From patchwork Thu Nov 29 19:05:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Faiz Abbas X-Patchwork-Id: 10705209 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 D8DDB1057 for ; Thu, 29 Nov 2018 19:02:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CC7EC2F8B9 for ; Thu, 29 Nov 2018 19:02:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C923F2F888; Thu, 29 Nov 2018 19:02:41 +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 078E32F888 for ; Thu, 29 Nov 2018 19:02:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726393AbeK3GJD (ORCPT ); Fri, 30 Nov 2018 01:09:03 -0500 Received: from lelv0143.ext.ti.com ([198.47.23.248]:52218 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725871AbeK3GJD (ORCPT ); Fri, 30 Nov 2018 01:09:03 -0500 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id wATJ2JJv085895; Thu, 29 Nov 2018 13:02:19 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1543518139; bh=P67qTiKV9f6NBFewvswx6pcdyuMIU2m586LqwloO8d0=; h=From:To:CC:Subject:Date; b=j752T0MyUae2rhmwbWLBamIKacQrn7trSPun9zIFCpEsCF/jY60OwKVyVYd1UWJbj 8VYE3jiMF9ls8FmKWz5geXJWaprMGna00G0N9FRmTsIc5JhUr2QAk2T9gGvy2N/tfP /xiwBoR9oSTXxw867ABjyFzqICwVIdw1C6KGP3V0= Received: from DFLE115.ent.ti.com (dfle115.ent.ti.com [10.64.6.36]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id wATJ2Ji1063510 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 29 Nov 2018 13:02:19 -0600 Received: from DFLE111.ent.ti.com (10.64.6.32) by DFLE115.ent.ti.com (10.64.6.36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1591.10; Thu, 29 Nov 2018 13:02:19 -0600 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE111.ent.ti.com (10.64.6.32) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1591.10 via Frontend Transport; Thu, 29 Nov 2018 13:02:19 -0600 Received: from a0230074-OptiPlex-7010.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id wATJ2G5j013973; Thu, 29 Nov 2018 13:02:17 -0600 From: Faiz Abbas To: , CC: , , , Subject: [PATCH] mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929) Date: Fri, 30 Nov 2018 00:35:03 +0530 Message-ID: <20181129190503.6040-1-faiz_abbas@ti.com> X-Mailer: git-send-email 2.19.2 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 1b58739d9744..6d3553f06f27 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -969,6 +969,8 @@ 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 b3cb39d0db6f..9ccce7ef3a60 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" @@ -286,14 +287,18 @@ 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; 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) @@ -303,6 +308,16 @@ 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); @@ -317,6 +332,11 @@ 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); @@ -324,10 +344,15 @@ 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) { @@ -345,13 +370,76 @@ 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;