mmc: sdhci-pci: Avoid 3.3V signaling on some NI 904x

On some NI 904x devices, using 3.3V signaling for extended periods of
time will physically damage the pads connected to the SDHC, eventually
causing complete failure of the controller. To work around this,
require that we avoid 3.3V signaling.
Signed-off-by: NKyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: NJennifer Dahm <jennifer.dahm@ni.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-pci-core.c

@@ -832,6 +832,10 @@ static int byt_sd_probe_slot(struct sdhci_pci_slot *slot)
 	    slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_GLK_SD)
 		slot->host->mmc_host_ops.get_cd = bxt_get_cd;
 
+	if (slot->chip->pdev->subsystem_vendor == PCI_VENDOR_ID_NI &&
+	    slot->chip->pdev->subsystem_device == PCI_SUBDEVICE_ID_NI_78E3)
+		slot->host->mmc->caps2 |= MMC_CAP2_AVOID_3_3V;
+
 	return 0;
 }
 

drivers/mmc/host/sdhci-pci.h

@@ -54,6 +54,7 @@
 #define PCI_DEVICE_ID_REALTEK_5250	0x5250
 
 #define PCI_SUBDEVICE_ID_NI_7884	0x7884
+#define PCI_SUBDEVICE_ID_NI_78E3	0x78e3
 
 #define PCI_VENDOR_ID_ARASAN		0x16e6
 #define PCI_DEVICE_ID_ARASAN_PHY_EMMC	0x0670