From cc4f414c885cd04f7227ad9bcd6b18fd78d718d9 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 6 Feb 2015 14:12:58 +0200 Subject: [PATCH] mmc: mmc: Add driver strength selection Add the ability to set eMMC driver strength for HS200 and HS400. Signed-off-by: Adrian Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/core/mmc.c | 45 ++++++++++++++++++++++++++++++++++++++------- include/linux/mmc/mmc.h | 3 +++ 2 files changed, 41 insertions(+), 7 deletions(-) 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 @@ 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) 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 @@ 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 */ -- 2.7.4