diff options
| -rw-r--r-- | Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt | 5 | ||||
| -rw-r--r-- | drivers/mmc/host/sdhci-esdhc-imx.c | 18 | ||||
| -rw-r--r-- | include/linux/platform_data/mmc-esdhc-imx.h | 1 |
3 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt index 1dd622546d06..9046ba06c47a 100644 --- a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt @@ -12,6 +12,11 @@ Required properties: Optional properties: - fsl,cd-controller : Indicate to use controller internal card detection - fsl,wp-controller : Indicate to use controller internal write protection +- fsl,delay-line : Specify the number of delay cells for override mode. + This is used to set the clock delay for DLL(Delay Line) on override mode + to select a proper data sampling window in case the clock quality is not good + due to signal path is too long on the board. Please refer to eSDHC/uSDHC + chapter, DLL (Delay Line) section in RM for details. Examples: diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 915fa68e5122..260a81fde18d 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -46,6 +46,11 @@ /* Bits 3 and 6 are not SDHCI standard definitions */ #define ESDHC_MIX_CTRL_SDHCI_MASK 0xb7 +/* dll control register */ +#define ESDHC_DLL_CTRL 0x60 +#define ESDHC_DLL_OVERRIDE_VAL_SHIFT 9 +#define ESDHC_DLL_OVERRIDE_EN_SHIFT 8 + /* tune control register */ #define ESDHC_TUNE_CTRL_STATUS 0x68 #define ESDHC_TUNE_CTRL_STEP 1 @@ -817,6 +822,7 @@ static int esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs) { 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; switch (uhs) { case MMC_TIMING_UHS_SDR12: @@ -837,6 +843,15 @@ static int esdhc_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs) ESDHC_MIX_CTRL_DDREN, host->ioaddr + ESDHC_MIX_CTRL); imx_data->is_ddr = 1; + if (boarddata->delay_line) { + u32 v; + v = boarddata->delay_line << + ESDHC_DLL_OVERRIDE_VAL_SHIFT | + (1 << ESDHC_DLL_OVERRIDE_EN_SHIFT); + if (is_imx53_esdhc(imx_data)) + v <<= 1; + writel(v, host->ioaddr + ESDHC_DLL_CTRL); + } break; } @@ -901,6 +916,9 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, else boarddata->support_vsel = true; + if (of_property_read_u32(np, "fsl,delay-line", &boarddata->delay_line)) + boarddata->delay_line = 0; + return 0; } #else diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h index a0f5a8f9b3bc..75f70f6ac137 100644 --- a/include/linux/platform_data/mmc-esdhc-imx.h +++ b/include/linux/platform_data/mmc-esdhc-imx.h @@ -45,5 +45,6 @@ struct esdhc_platform_data { int max_bus_width; unsigned int f_max; bool support_vsel; + unsigned int delay_line; }; #endif /* __ASM_ARCH_IMX_ESDHC_H */ |