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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 E5690C83000 for ; Tue, 28 Apr 2020 06:50:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C844A206B8 for ; Tue, 28 Apr 2020 06:50:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726303AbgD1Gum (ORCPT ); Tue, 28 Apr 2020 02:50:42 -0400 Received: from mga12.intel.com ([192.55.52.136]:2840 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725867AbgD1Gum (ORCPT ); Tue, 28 Apr 2020 02:50:42 -0400 IronPort-SDR: s9gWuiHmPfAveqOaQF77YGqMrgRQM+L2kvN6D4ZIyzZpRfks9ijMSrDNVgUEbUVdNVE4zz3OIt AQSf6NHWNlVg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2020 23:50:41 -0700 IronPort-SDR: qBH1RyAmnBgQYi/MRH91glO2akW96oT18OTSmcxvz2OqdEf5EIj8JoKwMQc1ApE/L5eV1rb0fI kEAMVUGjr/Xw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,327,1583222400"; d="scan'208";a="293775405" Received: from linux.intel.com ([10.54.29.200]) by orsmga008.jf.intel.com with ESMTP; 27 Apr 2020 23:50:41 -0700 Received: from [10.214.149.60] (vramuthx-MOBL1.gar.corp.intel.com [10.214.149.60]) by linux.intel.com (Postfix) with ESMTP id E6E585802C8; Mon, 27 Apr 2020 23:50:36 -0700 (PDT) Reply-To: vadivel.muruganx.ramuthevar@linux.intel.com Subject: Re: [PATCH v3 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC To: Boris Brezillon Cc: Miquel Raynal , linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, cheol.yong.kim@intel.com, hauke.mehrtens@intel.com, qi-ming.wu@intel.com, vigneshr@ti.com, arnd@arndb.de, richard@nod.at, brendanhiggins@google.com, linux-mips@vger.kernel.org, robh+dt@kernel.org, tglx@linutronix.de, masonccyang@mxic.com.tw, andriy.shevchenko@intel.com References: <20200423162113.38055-1-vadivel.muruganx.ramuthevar@linux.intel.com> <20200423162113.38055-3-vadivel.muruganx.ramuthevar@linux.intel.com> <20200424183612.4cfdbb6a@collabora.com> <20200427175127.0518c193@xps13> <20200428082759.25065146@collabora.com> <38334812-21b9-5b2c-db84-01c9eacc84d0@linux.intel.com> <20200428084704.5e04232a@collabora.com> From: "Ramuthevar, Vadivel MuruganX" Message-ID: Date: Tue, 28 Apr 2020 14:50:35 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200428084704.5e04232a@collabora.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Boris, On 28/4/2020 2:47 pm, Boris Brezillon wrote: > On Tue, 28 Apr 2020 14:40:58 +0800 > "Ramuthevar, Vadivel MuruganX" > wrote: > >> Hi Boris, >> >> On 28/4/2020 2:27 pm, Boris Brezillon wrote: >>> On Tue, 28 Apr 2020 14:17:30 +0800 >>> "Ramuthevar, Vadivel MuruganX" >>> wrote: >>> >>>> Hi Miquel, >>>> >>>> Thank you very much for the review comments and your time... >>>> >>>> On 27/4/2020 11:51 pm, Miquel Raynal wrote: >>>>> Hi Ramuthevar, >>>>> >>>>>>> +static int ebu_nand_probe(struct platform_device *pdev) >>>>>>> +{ >>>>>>> + struct device *dev = &pdev->dev; >>>>>>> + struct ebu_nand_controller *ebu_host; >>>>>>> + struct nand_chip *nand; >>>>>>> + phys_addr_t nandaddr_pa; >>>>>>> + struct mtd_info *mtd; >>>>>>> + struct resource *res; >>>>>>> + int ret; >>>>>>> + u32 cs; >>>>>>> + >>>>>>> + ebu_host = devm_kzalloc(dev, sizeof(*ebu_host), GFP_KERNEL); >>>>>>> + if (!ebu_host) >>>>>>> + return -ENOMEM; >>>>>>> + >>>>>>> + ebu_host->dev = dev; >>>>>>> + nand_controller_init(&ebu_host->controller); >>>>>>> + >>>>>>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ebunand"); >>>>>>> + ebu_host->ebu_addr = devm_ioremap_resource(&pdev->dev, res); >>>>>>> + if (IS_ERR(ebu_host->ebu_addr)) >>>>>>> + return PTR_ERR(ebu_host->ebu_addr); >>>>>>> + >>>>>>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hsnand"); >>>>>>> + ebu_host->nand_addr = devm_ioremap_resource(&pdev->dev, res); >>>>>>> + if (IS_ERR(ebu_host->nand_addr)) >>>>>>> + return PTR_ERR(ebu_host->nand_addr); >>>>>>> + >>>>>>> + ret = device_property_read_u32(dev, "nand,cs", &cs); >>>>>> >>>>>> CS ids should be encoded in the reg property (see [1]). >>>>> >>>>> Is it your choice to only support a single CS or is it actually a >>>>> controller limitation? >>>> >>>> Yes , its controller limitation to support only one CS >>> >>> I'm pretty sure that's not true, otherwise you wouldn't have to select >>> the CS you want to use :P. >> >> At a time it supports only one chip select. > > Yes, like 99% of the NAND controllers, but that doesn't mean you can't > support multi-CS chips. All you have to do is attach an array of > ebu_nand_cs to your ebu_nand_chip (as done in the atmel driver I > pointed to). nand_operation.cs tells you which CS (index in your > ebu_nand_cs array) a specific operation is targeting, and you can pick > the right MMIO range/reg value based on that. Agreed, sure I will add that and update next series of patches . Thanks! a lot Boris Regards Vadivel >