From patchwork Wed Jul 4 15:07:45 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Agner X-Patchwork-Id: 10507189 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A7EA8600F5 for ; Wed, 4 Jul 2018 15:07:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9558E28D96 for ; Wed, 4 Jul 2018 15:07:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 895C428D9A; Wed, 4 Jul 2018 15:07:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C48A228D96 for ; Wed, 4 Jul 2018 15:07:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752496AbeGDPHz (ORCPT ); Wed, 4 Jul 2018 11:07:55 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:57572 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752218AbeGDPHy (ORCPT ); Wed, 4 Jul 2018 11:07:54 -0400 Received: from trochilidae.toradex.int (unknown [46.140.72.82]) by mail.kmu-office.ch (Postfix) with ESMTPSA id DAD2D5C02AD; Wed, 4 Jul 2018 17:07:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=agner.ch; s=dkim; t=1530716873; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:content-type:content-transfer-encoding: in-reply-to:references; bh=Bc6t6m7OBA3M4CoNr39md6xKDwamVrWxogMgmAw5iSo=; b=Jd/WhUjE9VO5j7xQ3iXHTh6NMF2x8F8ZqgR0LYXT3Hs531NC66N0sY2lv92nh1trNX0YMe Sabu6Dug8VjkJt73wPy2HtN6J6SKgNxrGExMEjfPcc0thr5edRPZNXlHcQ1lyJL7xDOpPe YzJUhKmQ9A1tH30g9qbYwkXhlTWosC4= From: Stefan Agner To: adrian.hunter@intel.com, ulf.hansson@linaro.org Cc: fabio.estevam@nxp.com, haibo.chen@nxp.com, aisheng.dong@nxp.com, michael@amarulasolutions.com, rmk+kernel@armlinux.org.uk, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Agner Subject: [PATCH v2] mmc: sdhci-esdhc-imx: allow 1.8V modes without 100/200MHz pinctrl states Date: Wed, 4 Jul 2018 17:07:45 +0200 Message-Id: <20180704150745.21003-1-stefan@agner.ch> X-Mailer: git-send-email 2.18.0 X-Spamd-Result: default: False [-2.10 / 15.00]; TO_MATCH_ENVRCPT_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%]; TAGGED_RCPT(0.00)[kernel]; MIME_GOOD(-0.10)[text/plain]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_SEVEN(0.00)[10]; FROM_EQ_ENVFROM(0.00)[]; DKIM_SIGNED(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_ZERO(0.00)[0]; MID_CONTAINS_FROM(1.00)[]; ASN(0.00)[asn:6830, ipnet:46.140.0.0/17, country:AT]; RCVD_TLS_ALL(0.00)[]; ARC_NA(0.00)[] Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If pinctrl nodes for 100/200MHz are missing, the controller should not select any mode which need signal frequencies 100MHz or higher. To prevent such speed modes the driver currently uses the quirk flag SDHCI_QUIRK2_NO_1_8_V. This works nicely for SD cards since 1.8V signaling is required for all faster modes and slower modes use 3.3V signaling only. However, there are eMMC modes which use 1.8V signaling and run below 100MHz, e.g. DDR52 at 1.8V. With using SDHCI_QUIRK2_NO_1_8_V this mode is prevented. When using a fixed 1.8V regulator as vqmmc-supply the stack has no valid mode to use. In this tenuous situation the kernel continuously prints voltage switching errors: mmc1: Switching to 3.3V signalling voltage failed Avoid using SDHCI_QUIRK2_NO_1_8_V and prevent faster modes by altering the SDHCI capability register. With that the stack is able to select 1.8V modes even if no faster pinctrl states are available: # cat /sys/kernel/debug/mmc1/ios ... timing spec: 8 (mmc DDR52) signal voltage: 1 (1.80 V) ... Link: http://lkml.kernel.org/r/20180628081331.13051-1-stefan@agner.ch Signed-off-by: Stefan Agner --- drivers/mmc/host/sdhci-esdhc-imx.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 20a420b765b3..e96d969ab2c3 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -312,6 +312,15 @@ static u32 esdhc_readl_le(struct sdhci_host *host, int reg) if (imx_data->socdata->flags & ESDHC_FLAG_HS400) val |= SDHCI_SUPPORT_HS400; + + /* + * Do not advertise faster UHS modes if there are no + * pinctrl states for 100MHz/200MHz. + */ + if (IS_ERR_OR_NULL(imx_data->pins_100mhz) || + IS_ERR_OR_NULL(imx_data->pins_200mhz)) + val &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50 + | SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_HS400); } } @@ -1157,18 +1166,6 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, ESDHC_PINCTRL_STATE_100MHZ); imx_data->pins_200mhz = pinctrl_lookup_state(imx_data->pinctrl, ESDHC_PINCTRL_STATE_200MHZ); - if (IS_ERR(imx_data->pins_100mhz) || - IS_ERR(imx_data->pins_200mhz)) { - dev_warn(mmc_dev(host->mmc), - "could not get ultra high speed state, work on normal mode\n"); - /* - * fall back to not supporting uhs by specifying no - * 1.8v quirk - */ - host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; - } - } else { - host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; } /* call to generic mmc_of_parse to support additional capabilities */