[libata] AHCI: Add support for Marvell AHCI-like chips (initially 6145)

Add support for the SATA portion of Marvell's AHCI-compatible chips.
The PATA port capability, also available via AHCI, is disabled until
support is completed.

NCQ and PCI MSI are disabled by default.  Marvell says "we use NCQ" in
their drivers but "we do not use PCI MSI."  Theoretically that implies
we need to fix ahci.c to work with Marvell NCQ, but one wonders why
Marvell NCQ is any different from other AHCI chips.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index f66e2a5..11e4eb9 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -46,7 +46,7 @@
 #include <linux/libata.h>
 
 #define DRV_NAME	"ahci"
-#define DRV_VERSION	"2.2"
+#define DRV_VERSION	"2.3"
 
 
 enum {
@@ -81,6 +81,7 @@
 	board_ahci_vt8251	= 2,
 	board_ahci_ign_iferr	= 3,
 	board_ahci_sb600	= 4,
+	board_ahci_mv		= 5,
 
 	/* global controller registers */
 	HOST_CAP		= 0x00, /* host capabilities */
@@ -171,6 +172,8 @@
 	AHCI_FLAG_HONOR_PI		= (1 << 26), /* honor PORTS_IMPL */
 	AHCI_FLAG_IGN_SERR_INTERNAL	= (1 << 27), /* ignore SERR_INTERNAL */
 	AHCI_FLAG_32BIT_ONLY		= (1 << 28), /* force 32bit */
+	AHCI_FLAG_MV_PATA		= (1 << 29), /* PATA port */
+	AHCI_FLAG_NO_MSI		= (1 << 30), /* no PCI MSI */
 
 	AHCI_FLAG_COMMON		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
 					  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
@@ -364,6 +367,18 @@
 		.udma_mask	= ATA_UDMA6,
 		.port_ops	= &ahci_ops,
 	},
+	/* board_ahci_mv */
+	{
+		.sht		= &ahci_sht,
+		.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
+				  ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
+				  ATA_FLAG_SKIP_D2H_BSY | AHCI_FLAG_HONOR_PI |
+				  AHCI_FLAG_NO_NCQ | AHCI_FLAG_NO_MSI |
+				  AHCI_FLAG_MV_PATA,
+		.pio_mask	= 0x1f, /* pio0-4 */
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &ahci_ops,
+	},
 };
 
 static const struct pci_device_id ahci_pci_tbl[] = {
@@ -459,6 +474,9 @@
 	{ PCI_VDEVICE(SI, 0x1185), board_ahci }, /* SiS 966 */
 	{ PCI_VDEVICE(SI, 0x0186), board_ahci }, /* SiS 968 */
 
+	/* Marvell */
+	{ PCI_VDEVICE(MARVELL, 0x6145), board_ahci_mv },	/* 6145 */
+
 	/* Generic, PCI class code for AHCI */
 	{ PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
 	  PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff, board_ahci },
@@ -544,6 +562,20 @@
 		hpriv->saved_port_map = port_map;
 	}
 
+	/*
+	 * Temporary Marvell 6145 hack: PATA port presence
+	 * is asserted through the standard AHCI port
+	 * presence register, as bit 4 (counting from 0)
+	 */
+	if (pi->flags & AHCI_FLAG_MV_PATA) {
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "MV_AHCI HACK: port_map %x -> %x\n",
+			   hpriv->port_map,
+			   hpriv->port_map & 0xf);
+
+		port_map &= 0xf;
+	}
+
 	/* cross check port_map and cap.n_ports */
 	if (pi->flags & AHCI_FLAG_HONOR_PI) {
 		u32 tmp_port_map = port_map;
@@ -856,12 +888,25 @@
 	struct pci_dev *pdev = to_pci_dev(host->dev);
 	void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
 	int i;
+	void __iomem *port_mmio;
 	u32 tmp;
 
+	if (host->ports[0]->flags & AHCI_FLAG_MV_PATA) {
+		port_mmio = __ahci_port_base(host, 4);
+
+		writel(0, port_mmio + PORT_IRQ_MASK);
+
+		/* clear port IRQ */
+		tmp = readl(port_mmio + PORT_IRQ_STAT);
+		VPRINTK("PORT_IRQ_STAT 0x%x\n", tmp);
+		if (tmp)
+			writel(tmp, port_mmio + PORT_IRQ_STAT);
+	}
+
 	for (i = 0; i < host->n_ports; i++) {
 		struct ata_port *ap = host->ports[i];
-		void __iomem *port_mmio = ahci_port_base(ap);
 
+		port_mmio = ahci_port_base(ap);
 		if (ata_port_is_dummy(ap))
 			continue;
 
@@ -1738,7 +1783,7 @@
 	if (rc)
 		return rc;
 
-	if (pci_enable_msi(pdev))
+	if ((pi.flags & AHCI_FLAG_NO_MSI) || pci_enable_msi(pdev))
 		pci_intx(pdev, 1);
 
 	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);