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>
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 9b808d1..e519e31 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1044,6 +1044,7 @@
{
struct mmc_host *host = card->host;
int err = 0;
+ u8 val;
/*
* HS400 mode requires 8-bit bus width
@@ -1059,8 +1060,10 @@
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 @@
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 @@
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 @@
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 @@
}
/* 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 @@
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 @@
{
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 @@
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)
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 4819cfb..15f2c4a 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -391,6 +391,7 @@
#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 @@
#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 */