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 7BA30C636D7 for ; Thu, 23 Feb 2023 09:29:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233989AbjBWJ3H (ORCPT ); Thu, 23 Feb 2023 04:29:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233957AbjBWJ2y (ORCPT ); Thu, 23 Feb 2023 04:28:54 -0500 Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F4364C6D2 for ; Thu, 23 Feb 2023 01:28:52 -0800 (PST) Received: by mail-wr1-x431.google.com with SMTP id h14so1442330wru.4 for ; Thu, 23 Feb 2023 01:28:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=gb2qxqmKS0rtdO++khKuhDFOUfUplSmtQFJjeC7elRk=; b=KN2AKHoO96bfhSZx+IPwU/tbpQPchmaFp81rNz+ltuEuiZU09uMVGjD1JKiKbjRmRa OQcqfWt7sTKFnS1LK56f5SAunmpKwGUI93gfW3wxd8rWUrU5SGkAKGfnZUn3R0L8QWHq 8WyXfLzZdyI5vM6uqx84dNcvxQuRjeUNW81mPEEaZhDcdDiyvSUNPDP65Jt5VrDt/faD c1FkM9GWtxEA+juEK/t9LIfKYc3RfzgqZDQ5tJoG5u3j8DTl/xBTMPV2ruhLZnmnc7mY 1I5tjLKZ8bIFIQM+lVlGnU7OXnmfHfbpU8E6qozvdCp9B/+hr5FdmcRVuR/y8q0yEDIB flcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=gb2qxqmKS0rtdO++khKuhDFOUfUplSmtQFJjeC7elRk=; b=STeezRdWDT7ymL2KQ2k+02rLpmxy/Muzl5TAvVXbOcGFLT1hQLW2JcMbUP9MevCO/D 4Ep9f06ghydtEy/uECzed+dZnB045sLMLk3pSGPAHsAEPlrLhdrSKdaLZXYGW2BaPy7R VDWVHwVg7JINc9/TQECvv1BTqRWXGTk2WyjmFyV65IYgh2oTH5pZtWP61qF5BwJLL1lE 03okzH/xcSM3Opn2W7Onl/aT/tXtHpHDibPqAl6SFJs7z8oaK5vW3qB/mk3OO4PCt+Pr J+Jd2OoZnbFxW2juW3iRtOcVKnaLhk6C4x5h77fPYaopldQ0zaD7KVBk9/uI/oo0+d0u HGkw== X-Gm-Message-State: AO0yUKVrs1JjRCPbmwOCCm6KkMpMMjyOKwxSI3lCRPXf5/T/JRN7lRt3 1/pWIddVMNyH/80y24GM0ypqyw== X-Google-Smtp-Source: AK7set+MOmXu33I9nFWggqC/PShcnHbeYlNKSpRLAYvmxxPXpSzF23457FlD7byxWvQBb18MzZRLYA== X-Received: by 2002:a5d:4b81:0:b0:2c5:4de1:ba23 with SMTP id b1-20020a5d4b81000000b002c54de1ba23mr9910494wrt.19.1677144530866; Thu, 23 Feb 2023 01:28:50 -0800 (PST) Received: from [192.168.1.109] ([178.197.216.144]) by smtp.gmail.com with ESMTPSA id d8-20020adffbc8000000b002c5d3f0f737sm8757431wrs.30.2023.02.23.01.28.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 23 Feb 2023 01:28:50 -0800 (PST) Message-ID: <5c255eb3-ec9e-d66f-4a2b-ccc32edf5672@linaro.org> Date: Thu, 23 Feb 2023 10:28:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v5 1/2] dt-bindings: i2c: Add support for ASPEED i2Cv2 Content-Language: en-US To: Ryan Chen , Rob Herring , Krzysztof Kozlowski , Joel Stanley , Andrew Jeffery , Philipp Zabel , "openbmc@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" References: <20230220061745.1973981-1-ryan_chen@aspeedtech.com> <20230220061745.1973981-2-ryan_chen@aspeedtech.com> <676c7777-635c-cc1f-b919-d33e84a45442@linaro.org> <80d873d4-d813-6c25-8f47-f5ff9af718ec@linaro.org> <94238c42-1250-4d51-86e5-0a960dea0ffc@linaro.org> From: Krzysztof Kozlowski In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/02/2023 11:47, Ryan Chen wrote: >>>> connector. That slave will keep state to drive clock stretching. >>>>> So it is specific enable in i2c bus#1. Others is not needed enable timeout. >>>>> Does this draw is more clear in scenario? >>>> >>>> I2C bus #1 works in slave mode? So you always need it for slave work? >>> >>> Yes, it is both slave/master mode. It is always dual role. Slave must always >> work. >>> Due to another board master will send. >> >> I meant that you need this property when it works in slave mode? It would be >> then redundant to have in DT as it is implied by the mode. > > But timeout feature is also apply in master. It for avoid suddenly slave miss(un-plug) > Master can timeout and release the SDA/SCL, return. OK, yet the property should describe the hardware, not the register feature you want to program. You need to properly model it in DT binding to represent hardware setup, not your desired Linux driver behavior. >>>>> The same draw, in this case, i2c bus#1 that is multi-master transfer >>>> architecture. >>>>> Both will inactive with trunk data. That cane enable i2c#1 use DMA >>>>> transfer >>>> to reduce CPU utilized. >>>>> Others (bus#2/3) can keep byte/buff mode. >>>> >>>> Isn't then current bus configuration for I2C#1 known to the driver? >>>> Jeremy asked few other questions around here... >>> >>> No, The driver don't know currently board configuration. >> >> It knows whether it is working in multi-master/slave mode. > > But in DT can decide which i2c bus number can use dma or buffer mode transfer. > If in another i2c bus support master only, also can use dma to transfer trunk data to another slave. and none of these were explained in commit msg or device description. Best regards, Krzysztof 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 23EDCC61DA4 for ; Thu, 23 Feb 2023 09:30:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LNHRtPQJUM1fnlWou55rSizFAGg19ySfJwFArw7qWXE=; b=kCSJugUuFUODT7 Hkgh5k1Q7vUsENbB5MX+Ku1LlEAHjFsHTjtiSk+ggXiwfj5reDhcFJwpmcEfSl4kRSFjspEFhKtrG oo6AZeQqV99f88d9DN39WWbmCkl/YA/UpykEPft2SjjKXHOSVBHqzH/gy0EceEpUQZG/NV5ENsIs5 vagjrE31CXkK1J9IxvUCpclZw71j6g+kONnPMKqzVBIMXFM3FbIkmV86Jzw4pvMKS0M4H88m0Xh9m bWc26/MZp8bVmi5GR0EvGel6xkz2H7AQj3rXTZvCe4dmbxksot0jfDuLLrHhcpoOahbbWEJtcVzfb h4RDw/OLSKMlLfck5JIg==; 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Thu, 23 Feb 2023 01:28:50 -0800 (PST) Message-ID: <5c255eb3-ec9e-d66f-4a2b-ccc32edf5672@linaro.org> Date: Thu, 23 Feb 2023 10:28:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v5 1/2] dt-bindings: i2c: Add support for ASPEED i2Cv2 Content-Language: en-US To: Ryan Chen , Rob Herring , Krzysztof Kozlowski , Joel Stanley , Andrew Jeffery , Philipp Zabel , "openbmc@lists.ozlabs.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" References: <20230220061745.1973981-1-ryan_chen@aspeedtech.com> <20230220061745.1973981-2-ryan_chen@aspeedtech.com> <676c7777-635c-cc1f-b919-d33e84a45442@linaro.org> <80d873d4-d813-6c25-8f47-f5ff9af718ec@linaro.org> <94238c42-1250-4d51-86e5-0a960dea0ffc@linaro.org> From: Krzysztof Kozlowski In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230223_012854_600141_3A58A016 X-CRM114-Status: GOOD ( 13.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 22/02/2023 11:47, Ryan Chen wrote: >>>> connector. That slave will keep state to drive clock stretching. >>>>> So it is specific enable in i2c bus#1. Others is not needed enable timeout. >>>>> Does this draw is more clear in scenario? >>>> >>>> I2C bus #1 works in slave mode? So you always need it for slave work? >>> >>> Yes, it is both slave/master mode. It is always dual role. Slave must always >> work. >>> Due to another board master will send. >> >> I meant that you need this property when it works in slave mode? It would be >> then redundant to have in DT as it is implied by the mode. > > But timeout feature is also apply in master. It for avoid suddenly slave miss(un-plug) > Master can timeout and release the SDA/SCL, return. OK, yet the property should describe the hardware, not the register feature you want to program. You need to properly model it in DT binding to represent hardware setup, not your desired Linux driver behavior. >>>>> The same draw, in this case, i2c bus#1 that is multi-master transfer >>>> architecture. >>>>> Both will inactive with trunk data. That cane enable i2c#1 use DMA >>>>> transfer >>>> to reduce CPU utilized. >>>>> Others (bus#2/3) can keep byte/buff mode. >>>> >>>> Isn't then current bus configuration for I2C#1 known to the driver? >>>> Jeremy asked few other questions around here... >>> >>> No, The driver don't know currently board configuration. >> >> It knows whether it is working in multi-master/slave mode. > > But in DT can decide which i2c bus number can use dma or buffer mode transfer. > If in another i2c bus support master only, also can use dma to transfer trunk data to another slave. and none of these were explained in commit msg or device description. Best regards, Krzysztof _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel