>>> Reviewed-by: Jernej Skrabec <jernej.skrabec at gmail.com>
>>>
>>> I guess this one goes through sunxi tree, right?
>>
>> I'll pick this patch along with the patch 2-6, so through the thermal
>> tree. The patch 7/7 will go indeed via the sunxi tree
> 
> many thanks for picking those up! I see them in your bleeding-edge branch,
> but are they on route for 6.9, so will you put them in -next soon? Or are
> you waiting for more ACKs?

I've enough ack. The bleeding-edge is merged with the linux-pm tree. If 
everything is going well, I will move it to the linux-next branch 
probably today or Monday



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