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From: Johan Hovold <johan+linaro@kernel.org>
To: Marcel Holtmann <marcel@holtmann.org>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	Bjorn Andersson <andersson@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	cros-qcom-dts-watchers@chromium.org,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	Balakrishna Godavarthi <quic_bgodavar@quicinc.com>,
	Matthias Kaehlcke <mka@chromium.org>,
	Douglas Anderson <dianders@chromium.org>,
	Rocky Liao <quic_rjliao@quicinc.com>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	linux-bluetooth@vger.kernel.org,
	netdev@vger.kernel.org,
	devicetree@vger.kernel.org,
	linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Johan Hovold <johan+linaro@kernel.org>
Subject: [PATCH v3 1/5] dt-bindings: bluetooth: add 'qcom,local-bd-address-broken'
Date: Tue, 19 Mar 2024 16:29:22 +0100
Message-ID: <20240319152926.1288-2-johan+linaro@kernel.org>
In-Reply-To: <20240319152926.1288-1-johan+linaro@kernel.org>
References: <20240319152926.1288-1-johan+linaro@kernel.org>
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Several Qualcomm Bluetooth controllers lack persistent storage for the
device address and instead one can be provided by the boot firmware
using the 'local-bd-address' devicetree property.

The Bluetooth bindings clearly states that the address should be
specified in little-endian order, but due to a long-standing bug in the
Qualcomm driver which reversed the address some boot firmware has been
providing the address in big-endian order instead.

The only device out there that should be affected by this is the WCN3991
used in some Chromebooks.

Add a 'qcom,local-bd-address-broken' property which can be set on these
platforms to indicate that the boot firmware is using the wrong byte
order.

Note that ChromeOS always updates the kernel and devicetree in lockstep
so that there is no need to handle backwards compatibility with older
devicetrees.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 .../devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml  | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml b/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml
index eba2f3026ab0..e099ef83e7b1 100644
--- a/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml
+++ b/Documentation/devicetree/bindings/net/bluetooth/qualcomm-bluetooth.yaml
@@ -94,6 +94,9 @@ properties:
 
   local-bd-address: true
 
+  qcom,local-bd-address-broken: true
+    description: >
+      boot firmware is incorrectly passing the address in big-endian order
 
 required:
   - compatible
-- 
2.43.2