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From:   Serge Semin <Sergey.Semin@baikalelectronics.ru>
To:     Mathias Nyman <mathias.nyman@intel.com>,
        Felipe Balbi <balbi@kernel.org>,
        Krzysztof Kozlowski <krzk@kernel.org>,
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        Rob Herring <robh+dt@kernel.org>,
        Chunfeng Yun <chunfeng.yun@mediatek.com>
CC:     Serge Semin <Sergey.Semin@baikalelectronics.ru>,
        Serge Semin <fancer.lancer@gmail.com>,
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        Rob Herring <robh@kernel.org>
Subject: [PATCH v5 13/19] dt-bindings: usb: dwc3: Add Tx De-emphasis constraints
Date:   Sat, 5 Dec 2020 18:24:20 +0300
Message-ID: <20201205152427.29537-14-Sergey.Semin@baikalelectronics.ru>
In-Reply-To: <20201205152427.29537-1-Sergey.Semin@baikalelectronics.ru>
References: <20201205152427.29537-1-Sergey.Semin@baikalelectronics.ru>
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In accordance with the driver comments the PIPE3 de-emphasis can be tuned
to be either -6dB, -2.5dB or disabled. Let's add the de-emphasis
property constraints so the DT schema would make sure the controller DT
node is equipped with correct value.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>

---

Changelog v2:
- Grammar fix: "s/tunned/tuned"
- Grammar fix: remove redundant "or" conjunction.
---
 Documentation/devicetree/bindings/usb/snps,dwc3.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
index b1890558affe..e39ad899c92e 100644
--- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
+++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
@@ -156,6 +156,10 @@ properties:
       The value driven to the PHY is controlled by the LTSSM during USB3
       Compliance mode.
     $ref: /schemas/types.yaml#/definitions/uint8
+    enum:
+      - 0 # -6dB de-emphasis
+      - 1 # -3.5dB de-emphasis
+      - 2 # No de-emphasis
 
   snps,dis_u3_susphy_quirk:
     description: When set core will disable USB3 suspend phy
-- 
2.29.2