mmc: sdhci-pci: add Intel Merrifield support

Implement initial SDHCI Intel Merrifield support.  This patch is based
on previous one from Yunpeng Gao <yunpeng.gao@intel.com>.
Signed-off-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-pci.c

@@ -37,6 +37,7 @@
 #define PCI_DEVICE_ID_INTEL_BYT_SDIO	0x0f15
 #define PCI_DEVICE_ID_INTEL_BYT_SD	0x0f16
 #define PCI_DEVICE_ID_INTEL_BYT_EMMC2	0x0f50
+#define PCI_DEVICE_ID_INTEL_MRFL_MMC	0x1190
 
 /*
  * PCI registers
@@ -356,6 +357,28 @@ static const struct sdhci_pci_fixes sdhci_intel_byt_sd = {
 	.allow_runtime_pm = true,
 };
 
+/* Define Host controllers for Intel Merrifield platform */
+#define INTEL_MRFL_EMMC_0	0
+#define INTEL_MRFL_EMMC_1	1
+
+static int intel_mrfl_mmc_probe_slot(struct sdhci_pci_slot *slot)
+{
+	if ((PCI_FUNC(slot->chip->pdev->devfn) != INTEL_MRFL_EMMC_0) &&
+	    (PCI_FUNC(slot->chip->pdev->devfn) != INTEL_MRFL_EMMC_1))
+		/* SD support is not ready yet */
+		return -ENODEV;
+
+	slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
+				 MMC_CAP_1_8V_DDR;
+
+	return 0;
+}
+
+static const struct sdhci_pci_fixes sdhci_intel_mrfl_mmc = {
+	.quirks		= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
+	.probe_slot	= intel_mrfl_mmc_probe_slot,
+};
+
 /* O2Micro extra registers */
 #define O2_SD_LOCK_WP		0xD3
 #define O2_SD_MULTI_VCC3V	0xEE
@@ -939,6 +962,13 @@ static const struct pci_device_id pci_ids[] = {
 		.driver_data	= (kernel_ulong_t)&sdhci_intel_byt_emmc,
 	},
 
+	{
+		.vendor		= PCI_VENDOR_ID_INTEL,
+		.device		= PCI_DEVICE_ID_INTEL_MRFL_MMC,
+		.subvendor	= PCI_ANY_ID,
+		.subdevice	= PCI_ANY_ID,
+		.driver_data	= (kernel_ulong_t)&sdhci_intel_mrfl_mmc,
+	},
 	{
 		.vendor		= PCI_VENDOR_ID_O2,
 		.device		= PCI_DEVICE_ID_O2_8120,