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| author | Manu Gautam <mgautam@codeaurora.org> | 2018-05-03 02:36:13 +0530 |
|---|---|---|
| committer | Kishon Vijay Abraham I <kishon@ti.com> | 2018-05-20 21:51:31 +0530 |
| commit | a8b70ccf10e38775785d9cb12ead916474549f99 (patch) | |
| tree | 779efd7e36d0fdb9851d1f4dbfd4c4a6f75df79c /Documentation/devicetree | |
| parent | f6721e5c0bb4e8abde0c6ef59ffc16711525df8d (diff) | |
| download | linux-a8b70ccf10e38775785d9cb12ead916474549f99.tar.bz2 | |
dt-bindings: phy-qcom-usb2: Add support to override tuning values
To improve eye diagram for PHYs on different boards of same SOC,
some parameters may need to be changed. Provide device tree
properties to override these from board specific device tree
files. While at it, replace "qcom,qusb2-v2-phy" with compatible
string for USB2 PHY on sdm845 which was earlier added for
sdm845 only.
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Diffstat (limited to 'Documentation/devicetree')
| -rw-r--r-- | Documentation/devicetree/bindings/phy/qcom-qusb2-phy.txt | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/phy/qcom-qusb2-phy.txt b/Documentation/devicetree/bindings/phy/qcom-qusb2-phy.txt index 42c97426836e..03025d97998b 100644 --- a/Documentation/devicetree/bindings/phy/qcom-qusb2-phy.txt +++ b/Documentation/devicetree/bindings/phy/qcom-qusb2-phy.txt @@ -6,7 +6,7 @@ QUSB2 controller supports LS/FS/HS usb connectivity on Qualcomm chipsets. Required properties: - compatible: compatible list, contains "qcom,msm8996-qusb2-phy" for 14nm PHY on msm8996, - "qcom,qusb2-v2-phy" for QUSB2 V2 PHY. + "qcom,sdm845-qusb2-phy" for 10nm PHY on sdm845. - reg: offset and length of the PHY register set. - #phy-cells: must be 0. @@ -27,6 +27,27 @@ Optional properties: tuning parameter value for qusb2 phy. - qcom,tcsr-syscon: Phandle to TCSR syscon register region. + - qcom,imp-res-offset-value: It is a 6 bit value that specifies offset to be + added to PHY refgen RESCODE via IMP_CTRL1 register. It is a PHY + tuning parameter that may vary for different boards of same SOC. + This property is applicable to only QUSB2 v2 PHY (sdm845). + - qcom,hstx-trim-value: It is a 4 bit value that specifies tuning for HSTX + output current. + Possible range is - 15mA to 24mA (stepsize of 600 uA). + See dt-bindings/phy/phy-qcom-qusb2.h for applicable values. + This property is applicable to only QUSB2 v2 PHY (sdm845). + Default value is 22.2mA for sdm845. + - qcom,preemphasis-level: It is a 2 bit value that specifies pre-emphasis level. + Possible range is 0 to 15% (stepsize of 5%). + See dt-bindings/phy/phy-qcom-qusb2.h for applicable values. + This property is applicable to only QUSB2 v2 PHY (sdm845). + Default value is 10% for sdm845. +- qcom,preemphasis-width: It is a 1 bit value that specifies how long the HSTX + pre-emphasis (specified using qcom,preemphasis-level) must be in + effect. Duration could be half-bit of full-bit. + See dt-bindings/phy/phy-qcom-qusb2.h for applicable values. + This property is applicable to only QUSB2 v2 PHY (sdm845). + Default value is full-bit width for sdm845. Example: hsusb_phy: phy@7411000 { |