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,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 77B36C33CA2 for ; Fri, 10 Jan 2020 11:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4EFEB2072A for ; Fri, 10 Jan 2020 11:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728076AbgAJLzo (ORCPT ); Fri, 10 Jan 2020 06:55:44 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2251 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727858AbgAJLzl (ORCPT ); Fri, 10 Jan 2020 06:55:41 -0500 Received: from lhreml701-cah.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id AFF0FA5C9FD9699058BD; Fri, 10 Jan 2020 11:55:39 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by lhreml701-cah.china.huawei.com (10.201.108.42) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 10 Jan 2020 11:55:39 +0000 Received: from [127.0.0.1] (10.202.226.43) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Fri, 10 Jan 2020 11:55:39 +0000 Subject: Re: [PATCH v2 2/3] spi: Add HiSilicon v3xx SPI NOR flash controller driver To: Mark Brown CC: , , , , , , , , References: <1575900490-74467-1-git-send-email-john.garry@huawei.com> <1575900490-74467-3-git-send-email-john.garry@huawei.com> <0dc5cb2e-b765-9e13-b05e-9e3c835c5985@huawei.com> <20200109212842.GK3702@sirena.org.uk> From: John Garry Message-ID: Date: Fri, 10 Jan 2020 11:55:37 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <20200109212842.GK3702@sirena.org.uk> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.43] X-ClientProxiedBy: lhreml729-chm.china.huawei.com (10.201.108.80) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/01/2020 21:28, Mark Brown wrote: > On Thu, Jan 09, 2020 at 03:54:00PM +0000, John Garry wrote: > >> From checking acpi_spi_add_resource() or anywhere else, I cannot see how >> SPI_RX_DUAL or the others are set for spi_device.mode. What am I missing? >> Are these just not supported yet for ACPI? Or should the spi-nor code not be >> relying on this since we should be able to get this info from the SPI NOR >> part? > Hi Mark, > I'm not aware of any work on integrating this sort of stuff into ACPI > platforms so I think it's just not yet supported in ACPI. I'm not > really sure what would be idiomatic for ACPI, figuring it out from what > the part supports might well be idiomatic there though I don't know how > common it is for people not to wire up all the data lines even if both > controller and device support wider transfers. OK, so I guess that is why we require the width property from the FW and can't blindly rely on SFDP. I've got a horrible > feeling that the idiomatic thing is a combination of that and a bunch of > per-device quirks. There may be a spec I'm not aware of though I'd be a > bit surprised. > I'm not sure on that. I don't see anything in the ACPI spec. I will note that PRP0001+"jedec,spi-nor" compatible DSD seems to be the defacto method to describe the SPI NOR-compat part for ACPI - that's what I'm using. We could add properties there, but that seems improper. I'll continue to look.... Thanks, John