[U-Boot] [PATCH 1/2] mmc: add HS400 support

[Peng Fan <van.freenix@gmail.com>]

Hi, 
On Mon, Mar 05, 2018 at 05:29:08PM +0100, Jean-Jacques Hiblot wrote:
>Hi Peng,
>
>I'm glad you are adding HS400 support. Thanks.
>
>
>On 05/03/2018 10:11, Peng Fan wrote:
>>Add HS400 support.
>>Selecting HS400 needs first select HS199 according to spec, so use
>>a dedicated function for HS400.
>>Add HS400 related macros.
>>Remove the restriction of only using the low 6 bits of
>>EXT_CSD_CARD_TYPE, using all the 8 bits.
>>
>>Signed-off-by: Peng Fan <peng.fan@nxp.com>
>>Cc: Jaehoon Chung <jh80.chung@samsung.com>
>>Cc: Jean-Jacques Hiblot <jjhiblot@ti.com>
>>Cc: Stefano Babic <sbabic@denx.de>
>>Cc: Simon Glass <sjg@chromium.org>
>>Cc: Kishon Vijay Abraham I <kishon@ti.com>
>>Cc: Bin Meng <bmeng.cn@gmail.com>
>>---
>>  drivers/mmc/Kconfig |   7 +++
>>  drivers/mmc/mmc.c   | 133 ++++++++++++++++++++++++++++++++++++++++++----------
>>  include/mmc.h       |  12 +++++
>>  3 files changed, 127 insertions(+), 25 deletions(-)
>>
>>diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
>>index 5f67e336db..e9be18b333 100644
>>--- a/drivers/mmc/Kconfig
>>+++ b/drivers/mmc/Kconfig
>>@@ -104,6 +104,13 @@ 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_SUPPORT
>>+	bool "enable HS400 support"
>>+	select MMC_HS200_SUPPORT
>I'd use "depends on" instead of select or maybe use the same option
>for both HS200 and HS400
>>+	help
>>+	  The HS400 mode is support by some eMMC. The bus frequency is up to
>>+	  200MHz. This mode requires tuning the IO.
>>+
>>  config MMC_HS200_SUPPORT
>>  	bool "enable HS200 support"
>>  	help
>>diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
>>index 92ea78b8af..eef229c8b4 100644
>>--- a/drivers/mmc/mmc.c
>>+++ b/drivers/mmc/mmc.c
>>@@ -169,6 +169,7 @@ const char *mmc_mode_name(enum bus_mode mode)
>>  	      [MMC_HS_52]	= "MMC High Speed (52MHz)",
>>  	      [MMC_DDR_52]	= "MMC DDR52 (52MHz)",
>>  	      [MMC_HS_200]	= "HS200 (200MHz)",
>>+	      [MMC_HS_400]	= "HS400 (200MHz)",
>>  	};
>>  	if (mode >= MMC_MODES_END)
>>@@ -193,6 +194,7 @@ static uint mmc_mode2freq(struct mmc *mmc, enum bus_mode mode)
>>  	      [UHS_DDR50]	= 50000000,
>>  	      [UHS_SDR104]	= 208000000,
>>  	      [MMC_HS_200]	= 200000000,
>>+	      [MMC_HS_400]	= 200000000,
>>  	};
>>  	if (mode == MMC_LEGACY)
>>@@ -790,6 +792,11 @@ static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode)
>>  	case MMC_HS_200:
>>  		speed_bits = EXT_CSD_TIMING_HS200;
>>  		break;
>>+#endif
>>+#if CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>>+	case MMC_HS_400:
>>+		speed_bits = EXT_CSD_TIMING_HS400;
>>+		break;
>>  #endif
>>  	case MMC_LEGACY:
>>  		speed_bits = EXT_CSD_TIMING_LEGACY;
>>@@ -837,7 +844,7 @@ static int mmc_get_capabilities(struct mmc *mmc)
>>  	mmc->card_caps |= MMC_MODE_4BIT | MMC_MODE_8BIT;
>>-	cardtype = ext_csd[EXT_CSD_CARD_TYPE] & 0x3f;
>>+	cardtype = ext_csd[EXT_CSD_CARD_TYPE];
>>  	mmc->cardtype = cardtype;
>>  #if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
>>@@ -845,6 +852,12 @@ static int mmc_get_capabilities(struct mmc *mmc)
>>  			EXT_CSD_CARD_TYPE_HS200_1_8V)) {
>>  		mmc->card_caps |= MMC_MODE_HS200;
>>  	}
>>+#endif
>>+#if CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>>+	if (cardtype & (EXT_CSD_CARD_TYPE_HS400_1_2V |
>>+			EXT_CSD_CARD_TYPE_HS400_1_8V)) {
>>+		mmc->card_caps |= MMC_MODE_HS400;
>>+	}
>>  #endif
>>  	if (cardtype & EXT_CSD_CARD_TYPE_52) {
>>  		if (cardtype & EXT_CSD_CARD_TYPE_DDR_52)
>>@@ -1748,6 +1761,12 @@ static int mmc_set_lowest_voltage(struct mmc *mmc, enum bus_mode mode,
>>  	u32 card_mask = 0;
>>  	switch (mode) {
>>+	case MMC_HS_400:
>>+		if (mmc->cardtype & EXT_CSD_CARD_TYPE_HS400_1_8V)
>>+			card_mask |= MMC_SIGNAL_VOLTAGE_180;
>>+		if (mmc->cardtype & EXT_CSD_CARD_TYPE_HS400_1_2V)
>>+			card_mask |= MMC_SIGNAL_VOLTAGE_120;
>>+		break;
>>  	case MMC_HS_200:
>>  		if (mmc->cardtype & EXT_CSD_CARD_TYPE_HS200_1_8V)
>>  			card_mask |= MMC_SIGNAL_VOLTAGE_180;
>>@@ -1787,6 +1806,13 @@ 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_SUPPORT)
>>+	{
>>+		.mode = MMC_HS_400,
>>+		.widths = MMC_MODE_8BIT | MMC_MODE_4BIT,
>>+		.tuning = MMC_CMD_SEND_TUNING_BLOCK_HS200
>>+	},
>>+#endif
>>  #if CONFIG_IS_ENABLED(MMC_HS200_SUPPORT)
>>  	{
>>  		.mode = MMC_HS_200,
>>@@ -1830,6 +1856,54 @@ static const struct ext_csd_bus_width {
>>  	{MMC_MODE_1BIT, false, EXT_CSD_BUS_WIDTH_1},
>>  };
>>+#if CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>>+static int mmc_select_hs400(struct mmc *mmc)
>>+{
>>+	int err;
>>+
>>+	/* Set timing to HS200 for tuning */
>>+	err = mmc_set_card_speed(mmc, MMC_HS_200);
>>+	if (err)
>>+		return err;
>>+
>>+	/* configure the bus mode (host) */
>>+	mmc_select_mode(mmc, MMC_HS_200);
>>+	mmc_set_clock(mmc, mmc->tran_speed, false);
>>+
>>+	/* execute tuning if needed */
>>+	err = mmc_execute_tuning(mmc, MMC_CMD_SEND_TUNING_BLOCK_HS200);
>>+	if (err) {
>>+		debug("tuning failed\n");
>>+		return err;
>>+	}
>>+
>>+	/* Set back to HS */
>>+	mmc_set_card_speed(mmc, MMC_HS);
>>+	mmc_set_clock(mmc, mmc_mode2freq(mmc, MMC_HS), false);
>>+
>>+	err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BUS_WIDTH,
>>+			 EXT_CSD_BUS_WIDTH_8 | EXT_CSD_DDR_FLAG);
>What happens if only 4 wires are used. It is a legit mode, isn't it ?

According to spec, HS400 only supports 8bits mode, see "5.3.6 HS400 Bus Speed Mode".

>>+	if (err)
>>+		return err;
>>+
>>+	err = mmc_set_card_speed(mmc, MMC_HS_400);
>>+	if (err)
>>+		return err;
>>+
>>+	mmc_select_mode(mmc, MMC_HS_400);
>>+	err = mmc_set_clock(mmc, mmc->tran_speed, false);
>>+	if (err)
>>+		return err;
>>+
>>+	return 0;
>>+}
>>+#else
>>+static int mmc_select_hs400(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);\
>>@@ -1883,37 +1957,46 @@ static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps)
>>  				goto error;
>>  			mmc_set_bus_width(mmc, bus_width(ecbw->cap));
>>-			/* configure the bus speed (card) */
>>-			err = mmc_set_card_speed(mmc, mwt->mode);
>>-			if (err)
>>-				goto error;
>>-
>>-			/*
>>-			 * configure the bus width AND the ddr mode (card)
>>-			 * The host side will be taken care of in the next step
>>-			 */
>>-			if (ecbw->ext_csd_bits & EXT_CSD_DDR_FLAG) {
>>-				err = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
>>-						 EXT_CSD_BUS_WIDTH,
>>-						 ecbw->ext_csd_bits);
>>+			if (mwt->mode == MMC_HS_400) {
>>+				err = mmc_select_hs400(mmc);
>>+				if (err)
>>+					goto error;
>>+			} else {
>>+				/* configure the bus speed (card) */
>>+				err = mmc_set_card_speed(mmc, mwt->mode);
>Instead of having?? a separate mmc_select_hs400() is not possible to
>leverage the existing code ?

hs400 requires first runs into HS200 mode, after tuning finished,
need switch back to HS mode to configure bus. It's not that straightforward
to use the existing code. Use a dedicated mmc_select_hs400 will make it
clearer compared with adding more logic in the existing flow.

Thanks,
Peng.

>
>JJ
>
>>  				if (err)
>>  					goto error;
>>-			}
>>-			/* configure the bus mode (host) */
>>-			mmc_select_mode(mmc, mwt->mode);
>>-			mmc_set_clock(mmc, mmc->tran_speed, false);
>>+				/*
>>+				 * configure the bus width AND the ddr mode
>>+				 * (card). The host side will be taken care
>>+				 * of in the next step
>>+				 */
>>+				if (ecbw->ext_csd_bits & EXT_CSD_DDR_FLAG) {
>>+					err = mmc_switch(mmc,
>>+							 EXT_CSD_CMD_SET_NORMAL,
>>+							 EXT_CSD_BUS_WIDTH,
>>+							 ecbw->ext_csd_bits);
>>+					if (err)
>>+						goto error;
>>+				}
>>+
>>+				/* configure the bus mode (host) */
>>+				mmc_select_mode(mmc, mwt->mode);
>>+				mmc_set_clock(mmc, mmc->tran_speed, false);
>>  #ifdef MMC_SUPPORTS_TUNING
>>-			/* execute tuning if needed */
>>-			if (mwt->tuning) {
>>-				err = mmc_execute_tuning(mmc, mwt->tuning);
>>-				if (err) {
>>-					pr_debug("tuning failed\n");
>>-					goto error;
>>+				/* execute tuning if needed */
>>+				if (mwt->tuning) {
>>+					err = mmc_execute_tuning(mmc,
>>+								 mwt->tuning);
>>+					if (err) {
>>+						pr_debug("tuning failed\n");
>>+						goto error;
>>+					}
>>  				}
>>-			}
>>  #endif
>>+			}
>>  			/* do a transfer to check the configuration */
>>  			err = mmc_read_and_compare_ext_csd(mmc);
>>diff --git a/include/mmc.h b/include/mmc.h
>>index 86f885b504..8c01c6a530 100644
>>--- a/include/mmc.h
>>+++ b/include/mmc.h
>>@@ -65,6 +65,7 @@
>>  #define MMC_MODE_HS_52MHz	MMC_CAP(MMC_HS_52)
>>  #define MMC_MODE_DDR_52MHz	MMC_CAP(MMC_DDR_52)
>>  #define MMC_MODE_HS200		MMC_CAP(MMC_HS_200)
>>+#define MMC_MODE_HS400		MMC_CAP(MMC_HS_400)
>>  #define MMC_MODE_8BIT		BIT(30)
>>  #define MMC_MODE_4BIT		BIT(29)
>>@@ -250,6 +251,11 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
>>  #define EXT_CSD_CARD_TYPE_HS200		(EXT_CSD_CARD_TYPE_HS200_1_8V | \
>>  					 EXT_CSD_CARD_TYPE_HS200_1_2V)
>>+#define EXT_CSD_CARD_TYPE_HS400_1_8V	BIT(6)
>>+#define EXT_CSD_CARD_TYPE_HS400_1_2V	BIT(7)
>>+#define EXT_CSD_CARD_TYPE_HS400		(EXT_CSD_CARD_TYPE_HS400_1_8V | \
>>+					 EXT_CSD_CARD_TYPE_HS400_1_2V)
>>+
>>  #define EXT_CSD_BUS_WIDTH_1	0	/* Card is in 1 bit mode */
>>  #define EXT_CSD_BUS_WIDTH_4	1	/* Card is in 4 bit mode */
>>  #define EXT_CSD_BUS_WIDTH_8	2	/* Card is in 8 bit mode */
>>@@ -260,6 +266,7 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
>>  #define EXT_CSD_TIMING_LEGACY	0	/* no high speed */
>>  #define EXT_CSD_TIMING_HS	1	/* HS */
>>  #define EXT_CSD_TIMING_HS200	2	/* HS200 */
>>+#define EXT_CSD_TIMING_HS400	3	/* HS400 */
>>  #define EXT_CSD_BOOT_ACK_ENABLE			(1 << 6)
>>  #define EXT_CSD_BOOT_PARTITION_ENABLE		(1 << 3)
>>@@ -520,6 +527,7 @@ enum bus_mode {
>>  	UHS_DDR50,
>>  	UHS_SDR104,
>>  	MMC_HS_200,
>>+	MMC_HS_400,
>>  	MMC_MODES_END
>>  };
>>@@ -533,6 +541,10 @@ static inline bool mmc_is_mode_ddr(enum bus_mode mode)
>>  #if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT)
>>  	else if (mode == UHS_DDR50)
>>  		return true;
>>+#endif
>>+#if CONFIG_IS_ENABLED(MMC_HS400_SUPPORT)
>>+	else if (mode == MMC_HS_400)
>>+		return true;
>>  #endif
>>  	else
>>  		return false;
>
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