From patchwork Fri Oct 16 04:25:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yangbo Lu X-Patchwork-Id: 11840847 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C27571752 for ; Fri, 16 Oct 2020 04:34:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2AC4206DD for ; Fri, 16 Oct 2020 04:34:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731506AbgJPEez (ORCPT ); Fri, 16 Oct 2020 00:34:55 -0400 Received: from inva021.nxp.com ([92.121.34.21]:40198 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731434AbgJPEez (ORCPT ); Fri, 16 Oct 2020 00:34:55 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 1345F20066A; Fri, 16 Oct 2020 06:34:53 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 1BB3D20020F; Fri, 16 Oct 2020 06:34:51 +0200 (CEST) Received: from localhost.localdomain (mega.ap.freescale.net [10.192.208.232]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 2AE3940243; Fri, 16 Oct 2020 06:34:48 +0200 (CEST) From: Yangbo Lu To: linux-mmc@vger.kernel.org Cc: Yangbo Lu , Adrian Hunter , Ulf Hansson Subject: [PATCH] mmc: sdhci-of-esdhc: make sure delay chain locked for HS400 Date: Fri, 16 Oct 2020 12:25:59 +0800 Message-Id: <20201016042559.25618-1-yangbo.lu@nxp.com> X-Mailer: git-send-email 2.17.1 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org For eMMC HS400 mode initialization, the DLL reset is a required step if DLL is enabled to use previously, like in bootloader. This step has not been documented in reference manual, but the RM will be fixed sooner or later. This patch is to add the step of DLL reset, and make sure delay chain locked for HS400. Signed-off-by: Yangbo Lu --- drivers/mmc/host/sdhci-esdhc.h | 2 ++ drivers/mmc/host/sdhci-of-esdhc.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h index a30796e..6de02f0 100644 --- a/drivers/mmc/host/sdhci-esdhc.h +++ b/drivers/mmc/host/sdhci-esdhc.h @@ -5,6 +5,7 @@ * Copyright (c) 2007 Freescale Semiconductor, Inc. * Copyright (c) 2009 MontaVista Software, Inc. * Copyright (c) 2010 Pengutronix e.K. + * Copyright 2020 NXP * Author: Wolfram Sang */ @@ -88,6 +89,7 @@ /* DLL Config 0 Register */ #define ESDHC_DLLCFG0 0x160 #define ESDHC_DLL_ENABLE 0x80000000 +#define ESDHC_DLL_RESET 0x40000000 #define ESDHC_DLL_FREQ_SEL 0x08000000 /* DLL Config 1 Register */ diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index 0b45eff..a39ff86 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -4,6 +4,7 @@ * * Copyright (c) 2007, 2010, 2012 Freescale Semiconductor, Inc. * Copyright (c) 2009 MontaVista Software, Inc. + * Copyright 2020 NXP * * Authors: Xiaobo Xie * Anton Vorontsov @@ -743,6 +744,29 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock) if (host->mmc->actual_clock == MMC_HS200_MAX_DTR) temp |= ESDHC_DLL_FREQ_SEL; sdhci_writel(host, temp, ESDHC_DLLCFG0); + + temp |= ESDHC_DLL_RESET; + sdhci_writel(host, temp, ESDHC_DLLCFG0); + udelay(1); + temp &= ~ESDHC_DLL_RESET; + sdhci_writel(host, temp, ESDHC_DLLCFG0); + + /* Wait max 20 ms */ + timeout = ktime_add_ms(ktime_get(), 20); + while (1) { + bool timedout = ktime_after(ktime_get(), timeout); + + if (sdhci_readl(host, ESDHC_DLLSTAT0) & + ESDHC_DLL_STS_SLV_LOCK) + break; + if (timedout) { + pr_err("%s: timeout for delay chain lock.\n", + mmc_hostname(host->mmc)); + break; + } + usleep_range(10, 20); + } + temp = sdhci_readl(host, ESDHC_TBCTL); sdhci_writel(host, temp | ESDHC_HS400_WNDW_ADJUST, ESDHC_TBCTL);