From af6a50d457ec3ca25ec248959c26f98950fddadc Mon Sep 17 00:00:00 2001 From: BOUGH CHEN Date: Fri, 28 Dec 2018 03:26:10 +0000 Subject: [PATCH] mmc: sdhci-esdhc-imx: add SD clock limitation for imx6ull i.MX6ULL has errata ERR010450, point out that due to SOC I/O timing limitation, for eMMC HS200 and SD/SDIO 3.0 SDR104, the clock rate can't exceed 150MHz. And for eMMC DDR52 and SD/SDIO DDR50 mode, the clock rate can't exceed 45MHz. This patch add this limit for imx6ull. Signed-off-by: Haibo Chen Acked-by: Adrian Hunter [Ulf: Fixed comments and whitespace] Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-esdhc-imx.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index d0730748629a..2e50e71cdae5 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -138,7 +138,12 @@ #define ESDHC_FLAG_HS200 BIT(8) /* The IP supports HS400 mode */ #define ESDHC_FLAG_HS400 BIT(9) - +/* + * The IP has errata ERR010450 + * uSDHC: Due to the I/O timing limit, for SDR mode, SD card clock can't + * exceed 150MHz, for DDR mode, SD card clock can't exceed 45MHz. + */ +#define ESDHC_FLAG_ERR010450 BIT(10) /* A clock frequency higher than this rate requires strobe dll control */ #define ESDHC_STROBE_DLL_CLK_FREQ 100000000 @@ -177,6 +182,12 @@ static const struct esdhc_soc_data usdhc_imx6sx_data = { | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200, }; +static const struct esdhc_soc_data usdhc_imx6ull_data = { + .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING + | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200 + | ESDHC_FLAG_ERR010450, +}; + static const struct esdhc_soc_data usdhc_imx7d_data = { .flags = ESDHC_FLAG_USDHC | ESDHC_FLAG_STD_TUNING | ESDHC_FLAG_HAVE_CAP1 | ESDHC_FLAG_HS200 @@ -227,6 +238,7 @@ static const struct of_device_id imx_esdhc_dt_ids[] = { { .compatible = "fsl,imx6sx-usdhc", .data = &usdhc_imx6sx_data, }, { .compatible = "fsl,imx6sl-usdhc", .data = &usdhc_imx6sl_data, }, { .compatible = "fsl,imx6q-usdhc", .data = &usdhc_imx6q_data, }, + { .compatible = "fsl,imx6ull-usdhc", .data = &usdhc_imx6ull_data, }, { .compatible = "fsl,imx7d-usdhc", .data = &usdhc_imx7d_data, }, { /* sentinel */ } }; @@ -733,6 +745,14 @@ static inline void esdhc_pltfm_set_clock(struct sdhci_host *host, | ESDHC_CLOCK_MASK); sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL); + if (imx_data->socdata->flags & ESDHC_FLAG_ERR010450) { + unsigned int max_clock; + + max_clock = imx_data->is_ddr ? 45000000 : 150000000; + + clock = min(clock, max_clock); + } + while (host_clock / (16 * pre_div * ddr_pre_div) > clock && pre_div < 256) pre_div *= 2; -- 2.11.0