[PATCH v2 08/15] dt-bindings: arm: cpus: Document qcom,msm8916-smp enable-method

From: Stephan Gerhold <stephan@gerhold.net>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Andy Gross <agross@kernel.org>,
	linux-arm-msm@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	~postmarketos/upstreaming@lists.sr.ht,
	phone-devel@vger.kernel.org,
	Stephan Gerhold <stephan@gerhold.net>
Subject: [PATCH v2 08/15] dt-bindings: arm: cpus: Document qcom,msm8916-smp enable-method
Date: Mon,  4 Oct 2021 22:49:48 +0200	[thread overview]
Message-ID: <20211004204955.21077-8-stephan@gerhold.net> (raw)
In-Reply-To: <20211004201921.18526-1-stephan@gerhold.net>

Since MSM8916 is an ARM v8 64-bit SoC the CPU cores are normally booted
using "psci" or "spin-table". Unfortunately, some devices come with signed
32-bit-only firmware without ARM64 and PSCI support. This setup is easy to
support since it's very similar to older 32-bit only Qualcomm SoCs
(e.g. MSM8226) and only requires adding a few new definitions to already
existing drivers.

Document the qcom,msm8916-smp enable-method. It is actually just an alias
of qcom,msm8226-smp since it should be implemented identically.
The enable-method is only valid on ARM32 and must not be used on ARM64.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
---
Changes in v2:
  - Clarify that this is only supposed to be used on ARM 32-bit
    (Add comment to commit message and DT schema)

The "see above for ARM v8 64-bit" comment refers to this a few lines
above in the DT schema:

      # On ARM v8 64-bit this property is required
      - enum:
          - psci
          - spin-table
---
 Documentation/devicetree/bindings/arm/cpus.yaml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/cpus.yaml b/Documentation/devicetree/bindings/arm/cpus.yaml
index 11e3e09da2e5..6a95b2a76bdc 100644
--- a/Documentation/devicetree/bindings/arm/cpus.yaml
+++ b/Documentation/devicetree/bindings/arm/cpus.yaml
@@ -211,6 +211,8 @@ properties:
           - qcom,kpss-acc-v1
           - qcom,kpss-acc-v2
           - qcom,msm8226-smp
+          # Only valid on ARM 32-bit, see above for ARM v8 64-bit
+          - qcom,msm8916-smp
           - renesas,apmu
           - renesas,r9a06g032-smp
           - rockchip,rk3036-smp
@@ -295,7 +297,8 @@ properties:
       Specifies the ACC* node associated with this CPU.
 
       Required for systems that have an "enable-method" property
-      value of "qcom,kpss-acc-v1", "qcom,kpss-acc-v2" or "qcom,msm8226-smp"
+      value of "qcom,kpss-acc-v1", "qcom,kpss-acc-v2", "qcom,msm8226-smp"
+      or "qcom,msm8916-smp".
 
       * arm/msm/qcom,kpss-acc.txt
 
-- 
2.33.0

