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 X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D212C433B4 for ; Wed, 14 Apr 2021 12:54:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF37161176 for ; Wed, 14 Apr 2021 12:54:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351019AbhDNMy3 (ORCPT ); Wed, 14 Apr 2021 08:54:29 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:43116 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347893AbhDNMyR (ORCPT ); Wed, 14 Apr 2021 08:54:17 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 13ECrPse019753; Wed, 14 Apr 2021 07:53:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1618404805; bh=oirPo/EsDII0H0wpLt+7P4CG1KGd+DxoUWbHd1hnL7k=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=UKxa+T3vhnZmmhiJHXkh5+qGHdkxP1xM7OOV/veTJiY3Dj/RAvKGCGonvi2BfT4n1 nvr1jA88uKx+nNn2fFaLtiCoJaMmLo5pmHa6y0+9qOJPQy3fZT13zTv10SryvxHBug RUupir4TkBgpl3icdq07CBAqxqCWUjnM1GqGq37A= Received: from DFLE115.ent.ti.com (dfle115.ent.ti.com [10.64.6.36]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 13ECrPYK044091 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 14 Apr 2021 07:53:25 -0500 Received: from DFLE108.ent.ti.com (10.64.6.29) by DFLE115.ent.ti.com (10.64.6.36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 14 Apr 2021 07:53:24 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2 via Frontend Transport; Wed, 14 Apr 2021 07:53:25 -0500 Received: from [172.24.145.148] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 13ECrKdA092197; Wed, 14 Apr 2021 07:53:21 -0500 Subject: Re: [PATCH 1/4] dt-bindings: phy: Add binding for TI TCAN104x CAN transceivers To: Rob Herring , Marc Kleine-Budde CC: Vignesh Raghavendra , Kishon Vijay Abraham I , Lokesh Vutla , Grygorii Strashko , Chandrasekar Ramakrishnan , Wolfgang Grandegger , "David S. Miller" , Jakub Kicinski , Vinod Koul , , netdev , , "linux-kernel@vger.kernel.org" , References: <20210409134056.18740-1-a-govindraju@ti.com> <20210409134056.18740-2-a-govindraju@ti.com> <20210412174956.GA4049952@robh.at.kernel.org> <20210413074106.gvgtjkofyrdp5yxt@pengutronix.de> From: Aswath Govindraju Message-ID: <9350f367-2c4f-1779-ec24-94066e152992@ti.com> Date: Wed, 14 Apr 2021 18:23:19 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Marc, On 13/04/21 6:45 pm, Rob Herring wrote: > On Tue, Apr 13, 2021 at 2:41 AM Marc Kleine-Budde wrote: >> >> On 12.04.2021 12:49:56, Rob Herring wrote: >>> On Mon, Apr 12, 2021 at 12:19:30PM +0200, Marc Kleine-Budde wrote: >>>> On 4/9/21 3:40 PM, Aswath Govindraju wrote: >>>>> Add binding documentation for TI TCAN104x CAN transceivers. >>>>> >>>>> Signed-off-by: Aswath Govindraju >>>>> --- >>>>> .../bindings/phy/ti,tcan104x-can.yaml | 56 +++++++++++++++++++ >>>>> 1 file changed, 56 insertions(+) >>>>> create mode 100644 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml >>>>> new file mode 100644 >>>>> index 000000000000..4abfc30a97d0 >>>>> --- /dev/null >>>>> +++ b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml >>>>> @@ -0,0 +1,56 @@ >>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >>>>> +%YAML 1.2 >>>>> +--- >>>>> +$id: "http://devicetree.org/schemas/phy/ti,tcan104x-can.yaml#" >>>>> +$schema: "http://devicetree.org/meta-schemas/core.yaml#" >>>>> + >>>>> +title: TCAN104x CAN TRANSCEIVER PHY >>>>> + >>>>> +maintainers: >>>>> + - Aswath Govindraju >>>>> + >>>>> +properties: >>>>> + $nodename: >>>>> + pattern: "^tcan104x-phy" >>>>> + >>>>> + compatible: >>>>> + enum: >>>>> + - ti,tcan1042 >>>>> + - ti,tcan1043 >>>> >>>> Can you create a generic standby only and a generic standby and enable transceiver? >>> >>> As a fallback compatible fine, but no generic binding please. A generic >>> binding can't describe any timing requirements between the 2 GPIO as >>> well as supplies when someone wants to add those (and they will). >> >> Right - that makes sense. >> So, I need not add any new compatible strings right because as a fallback the existing compatible strings can be used, as there are no timing constraints on them. Thanks, Aswath >>>>> + >>>>> + '#phy-cells': >>>>> + const: 0 >>>>> + >>>>> + standby-gpios: >>>>> + description: >>>>> + gpio node to toggle standby signal on transceiver >>>>> + maxItems: 1 >>>>> + >>>>> + enable-gpios: >>>>> + description: >>>>> + gpio node to toggle enable signal on transceiver >>>>> + maxItems: 1 >>>>> + >>>>> + max-bitrate: >>>>> + $ref: /schemas/types.yaml#/definitions/uint32 >>>>> + description: >>>>> + max bit rate supported in bps >>> >>> We already have 'max-speed' for serial devices, use that. >> >> There is already the neither Ethernet PHY (PHYLINK/PHYLIB) nor generic >> PHY (GENERIC_PHY) can-transceiver binding >> Documentation/devicetree/bindings/net/can/can-transceiver.yaml which >> specifies max-bitrate. I don't have strong feelings whether to use >> max-bitrate or max-speed. > > Okay, max-bitrate is fine. > >> >> Speaking about Ethernet PHYs, what are to pros and cons to use the >> generic PHY compared to the Ethernet PHY infrastructure? > > For higher speed ethernet, both are used. There's the serdes phy and > the ethernet phy with serdes phy using the generic phy binding. For > CAN, it probably comes down to what's a better fit. > > Rob >