Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Maxime Ripard]

On Tue, Mar 27, 2018 at 07:31:18AM +0800, Icenowy Zheng wrote:
> 
> 
> 于 2018年3月27日 GMT+08:00 上午6:22:58, Rob Herring  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"
> > 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
> >> > 
> >> >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?

We could have a single DT node that would export a syscon yes, just
like you did for the R40 ethernet case.

I'm not sure the SRAM controller itself needs to take the syscon, it
just can export its own.

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com


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Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Maxime Ripard]

On Tue, Mar 27, 2018 at 07:31:18AM +0800, Icenowy Zheng wrote:
> 
> 
> 于 2018年3月27日 GMT+08:00 上午6:22:58, Rob Herring  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"
> > 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
> >> > 
> >> >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?

We could have a single DT node that would export a syscon yes, just
like you did for the R40 ethernet case.

I'm not sure the SRAM controller itself needs to take the syscon, it
just can export its own.

Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com


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Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Icenowy Zheng]

于 2018年3月27日 GMT+08:00 上午6:22:58, Rob Herring  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"
> 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
>> > 
>> >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 majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>___
>linux-arm-kernel mailing list
>linux-arm-ker...@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Icenowy Zheng]

于 2018年3月27日 GMT+08:00 上午6:22:58, Rob Herring  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"
> 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
>> > 
>> >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 majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>___
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>linux-arm-ker...@lists.infradead.org
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Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Rob Herring]

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"  
> 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
> > 
> >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 majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Rob Herring]

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"  
> 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
> > 
> >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 majord...@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Icenowy Zheng]

于 2018年3月22日 GMT+08:00 上午1:13:42, "Jernej Škrabec"  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
> 
>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

Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Icenowy Zheng]

于 2018年3月22日 GMT+08:00 上午1:13:42, "Jernej Škrabec"  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
> 
>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

Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Jernej Škrabec]

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

Any suggestions?

BTW, H6 has same design in this regard.

Best regards,
Jernej

Re: [linux-sunxi] Re: [PATCH 2/7] dt-bindings: add binding for the Allwinner A64 DE2 bus

[Jernej Škrabec]

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

Any suggestions?

BTW, H6 has same design in this regard.

Best regards,
Jernej