From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FD0DC77B7D for ; Thu, 18 May 2023 08:30:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230222AbjERIaQ convert rfc822-to-8bit (ORCPT ); Thu, 18 May 2023 04:30:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230210AbjERIaK (ORCPT ); Thu, 18 May 2023 04:30:10 -0400 Received: from fd01.gateway.ufhost.com (fd01.gateway.ufhost.com [61.152.239.71]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F92D198A; Thu, 18 May 2023 01:30:06 -0700 (PDT) Received: from EXMBX165.cuchost.com (unknown [175.102.18.54]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "EXMBX165", Issuer "EXMBX165" (not verified)) by fd01.gateway.ufhost.com (Postfix) with ESMTP id 3F3347FFD; Thu, 18 May 2023 16:29:58 +0800 (CST) Received: from EXMBX062.cuchost.com (172.16.6.62) by EXMBX165.cuchost.com (172.16.6.75) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Thu, 18 May 2023 16:29:58 +0800 Received: from [192.168.120.43] (171.223.208.138) by EXMBX062.cuchost.com (172.16.6.62) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Thu, 18 May 2023 16:29:57 +0800 Message-ID: <492b3874-7fcd-f7c1-bbe1-594c2d795854@starfivetech.com> Date: Thu, 18 May 2023 16:29:55 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v2 2/2] net: phy: motorcomm: Add pad drive strength cfg support Content-Language: en-US From: Guo Samin To: Andrew Lunn CC: , , , Peter Geis , Frank , "David S . Miller" , "Eric Dumazet" , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Heiner Kallweit , Russell King , Yanhong Wang References: <20230505090558.2355-1-samin.guo@starfivetech.com> <20230505090558.2355-3-samin.guo@starfivetech.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" X-Originating-IP: [171.223.208.138] X-ClientProxiedBy: EXCAS064.cuchost.com (172.16.6.24) To EXMBX062.cuchost.com (172.16.6.62) X-YovoleRuleAgent: yovoleflag Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Re: [PATCH v2 2/2] net: phy: motorcomm: Add pad drive strength cfg support From: Guo Samin to: Andrew Lunn data: 2023/5/6 > > Re: [PATCH v2 2/2] net: phy: motorcomm: Add pad drive strength cfg support > From: Andrew Lunn > to: Samin Guo > data: 2023/5/5 > >>> #define YTPHY_DTS_OUTPUT_CLK_DIS 0 >>> @@ -1495,6 +1504,7 @@ static int yt8531_config_init(struct phy_device *phydev) >>> { >>> struct device_node *node = phydev->mdio.dev.of_node; >>> int ret; >>> + u32 ds, val; >> >> Reverse Christmas tree. Sort these longest first, shortest last. >> > Thanks, will fix. >> Otherwise this looks O.K. >> >> The only open question is if real unit should be used, uA, not some >> magic numbers. Lets see what the DT Maintainers say. >> >> Andrew > > Hi Andrew, > > As I communicated with Frank, Motorcomm doesn't give specific units on their datasheet, except for magic numbers. > Tried to ask Motorcomm last week, but it seems that they themselves do not know what the unit is and have no response so far. > > > Below is all the relevant information I found： > > Pad Drive Strength Cfg (EXT_0xA010) > > Bit | Symbol | Access | Default | Description > 15:13 | Rgmii_sw_dr_rx | RW | 0x3 | Drive strenght of rx_clk pad. > | 3'b111: strongest; 3'b000: weakest. > > 12 | Rgmii_sw_dr[2] | RW | 0x0 | Bit 2 of Rgmii_sw_dr[2:0], refer to ext A010[5:4] > > 5:4 | Rgmii_sw_dr[1:0] | RW | 0x3 | Bit 1 and 0 of Rgmii_sw_dr, Drive strenght of rxd/rx_ctl rgmii pad. > | 3'b111: strongest; 3'b000: weakest > > > > Best regards, > Samin Hi Andrew, We tried contacting motorcomm again, but so far we haven't been able to get any more information about unit. Also, I found a similar configuration in Documentation/devicetree/bindings/net/qca,ar803x.yaml, and they also used the 'magic numbers': qca,clk-out-strength: description: Clock output driver strength. $ref: /schemas/types.yaml#/definitions/uint32 enum: [0, 1, 2] Best regards, Samin