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SubjectRe: [PATCH v5 8/8] ARM: brcmstb: dts: add a reference DTS for Broadcom 7445
Hi Mark,

> As I commented on v3 [1], these are contiguous and can be described with
> a single entry:
>
> memory {
> device_type = "memory";
> reg = <0x0 0x00000000 0x0 0xc0000000>;
> };
>
> Is there any reason to have three entries?

Oopsies, sorry for missing that.

On BCM7445 and derivatives, there are 3 memory controllers. For each memory controller,
the first 1GB of physical DRAM is mapped to:

* 0x00_0000_0000
* 0x00_4000_0000
* 0x00_8000_0000

The memory controllers aren't interleaved. So, it's possible for the SoC to have a
discontiguous memory-mapping, where a designer chooses not to populate physical DRAM in
the middle.

The 'reg' property was broken-up to have each chunk of memory given a dedicated memblock.

All that said, if you like, I can rework the patch as you've suggested.

Thanks,
Marc C


On 01/24/2014 03:09 AM, Mark Rutland wrote:
> On Wed, Jan 22, 2014 at 03:30:52AM +0000, Marc Carino wrote:
>> Add a sample DTS which will allow bootup of a board populated
>> with the BCM7445 chip.
>>
>> Signed-off-by: Marc Carino <marc.ceeeee@gmail.com>
>> Acked-by: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>> arch/arm/boot/dts/bcm7445.dts | 111 +++++++++++++++++++++++++++++++++++++++++
>> 1 files changed, 111 insertions(+), 0 deletions(-)
>> create mode 100644 arch/arm/boot/dts/bcm7445.dts
>>
>> diff --git a/arch/arm/boot/dts/bcm7445.dts b/arch/arm/boot/dts/bcm7445.dts
>> new file mode 100644
>> index 0000000..ffa3305
>> --- /dev/null
>> +++ b/arch/arm/boot/dts/bcm7445.dts
>> @@ -0,0 +1,111 @@
>> +/dts-v1/;
>> +/include/ "skeleton.dtsi"
>> +
>> +/ {
>> + #address-cells = <2>;
>> + #size-cells = <2>;
>> + model = "Broadcom STB (bcm7445)";
>> + compatible = "brcm,bcm7445", "brcm,brcmstb";
>> + interrupt-parent = <&gic>;
>> +
>> + chosen {};
>> +
>> + memory {
>> + device_type = "memory";
>> + reg = <0x00 0x00000000 0x00 0x40000000>,
>> + <0x00 0x40000000 0x00 0x40000000>,
>> + <0x00 0x80000000 0x00 0x40000000>;
>> + };
> As I commented on v3 [1], these are contiguous and can be described with
> a single entry:
>
> memory {
> device_type = "memory";
> reg = <0x0 0x00000000 0x0 0xc0000000>;
> };
>
> Is there any reason to have three entries?
>
> Thanks,
> Mark.
>
> [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2014-January/225899.html
>



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