From 4c4cb171054230c2e58ed6574d7faa1871c75bbe Mon Sep 17 00:00:00 2001 From: Philip Rakity Date: Fri, 13 May 2011 11:17:18 +0530 Subject: [PATCH] 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 Reviewed-by: Arindam Nath Signed-off-by: Chris Ball --- drivers/mmc/core/core.c | 14 ++------------ drivers/mmc/core/core.h | 2 -- drivers/mmc/core/mmc.c | 35 ++++++++++++++++++++++++++++++----- include/linux/mmc/host.h | 1 + 4 files changed, 33 insertions(+), 19 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 94c8d5a..7863eed 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -718,22 +718,12 @@ void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode) } /* - * Change data bus width and DDR mode of a host. - */ -void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width, - unsigned int ddr) -{ - host->ios.bus_width = width; - host->ios.ddr = ddr; - mmc_set_ios(host); -} - -/* * Change data bus width of a host. */ void mmc_set_bus_width(struct mmc_host *host, unsigned int width) { - mmc_set_bus_width_ddr(host, width, MMC_SDR_MODE); + host->ios.bus_width = width; + mmc_set_ios(host); } /** diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h index 53d23c2..d9411ed 100644 --- a/drivers/mmc/core/core.h +++ b/drivers/mmc/core/core.h @@ -38,8 +38,6 @@ void mmc_ungate_clock(struct mmc_host *host); void mmc_set_ungated(struct mmc_host *host); void mmc_set_bus_mode(struct mmc_host *host, unsigned int mode); void mmc_set_bus_width(struct mmc_host *host, unsigned int width); -void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width, - unsigned int ddr); u32 mmc_select_voltage(struct mmc_host *host, u32 ocr); int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage, bool cmd11); diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index a2c795e..0433fe6 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); } } diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 6716bd1..de32e6a 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -66,6 +66,7 @@ struct mmc_ios { #define MMC_SIGNAL_VOLTAGE_330 0 #define MMC_SIGNAL_VOLTAGE_180 1 +#define MMC_SIGNAL_VOLTAGE_120 2 unsigned char drv_type; /* driver type (A, B, C, D) */ -- 2.7.4