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From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Date: Wed, 24 Jan 2024 13:06:35 +0530
Subject: [PATCH 07/14] phy: qcom: qmp-pcie: Add a comment to clarify the
 use of "aux and "phy_aux" clocks
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Message-Id: <20240124-pcie-aux-clk-fix-v1-7-d8a4852b6ba6@linaro.org>
References: <20240124-pcie-aux-clk-fix-v1-0-d8a4852b6ba6@linaro.org>
In-Reply-To: <20240124-pcie-aux-clk-fix-v1-0-d8a4852b6ba6@linaro.org>
To: Bjorn Andersson <andersson@kernel.org>, 
 Konrad Dybcio <konrad.dybcio@linaro.org>, Vinod Koul <vkoul@kernel.org>, 
 Kishon Vijay Abraham I <kishon@kernel.org>, 
 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
Cc: linux-arm-msm@vger.kernel.org, linux-phy@lists.infradead.org, 
 devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, 
 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

PCIe PHY hw on some SoCs require PCIE_PHY_AUX_CLK when the link enters L1SS
state. Historically, DTs of those SoCs passed this clock as "aux" clock.
But, SA8775P passed PCIE_PHY_AUX_CLK as "phy_aux" and PCIE_AUX_CLK as "aux"
mistakenly as the latter is not needed at all. Even though the SA8775P DT
got fixed, both of these clocks are kept here for backwards compatibility.

So add a comment to make it clear.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 9a220cbd9615..044e3c5ba341 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -2328,7 +2328,15 @@ static inline void qphy_clrbits(void __iomem *base, u32 offset, u32 val)
 	readl(base + offset);
 }
 
-/* list of clocks required by phy */
+/* list of clocks required by phy
+ *
+ * PCIe PHY hw on some SoCs require PCIE_PHY_AUX_CLK when the link enters L1SS
+ * state. Historically, DTs of those SoCs passed this clock as "aux" clock. But,
+ * SA8775P passed PCIE_PHY_AUX_CLK as "phy_aux" and PCIE_AUX_CLK as "aux"
+ * mistakenly as the latter is not needed at all. Even though the SA8775P DT got
+ * fixed, both of these clocks are kept here for backwards compatibility.
+ */
+
 static const char * const qmp_pciephy_clk_l[] = {
 	"aux", "cfg_ahb", "ref", "refgen", "rchng", "phy_aux",
 };

-- 
2.25.1