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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E0295C47255 for ; Mon, 11 May 2020 12:47:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B13EC20722 for ; Mon, 11 May 2020 12:47:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="RV1hQdYS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726410AbgEKMre (ORCPT ); Mon, 11 May 2020 08:47:34 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:48752 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726021AbgEKMrd (ORCPT ); Mon, 11 May 2020 08:47:33 -0400 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 04BCgaSN000396; Mon, 11 May 2020 14:47:12 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=STMicroelectronics; bh=q1p+Flxy4LUjmNbbMr/xBwFdwk21NI1E4pInfOilbgA=; b=RV1hQdYSrj2zbLFttnfrnSqexDNAj/rQjhPSvvQ95lXBkVuQg1ZD9RKlV+1lJtWwMrTZ J0S+OO7GEvSjx4SncBS6TWYvGPLgLBti2qCVz+e8apP95MukPQN2EKHCXI/wU92Gh6uU AT2E8FvmXviqWufcpbA3V9MYEpPivjiD3kbDEQ+Eq4BHfs4STtRE4RtT1ad733W+qWh/ iH0CPNiBYIZUc9AzdK+hrwqi5bSa0KiFozXMx93oMgCXbQt2MaB5FSe2w2Gt848oez1X /22NZiT3pHq/81ktr36J1z8ydvItor0+xGEqJbeDxgVi6JIVvminPNjq0DQtok42gngV Wg== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 30wkdgt30u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 11 May 2020 14:47:12 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id CBBCF10002A; Mon, 11 May 2020 14:47:11 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag6node2.st.com [10.75.127.17]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id ADEBB2B5E8D; Mon, 11 May 2020 14:47:11 +0200 (CEST) Received: from [10.211.5.64] (10.75.127.49) by SFHDAG6NODE2.st.com (10.75.127.17) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Mon, 11 May 2020 14:47:10 +0200 Subject: Re: [PATCH v4 10/10] mtd: rawnand: stm32_fmc2: get resources from parent node To: Miquel Raynal CC: , , , , , , , , , , References: <1588756279-17289-1-git-send-email-christophe.kerello@st.com> <1588756279-17289-11-git-send-email-christophe.kerello@st.com> <20200511111855.48216940@xps13> <3377adc6-3e5e-b9b7-12be-c7aa44bfac82@st.com> <20200511135926.3e5c622d@xps13> From: Christophe Kerello Message-ID: <0c704fea-f2a6-2cec-8741-d322acf6afd5@st.com> Date: Mon, 11 May 2020 14:47:09 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20200511135926.3e5c622d@xps13> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.75.127.49] X-ClientProxiedBy: SFHDAG8NODE3.st.com (10.75.127.24) To SFHDAG6NODE2.st.com (10.75.127.17) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.676 definitions=2020-05-11_05:2020-05-11,2020-05-11 signatures=0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Miquel, On 5/11/20 1:59 PM, Miquel Raynal wrote: > Hi Christophe, > > Christophe Kerello wrote on Mon, 11 May > 2020 12:21:03 +0200: > >> Hi Miquel, >> >> On 5/11/20 11:18 AM, Miquel Raynal wrote: >>> Hi Christophe, >>> >>> Christophe Kerello wrote on Wed, 6 May 2020 >>> 11:11:19 +0200: >>> >>>> FMC2 EBI support has been added. Common resources (registers base >>>> and clock) are now shared between the 2 drivers. It means that the >>>> common resources should now be found in the parent device when EBI >>>> node is available. >>>> >>>> Signed-off-by: Christophe Kerello >>>> --- >>> >>> [...] >>> >>>> + >>>> +static bool stm32_fmc2_nfc_check_for_parent(struct platform_device *pdev) >>>> +{ >>>> + u32 i; >>>> + int nb_resources = 0; >>>> + >>>> + /* Count the number of resources in reg property */ >>>> + for (i = 0; i < pdev->num_resources; i++) { >>>> + struct resource *res = &pdev->resource[i]; >>>> + >>>> + if (resource_type(res) == IORESOURCE_MEM) >>>> + nb_resources++; >>>> + } >>>> + >>>> + /* Each CS needs 3 resources defined (data, cmd and addr) */ >>>> + if (nb_resources % 3) >>>> + return false; >>>> + >>>> + return true; >>>> +} >>> >>> This function looks fragile. Why not just checking the compatible >>> string of the parent node? >>> >> >> Yes, it is another way to check that we have an EBI parent node. >> >> In this implementation, I was checking the number of reg tuples. >> In case we have 6, it means that the register base address is defined in the parent node (EBI node). >> In case we have 7, it means that the register base address is defined in the current node (NFC node). > > Yes, I understand what you are doing, but I kind of dislike the logic. > Relying on the number of reg tuples is something that can be done (I > used it myself one time), but I think this is more a hack that you do > when you have no other way to differentiate. I guess the proper way > would be to look at the parent's compatible. If it matches what you > expect, then you can store the dev->of_node->parent->dev somewhere in > your controller's structure and then use it to initialize the clock and > regmap. This way you don't have to move anything else in the probe path. > OK, I will check the compatible string of the parent device using of_device_is_compatible API in v5. In case of the parent is found, I will add it in the structure of the controller (dev_parent). I will rely on this field only to get the common resources (the register base address and the clock) in the NFC node or in the EBI node. Regards, Christophe Kerello. > > Thanks, > Miquèl >