From patchwork Tue Dec 11 14:22:53 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Faiz Abbas X-Patchwork-Id: 10723889 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6773113AF for ; Tue, 11 Dec 2018 14:20:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 565A42A914 for ; Tue, 11 Dec 2018 14:20:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 546BC2B15D; Tue, 11 Dec 2018 14:20:19 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 C904A2B16B for ; Tue, 11 Dec 2018 14:20:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726749AbeLKOUR (ORCPT ); Tue, 11 Dec 2018 09:20:17 -0500 Received: from fllv0016.ext.ti.com ([198.47.19.142]:37578 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726690AbeLKOUR (ORCPT ); Tue, 11 Dec 2018 09:20:17 -0500 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id wBBEKE36028121; Tue, 11 Dec 2018 08:20:14 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1544538014; bh=1bMkRlQJkzdHLIreuhrm8yfni2/SM2vZZaNj3wALKRg=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=MedEQy1H99fstlM82s08GFadm5cSQip0V/jgM7H20POwQElJQ1fvZNk85X5UgNaRl hh2LxZpJWUCdr9ZVQAQMxQvc7BICluv1HucLLAYM9ff+9qjjRjsies8QiYlCD6Jk0z j9NDJ9FMb+L7S7h/4bFI85NPW5A77NVh5QZHmCLU= Received: from DLEE100.ent.ti.com (dlee100.ent.ti.com [157.170.170.30]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id wBBEKEMI004345 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 11 Dec 2018 08:20:14 -0600 Received: from DLEE112.ent.ti.com (157.170.170.23) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1591.10; Tue, 11 Dec 2018 08:20:14 -0600 Received: from dlep33.itg.ti.com (157.170.170.75) by DLEE112.ent.ti.com (157.170.170.23) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1591.10 via Frontend Transport; Tue, 11 Dec 2018 08:20:14 -0600 Received: from a0230074-OptiPlex-7010.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id wBBEK6ef024675; Tue, 11 Dec 2018 08:20:12 -0600 From: Faiz Abbas To: , CC: , , , , Subject: [PATCH v2 2/2] mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929) Date: Tue, 11 Dec 2018 19:52:53 +0530 Message-ID: <20181211142253.23747-3-faiz_abbas@ti.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181211142253.23747-1-faiz_abbas@ti.com> References: <20181211142253.23747-1-faiz_abbas@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 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 Errata i929 in certain OMAP5/DRA7XX/AM57XX silicon revisions (SPRZ426D - November 2014 - Revised February 2018 [1]) mentions unexpected tuning pattern errors. A small failure band may be present in the tuning range which may be missed by the current algorithm. Furthermore, the failure bands vary with temperature leading to different optimum tuning values for different temperatures. As suggested in the related Application Report (SPRACA9B - October 2017 - Revised July 2018 [2]), tuning should be done in two stages. In stage 1, assign the optimum ratio in the maximum pass window for the current temperature. In stage 2, if the chosen value is close to the small failure band, move away from it in the appropriate direction. References: [1] http://www.ti.com/lit/pdf/sprz426 [2] http://www.ti.com/lit/pdf/SPRACA9 Signed-off-by: Faiz Abbas Acked-by: Adrian Hunter --- drivers/mmc/host/Kconfig | 2 + drivers/mmc/host/sdhci-omap.c | 90 ++++++++++++++++++++++++++++++++++- 2 files changed, 91 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 5fa580cec831..d8f984483ab0 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -977,6 +977,8 @@ config MMC_SDHCI_XENON config MMC_SDHCI_OMAP tristate "TI SDHCI Controller Support" depends on MMC_SDHCI_PLTFM && OF + select THERMAL + select TI_SOC_THERMAL help This selects the Secure Digital Host Controller Interface (SDHCI) support present in TI's DRA7 SOCs. The controller supports diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c index f588ab679cb0..b75c55011fcb 100644 --- a/drivers/mmc/host/sdhci-omap.c +++ b/drivers/mmc/host/sdhci-omap.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "sdhci-pltfm.h" @@ -286,15 +287,19 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) struct sdhci_host *host = mmc_priv(mmc); struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); + struct thermal_zone_device *thermal_dev; struct device *dev = omap_host->dev; struct mmc_ios *ios = &mmc->ios; u32 start_window = 0, max_window = 0; + bool single_point_failure = false; bool dcrc_was_enabled = false; u8 cur_match, prev_match = 0; u32 length = 0, max_len = 0; u32 phase_delay = 0; + int temperature; int ret = 0; u32 reg; + int i; /* clock tuning is not needed for upto 52MHz */ if (ios->clock <= 52000000) @@ -304,6 +309,16 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) if (ios->timing == MMC_TIMING_UHS_SDR50 && !(reg & CAPA2_TSDR50)) return 0; + thermal_dev = thermal_zone_get_zone_by_name("cpu_thermal"); + if (IS_ERR(thermal_dev)) { + dev_err(dev, "Unable to get thermal zone for tuning\n"); + return PTR_ERR(thermal_dev); + } + + ret = thermal_zone_get_temp(thermal_dev, &temperature); + if (ret) + return ret; + reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_DLL); reg |= DLL_SWT; sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg); @@ -321,6 +336,11 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) omap_host->is_tuning = true; + /* + * Stage 1: Search for a maximum pass window ignoring any + * any single point failures. If the tuning value ends up + * near it, move away from it in stage 2 below + */ while (phase_delay <= MAX_PHASE_DELAY) { sdhci_omap_set_dll(omap_host, phase_delay); @@ -328,10 +348,15 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) if (cur_match) { if (prev_match) { length++; + } else if (single_point_failure) { + /* ignore single point failure */ + length++; } else { start_window = phase_delay; length = 1; } + } else { + single_point_failure = prev_match; } if (length > max_len) { @@ -349,13 +374,76 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode) goto tuning_error; } + /* + * Assign tuning value as a ratio of maximum pass window based + * on temperature + */ + if (temperature < -20000) + phase_delay = min(max_window + 4 * max_len - 24, + max_window + + DIV_ROUND_UP(13 * max_len, 16) * 4); + else if (temperature < 20000) + phase_delay = max_window + DIV_ROUND_UP(9 * max_len, 16) * 4; + else if (temperature < 40000) + phase_delay = max_window + DIV_ROUND_UP(8 * max_len, 16) * 4; + else if (temperature < 70000) + phase_delay = max_window + DIV_ROUND_UP(7 * max_len, 16) * 4; + else if (temperature < 90000) + phase_delay = max_window + DIV_ROUND_UP(5 * max_len, 16) * 4; + else if (temperature < 120000) + phase_delay = max_window + DIV_ROUND_UP(4 * max_len, 16) * 4; + else + phase_delay = max_window + DIV_ROUND_UP(3 * max_len, 16) * 4; + + /* + * Stage 2: Search for a single point failure near the chosen tuning + * value in two steps. First in the +3 to +10 range and then in the + * +2 to -10 range. If found, move away from it in the appropriate + * direction by the appropriate amount depending on the temperature. + */ + for (i = 3; i <= 10; i++) { + sdhci_omap_set_dll(omap_host, phase_delay + i); + + if (mmc_send_tuning(mmc, opcode, NULL)) { + if (temperature < 10000) + phase_delay += i + 6; + else if (temperature < 20000) + phase_delay += i - 12; + else if (temperature < 70000) + phase_delay += i - 8; + else + phase_delay += i - 6; + + goto single_failure_found; + } + } + + for (i = 2; i >= -10; i--) { + sdhci_omap_set_dll(omap_host, phase_delay + i); + + if (mmc_send_tuning(mmc, opcode, NULL)) { + if (temperature < 10000) + phase_delay += i + 12; + else if (temperature < 20000) + phase_delay += i + 8; + else if (temperature < 70000) + phase_delay += i + 8; + else if (temperature < 90000) + phase_delay += i + 10; + else + phase_delay += i + 12; + + goto single_failure_found; + } + } + +single_failure_found: reg = sdhci_omap_readl(omap_host, SDHCI_OMAP_AC12); if (!(reg & AC12_SCLK_SEL)) { ret = -EIO; goto tuning_error; } - phase_delay = max_window + 4 * (max_len >> 1); sdhci_omap_set_dll(omap_host, phase_delay); omap_host->is_tuning = false;