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    SubjectRe: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus
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    于 2018年3月22日 GMT+08:00 上午1:13:42, "Jernej Škrabec" <jernej.skrabec@siol.net> 写到:
    >Hi all,
    >
    >Dne sreda, 21. marec 2018 ob 03:18:13 CET je Icenowy Zheng napisal(a):
    >> 于 2018年3月21日 GMT+08:00 上午2:46:46, Maxime Ripard
    ><maxime.ripard@bootlin.com>
    >写到:
    >> >On Sat, Mar 17, 2018 at 01:53:49AM +0800, Icenowy Zheng wrote:
    >> >> All the sub-blocks of Allwinner A64 DE2 needs the SRAM C on A64
    >SoC
    >> >
    >> >to
    >> >
    >> >> be claimed, otherwise the whole DE2 space is inaccessible.
    >> >>
    >> >> Add a device tree binding of the DE2 part as a sub-bus.
    >> >
    >> >Where did you get the info that it was a bus?
    >>
    >> There's no direct evidence, just some guess.
    >>
    >> The DE2 is a whole part that is just allocated a memory
    >> space at the user manual, and the SRAM controls the
    >> access to all modules in the DE2.
    >>
    >> So it might be a bus.
    >>
    >> Implement it as a bus is a clear representation on A64.
    >
    >Since there is already syscon for same mmio region, we migh as well use
    >it
    >when loading ccu-sun8i-de2 driver on A64.
    >
    >Other options, like SRAM driver or bus driver, might better represent
    >HW, but

    I think the device tree should properly represent the HW,
    it's a basic requirment.

    >then we would have two DT nodes covering same mmio region, which I
    >think is
    >not really acceptable.

    It's acceptable, and DE2 is not the only user of SRAM controller so far.

    VE will also need a SRAM region to be claimed.

    >
    >Any suggestions?
    >
    >BTW, H6 has same design in this regard.
    >
    >Best regards,
    >Jernej

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