Re: [PATCH 3/5] Documentation: synopsys-dw-mshc: add binding for fifo quirks

[Shawn Lin <shawn.lin@rock-chips.com>]

On 2016/10/25 10:16, Jaehoon Chung wrote:
> On 10/24/2016 09:19 PM, Shawn Lin wrote:
>> On 2016/10/24 17:11, Jun Nie wrote:
>>> Add fifo-addr-override property and fifo-watermark-quirk property to
>>> synopsys-dw-mshc bindings. It is intended to provide workarounds to
>>> support more SoCs that break current assumption.
>>>
>>> See Documentation/devicetree/bindings/reset/reset.txt for details.
>>>
>>> Signed-off-by: Jun Nie <jun.nie@linaro.org>
>>> ---
>>>  Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt | 13 +++++++++++++
>>>  1 file changed, 13 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
>>> index 4e00e85..eb64921 100644
>>> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
>>> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
>>> @@ -76,6 +76,17 @@ Optional properties:
>>>
>>>  * broken-cd: as documented in mmc core bindings.
>>>
>>> +* fifo-addr-override: Override fifo address with value provided by DT. The FIFO
>>> +  reg offset of version 0x210A break current assumption that 0x100 (version < 0x240A)
>>> +  and 0x200(version >= 0x240A) in some implementation. So this property serves as
>>> +  workaround.
>>
>> Can we hardcode this to the code by checking the host version?
>
> I think it should be not workaround..According to TRM, Address is equal or greater than 0x100.
> It means address can be 0x200, right?
> If you needs to overwrite the DATA register offset for your target, just can add the property for this.
>

I can't follow yours here as I don't have 210A TRM. Do you mean the TRM
for 210A say: "Address  is equal or greater than 0x100"  ?

>>
>>> +
>>> +* fifo-watermark-quirk: Data done irq is expected if data length is less than
>>> +  watermark in PIO mode. But fifo watermark is requested to be aligned with data
>>> +  length in some SoC so that TX/RX irq can be generated with data done irq. Add the
>>> +  watermark quirk to mark this requirement and force fifo watermark setting
>>> +  accordingly.
>>
>> I would like to know if this limitation is *really* related to some
>> Socs or the version of 210A dw_mmc?
>>
>>
>>> +
>>>  * vmmc-supply: The phandle to the regulator to use for vmmc.  If this is
>>>    specified we'll defer probe until we can find this regulator.
>>>
>>> @@ -103,6 +114,8 @@ board specific portions as listed below.
>>>          interrupts = <0 75 0>;
>>>          #address-cells = <1>;
>>>          #size-cells = <0>;
>>> +        fifo-addr-override = <0x200>;
>>> +        fifo-watermark-quirk;
>>>      };
>>>
>>>  [board specific internal DMA resources]
>>>
>>
>>
>
>
>
>


-- 
Best Regards
Shawn Lin