Hi,
On 02/27/2016 12:43 AM, Tony Lindgren wrote:
> Hi,
>
> * Vignesh R <vigneshr@xxxxxx> [160224 20:49]:
>> According to Data Manual(SPRS915P) of AM57x, TI QSPI controller on
>> DRA74(rev 1.1+) can support up to 64MHz in MODE-0, whereas MODE-3 is
>> limited to 48MHz. Hence, switch to MODE-0 for better throughput.
>>
>> Signed-off-by: Vignesh R <vigneshr@xxxxxx>
>> ---
>> arch/arm/boot/dts/dra7-evm.dts | 6 ++----
>> 1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/dra7-evm.dts b/arch/arm/boot/dts/dra7-evm.dts
>> index cfc24e52244e..15f10bdc8c31 100644
>> --- a/arch/arm/boot/dts/dra7-evm.dts
>> +++ b/arch/arm/boot/dts/dra7-evm.dts
>> @@ -653,15 +653,13 @@
>> pinctrl-names = "default";
>> pinctrl-0 = <&qspi1_pins>;
>>
>> - spi-max-frequency = <48000000>;
>> + spi-max-frequency = <64000000>;
>> m25p80@0 {
>> compatible = "s25fl256s1";
>> - spi-max-frequency = <48000000>;
>> + spi-max-frequency = <64000000>;
>> reg = <0>;
>> spi-tx-bus-width = <1>;
>> spi-rx-bus-width = <4>;
>> - spi-cpol;
>> - spi-cpha;
>> #address-cells = <1>;
>> #size-cells = <1>;
>>
>
> Do we have any earlier pre DRA74(rev 1.1)versions in use too?
Yes, there are pre 1.1 boards (production boards are all rev 1.1+), but
QSPI is broken on them due to erratas (even w/o this patch).
>
> What about the spi-cpol and spi-cpha changes? Those should be
> at least documented?
>
Ok, I will add a NOTE in the documentation saying "spi-cpol" and
"spi-cpha" are not supported by ti-qspi in
Documentation/devicetree/bindings/spi/ti_qspi.txt.
--
Regards
Vignesh
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