From 0b320d998d7c1ff43231682f6ab5a97f476249f7 Mon Sep 17 00:00:00 2001
From: Anna Horstmann <ahorstmann@phytec.com>
Date: Wed, 12 Apr 2017 15:17:06 -0700
Subject: [PATCH] IMX7FLY-84 mmc: sdhci-esdhc-imx: add dts property
 no-mmc-hs400

The phyCORE-i.MX7 SOM (PCM-061-2110111C.A1) with eMMC 5.0 has read
errors when operating in the default HS400 mode. Added property
"no-mmc-hs400".

Signed-off-by: Anna Horstmann <ahorstmann@phytec.com>

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index a02edfc..6ecf6f8 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -297,6 +297,8 @@ static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct pltfm_imx_data *imx_data = pltfm_host->priv;
+	struct esdhc_platform_data *boarddata = &imx_data->boarddata;
+
 	u32 val = readl(host->ioaddr + reg);
 
 	if (unlikely(reg == SDHCI_PRESENT_STATE)) {
@@ -338,7 +340,7 @@ static u32 esdhc_readl_le(struct sdhci_host *host, int reg)
 					| SDHCI_USE_SDR50_TUNING
 					| (SDHCI_TUNING_MODE_3 << SDHCI_RETUNING_MODE_SHIFT);
 
-			if (imx_data->socdata->flags & ESDHC_FLAG_HS400)
+			if (imx_data->socdata->flags & ESDHC_FLAG_HS400 && boarddata->support_mmc_hs400)
 				val |= SDHCI_SUPPORT_HS400;
 		}
 	}
@@ -1118,6 +1120,13 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
 		host->quirks2 |= SDHCI_QUIRK2_SDIO_IRQ_THREAD;
 		dev_info(mmc_dev(host->mmc), "assigned as wifi host\n");
 	}
+	if (of_find_property(np, "no-mmc-hs400", NULL))
+		boarddata->support_mmc_hs400 = false;
+	else
+		boarddata->support_mmc_hs400 = true;
+
+	if ((!boarddata->support_mmc_hs400))
+		host->quirks2 &= ~SDHCI_QUIRK2_CAPS_BIT63_FOR_HS400;
 
 	return 0;
 }
diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h
index 7daa78a..87f5a44 100644
--- a/include/linux/platform_data/mmc-esdhc-imx.h
+++ b/include/linux/platform_data/mmc-esdhc-imx.h
@@ -47,5 +47,6 @@ struct esdhc_platform_data {
 	unsigned int delay_line;
 	unsigned int tuning_step;       /* The delay cell steps in tuning procedure */
 	unsigned int tuning_start_tap;	/* The start delay cell point in tuning procedure */
+	bool support_mmc_hs400;
 };
 #endif /* __ASM_ARCH_IMX_ESDHC_H */
-- 
1.9.1