mmc: sdhci: sdhci-pci-o2micro: Check if controller supports 8-bit width

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 <rrangel@chromium.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c
index dd21315922c87da795852e75ac24a7de4a9a19cf..9dc4548271b4b25d95c82f035b98f4f62f1e3c29 100644 (file)
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -395,11 +395,21 @@ 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: