The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 011fde48394b7dc8dfd6660d1013b26a00157b80 Mon Sep 17 00:00:00 2001 From: Yangbo Lu <yangbo.lu@xxxxxxx> Date: Tue, 20 Oct 2020 16:11:16 +0800 Subject: [PATCH] mmc: sdhci-of-esdhc: make sure delay chain locked for HS400 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 <yangbo.lu@xxxxxxx> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Link: https://lore.kernel.org/r/20201020081116.20918-1-yangbo.lu@xxxxxxx Fixes: 54e08d9a95ca ("mmc: sdhci-of-esdhc: add hs400 mode support") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h index a30796e79b1c..6de02f09c322 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 <kernel@xxxxxxxxxxxxxx> */ @@ -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 baf7801a1804..bb094459196a 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 <X.Xie@xxxxxxxxxxxxx> * Anton Vorontsov <avorontsov@xxxxxxxxxxxxx> @@ -19,6 +20,7 @@ #include <linux/clk.h> #include <linux/ktime.h> #include <linux/dma-mapping.h> +#include <linux/iopoll.h> #include <linux/mmc/host.h> #include <linux/mmc/mmc.h> #include "sdhci-pltfm.h" @@ -743,6 +745,21 @@ 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 */ + if (read_poll_timeout(sdhci_readl, temp, + temp & ESDHC_DLL_STS_SLV_LOCK, + 10, 20000, false, + host, ESDHC_DLLSTAT0)) + pr_err("%s: timeout for delay chain lock.\n", + mmc_hostname(host->mmc)); + temp = sdhci_readl(host, ESDHC_TBCTL); sdhci_writel(host, temp | ESDHC_HS400_WNDW_ADJUST, ESDHC_TBCTL);
