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From:   Richard Zhu <hongxing.zhu@nxp.com>
To:     l.stach@pengutronix.de, andrew.smirnov@gmail.com,
        shawnguo@kernel.org, kw@linux.com, bhelgaas@google.com,
        stefan@agner.ch, lorenzo.pieralisi@arm.com
Cc:     linux-pci@vger.kernel.org, linux-imx@nxp.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kernel@pengutronix.de, Richard Zhu <hongxing.zhu@nxp.com>
Subject: [PATCH 1/3] dt-bindings: imx6q-pcie: specify the imx8mq pcie phy voltage
Date:   Fri, 19 Mar 2021 16:24:05 +0800
Message-Id: <1616142247-13789-1-git-send-email-hongxing.zhu@nxp.com>
Precedence: bulk

Both 1.8v and 3.3v power supplies can be feeded to i.MX8MQ PCIe PHY.
In default, the PCIE_VPH voltage is suggested to be 1.8v refer to data
sheet. When PCIE_VPH is supplied by 3.3v in the HW schematic design,
the VREG_BYPASS bits of GPR registers should be cleared from default
value 1b'1 to 1b'0.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
 Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index de4b2baf91e8..23efbad9e804 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -59,6 +59,10 @@ Additional required properties for imx7d-pcie and imx8mq-pcie:
 Additional required properties for imx8mq-pcie:
 - clock-names: Must include the following additional entries:
 	- "pcie_aux"
+- pcie-vph-3v3: If present then PCIE_VPH is feeded by 3.3v in the HW
+  schematic design. The PCIE_VPH is suggested to be 1.8v refer to the
+  data sheet. If the PCIE_VPH is supplied by 3.3V, the VREG_BYPASS
+  should be cleared to zero accordingly.
 
 Example:
 
-- 
2.17.1