mmc: sdhci-iproc: Enable eMMC DDR 3.3V support for bcm2711

The emmc2 interface on the bcm2711 supports DDR modes for eMMC devices
running at 3.3V. This allows to run eMMC module with 3.3V signaling voltage
at DDR52 mode on the Raspberry Pi 4 using a SD adapter:

  clock: 52000000 Hz
  actual clock: 50000000 Hz
  vdd: 21 (3.3 ~ 3.4 V)
  bus mode: 2 (push-pull)
  chip select: 0 (don't care)
  power mode: 2 (on)
  bus width: 2 (4 bits)
  timing spec: 8 (mmc DDR52)
  signal voltage: 0 (3.30 V)
  driver type: 0 (driver type B)

Link: https://github.com/raspberrypi/linux/issues/3802
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/1598651234-29826-1-git-send-email-stefan.wahren@i2se.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c
index e2d8dfe90077e7db88e6ceb4d0197197ba784cad..b540aa6faacbc0ee4da9052d484bb48d7fde9de8 100644 (file)
--- a/drivers/mmc/host/sdhci-iproc.c
+++ b/drivers/mmc/host/sdhci-iproc.c
@@ -283,6 +283,7 @@ static const struct sdhci_pltfm_data sdhci_bcm2711_pltfm_data = {
 
 static const struct sdhci_iproc_data bcm2711_data = {
        .pdata = &sdhci_bcm2711_pltfm_data,
+       .mmc_caps = MMC_CAP_3_3V_DDR,
 };
 
 static const struct of_device_id sdhci_iproc_of_match[] = {