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 <[email protected]> Acked-by: Adrian Hunter <[email protected]> Signed-off-by: Ulf Hansson <[email protected]>
jangid · Jun 18, 2019 · de23f0b · de23f0b
1 parent 99a9344
commit de23f0b
Showing 1 changed file with 11 additions and 1 deletion.
diff --git 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: