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=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 4AD95C433E2 for ; Mon, 14 Sep 2020 06:36:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 180562192A for ; Mon, 14 Sep 2020 06:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726100AbgINGgc (ORCPT ); Mon, 14 Sep 2020 02:36:32 -0400 Received: from mga04.intel.com ([192.55.52.120]:5622 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726051AbgINGga (ORCPT ); Mon, 14 Sep 2020 02:36:30 -0400 IronPort-SDR: qUQVRwYCqeeDo2iVqK2wEy0OvdT4Z+LUSDqmp/L6NzdLwqVxD2163atD9t10THoHRrYIAwtpS/ 7QyfdBrB53+A== X-IronPort-AV: E=McAfee;i="6000,8403,9743"; a="156427340" X-IronPort-AV: E=Sophos;i="5.76,425,1592895600"; d="scan'208";a="156427340" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2020 23:36:30 -0700 IronPort-SDR: +NXA1uT6k9Cy9jdPgS8Cm0Qg72jTm41S2Q5F7VrJc4ChQ3JCB6gu3N2WP0iJZH2Y96RjsEGOji KjniniGqAB5g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,425,1592895600"; d="scan'208";a="408770350" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.190]) ([10.237.72.190]) by fmsmga001.fm.intel.com with ESMTP; 13 Sep 2020 23:36:28 -0700 Subject: Re: [RFC PATCH V3 15/21] mmc: sdhci: UHS-II support, modify set_power() to handle vdd2 To: AKASHI Takahiro , Ben Chuang , ulf.hansson@linaro.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, ben.chuang@genesyslogic.com.tw, greg.tu@genesyslogic.com.tw References: <20200710111140.29725-1-benchuanggli@gmail.com> <97c43596-a18f-4c7a-c226-5209772d91d1@intel.com> <20200914054537.GA2738017@laputa> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Mon, 14 Sep 2020 09:36:02 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200914054537.GA2738017@laputa> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On 14/09/20 8:45 am, AKASHI Takahiro wrote: > Adrian, > > On Fri, Aug 21, 2020 at 05:11:18PM +0300, Adrian Hunter wrote: >> On 10/07/20 2:11 pm, Ben Chuang wrote: >>> From: AKASHI Takahiro >>> >>> VDD2 is used for powering UHS-II interface. >>> Modify sdhci_set_power_and_bus_voltage(), sdhci_set_power_noreg() >>> and sdhci_set_power_noreg() to handle VDD2. >> >> vdd2 is always 1.8 V and I suspect there may never be support for anything >> else, so we should start with 1.8 V only. > > What do you mean here? > You don't want to add an extra argument, vdd2, to sdhci_set_power(). > Correct? Yes > >> Also can we create uhs2_set_power_reg() and uhs2_set_power_noreg() and use >> the existing ->set_power() callback > > Again what do you expect here? > > Do you want to see any platform-specific mmc driver who supports UHS-II > to implement its own call back like: Not exactly. I expect there to be a common implementation in sdhci-uhs2.c called sdhci_uhs2_set_power() for example, that drivers can use by setting their .set_power = sdhci_uhs2_set_power. If they need platform-specific code as well then their platform-specific code can call sdhci_uhs2_set_power() if desired. > > void sdhci_foo_set_power(struct sdhci_host *host, unsigned char mode, > unsigned short vdd) > { > sdhci_set_power(host, mode,vdd); > > /* in case that sdhci_uhs2 module is not inserted */ > if (!(mmc->caps & MMC_CAP_UHS2)) > return; > > /* vdd2 specific operation */ > if (IS_ERR_OR_NULL(host->mmc->supply.vmmc2)) > sdhci_uhs2_set_power_noreg(host, mode); > else > sdhci_uhs2_set_power_reg(host, mode); > > /* maybe more platform-specific initialization */ > } > > struct sdhci_ops sdhci_foo_ops = { > .set_power = sdhci_foo_set_power, > ... > } > > Is this what you mean? > (I'm not quite sure yet that sdhci_ush2_set_power_noreg() can be split off > from sdhci_set_power_noreg().) > > -Takahiro Akashi