Commit cc4f414c authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
Browse files

mmc: mmc: Add driver strength selection 



Add the ability to set eMMC driver strength
for HS200 and HS400.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent b097e07f

drivers/mmc/core/mmc.c

+38 −7
Original line number Diff line number Diff line
@@ -1044,6 +1044,7 @@ static int mmc_select_hs400(struct mmc_card *card) 
{

	struct mmc_host *host = card->host;

	int err = 0;

	u8 val;



	/*

	 * HS400 mode requires 8-bit bus width
@@ -1059,8 +1060,10 @@ static int mmc_select_hs400(struct mmc_card *card) 
	mmc_set_timing(card->host, MMC_TIMING_MMC_HS);

	mmc_set_bus_speed(card);



	val = EXT_CSD_TIMING_HS |

	      card->drive_strength << EXT_CSD_DRV_STR_SHIFT;

	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,

			   EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS,

			   EXT_CSD_HS_TIMING, val,

			   card->ext_csd.generic_cmd6_time,

			   true, true, true);

	if (err) {
@@ -1079,8 +1082,10 @@ static int mmc_select_hs400(struct mmc_card *card) 
		return err;

	}



	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, EXT_CSD_TIMING_HS400,

			   EXT_CSD_HS_TIMING, val,

			   card->ext_csd.generic_cmd6_time,

			   true, true, true);

	if (err) {
@@ -1119,6 +1124,7 @@ int mmc_hs400_to_hs200(struct mmc_card *card) 
	bool send_status = true;

	unsigned int max_dtr;

	int err;

	u8 val;



	if (host->caps & MMC_CAP_WAIT_WHILE_BUSY)

		send_status = false;
@@ -1128,8 +1134,10 @@ int mmc_hs400_to_hs200(struct mmc_card *card) 
	mmc_set_clock(host, max_dtr);



	/* Switch HS400 to HS DDR */

	val = EXT_CSD_TIMING_HS |

	      card->drive_strength << EXT_CSD_DRV_STR_SHIFT;

	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,

			   EXT_CSD_TIMING_HS, card->ext_csd.generic_cmd6_time,

			   val, card->ext_csd.generic_cmd6_time,

			   true, send_status, true);

	if (err)

		goto out_err;
@@ -1158,10 +1166,11 @@ int mmc_hs400_to_hs200(struct mmc_card *card) 
	}



	/* Switch HS to HS200 */

	val = EXT_CSD_TIMING_HS200 |

	      card->drive_strength << EXT_CSD_DRV_STR_SHIFT;

	err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_HS_TIMING,

			   EXT_CSD_TIMING_HS200,

			   card->ext_csd.generic_cmd6_time, true, send_status,

			   true);

			   val, card->ext_csd.generic_cmd6_time, true,

			   send_status, true);

	if (err)

		goto out_err;
@@ -1183,6 +1192,23 @@ int mmc_hs400_to_hs200(struct mmc_card *card) 
	return err;

}



static void mmc_select_driver_type(struct mmc_card *card)

{

	int card_drv_type, drive_strength, drv_type;



	card_drv_type = card->ext_csd.raw_driver_strength |

			mmc_driver_type_mask(0);



	drive_strength = mmc_select_drive_strength(card,

						   card->ext_csd.hs200_max_dtr,

						   card_drv_type, &drv_type);



	card->drive_strength = drive_strength;



	if (drv_type)

		mmc_set_driver_type(card->host, drv_type);

}



/*

 * For device supporting HS200 mode, the following sequence

 * should be done before executing the tuning process.
@@ -1194,6 +1220,7 @@ static int mmc_select_hs200(struct mmc_card *card) 
{

	struct mmc_host *host = card->host;

	int err = -EINVAL;

	u8 val;



	if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V)

		err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
@@ -1205,14 +1232,18 @@ static int mmc_select_hs200(struct mmc_card *card) 
	if (err)

		goto err;



	mmc_select_driver_type(card);



	/*

	 * Set the bus width(4 or 8) with host's support and

	 * switch to HS200 mode if bus width is set successfully.

	 */

	err = mmc_select_bus_width(card);

	if (!IS_ERR_VALUE(err)) {

		val = EXT_CSD_TIMING_HS200 |

		      card->drive_strength << EXT_CSD_DRV_STR_SHIFT;

		err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,

				   EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS200,

				   EXT_CSD_HS_TIMING, val,

				   card->ext_csd.generic_cmd6_time,

				   true, true, true);

		if (!err)

include/linux/mmc/mmc.h

+3 −0
Original line number Diff line number Diff line
@@ -391,6 +391,7 @@ struct _mmc_csd { 
#define EXT_CSD_TIMING_HS	1	/* High speed */

#define EXT_CSD_TIMING_HS200	2	/* HS200 */

#define EXT_CSD_TIMING_HS400	3	/* HS400 */

#define EXT_CSD_DRV_STR_SHIFT	4	/* Driver Strength shift */



#define EXT_CSD_SEC_ER_EN	BIT(0)

#define EXT_CSD_SEC_BD_BLK_EN	BIT(2)
@@ -442,4 +443,6 @@ struct _mmc_csd { 
#define MMC_SWITCH_MODE_CLEAR_BITS	0x02	/* Clear bits which are 1 in value */

#define MMC_SWITCH_MODE_WRITE_BYTE	0x03	/* Set target to value */



#define mmc_driver_type_mask(n)		(1 << (n))



#endif /* LINUX_MMC_MMC_H */