[PATCH v12 8/9] mmc: cavium: Support DDR mode for eMMC devices

Jan Glauber
2017-03-10T13:25:06Z

Add support for switching to DDR mode for eMMC devices.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
drivers/mmc/host/cavium-mmc.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/cavium-mmc.c b/drivers/mmc/host/cavium-mmc.c
index fb6e1c1..e340b95 100644
--- a/drivers/mmc/host/cavium-mmc.c
+++ b/drivers/mmc/host/cavium-mmc.c
@@ -865,6 +865,10 @@ static void cvm_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
break;
}

+ /* DDR is available for 4/8 bit bus width */
+ if (ios->bus_width && ios->timing == MMC_TIMING_MMC_DDR52)
+ bus_width |= 4;
+
slot->bus_width = bus_width;

/* Change the clock frequency. */
@@ -1057,8 +1061,14 @@ int cvm_mmc_of_slot_probe(struct device *dev, struct cvm_mmc_host *host)
/* Set up host parameters */
mmc->ops = &cvm_mmc_ops;

+ /*
+ * We only have a 3.3v supply, we cannot support any
+ * of the UHS modes. We do support the high speed DDR
+ * modes up to 52MHz.
+ */
mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
- MMC_CAP_ERASE | MMC_CAP_CMD23 | MMC_CAP_POWER_OFF_CARD;
+ MMC_CAP_ERASE | MMC_CAP_CMD23 | MMC_CAP_POWER_OFF_CARD |
+ MMC_CAP_3_3V_DDR;

if (host->use_sg)
mmc->max_segs = 16;
--
2.9.0.rc0.21.g7777322