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mmc: mmc: Add driver strength selection 

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

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Adrian Hunter 2015-02-06 14:12:58 +02:00 committed by Ulf Hansson
parent b097e07f57
commit cc4f414c88
2 changed files with 41 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
drivers/mmc/core/mmc.c
View File

@ -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 @@ out_err:
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)

3
include/linux/mmc/mmc.h
View File

@ -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 */