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Date:   Tue, 20 Jun 2023 15:29:04 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Guo Samin <samin.guo@starfivetech.com>
Cc:     Conor Dooley <conor@kernel.org>, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, netdev@vger.kernel.org,
        Peter Geis <pgwipeout@gmail.com>,
        Frank <Frank.Sae@motor-comm.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        Yanhong Wang <yanhong.wang@starfivetech.com>
Subject: Re: [PATCH v3 1/2] dt-bindings: net: motorcomm: Add pad driver
 strength cfg
Message-ID: <b0a61cf4-adb1-4261-b6a5-aeb1e3c1b1aa@lunn.ch>
References: <20230526090502.29835-1-samin.guo@starfivetech.com>
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> I just got the detailed data of Driver Strength(DS) from Motorcomm ,
> which applies to both rx_clk and rx_data.
> 
> |----------------------|
> |     ds map table     |
> |----------------------|
> | DS(3b) | Current (mA)|
> |--------|-------------|
> |   000  |     1.20    |
> |   001  |     2.10    |
> |   010  |     2.70    |
> |   011  |     2.91    |
> |   100  |     3.11    |
> |   101  |     3.60    |
> |   110  |     3.97    |
> |   111  |     4.35    |
> |--------|-------------|
>
> Since these currents are not integer values

Integers is not a problem. Simply use uA.

> and have no regularity, it is not very good to use in the drive/dts
> in my opinion.

I think they are fine to use. Add a lookup table, microamps to
register value. Return -EINVAL if the requested value is not in the
table. List the valid values in the schema, so the checker tool might
point out problems.

      Andrew