Re: [PATCH v3 2/4] dt-bindings: nvmem: Add properties needed for blowing fuses

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: Douglas Anderson <dianders@chromium.org>,
	Rob Herring <robh+dt@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Andy Gross <agross@kernel.org>
Cc: dhavalp@codeaurora.org, mturney@codeaurora.org,
	rnayak@codeaurora.org, Ravi Kumar Bokka <rbokka@codeaurora.org>,
	linux-arm-msm@vger.kernel.org, saiprakash.ranjan@codeaurora.org,
	sparate@codeaurora.org, mkurumel@codeaurora.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/4] dt-bindings: nvmem: Add properties needed for blowing fuses
Date: Wed, 17 Jun 2020 16:19:01 +0100	[thread overview]
Message-ID: <254998b9-c45e-bd6b-bc9a-b5934c0fea8e@linaro.org> (raw)
In-Reply-To: <20200617074930.v3.2.I3b5c3bfaf5fb2d28d63f1b5ee92980900e3f8251@changeid>

On 17/06/2020 15:51, Douglas Anderson wrote:
> From: Ravi Kumar Bokka <rbokka@codeaurora.org>
> 
> On some systems it's possible to actually blow the fuses in the qfprom
> from the kernel.  Add properties to support that.
> 
> NOTE: Whether this is possible depends on the BIOS settings and
> whether the kernel has permissions here, so not all boards will be
> able to blow fuses in the kernel.
> 
> Signed-off-by: Ravi Kumar Bokka <rbokka@codeaurora.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
> Changes in v3:
> - Add an extra reg range (at 0x6000 offset for SoCs checked)
> - Define two options for reg: 1 item or 4 items.
> - No reg-names.
> - Add "clocks" and "clock-names" to list of properties.
> - Clock is now "sec", not "secclk".
> - Add "vcc-supply" to list of properties.
> - Fixed up example.
> 
>   .../bindings/nvmem/qcom,qfprom.yaml           | 45 ++++++++++++++++++-
>   1 file changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> index 5efa5e7c4d81..b195212c6193 100644
> --- a/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/qcom,qfprom.yaml
> @@ -17,8 +17,27 @@ properties:
>       const: qcom,qfprom
>   
>     reg:
> -    items:
> -      - description: The corrected region.
> +    # If the QFPROM is read-only OS image then only the corrected region
> +    # needs to be provided.  If the QFPROM is writable then all 4 regions
> +    # must be provided.
> +    oneOf:
> +      - items:
> +          - description: The corrected region.
> +      - items:
> +          - description: The corrected region.
> +          - description: The raw region.
> +          - description: The config region.
> +          - description: The security control region.
> +
> +  # Clock must be provided if QFPROM is writable from the OS image.
> +  clocks:
> +    maxItems: 1

> +  clock-names:
> +    const: sec

Do we need clock-names for just one clock here?

> +
> +  # Supply reference must be provided if QFPROM is writable from the OS image.
> +  vcc-supply:
> +    description: Our power supply.
>   
>     # Needed if any child nodes are present.
>     "#address-cells":
> @@ -31,6 +50,28 @@ required:
>      - reg
>   
>   examples:
> +  - |
> +    #include <dt-bindings/clock/qcom,gcc-sc7180.h>
> +
> +    efuse@784000 {
> +      compatible = "qcom,qfprom";
> +      reg = <0 0x00784000 0 0x8ff>,
> +            <0 0x00780000 0 0x7a0>,
> +            <0 0x00782000 0 0x100>,
> +            <0 0x00786000 0 0x1fff>;
> +      clocks = <&gcc GCC_SEC_CTRL_CLK_SRC>;
> +      clock-names = "sec";
> +      #address-cells = <1>;
> +      #size-cells = <1>;
> +
> +      vcc-supply = <&vreg_l11a_1p8>;
> +
> +      hstx-trim-primary@25b {
> +        reg = <0x25b 0x1>;
> +        bits = <1 3>;
> +      };
> +    };
> +
>     - |
>       efuse@784000 {
>         compatible = "qcom,qfprom";
> 