diff options
| author | Philip Rakity <prakity@marvell.com> | 2011-05-13 09:47:18 +0400 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2011-05-25 07:53:58 +0400 |
| commit | 4c4cb171054230c2e58ed6574d7faa1871c75bbe (patch) | |
| tree | 8ba336234def08a99ae98d29047da69de41cdcb0 /drivers/mmc/core/mmc.c | |
| parent | 261bbd463a091b939770255d559bbc89b1bad568 (diff) | |
| download | linux-4c4cb171054230c2e58ed6574d7faa1871c75bbe.tar.xz | |
mmc: core: add support for eMMC Dual Data Rate
eMMC voltage change not required for 1.8V. 3.3V and 1.8V vcc
are capable of doing DDR. vccq of 1.8v is not required.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core/mmc.c')
| -rw-r--r-- | drivers/mmc/core/mmc.c | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index a2c795e8f9dd..0433fe66cbad 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -20,6 +20,7 @@ #include "core.h" #include "bus.h" #include "mmc_ops.h" +#include "sd_ops.h" static const unsigned int tran_exp[] = { 10000, 100000, 1000000, 10000000, @@ -633,10 +634,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, */ if (mmc_card_highspeed(card)) { if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_8V) - && (host->caps & (MMC_CAP_1_8V_DDR))) + && ((host->caps & (MMC_CAP_1_8V_DDR | + MMC_CAP_UHS_DDR50)) + == (MMC_CAP_1_8V_DDR | MMC_CAP_UHS_DDR50))) ddr = MMC_1_8V_DDR_MODE; else if ((card->ext_csd.card_type & EXT_CSD_CARD_TYPE_DDR_1_2V) - && (host->caps & (MMC_CAP_1_2V_DDR))) + && ((host->caps & (MMC_CAP_1_2V_DDR | + MMC_CAP_UHS_DDR50)) + == (MMC_CAP_1_2V_DDR | MMC_CAP_UHS_DDR50))) ddr = MMC_1_2V_DDR_MODE; } @@ -670,8 +675,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, ext_csd_bits[idx][0], 0); if (!err) { - mmc_set_bus_width_ddr(card->host, - bus_width, MMC_SDR_MODE); + mmc_set_bus_width(card->host, bus_width); /* * If controller can't handle bus width test, * use the highest bus width to maintain @@ -697,8 +701,29 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr, 1 << bus_width, ddr); goto free_card; } else if (ddr) { + /* + * eMMC cards can support 3.3V to 1.2V i/o (vccq) + * signaling. + * + * EXT_CSD_CARD_TYPE_DDR_1_8V means 3.3V or 1.8V vccq. + * + * 1.8V vccq at 3.3V core voltage (vcc) is not required + * in the JEDEC spec for DDR. + * + * Do not force change in vccq since we are obviously + * working and no change to vccq is needed. + * + * WARNING: eMMC rules are NOT the same as SD DDR + */ + if (ddr == EXT_CSD_CARD_TYPE_DDR_1_2V) { + err = mmc_set_signal_voltage(host, + MMC_SIGNAL_VOLTAGE_120, 0); + if (err) + goto err; + } mmc_card_set_ddr_mode(card); - mmc_set_bus_width_ddr(card->host, bus_width, ddr); + mmc_set_timing(card->host, MMC_TIMING_UHS_DDR50); + mmc_set_bus_width(card->host, bus_width); } } |