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

>
> 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

\
 
 \ /
  Last update: 2018-03-27 00:24    [W:0.064 / U:8.508 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site