3 files changed, 93 insertions, 3 deletions

diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
index 4bc48f1..c64266f 100644
--- a/drivers/mmc/core/bus.c
+++ b/drivers/mmc/core/bus.c
@@ -332,12 +332,13 @@ int mmc_add_card(struct mmc_card *card)
 			mmc_card_ddr52(card) ? "DDR " : "",
 			type);
 	} else {
-		pr_info("%s: new %s%s%s%s%s card at address %04x\n",
+		pr_info("%s: new %s%s%s%s%s%s card at address %04x\n",
 			mmc_hostname(card->host),
 			mmc_card_uhs(card) ? "ultra high speed " :
 			(mmc_card_hs(card) ? "high speed " : ""),
 			mmc_card_hs400(card) ? "HS400 " :
 			(mmc_card_hs200(card) ? "HS200 " : ""),
+			mmc_card_hs400es(card) ? "Enhanced strobe " : "",
 			mmc_card_ddr52(card) ? "DDR " : "",
 			uhs_bus_speed_mode, type, card->rca);
 	}
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 8b4dfd4..e864187 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1127,6 +1127,15 @@ void mmc_set_initial_state(struct mmc_host *host)
 	host->ios.bus_width = MMC_BUS_WIDTH_1;
 	host->ios.timing = MMC_TIMING_LEGACY;
 	host->ios.drv_type = 0;
+	host->ios.enhanced_strobe = false;
+
+	/*
+	 * Make sure we are in non-enhanced strobe mode before we
+	 * actually enable it in ext_csd.
+	 */
+	if ((host->caps2 & MMC_CAP2_HS400_ES) &&
+	     host->ops->hs400_enhanced_strobe)
+		host->ops->hs400_enhanced_strobe(host, &host->ios);
 
 	mmc_set_ios(host);
 }
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 5d438ad..97a664f 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -235,6 +235,11 @@ static void mmc_select_card_type(struct mmc_card *card)
 		avail_type |= EXT_CSD_CARD_TYPE_HS400_1_2V;
 	}
 
+	if ((caps2 & MMC_CAP2_HS400_ES) &&
+	    card->ext_csd.strobe_support &&
+	    (avail_type & EXT_CSD_CARD_TYPE_HS400))
+		avail_type |= EXT_CSD_CARD_TYPE_HS400ES;
+
 	card->ext_csd.hs_max_dtr = hs_max_dtr;
 	card->ext_csd.hs200_max_dtr = hs200_max_dtr;
 	card->mmc_avail_type = avail_type;
@@ -386,6 +391,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
 			mmc_card_set_blockaddr(card);
 	}
 
+	card->ext_csd.strobe_support = ext_csd[EXT_CSD_STROBE_SUPPORT];
 	card->ext_csd.raw_card_type = ext_csd[EXT_CSD_CARD_TYPE];
 	mmc_select_card_type(card);
 
@@ -1223,6 +1229,78 @@ out_err:
 	return err;
 }
 
+static int mmc_select_hs400es(struct mmc_card *card)
+{
+	struct mmc_host *host = card->host;
+	int err = 0;
+	u8 val;
+
+	if (!(host->caps & MMC_CAP_8_BIT_DATA)) {
+		err = -ENOTSUPP;
+		goto out_err;
+	}
+
+	err = mmc_select_bus_width(card);
+	if (err < 0)
+		goto out_err;
+
+	/* Switch card to HS mode */
+	err = mmc_select_hs(card);
+	if (err) {
+		pr_err("%s: switch to high-speed failed, err:%d\n",
+			mmc_hostname(host), err);
+		goto out_err;
+	}
+
+	err = mmc_switch_status(card);
+	if (err)
+		goto out_err;
+
+	/* Switch card to DDR with strobe bit */
+	val = EXT_CSD_DDR_BUS_WIDTH_8 | EXT_CSD_BUS_WIDTH_STROBE;
+	err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			 EXT_CSD_BUS_WIDTH,
+			 val,
+			 card->ext_csd.generic_cmd6_time);
+	if (err) {
+		pr_err("%s: switch to bus width for hs400es failed, err:%d\n",
+			mmc_hostname(host), err);
+		goto out_err;
+	}
+
+	/* Switch card to HS400 */
+	val = EXT_CSD_TIMING_HS400 |
+	      card->drive_strength << EXT_CSD_DRV_STR_SHIFT;
+	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+			   EXT_CSD_HS_TIMING, val,
+			   card->ext_csd.generic_cmd6_time,
+			   true, false, true);
+	if (err) {
+		pr_err("%s: switch to hs400es failed, err:%d\n",
+			mmc_hostname(host), err);
+		goto out_err;
+	}
+
+	/* Set host controller to HS400 timing and frequency */
+	mmc_set_timing(host, MMC_TIMING_MMC_HS400);
+
+	/* Controller enable enhanced strobe function */
+	host->ios.enhanced_strobe = true;
+	if (host->ops->hs400_enhanced_strobe)
+		host->ops->hs400_enhanced_strobe(host, &host->ios);
+
+	err = mmc_switch_status(card);
+	if (err)
+		goto out_err;
+
+	return 0;
+
+out_err:
+	pr_err("%s: %s failed, error %d\n", mmc_hostname(card->host),
+	       __func__, err);
+	return err;
+}
+
 static void mmc_select_driver_type(struct mmc_card *card)
 {
 	int card_drv_type, drive_strength, drv_type;
@@ -1310,7 +1388,7 @@ err:
 }
 
 /*
- * Activate High Speed or HS200 mode if supported.
+ * Activate High Speed, HS200 or HS400ES mode if supported.
  */
 static int mmc_select_timing(struct mmc_card *card)
 {
@@ -1319,7 +1397,9 @@ static int mmc_select_timing(struct mmc_card *card)
 	if (!mmc_can_ext_csd(card))
 		goto bus_speed;
 
-	if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
+	if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS400ES)
+		err = mmc_select_hs400es(card);
+	else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
 		err = mmc_select_hs200(card);
 	else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS)
 		err = mmc_select_hs(card);