From af6a50d457ec3ca25ec248959c26f98950fddadc Mon Sep 17 00:00:00 2001
From: BOUGH CHEN <haibo.chen@nxp.com>
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 <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
[Ulf: Fixed comments and whitespace]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
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 d0730748629a8..2e50e71cdae5b 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;
--
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