From patchwork Thu May 6 10:03:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Lee X-Patchwork-Id: 432375 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 B2AD9C433ED for ; Thu, 6 May 2021 10:06:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A686611AC for ; Thu, 6 May 2021 10:06:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234320AbhEFKHH (ORCPT ); Thu, 6 May 2021 06:07:07 -0400 Received: from twspam01.aspeedtech.com ([211.20.114.71]:30082 "EHLO twspam01.aspeedtech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234328AbhEFKHA (ORCPT ); Thu, 6 May 2021 06:07:00 -0400 Received: from mail.aspeedtech.com ([192.168.0.24]) by twspam01.aspeedtech.com with ESMTP id 1469pQMd024637; Thu, 6 May 2021 17:51:26 +0800 (GMT-8) (envelope-from steven_lee@aspeedtech.com) Received: from localhost.localdomain (192.168.100.253) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 6 May 2021 18:03:13 +0800 From: Steven Lee To: Andrew Jeffery , Ulf Hansson , Rob Herring , Joel Stanley , "Adrian Hunter" , Philipp Zabel , Ryan Chen , "moderated list:ASPEED SD/MMC DRIVER" , "moderated list:ASPEED SD/MMC DRIVER" , "open list:ASPEED SD/MMC DRIVER" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "moderated list:ARM/ASPEED MACHINE SUPPORT" , open list CC: , , , Subject: [PATCH v3 2/5] ARM: dts: aspeed: ast2600evb: Add comment for gpio regulator of sdhci Date: Thu, 6 May 2021 18:03:09 +0800 Message-ID: <20210506100312.1638-3-steven_lee@aspeedtech.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210506100312.1638-1-steven_lee@aspeedtech.com> References: <20210506100312.1638-1-steven_lee@aspeedtech.com> MIME-Version: 1.0 X-Originating-IP: [192.168.100.253] X-ClientProxiedBy: TWMBX02.aspeed.com (192.168.0.24) To TWMBX02.aspeed.com (192.168.0.24) X-DNSRBL: X-MAIL: twspam01.aspeedtech.com 1469pQMd024637 Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org Add the description for describing the AST2600-A2 EVB reference design of GPIO regulators. Signed-off-by: Steven Lee --- arch/arm/boot/dts/aspeed-ast2600-evb.dts | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/arm/boot/dts/aspeed-ast2600-evb.dts b/arch/arm/boot/dts/aspeed-ast2600-evb.dts index 2772796e215e..1ae0facc3d5f 100644 --- a/arch/arm/boot/dts/aspeed-ast2600-evb.dts +++ b/arch/arm/boot/dts/aspeed-ast2600-evb.dts @@ -104,6 +104,21 @@ status = "okay"; }; +/* + * The signal voltage of sdhci0 and sdhci1 on AST2600-A2 EVB is able to be + * toggled by GPIO pins. + * In the reference design, GPIOV0 of AST2600-A2 EVB is connected to the + * power load switch that providing 3.3v to sdhci0 vdd, GPIOV1 is connected to + * a 1.8v and a 3.3v power load switch that providing signal voltage to + * sdhci0 bus. + * If GPIOV0 is active high, sdhci0 is enabled, otherwise, sdhci0 is disabled. + * If GPIOV1 is active high, 3.3v power load switch is enabled, sdhci0 signal + * voltage is 3.3v, otherwise, 1.8v power load switch will be enabled, + * sdhci0 signal voltage becomes 1.8v. + * AST2600-A2 EVB also support toggling signal voltage for sdhci1. + * The design is the same as sdhci0, it uses GPIOV2 as power-gpio and GPIOV3 + * as power-switch-gpio. + */ &emmc { non-removable; bus-width = <4>;