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=-0.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 174C8C28CF6 for ; Wed, 1 Aug 2018 16:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C84E5208A4 for ; Wed, 1 Aug 2018 16:33:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C84E5208A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390597AbeHASUQ (ORCPT ); Wed, 1 Aug 2018 14:20:16 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:2830 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390113AbeHASUP (ORCPT ); Wed, 1 Aug 2018 14:20:15 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1, AES128-SHA) id ; Wed, 01 Aug 2018 09:33:38 -0700 Received: from HQMAIL106.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Wed, 01 Aug 2018 09:33:43 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Wed, 01 Aug 2018 09:33:43 -0700 Received: from HQMAIL107.nvidia.com (172.20.187.13) by HQMAIL106.nvidia.com (172.18.146.12) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Wed, 1 Aug 2018 16:33:42 +0000 Received: from hqnvemgw02.nvidia.com (172.16.227.111) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1347.2 via Frontend Transport; Wed, 1 Aug 2018 16:33:43 +0000 Received: from dhcp-10-21-25-168.Nvidia.com (Not Verified[10.21.25.201]) by hqnvemgw02.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Wed, 01 Aug 2018 09:33:42 -0700 From: Aapo Vienamo To: Rob Herring , Mark Rutland , Thierry Reding , Jonathan Hunter , Ulf Hansson , Adrian Hunter , Mikko Perttunen , Stefan Agner CC: , , , , Aapo Vienamo Subject: [PATCH 20/40] mmc: tegra: Add a workaround for tap value change glitch Date: Wed, 1 Aug 2018 19:32:10 +0300 Message-ID: <1533141150-10511-21-git-send-email-avienamo@nvidia.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1533141150-10511-1-git-send-email-avienamo@nvidia.com> References: <1533141150-10511-1-git-send-email-avienamo@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add quirk to disable the card clock during configuration of the tap value in tegra_sdhci_set_tap() and issue sdhci_reset() after value change. This is a workaround to avoid propagation of a potential glitch caused by setting the tap value. Signed-off-by: Aapo Vienamo --- drivers/mmc/host/sdhci-tegra.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c index 3c10451..a2375ad 100644 --- a/drivers/mmc/host/sdhci-tegra.c +++ b/drivers/mmc/host/sdhci-tegra.c @@ -47,6 +47,9 @@ #define SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 0x20 #define SDHCI_MISC_CTRL_ENABLE_DDR50 0x200 +#define SDHCI_VNDR_TUN_CTRL0_0 0x1c0 +#define SDHCI_VNDR_TUN_CTRL0_TUN_HW_TAP 0x20000 + #define SDHCI_TEGRA_AUTO_CAL_CONFIG 0x1e4 #define SDHCI_AUTO_CAL_START BIT(31) #define SDHCI_AUTO_CAL_ENABLE BIT(29) @@ -68,6 +71,7 @@ #define NVQUIRK_ENABLE_DDR50 BIT(5) #define NVQUIRK_HAS_PADCALIB BIT(6) #define NVQUIRK_NEEDS_PAD_CONTROL BIT(7) +#define NVQUIRK_DIS_CARD_CLK_CONFIG_TAP BIT(8) struct sdhci_tegra_soc_data { const struct sdhci_pltfm_data *pdata; @@ -499,12 +503,32 @@ static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host) static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap) { + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host); + const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data; + bool card_clk_enabled = false; u32 reg; + /* + * Touching the tap values is a bit tricky on some SoC generations. + * The quirk enables a workaround for a glitch that sometimes occurs if + * the tap values are changed. + */ + + if (soc_data->nvquirks & NVQUIRK_DIS_CARD_CLK_CONFIG_TAP) + card_clk_enabled = tegra_sdhci_configure_card_clk(host, false); + reg = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL); reg &= ~SDHCI_CLOCK_CTRL_TAP_MASK; reg |= tap << SDHCI_CLOCK_CTRL_TAP_SHIFT; sdhci_writel(host, reg, SDHCI_TEGRA_VENDOR_CLOCK_CTRL); + + if (soc_data->nvquirks & NVQUIRK_DIS_CARD_CLK_CONFIG_TAP && + card_clk_enabled) { + udelay(1); + sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA); + tegra_sdhci_configure_card_clk(host, card_clk_enabled); + } } static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode) @@ -758,7 +782,8 @@ static const struct sdhci_pltfm_data sdhci_tegra210_pdata = { static const struct sdhci_tegra_soc_data soc_data_tegra210 = { .pdata = &sdhci_tegra210_pdata, .nvquirks = NVQUIRK_NEEDS_PAD_CONTROL | - NVQUIRK_HAS_PADCALIB, + NVQUIRK_HAS_PADCALIB | + NVQUIRK_DIS_CARD_CLK_CONFIG_TAP, }; static const struct sdhci_pltfm_data sdhci_tegra186_pdata = { @@ -783,7 +808,8 @@ static const struct sdhci_pltfm_data sdhci_tegra186_pdata = { static const struct sdhci_tegra_soc_data soc_data_tegra186 = { .pdata = &sdhci_tegra186_pdata, .nvquirks = NVQUIRK_NEEDS_PAD_CONTROL | - NVQUIRK_HAS_PADCALIB, + NVQUIRK_HAS_PADCALIB | + NVQUIRK_DIS_CARD_CLK_CONFIG_TAP, }; static const struct of_device_id sdhci_tegra_dt_match[] = { -- 2.7.4