> >> -----Original Message----- >> From: Philip Rakity [mailto:prakity@xxxxxxxxxxx] >> Sent: Sunday, March 20, 2011 11:41 AM >> To: Nath, Arindam >> Subject: eMMC now working on old patch set -- SDIO more complicated >> >> Hi Arindam, >> >> Have eMMC working. Note the comment about voltage ! >> >> SDIO cannot validate as trace lines for plug in card are too long to >> support SDR50. If I force the clock down to 50MHz then it is okay. >> says ultra high speed. Not a validation but a data point. >> >> I will need a host->ops in sdhci.c -- already have a patch for this but >> will resubmit. Our controller requires we set 18V enable when we do >> UHS. Setting the bit does not affect the voltage. >> >> Philip >> >> >> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c >> index 87dae37..b51165c 100644 >> --- a/drivers/mmc/core/core.c >> +++ b/drivers/mmc/core/core.c >> @@ -718,7 +718,7 @@ 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; >> + host->ios.timing = ddr; >> mmc_set_ios(host); >> } >> >> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c >> index 14e95f3..d3896b8 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, >> @@ -668,8 +669,27 @@ 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_start_voltage_switch(host); >> + if (err) >> + goto err; >> + } >> mmc_card_set_ddr_mode(card); >> - mmc_set_bus_width_ddr(card->host, bus_width, ddr); >> + mmc_set_bus_width_ddr(card->host, bus_width, >> MMC_TIMING_UHS_DDR50); >> } >> } >> >> >> >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
