mmc: sdio: support SDIO UHS cards

This patch adds support for sdio UHS cards per the version 3.0
spec.

UHS mode is only enabled for version 3.0 cards when both the
host and the controller support UHS modes.

1.8v signaling support is removed if both the card and the
host do not support UHS.  This is done to maintain
compatibility and some system/card combinations break when
1.8v signaling is enabled when the host does not support UHS.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Aaron Lu <Aaron.lu@amd.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Tested-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 304 insertions, 25 deletions

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 3ab565e32a6a..8c04f7f46dec 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -102,6 +102,7 @@ static int sdio_read_cccr(struct mmc_card *card)
 	int ret;
 	int cccr_vsn;
 	unsigned char data;
+	unsigned char speed;
 
 	memset(&card->cccr, 0, sizeof(struct sdio_cccr));
 
@@ -140,12 +141,60 @@ static int sdio_read_cccr(struct mmc_card *card)
 	}
 
 	if (cccr_vsn >= SDIO_CCCR_REV_1_20) {
-		ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &data);
+		ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
 		if (ret)
 			goto out;
 
-		if (data & SDIO_SPEED_SHS)
-			card->cccr.high_speed = 1;
+		card->scr.sda_spec3 = 0;
+		card->sw_caps.sd3_bus_mode = 0;
+		card->sw_caps.sd3_drv_type = 0;
+		if (cccr_vsn >= SDIO_CCCR_REV_3_00) {
+			card->scr.sda_spec3 = 1;
+			ret = mmc_io_rw_direct(card, 0, 0,
+				SDIO_CCCR_UHS, 0, &data);
+			if (ret)
+				goto out;
+
+			if (card->host->caps &
+				(MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
+				 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
+				 MMC_CAP_UHS_DDR50)) {
+				if (data & SDIO_UHS_DDR50)
+					card->sw_caps.sd3_bus_mode
+						|= SD_MODE_UHS_DDR50;
+
+				if (data & SDIO_UHS_SDR50)
+					card->sw_caps.sd3_bus_mode
+						|= SD_MODE_UHS_SDR50;
+
+				if (data & SDIO_UHS_SDR104)
+					card->sw_caps.sd3_bus_mode
+						|= SD_MODE_UHS_SDR104;
+			}
+
+			ret = mmc_io_rw_direct(card, 0, 0,
+				SDIO_CCCR_DRIVE_STRENGTH, 0, &data);
+			if (ret)
+				goto out;
+
+			if (data & SDIO_DRIVE_SDTA)
+				card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_A;
+			if (data & SDIO_DRIVE_SDTC)
+				card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_C;
+			if (data & SDIO_DRIVE_SDTD)
+				card->sw_caps.sd3_drv_type |= SD_DRIVER_TYPE_D;
+		}
+
+		/* if no uhs mode ensure we check for high speed */
+		if (!card->sw_caps.sd3_bus_mode) {
+			if (speed & SDIO_SPEED_SHS) {
+				card->cccr.high_speed = 1;
+				card->sw_caps.hs_max_dtr = 50000000;
+			} else {
+				card->cccr.high_speed = 0;
+				card->sw_caps.hs_max_dtr = 25000000;
+			}
+		}
 	}
 
 out:
@@ -327,6 +376,193 @@ static unsigned mmc_sdio_get_max_clock(struct mmc_card *card)
 	return max_dtr;
 }
 
+static unsigned char host_drive_to_sdio_drive(int host_strength)
+{
+	switch (host_strength) {
+	case MMC_SET_DRIVER_TYPE_A:
+		return SDIO_DTSx_SET_TYPE_A;
+	case MMC_SET_DRIVER_TYPE_B:
+		return SDIO_DTSx_SET_TYPE_B;
+	case MMC_SET_DRIVER_TYPE_C:
+		return SDIO_DTSx_SET_TYPE_C;
+	case MMC_SET_DRIVER_TYPE_D:
+		return SDIO_DTSx_SET_TYPE_D;
+	default:
+		return SDIO_DTSx_SET_TYPE_B;
+	}
+}
+
+static void sdio_select_driver_type(struct mmc_card *card)
+{
+	int host_drv_type = SD_DRIVER_TYPE_B;
+	int card_drv_type = SD_DRIVER_TYPE_B;
+	int drive_strength;
+	unsigned char card_strength;
+	int err;
+
+	/*
+	 * If the host doesn't support any of the Driver Types A,C or D,
+	 * or there is no board specific handler then default Driver
+	 * Type B is used.
+	 */
+	if (!(card->host->caps &
+		(MMC_CAP_DRIVER_TYPE_A |
+		 MMC_CAP_DRIVER_TYPE_C |
+		 MMC_CAP_DRIVER_TYPE_D)))
+		return;
+
+	if (!card->host->ops->select_drive_strength)
+		return;
+
+	if (card->host->caps & MMC_CAP_DRIVER_TYPE_A)
+		host_drv_type |= SD_DRIVER_TYPE_A;
+
+	if (card->host->caps & MMC_CAP_DRIVER_TYPE_C)
+		host_drv_type |= SD_DRIVER_TYPE_C;
+
+	if (card->host->caps & MMC_CAP_DRIVER_TYPE_D)
+		host_drv_type |= SD_DRIVER_TYPE_D;
+
+	if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_A)
+		card_drv_type |= SD_DRIVER_TYPE_A;
+
+	if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_C)
+		card_drv_type |= SD_DRIVER_TYPE_C;
+
+	if (card->sw_caps.sd3_drv_type & SD_DRIVER_TYPE_D)
+		card_drv_type |= SD_DRIVER_TYPE_D;
+
+	/*
+	 * The drive strength that the hardware can support
+	 * depends on the board design.  Pass the appropriate
+	 * information and let the hardware specific code
+	 * return what is possible given the options
+	 */
+	drive_strength = card->host->ops->select_drive_strength(
+		card->sw_caps.uhs_max_dtr,
+		host_drv_type, card_drv_type);
+
+	/* if error just use default for drive strength B */
+	err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_DRIVE_STRENGTH, 0,
+		&card_strength);
+	if (err)
+		return;
+
+	card_strength &= ~(SDIO_DRIVE_DTSx_MASK<<SDIO_DRIVE_DTSx_SHIFT);
+	card_strength |= host_drive_to_sdio_drive(drive_strength);
+
+	err = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_DRIVE_STRENGTH,
+		card_strength, NULL);
+
+	/* if error default to drive strength B */
+	if (!err)
+		mmc_set_driver_type(card->host, drive_strength);
+}
+
+
+static int sdio_set_bus_speed_mode(struct mmc_card *card)
+{
+	unsigned int bus_speed, timing;
+	int err;
+	unsigned char speed;
+
+	/*
+	 * If the host doesn't support any of the UHS-I modes, fallback on
+	 * default speed.
+	 */
+	if (!(card->host->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
+	    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_DDR50)))
+		return 0;
+
+	bus_speed = SDIO_SPEED_SDR12;
+	timing = MMC_TIMING_UHS_SDR12;
+	if ((card->host->caps & MMC_CAP_UHS_SDR104) &&
+	    (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR104)) {
+			bus_speed = SDIO_SPEED_SDR104;
+			timing = MMC_TIMING_UHS_SDR104;
+			card->sw_caps.uhs_max_dtr = UHS_SDR104_MAX_DTR;
+	} else if ((card->host->caps & MMC_CAP_UHS_DDR50) &&
+		   (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_DDR50)) {
+			bus_speed = SDIO_SPEED_DDR50;
+			timing = MMC_TIMING_UHS_DDR50;
+			card->sw_caps.uhs_max_dtr = UHS_DDR50_MAX_DTR;
+	} else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
+		    MMC_CAP_UHS_SDR50)) && (card->sw_caps.sd3_bus_mode &
+		    SD_MODE_UHS_SDR50)) {
+			bus_speed = SDIO_SPEED_SDR50;
+			timing = MMC_TIMING_UHS_SDR50;
+			card->sw_caps.uhs_max_dtr = UHS_SDR50_MAX_DTR;
+	} else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
+		    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25)) &&
+		   (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR25)) {
+			bus_speed = SDIO_SPEED_SDR25;
+			timing = MMC_TIMING_UHS_SDR25;
+			card->sw_caps.uhs_max_dtr = UHS_SDR25_MAX_DTR;
+	} else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
+		    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25 |
+		    MMC_CAP_UHS_SDR12)) && (card->sw_caps.sd3_bus_mode &
+		    SD_MODE_UHS_SDR12)) {
+			bus_speed = SDIO_SPEED_SDR12;
+			timing = MMC_TIMING_UHS_SDR12;
+			card->sw_caps.uhs_max_dtr = UHS_SDR12_MAX_DTR;
+	}
+
+	err = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_SPEED, 0, &speed);
+	if (err)
+		return err;
+
+	speed &= ~SDIO_SPEED_BSS_MASK;
+	speed |= bus_speed;
+	err = mmc_io_rw_direct(card, 1, 0, SDIO_CCCR_SPEED, speed, NULL);
+	if (err)
+		return err;
+
+	if (bus_speed) {
+		mmc_set_timing(card->host, timing);
+		mmc_set_clock(card->host, card->sw_caps.uhs_max_dtr);
+	}
+
+	return 0;
+}
+
+/*
+ * UHS-I specific initialization procedure
+ */
+static int mmc_sdio_init_uhs_card(struct mmc_card *card)
+{
+	int err;
+
+	if (!card->scr.sda_spec3)
+		return 0;
+
+	/*
+	 * Switch to wider bus (if supported).
+	 */
+	if (card->host->caps & MMC_CAP_4_BIT_DATA) {
+		err = sdio_enable_4bit_bus(card);
+		if (err > 0) {
+			mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
+			err = 0;
+		}
+	}
+
+	/* Set the driver strength for the card */
+	sdio_select_driver_type(card);
+
+	/* Set bus speed mode of the card */
+	err = sdio_set_bus_speed_mode(card);
+	if (err)
+		goto out;
+
+	/* Initialize and start re-tuning timer */
+	if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning)
+		err = card->host->ops->execute_tuning(card->host);
+
+out:
+
+	return err;
+}
+
 /*
  * Handle the detection and initialisation of a card.
  *
@@ -394,6 +630,30 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 		host->ops->init_card(host, card);
 
 	/*
+	 * If the host and card support UHS-I mode request the card
+	 * to switch to 1.8V signaling level.  No 1.8v signalling if
+	 * UHS mode is not enabled to maintain compatibilty and some
+	 * systems that claim 1.8v signalling in fact do not support
+	 * it.
+	 */
+	if ((ocr & R4_18V_PRESENT) &&
+		(host->caps &
+			(MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
+			 MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
+			 MMC_CAP_UHS_DDR50))) {
+		err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180,
+				true);
+		if (err) {
+			ocr &= ~R4_18V_PRESENT;
+			host->ocr &= ~R4_18V_PRESENT;
+		}
+		err = 0;
+	} else {
+		ocr &= ~R4_18V_PRESENT;
+		host->ocr &= ~R4_18V_PRESENT;
+	}
+
+	/*
 	 * For native busses:  set card RCA and quit open drain mode.
 	 */
 	if (!powered_resume && !mmc_host_is_spi(host)) {
@@ -492,29 +752,39 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
 	if (err)
 		goto remove;
 
-	/*
-	 * Switch to high-speed (if supported).
-	 */
-	err = sdio_enable_hs(card);
-	if (err > 0)
-		mmc_sd_go_highspeed(card);
-	else if (err)
-		goto remove;
+	/* Initialization sequence for UHS-I cards */
+	/* Only if card supports 1.8v and UHS signaling */
+	if ((ocr & R4_18V_PRESENT) && card->sw_caps.sd3_bus_mode) {
+		err = mmc_sdio_init_uhs_card(card);
+		if (err)
+			goto remove;
 
-	/*
-	 * Change to the card's maximum speed.
-	 */
-	mmc_set_clock(host, mmc_sdio_get_max_clock(card));
+		/* Card is an ultra-high-speed card */
+		mmc_card_set_uhs(card);
+	} else {
+		/*
+		 * Switch to high-speed (if supported).
+		 */
+		err = sdio_enable_hs(card);
+		if (err > 0)
+			mmc_sd_go_highspeed(card);
+		else if (err)
+			goto remove;
 
-	/*
-	 * Switch to wider bus (if supported).
-	 */
-	err = sdio_enable_4bit_bus(card);
-	if (err > 0)
-		mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
-	else if (err)
-		goto remove;
+		/*
+		 * Change to the card's maximum speed.
+		 */
+		mmc_set_clock(host, mmc_sdio_get_max_clock(card));
 
+		/*
+		 * Switch to wider bus (if supported).
+		 */
+		err = sdio_enable_4bit_bus(card);
+		if (err > 0)
+			mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
+		else if (err)
+			goto remove;
+	}
 finish:
 	if (!oldcard)
 		host->card = card;
@@ -797,8 +1067,17 @@ int mmc_attach_sdio(struct mmc_host *host)
 	 * Detect and init the card.
 	 */
 	err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
-	if (err)
-		goto err;
+	if (err) {
+		if (err == -EAGAIN) {
+			/*
+			 * Retry initialization with S18R set to 0.
+			 */
+			host->ocr &= ~R4_18V_PRESENT;
+			err = mmc_sdio_init_card(host, host->ocr, NULL, 0);
+		}
+		if (err)
+			goto err;
+	}
 	card = host->card;
 
 	/*