MLK-18161-15 mmc: Add HS400 Enhanced Strobe mode support

The eMMC 5.1 supports the HS400 Enhanced Strobe mode, add this
support to mmc.

Signed-off-by: Ye Li <ye.li@nxp.com>

3 files changed, 94 insertions, 1 deletions

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index e9be18b333f..c4df67d511d 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -104,6 +104,12 @@ config SPL_MMC_UHS_SUPPORT
 	  cards. The IO voltage must be switchable from 3.3v to 1.8v. The bus
 	  frequency can go up to 208MHz (SDR104)
 
+config MMC_HS400_ES_SUPPORT
+	bool "enable HS400 Enhanced Strobe support"
+	help
+	  The HS400 Enhanced Strobe mode is support by some eMMC. The bus frequency is up to
+	  200MHz. This mode does not tune the IO.
+
 config MMC_HS400_SUPPORT
 	bool "enable HS400 support"
 	select MMC_HS200_SUPPORT
diff --git a/drivers/mmc/mmc-uclass.c b/drivers/mmc/mmc-uclass.c
index a3536b15ae6..cf628a8b254 100644
--- a/drivers/mmc/mmc-uclass.c
+++ b/drivers/mmc/mmc-uclass.c
@@ -123,6 +123,21 @@ int mmc_execute_tuning(struct mmc *mmc, uint opcode)
 }
 #endif
 
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+void dm_mmc_set_enhanced_strobe(struct udevice *dev)
+{
+	struct dm_mmc_ops *ops = mmc_get_ops(dev);
+
+	if (ops->set_enhanced_strobe)
+		ops->set_enhanced_strobe(dev);
+}
+
+void mmc_set_enhanced_strobe(struct mmc *mmc)
+{
+	dm_mmc_set_enhanced_strobe(mmc->dev);
+}
+#endif
+
 int mmc_of_parse(struct udevice *dev, struct mmc_config *cfg)
 {
 	int val;
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index eef229c8b4b..4a80f556a0b 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -170,6 +170,7 @@ const char *mmc_mode_name(enum bus_mode mode)
 	      [MMC_DDR_52]	= "MMC DDR52 (52MHz)",
 	      [MMC_HS_200]	= "HS200 (200MHz)",
 	      [MMC_HS_400]	= "HS400 (200MHz)",
+	      [MMC_HS_400_ES]	= "HS400ES (200MHz)",
 	};
 
 	if (mode >= MMC_MODES_END)
@@ -195,6 +196,7 @@ static uint mmc_mode2freq(struct mmc *mmc, enum bus_mode mode)
 	      [UHS_SDR104]	= 208000000,
 	      [MMC_HS_200]	= 200000000,
 	      [MMC_HS_400]	= 200000000,
+	      [MMC_HS_400_ES]	= 200000000,
 	};
 
 	if (mode == MMC_LEGACY)
@@ -798,6 +800,11 @@ static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode)
 		speed_bits = EXT_CSD_TIMING_HS400;
 		break;
 #endif
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+	case MMC_HS_400_ES:
+		  speed_bits = EXT_CSD_TIMING_HS400;
+		  break;
+#endif
 	case MMC_LEGACY:
 		speed_bits = EXT_CSD_TIMING_LEGACY;
 		break;
@@ -853,7 +860,7 @@ static int mmc_get_capabilities(struct mmc *mmc)
 		mmc->card_caps |= MMC_MODE_HS200;
 	}
 #endif
-#if CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
+#if (CONFIG_IS_ENABLED(MMC_HS400_SUPPORT) || CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT))
 	if (cardtype & (EXT_CSD_CARD_TYPE_HS400_1_2V |
 			EXT_CSD_CARD_TYPE_HS400_1_8V)) {
 		mmc->card_caps |= MMC_MODE_HS400;
@@ -867,6 +874,11 @@ static int mmc_get_capabilities(struct mmc *mmc)
 	if (cardtype & EXT_CSD_CARD_TYPE_26)
 		mmc->card_caps |= MMC_MODE_HS;
 
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+	if (ext_csd[EXT_CSD_STROBE_SUPPORT] && (mmc->card_caps & MMC_MODE_HS400))
+		mmc->card_caps |= MMC_MODE_HS400_ES;
+#endif
+
 	return 0;
 }
 
@@ -1761,6 +1773,7 @@ static int mmc_set_lowest_voltage(struct mmc *mmc, enum bus_mode mode,
 	u32 card_mask = 0;
 
 	switch (mode) {
+	case MMC_HS_400_ES:
 	case MMC_HS_400:
 		if (mmc->cardtype & EXT_CSD_CARD_TYPE_HS400_1_8V)
 			card_mask |= MMC_SIGNAL_VOLTAGE_180;
@@ -1806,6 +1819,12 @@ static inline int mmc_set_lowest_voltage(struct mmc *mmc, enum bus_mode mode,
 #endif
 
 static const struct mode_width_tuning mmc_modes_by_pref[] = {
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+	{
+		.mode = MMC_HS_400_ES,
+		.widths = MMC_MODE_8BIT,
+	},
+#endif
 #if CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
 	{
 		.mode = MMC_HS_400,
@@ -1904,6 +1923,55 @@ static int mmc_select_hs400(struct mmc *mmc)
 }
 #endif
 
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+#if !CONFIG_IS_ENABLED(DM_MMC)
+static void mmc_set_enhanced_strobe(struct mmc *mmc)
+{
+	return;
+}
+#endif
+
+static int mmc_select_hs400es(struct mmc *mmc)
+{
+	int err;
+
+	err = mmc_set_card_speed(mmc, MMC_HS);
+	if (err)
+		return err;
+
+	/* configure the bus mode (host) */
+	mmc_select_mode(mmc, MMC_HS);
+	mmc_set_clock(mmc, mmc->tran_speed, false);
+
+	err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
+		EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_8 |
+		EXT_CSD_DDR_FLAG | EXT_CSD_BUS_WIDTH_STROBE);
+	if (err) {
+		printf("switch to bus width for hs400 failed\n");
+		return err;
+	}
+	/* TODO: driver strength */
+	err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
+		EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS400 | (0 << EXT_CSD_DRV_STR_SHIFT));
+	if (err) {
+		printf("switch to hs400 failed\n");
+		return err;
+	}
+
+	mmc_select_mode(mmc, MMC_HS_400_ES);
+	mmc_set_clock(mmc, mmc->tran_speed, false);
+	mmc_set_enhanced_strobe(mmc);
+
+	return 0;
+}
+
+#else
+static int mmc_select_hs400es(struct mmc *mmc)
+{
+	return -ENOTSUPP;
+}
+#endif
+
 #define for_each_supported_width(caps, ddr, ecbv) \
 	for (ecbv = ext_csd_bus_width;\
 	    ecbv < ext_csd_bus_width + ARRAY_SIZE(ext_csd_bus_width);\
@@ -1961,6 +2029,10 @@ static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps)
 				err = mmc_select_hs400(mmc);
 				if (err)
 					goto error;
+			} else if (mwt->mode == MMC_HS_400_ES) {
+				err = mmc_select_hs400es(mmc);
+				if (err)
+					goto error;
 			} else {
 				/* configure the bus speed (card) */
 				err = mmc_set_card_speed(mmc, mwt->mode);