diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt index f707b8bee304..d50144f5f1d2 100644 --- a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt @@ -38,6 +38,11 @@ Optional properties: This property allows user to change the tuning step to more than one delay cells which is useful for some special boards or cards when the default tuning step can't find the proper delay window within limited tuning retries. +- fsl,strobe-dll-delay-target: Specify the strobe dll control slave delay target. + This delay target programming host controller loopback read clock, and this + property allows user to change the delay target for the strobe input read clock. + If not use this property, driver default set the delay target to value 7. + Only eMMC HS400 mode need to take care of this property. Examples: diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index c6f8b2ff6886..a6dffec11313 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -73,6 +73,7 @@ #define ESDHC_STROBE_DLL_CTRL 0x70 #define ESDHC_STROBE_DLL_CTRL_ENABLE (1 << 0) #define ESDHC_STROBE_DLL_CTRL_RESET (1 << 1) +#define ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_DEFAULT 0x7 #define ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT 3 #define ESDHC_STROBE_DLL_CTRL_SLV_UPDATE_INT_DEFAULT (4 << 20) @@ -995,6 +996,9 @@ static int esdhc_change_pinstate(struct sdhci_host *host, */ static void esdhc_set_strobe_dll(struct sdhci_host *host) { + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host); + u32 strobe_delay; u32 v; /* disable clock before enabling strobe dll */ @@ -1012,9 +1016,13 @@ static void esdhc_set_strobe_dll(struct sdhci_host *host) * enable strobe dll ctrl and adjust the delay target * for the uSDHC loopback read clock */ + if (imx_data->boarddata.strobe_dll_delay_target) + strobe_delay = imx_data->boarddata.strobe_dll_delay_target; + else + strobe_delay = ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_DEFAULT; v = ESDHC_STROBE_DLL_CTRL_ENABLE | ESDHC_STROBE_DLL_CTRL_SLV_UPDATE_INT_DEFAULT | - (7 << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT); + (strobe_delay << ESDHC_STROBE_DLL_CTRL_SLV_DLY_TARGET_SHIFT); writel(v, host->ioaddr + ESDHC_STROBE_DLL_CTRL); /* wait 5us to make sure strobe dll status register stable */ udelay(5); @@ -1340,6 +1348,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, of_property_read_u32(np, "fsl,tuning-start-tap", &boarddata->tuning_start_tap); + of_property_read_u32(np, "fsl,strobe-dll-delay-target", + &boarddata->strobe_dll_delay_target); if (of_find_property(np, "no-1-8-v", NULL)) host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h index 6c006078c8a1..0434f68eda86 100644 --- a/include/linux/platform_data/mmc-esdhc-imx.h +++ b/include/linux/platform_data/mmc-esdhc-imx.h @@ -37,5 +37,6 @@ 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 */ + unsigned int strobe_dll_delay_target; /* The delay cell for strobe pad (read clock) */ }; #endif /* __ASM_ARCH_IMX_ESDHC_H */