From: Raul E Rangel <rran...@chromium.org>

[ Upstream commit de23f0b757766d9fae59df97da6e8bdc5b231351 ]

The O2 controller supports 8-bit EMMC access.

JESD84-B51 section A.6.3.a defines the bus testing procedure that
`mmc_select_bus_width()` implements. This is used to determine the actual
bus width of the eMMC.

Signed-off-by: Raul E Rangel <rran...@chromium.org>
Acked-by: Adrian Hunter <adrian.hun...@intel.com>
Signed-off-by: Ulf Hansson <ulf.hans...@linaro.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/mmc/host/sdhci-pci-o2micro.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c 
b/drivers/mmc/host/sdhci-pci-o2micro.c
index 423c3339c03b..fb35ca205e04 100644
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -404,11 +404,21 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
 {
        struct sdhci_pci_chip *chip;
        struct sdhci_host *host;
-       u32 reg;
+       u32 reg, caps;
        int ret;
 
        chip = slot->chip;
        host = slot->host;
+
+       caps = sdhci_readl(host, SDHCI_CAPABILITIES);
+
+       /*
+        * mmc_select_bus_width() will test the bus to determine the actual bus
+        * width.
+        */
+       if (caps & SDHCI_CAN_DO_8BIT)
+               host->mmc->caps |= MMC_CAP_8_BIT_DATA;
+
        switch (chip->pdev->device) {
        case PCI_DEVICE_ID_O2_SDS0:
        case PCI_DEVICE_ID_O2_SEABIRD0:
-- 
2.20.1

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