[PATCH AUTOSEL 5.1 055/141] mmc: sdhci: sdhci-pci-o2micro: Check if controller supports 8-bit width

Sasha Levin
2019-07-19T04:04:45Z

From: Raul E Rangel <rrangel@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 <rrangel@chromium.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@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