Message-ID: <0b224700-4774-0c34-7ce1-0a984b62b3c0@quicinc.com>
Date:   Mon, 23 Jan 2023 10:14:26 +0530
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Subject: Re: [PATCH 2/2] arm64: dts: qcom: ipq8074: add QFPROM node
To:     Robert Marko <robimarko@gmail.com>
CC:     <agross@kernel.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.org>, <srinivas.kandagatla@linaro.org>,
        <robh+dt@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
        <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20230121112358.52216-1-robimarko@gmail.com>
 <20230121112358.52216-2-robimarko@gmail.com>
 <ebdd9932-e251-0cd7-6c98-3c735ecb74a6@quicinc.com>
 <CAOX2RU7p-0ZTx8fkY4hOk=Zmx6RT+1PwVL+CQxkjzVadm0ehTA@mail.gmail.com>
 <29d9de45-1ce7-d6e5-bf02-052e911a067b@quicinc.com>
 <CAOX2RU7BfESmsUdZ5jBfYjWXUnDWmFizT8UiPwgzb_SsrT0jnA@mail.gmail.com>
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From:   Kathiravan Thirumoorthy <quic_kathirav@quicinc.com>
In-Reply-To: <CAOX2RU7BfESmsUdZ5jBfYjWXUnDWmFizT8UiPwgzb_SsrT0jnA@mail.gmail.com>
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On 1/22/2023 10:39 PM, Robert Marko wrote:
> On Sun, 22 Jan 2023 at 18:05, Kathiravan Thirumoorthy
> <quic_kathirav@quicinc.com> wrote:
>>
>> On 1/22/2023 10:29 PM, Robert Marko wrote:
>>> On Sun, 22 Jan 2023 at 17:57, Kathiravan Thirumoorthy
>>> <quic_kathirav@quicinc.com> wrote:
>>>> On 1/21/2023 4:53 PM, Robert Marko wrote:
>>>>> IPQ8074 has efuses like other Qualcomm SoC-s that are required for
>>>>> determining various HW quirks which will be required later for CPR etc,
>>>>> so lets add the QFPROM node for start.
>>>>>
>>>>> Individidual fuses will be added as they are required.
>>>>>
>>>>> Signed-off-by: Robert Marko <robimarko@gmail.com>
>>>>> ---
>>>>>     arch/arm64/boot/dts/qcom/ipq8074.dtsi | 7 +++++++
>>>>>     1 file changed, 7 insertions(+)
>>>>>
>>>>> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>>>>> index 8eba586065a3..f29491f647fe 100644
>>>>> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>>>>> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>>>>> @@ -301,6 +301,13 @@ mdio: mdio@90000 {
>>>>>                         status = "disabled";
>>>>>                 };
>>>>>
>>>>> +             qfprom: efuse@a4000 {
>>>>> +                     compatible = "qcom,ipq8074-qfprom", "qcom,qfprom";
>>>>> +                     reg = <0x000a4000 0x1000>;
>>>>    From the HW document, I see the overall size of this region is 0x2000,
>>>> any reason to stick with 0x1000?
>>> Like always, I dont have access to docs and 0x1000 is all I could find
>>> downstream
>>> being used.
>>>
>>> Any chance you can share the regions inside of QFPROM, it would be great to use
>>> the ECC corrected one if available.
>> Sorry, What do you refer by "ECC corrected" here?
> Isnt there a corrected region in the QFPROM meant for reading?
> As far as I understand it's protected by FEC.


Yes, there are two regions for the QFPROM, the region which you used 
here is the one used for reading and there is a error correction logic 
for it and it is size is 8KB not 4KB.

Thanks, Kathiravan T.

>
> Regards,
> Robert
>> Thanks, Kathiravan T.
>>
>>
>>> Regards,
>>> Robert
>>>> Thanks, Kathiravan T.
>>>>
>>>>
>>>>> +                     #address-cells = <1>;
>>>>> +                     #size-cells = <1>;
>>>>> +             };
>>>>> +
>>>>>                 prng: rng@e3000 {
>>>>>                         compatible = "qcom,prng-ee";
>>>>>                         reg = <0x000e3000 0x1000>;