lkml.org 
[lkml]   [2018]   [Mar]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus
From


于 2018年3月27日 GMT+08:00 上午6:22:58, Rob Herring <robh@kernel.org> 写到:
>On Thu, Mar 22, 2018 at 02:08:43PM +0800, Icenowy Zheng wrote:
>>
>>
>> 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.
>
>No, it's not acceptable. Don't create overlapping mmio regions in DT.

Then should the SRAM controller driver be configured to take the syscon?

>
>>
>> VE will also need a SRAM region to be claimed.
>>
>> >
>> >Any suggestions?
>> >
>> >BTW, H6 has same design in this regard.
>> >
>> >Best regards,
>> >Jernej
>> --
>> To unsubscribe from this list: send the line "unsubscribe devicetree"
>in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

\
 
 \ /
  Last update: 2018-03-27 01:32    [W:0.065 / U:0.136 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site