From patchwork Thu Sep 21 07:44:09 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 9963437 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 0F9986020C for ; Thu, 21 Sep 2017 07:50:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 000BC2890F for ; Thu, 21 Sep 2017 07:50:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E8D9228923; Thu, 21 Sep 2017 07:50:53 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI 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 3C58C2890F for ; Thu, 21 Sep 2017 07:50:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751524AbdIUHuw (ORCPT ); Thu, 21 Sep 2017 03:50:52 -0400 Received: from mga02.intel.com ([134.134.136.20]:28606 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484AbdIUHuv (ORCPT ); Thu, 21 Sep 2017 03:50:51 -0400 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Sep 2017 00:50:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,424,1500966000"; d="scan'208";a="902487132" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.168]) ([10.237.72.168]) by FMSMGA003.fm.intel.com with ESMTP; 21 Sep 2017 00:50:49 -0700 Subject: [PATCH RFC] mmc: sd: Fix signal voltage when there is no power cycle To: Shawn Lin , Zhoujie Wu Cc: Ulf Hansson , "linux-mmc@vger.kernel.org" References: <1503978827-202915-1-git-send-email-shawn.lin@rock-chips.com> <59A5E6F2.5000407@marvell.com> <745b195b-bdd1-e675-a36a-ca22eb41feaa@rock-chips.com> <59A9E5CD.3000703@marvell.com> <12498751-b7cc-03a4-efa5-cd0134dd57d3@rock-chips.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Thu, 21 Sep 2017 10:44:09 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <12498751-b7cc-03a4-efa5-cd0134dd57d3@rock-chips.com> Content-Language: en-US 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 the card has not been power cycled, it may still be using 1.8V signaling. According to the SD spec., the Bus Speed Mode (function group 1) bits 2 to 4 are zero if the card is initialized at 3.3V signal level. Thus they can be used to determine if the card has already switched to 1.8V signaling. Detect that situation and try to initialize a UHS-I (1.8V) transfer mode. Tested with the following cards: Transcend 4GB High Speed Kingston 64GB SDR104 Lexar by Micron HIGH-PERFORMANCE 300x 16GB DDR50 SanDisk Ultra 8GB DDR50 Transcend Ultimate 600x 16GB SDR104 Transcend Premium 300x 64GB SDR104 Lexar by Micron Professional 1000x 32GB UHS-II SDR104 SanDisk Extreme Pro 16GB SDR104 Signed-off-by: Adrian Hunter Tested-by: Zhoujie Wu Reviewed-by: Shawn Lin --- Here is an alternative approach to Shawn's that uses CMD6 to identify the card's signal voltage. It has the advantages that it does not depend on knowing about the regulator, and it works even when unbinding / re-binding the host controller. drivers/mmc/core/core.c | 38 ++++++++++++++++++++++++-------------- drivers/mmc/core/core.h | 1 + drivers/mmc/core/sd.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-- 3 files changed, 70 insertions(+), 16 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 24a73f387482..161c1d105d91 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1723,11 +1723,33 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage) } +int mmc_host_set_uhs_voltage(struct mmc_host *host) +{ + u32 clock; + + /* + * During a signal voltage level switch, the clock must be gated + * for 5 ms according to the SD spec + */ + clock = host->ios.clock; + host->ios.clock = 0; + mmc_set_ios(host); + + if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180)) + return -EAGAIN; + + /* Keep clock gated for at least 10 ms, though spec only says 5 ms */ + mmc_delay(10); + host->ios.clock = clock; + mmc_set_ios(host); + + return 0; +} + int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr) { struct mmc_command cmd = {}; int err = 0; - u32 clock; /* * If we cannot switch voltages, return failure so the caller @@ -1759,15 +1781,8 @@ int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr) err = -EAGAIN; goto power_cycle; } - /* - * During a signal voltage level switch, the clock must be gated - * for 5 ms according to the SD spec - */ - clock = host->ios.clock; - host->ios.clock = 0; - mmc_set_ios(host); - if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180)) { + if (mmc_host_set_uhs_voltage(host)) { /* * Voltages may not have been switched, but we've already * sent CMD11, so a power cycle is required anyway @@ -1776,11 +1791,6 @@ int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr) goto power_cycle; } - /* Keep clock gated for at least 10 ms, though spec only says 5 ms */ - mmc_delay(10); - host->ios.clock = clock; - mmc_set_ios(host); - /* Wait for at least 1 ms according to spec */ mmc_delay(1); diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h index 03e0f8384b1c..2b2690d0d877 100644 --- a/drivers/mmc/core/core.h +++ b/drivers/mmc/core/core.h @@ -51,6 +51,7 @@ struct device_node *mmc_of_find_child_device(struct mmc_host *host, void mmc_set_bus_width(struct mmc_host *host, unsigned int width); u32 mmc_select_voltage(struct mmc_host *host, u32 ocr); int mmc_set_uhs_voltage(struct mmc_host *host, u32 ocr); +int mmc_host_set_uhs_voltage(struct mmc_host *host); int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage); void mmc_set_timing(struct mmc_host *host, unsigned int timing); void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type); diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 4fd1620b732d..35e1f52cb3f9 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -908,6 +908,18 @@ unsigned mmc_sd_get_max_clock(struct mmc_card *card) return max_dtr; } +static bool mmc_sd_card_using_v18(struct mmc_card *card) +{ + /* + * According to the SD spec., the Bus Speed Mode (function group 1) bits + * 2 to 4 are zero if the card is initialized at 3.3V signal level. Thus + * they can be used to determine if the card has already switched to + * 1.8V signaling. + */ + return card->sw_caps.sd3_bus_mode & + (SD_MODE_UHS_SDR50 | SD_MODE_UHS_SDR104 | SD_MODE_UHS_DDR50); +} + /* * Handle the detection and initialisation of a card. * @@ -921,9 +933,10 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, int err; u32 cid[4]; u32 rocr = 0; + bool v18_fixup_failed = false; WARN_ON(!host->claimed); - +retry: err = mmc_sd_get_cid(host, ocr, cid, &rocr); if (err) return err; @@ -989,6 +1002,36 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, if (err) goto free_card; + /* + * If the card has not been power cycled, it may still be using 1.8V + * signaling. Detect that situation and try to initialize a UHS-I (1.8V) + * transfer mode. + */ + if (!v18_fixup_failed && !mmc_host_is_spi(host) && mmc_host_uhs(host) && + mmc_sd_card_using_v18(card) && + host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) { + /* + * Re-read switch information in case it has changed since + * oldcard was initialized. + */ + if (oldcard) { + err = mmc_read_switch(card); + if (err) + goto free_card; + } + if (mmc_sd_card_using_v18(card)) { + if (mmc_host_set_uhs_voltage(host) || + mmc_sd_init_uhs_card(card)) { + v18_fixup_failed = true; + mmc_power_cycle(host, ocr); + if (!oldcard) + mmc_remove_card(card); + goto retry; + } + goto done; + } + } + /* Initialization sequence for UHS-I cards */ if (rocr & SD_ROCR_S18A) { err = mmc_sd_init_uhs_card(card); @@ -1021,7 +1064,7 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, mmc_set_bus_width(host, MMC_BUS_WIDTH_4); } } - +done: host->card = card; return 0;