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Message-ID: <38c3977a-0196-1832-ff94-317064cbc439@linaro.org>
Date:   Tue, 9 Aug 2022 07:18:34 +0300
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Subject: Re: [PATCH 1/3] dt-bindings: spi: stm32: Add st,dual-flash property
 in st,stm32-qspi.yaml
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To:     Patrice CHOTARD <patrice.chotard@foss.st.com>,
        Mark Brown <broonie@kernel.org>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org
Cc:     linux-spi@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        christophe.kerello@foss.st.com, devicetree@vger.kernel.org
References: <20220808074051.44736-1-patrice.chotard@foss.st.com>
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 <79fd7e19-ceef-14fb-5a83-603740735f8f@foss.st.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <79fd7e19-ceef-14fb-5a83-603740735f8f@foss.st.com>
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On 08/08/2022 19:08, Patrice CHOTARD wrote:
> Hi Krzystof
> 
> On 8/8/22 11:01, Krzysztof Kozlowski wrote:
>> On 08/08/2022 10:40, patrice.chotard@foss.st.com wrote:
>>> From: Patrice Chotard <patrice.chotard@foss.st.com>
>>>
>>> Add new property st,dual-flash which allows to use the QSPI interface as a
>>> communication channel using up to 8 qspi line.
>>> This mode can only be used if cs-gpios property is defined.
>>>
>>> Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
>>> ---
>>>  Documentation/devicetree/bindings/spi/st,stm32-qspi.yaml | 8 ++++++++
>>>  1 file changed, 8 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/spi/st,stm32-qspi.yaml b/Documentation/devicetree/bindings/spi/st,stm32-qspi.yaml
>>> index 6ec6f556182f..5e4f9109799e 100644
>>> --- a/Documentation/devicetree/bindings/spi/st,stm32-qspi.yaml
>>> +++ b/Documentation/devicetree/bindings/spi/st,stm32-qspi.yaml
>>> @@ -46,6 +46,14 @@ properties:
>>>        - const: tx
>>>        - const: rx
>>>  
>>> +  st,dual-flash:
>>> +    type: boolean
>>> +    description:
>>> +      Allows to use 8 data lines in case cs-gpios property is defined.
>>
>> It's named dual-flash, but what if you want to use QSPI to connect for
>> example to FPGA?
>>
>> Also how is this related to parallel-memories property?
> 
> I called it "dual-flash" simply because it enable the dual flash feature of the QSPI block (bit CR_DFM : Dual Flash Mode)
> which allows to use the 8 lines simultaneously of our dual QSPI block.

And how is it related to existing parallel-memories property?

Best regards,
Krzysztof