[OpenWrt-Devel,2/4] PCI: add driver for Faraday Technology Host Bridge

Submitted by Linus Walleij on Feb. 11, 2017, 12:52 p.m.

Details

Message ID 20170211125220.10273-2-linus.walleij@linaro.org
State New
Headers show

Commit Message

Linus Walleij Feb. 11, 2017, 12:52 p.m.
This adds a host bridge driver for the Faraday Technology
PCI host bridge, used for Cortina Systems Gemini SoC (SL3516)
PCI Host Bridge.

This code is inspired by the out-of-tree OpenWRT patch and
then extensively rewritten for device tree and using the modern
helpers to cut down and modernize the code to all new PCI
frameworks.

Tested on the ITian Square One SQ201 NAS with the following
result in the boot log (trimmed to relevant parts):

OF: PCI: host bridge /soc/pci@50000000 ranges:
OF: PCI:    IO 0x50000000..0x500fffff -> 0x00000000
OF: PCI:   MEM 0x58000000..0x5fffffff -> 0x58000000
gemini-pci 50000000.pci: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [bus 00-ff]
pci_bus 0000:00: root bus resource [io  0x0000-0xfffff]
pci_bus 0000:00: root bus resource [mem 0x58000000-0x5fffffff]
pci 0000:00:00.0: [159b:4321] type 00 class 0x060000
pci 0000:00:09.0: [1106:3038] type 00 class 0x0c0300
pci 0000:00:09.0: reg 0x20: [io  0xfce0-0xfcff]
pci 0000:00:09.0: supports D1 D2
pci 0000:00:09.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:09.1: [1106:3038] type 00 class 0x0c0300
pci 0000:00:09.1: reg 0x20: [io  0xfce0-0xfcff]
pci 0000:00:09.1: supports D1 D2
pci 0000:00:09.1: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:09.2: [1106:3104] type 00 class 0x0c0320
pci 0000:00:09.2: reg 0x10: [mem 0x00000000-0x000000ff]
pci 0000:00:09.2: supports D1 D2
pci 0000:00:09.2: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:0c.0: [1814:0301] type 00 class 0x028000
pci 0000:00:0c.0: reg 0x10: [mem 0xffff8000-0xffffffff]
PCI: bus0: Fast back to back transfers disabled
gemini-pci 50000000.pci: clear all IRQs
gemini-pci 50000000.pci: setting up PCI DMA
pci 0000:00:00.0: of_irq_parse_pci() failed with rc=-22
pci 0000:00:0c.0: BAR 0: assigned [mem 0x58000000-0x58007fff]
pci 0000:00:09.2: BAR 0: assigned [mem 0x58008000-0x580080ff]
pci 0000:00:09.0: BAR 4: assigned [io  0x1000-0x101f]
pci 0000:00:09.1: BAR 4: assigned [io  0x1020-0x103f]
pci 0000:00:09.0: enabling device (0140 -> 0141)
pci 0000:00:09.0: HCRESET not completed yet!
pci 0000:00:09.1: enabling device (0140 -> 0141)
pci 0000:00:09.1: HCRESET not completed yet!
pci 0000:00:09.2: enabling device (0140 -> 0142)
rt61pci 0000:00:0c.0: enabling device (0140 -> 0142)
ieee80211 phy0: rt2x00_set_chip: Info - Chipset detected -
  rt: 2561, rf: 0003, rev: 000c
ieee80211 phy0: Selected rate control algorithm 'minstrel_ht'
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-pci: EHCI PCI platform driver
ehci-pci 0000:00:09.2: EHCI Host Controller
ehci-pci 0000:00:09.2: new USB bus registered, assigned bus number 1
ehci-pci 0000:00:09.2: irq 125, io mem 0x58008000
ehci-pci 0000:00:09.2: USB 2.0 started, EHCI 1.00
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 4 ports detected
uhci_hcd: USB Universal Host Controller Interface driver
uhci_hcd 0000:00:09.0: UHCI Host Controller
uhci_hcd 0000:00:09.0: new USB bus registered, assigned bus number 2
uhci_hcd 0000:00:09.0: HCRESET not completed yet!
uhci_hcd 0000:00:09.0: irq 123, io base 0x00001000
hub 2-0:1.0: USB hub found
hub 2-0:1.0: config failed, hub doesn't have any ports! (err -19)
uhci_hcd 0000:00:09.1: UHCI Host Controller
uhci_hcd 0000:00:09.1: new USB bus registered, assigned bus number 3
uhci_hcd 0000:00:09.1: HCRESET not completed yet!
uhci_hcd 0000:00:09.1: irq 124, io base 0x00001020
hub 3-0:1.0: USB hub found
hub 3-0:1.0: config failed, hub doesn't have any ports! (err -19)
usb 1-2: new high-speed USB device number 2 using ehci-pci
usb-storage 1-2:1.0: USB Mass Storage device detected
scsi host0: usb-storage 1-2:1.0
scsi 0:0:0:0: Direct-Access     USB      Flash Disk       1.00 PQ: 0 ANSI: 2
sd 0:0:0:0: [sda] 7900336 512-byte logical blocks: (4.04 GB/3.77 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 0b 00 00 08
sd 0:0:0:0: [sda] No Caching mode page found
sd 0:0:0:0: [sda] Assuming drive cache: write through
 sda: sda1 sda2 sda3
sd 0:0:0:0: [sda] Attached SCSI removable disk
ieee80211 phy0: rt2x00lib_request_firmware: Info -
  Loading firmware file 'rt2561s.bin'
ieee80211 phy0: rt2x00lib_request_firmware: Info -
  Firmware detected - version: 0.8
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready

$ lspci
00:00.0 Class 0600: 159b:4321
00:09.2 Class 0c03: 1106:3104
00:09.0 Class 0c03: 1106:3038
00:09.1 Class 0c03: 1106:3038
00:0c.0 Class 0280: 1814:0301

cat /proc/interrupts
          CPU0
 16:       3402    GEMINI  14 Edge      Gemini Timer Tick
 17:          0    GEMINI   3 Level     watchdog bark
 18:       1305    GEMINI  18 Level     serial
 21:          0    GEMINI  17 Level     45000000.rtc
 22:          1    GEMINI  26 Edge      poweroff
 44:          0      GPIO  18 Edge      factory reset
123:          0       PCI   0 Edge      uhci_hcd:usb2
124:          0       PCI   1 Edge      uhci_hcd:usb3
125:        160       PCI   2 Edge      ehci_hcd:usb1
126:       1148       PCI   3 Edge      rt61pci

cat /proc/iomem
00000000-07ffffff : System RAM
  00008000-006fffff : Kernel code
  00900000-0095f007 : Kernel data
30000000-30ffffff : 30000000.flash
41000000-41000fff : /soc/watchdog@41000000
42000000-420000ff : serial
4b000000-4b0000ff : /soc/power-controller@4b000000
4d000000-4d0000ff : /soc/gpio@4d000000
4e000000-4e0000ff : /soc/gpio@4e000000
4f000000-4f0000ff : /soc/gpio@4f000000
50000000-500000ff : /soc/pci@50000000
58000000-5fffffff : Gemini PCI MEM
  58000000-58007fff : 0000:00:0c.0
    58000000-58007fff : 0000:00:0c.0
  58008000-580080ff : 0000:00:09.2
    58008000-580080ff : ehci_hcd

Well the EHCI USB hub works fine, I can mount and manage
files and the IRQs just keep ticking up. I can issue
iwlist wlan0 scanning and see all the WLANs here, I don't have
wpa_supplicant so have not tried connecting to them.

Cc: Janos Laube <janos.dev@gmail.com>
Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Gavin Guo <gavinguo@andestech.com>
Cc: Macpaul Lin <macpaul@andestech.com>
Cc: Feng-Hsin Chiang <john453@faraday-tech.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Rename the bridge and symbols to reflect Faraday technology
  as this IP block is clearly a Faraday block and not from
  Storlink/Storm/Cortina at all.
- Support both the regular and "dual" versions of the bridge,
  where the regular has a cascaded IRQ controller and the dual
  does not.
- Encode per-variant characteristics in a variant struct in
  the .data field of the OF match.
- Drop the pointless spinlock in the config space accessors.
- Drop manipulation of pcibios_min_io and pcibios_min_mem
- Get the IO range size from the device tree, and set up the
  bridge properly according to this. Currently we only support
  a 1MiB size IO range, but hey, it's at least dynamic and
  logical.

This can be merged to the PCI tree whenever it is considered
fine for inclusion.

Andestech and Faraday guys: you are more likely than me to
actually have documentation for this bridge. Please share with
me if you can, especially the register defintions, because I
want to set up IO and MEM windows properly from the device tree,
not just rely on defaults. There are defines for these registers
but no use or documentation.
---
 drivers/pci/host/Kconfig       |   5 +
 drivers/pci/host/Makefile      |   1 +
 drivers/pci/host/pci-faraday.c | 399 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 405 insertions(+)
 create mode 100644 drivers/pci/host/pci-faraday.c

Patch hide | download patch | download mbox

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 898d2c48239c..ab5536101ffb 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -60,6 +60,11 @@  config PCI_EXYNOS
 	select PCIEPORTBUS
 	select PCIE_DW
 
+config PCI_FARADAY
+	bool "Faraday Technology PCI controller"
+	depends on OF
+	default ARCH_GEMINI
+
 config PCI_IMX6
 	bool "Freescale i.MX6 PCIe controller"
 	depends on SOC_IMX6Q
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index bfe3179ae74c..71bd839127a4 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -2,6 +2,7 @@  obj-$(CONFIG_PCIE_DW) += pcie-designware.o
 obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
 obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
 obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
+obj-$(CONFIG_PCI_FARADAY) += pci-faraday.o
 obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
 obj-$(CONFIG_PCI_HYPERV) += pci-hyperv.o
 obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
diff --git a/drivers/pci/host/pci-faraday.c b/drivers/pci/host/pci-faraday.c
new file mode 100644
index 000000000000..29e893381c89
--- /dev/null
+++ b/drivers/pci/host/pci-faraday.c
@@ -0,0 +1,399 @@ 
+/*
+ * Support for Faraday Technologt PCI Controller
+ *
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Based on the out-of-tree OpenWRT patch for Cortina Gemini:
+ * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
+ * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ * Based on SL2312 PCI controller code
+ * Storlink (C) 2003
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/bitops.h>
+#include <linux/irq.h>
+
+#define FARADAY_PCI_IOSIZE_1M		0x0000
+
+#define FARADAY_PCI_PMC			0x40
+#define FARADAY_PCI_PMCSR		0x44
+#define FARADAY_PCI_CTRL1		0x48
+#define FARADAY_PCI_CTRL2		0x4C
+#define FARADAY_PCI_MEM1_BASE_SIZE	0x50
+#define FARADAY_PCI_MEM2_BASE_SIZE	0x54
+#define FARADAY_PCI_MEM3_BASE_SIZE	0x58
+
+#define PCI_CTRL2_INTSTS_SHIFT		28
+#define PCI_CTRL2_INTMASK_SHIFT		22
+
+#define FARADAY_PCI_DMA_MASK		0xFFF00000
+#define FARADAY_PCI_DMA_MEM1_BASE	0x00000000
+#define FARADAY_PCI_DMA_MEM2_BASE	0x00000000
+#define FARADAY_PCI_DMA_MEM3_BASE	0x00000000
+#define FARADAY_PCI_DMA_MEM1_SIZE	7
+#define FARADAY_PCI_DMA_MEM2_SIZE	6
+#define FARADAY_PCI_DMA_MEM3_SIZE	6
+
+#define PCI_CONF_ENABLE		BIT(31)
+#define PCI_CONF_WHERE(r)	((r) & 0xFC)
+#define PCI_CONF_BUS(b)		(((b) & 0xFF) << 16)
+#define PCI_CONF_DEVICE(d)	(((d) & 0x1F) << 11)
+#define PCI_CONF_FUNCTION(f)	(((f) & 0x07) << 8)
+
+/*
+ * Special configuration registers directly in the first few words
+ * in he I/O space.
+ */
+#define PCI_IOSIZE	0x00
+#define PCI_PROT	0x04
+#define PCI_CTRL	0x08
+#define PCI_SOFTRST	0x10
+#define PCI_CONFIG	0x28
+#define PCI_DATA	0x2C
+
+/**
+ * struct faraday_pci_variant - encodes IP block differences
+ * @cascaded_irq: this host has cascaded IRQs from an interrupt controller
+ *	embedded in the host bridge.
+ */
+struct faraday_pci_variant {
+	bool cascaded_irq;
+};
+
+struct faraday_pci {
+	struct device *dev;
+	void __iomem *base;
+	struct irq_domain *irqdomain;
+	struct pci_bus *bus;
+};
+
+static int faraday_pci_read_config(struct pci_bus *bus, unsigned int fn,
+				  int config, int size, u32 *value)
+{
+	struct faraday_pci *p = bus->sysdata;
+
+	writel(PCI_CONF_BUS(bus->number) |
+			PCI_CONF_DEVICE(PCI_SLOT(fn)) |
+			PCI_CONF_FUNCTION(PCI_FUNC(fn)) |
+			PCI_CONF_WHERE(config) |
+			PCI_CONF_ENABLE,
+			p->base + PCI_CONFIG);
+
+	*value = readl(p->base + PCI_DATA);
+
+	if (size == 1)
+		*value = (*value >> (8 * (config & 3))) & 0xFF;
+	else if (size == 2)
+		*value = (*value >> (8 * (config & 3))) & 0xFFFF;
+
+	dev_dbg(&bus->dev,
+		"[read]  slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
+		PCI_SLOT(fn), PCI_FUNC(fn), config, size, *value);
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int faraday_pci_write_config(struct pci_bus *bus, unsigned int fn,
+				   int config, int size, u32 value)
+{
+	struct faraday_pci *p = bus->sysdata;
+	int ret = PCIBIOS_SUCCESSFUL;
+
+	dev_dbg(&bus->dev,
+		"[write] slt: %.2d, fnc: %d, cnf: 0x%.2X, val (%d bytes): 0x%.8X\n",
+		PCI_SLOT(fn), PCI_FUNC(fn), config, size, value);
+
+	writel(PCI_CONF_BUS(bus->number) |
+			PCI_CONF_DEVICE(PCI_SLOT(fn)) |
+			PCI_CONF_FUNCTION(PCI_FUNC(fn)) |
+			PCI_CONF_WHERE(config) |
+			PCI_CONF_ENABLE,
+			p->base + PCI_CONFIG);
+
+	switch (size) {
+	case 4:
+		writel(value, p->base + PCI_DATA);
+		break;
+	case 2:
+		writew(value, p->base + PCI_DATA + (config & 3));
+		break;
+	case 1:
+		writeb(value, p->base + PCI_DATA + (config & 3));
+		break;
+	default:
+		ret = PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	return ret;
+}
+
+static struct pci_ops faraday_pci_ops = {
+	.read	= faraday_pci_read_config,
+	.write	= faraday_pci_write_config,
+};
+
+static void faraday_pci_ack_irq(struct irq_data *d)
+{
+	struct faraday_pci *p = irq_data_get_irq_chip_data(d);
+	unsigned int reg;
+
+	faraday_pci_read_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, &reg);
+	reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
+	reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTSTS_SHIFT);
+	faraday_pci_write_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, reg);
+}
+
+static void faraday_pci_mask_irq(struct irq_data *d)
+{
+	struct faraday_pci *p = irq_data_get_irq_chip_data(d);
+	unsigned int reg;
+
+	faraday_pci_read_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, &reg);
+	reg &= ~((0xF << PCI_CTRL2_INTSTS_SHIFT)
+		 | BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT));
+	faraday_pci_write_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, reg);
+}
+
+static void faraday_pci_unmask_irq(struct irq_data *d)
+{
+	struct faraday_pci *p = irq_data_get_irq_chip_data(d);
+	unsigned int reg;
+
+	faraday_pci_read_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, &reg);
+	reg &= ~(0xF << PCI_CTRL2_INTSTS_SHIFT);
+	reg |= BIT(irqd_to_hwirq(d) + PCI_CTRL2_INTMASK_SHIFT);
+	faraday_pci_write_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, reg);
+}
+
+static void faraday_pci_irq_handler(struct irq_desc *desc)
+{
+	struct faraday_pci *p = irq_desc_get_handler_data(desc);
+	struct irq_chip *irqchip = irq_desc_get_chip(desc);
+	unsigned int irq_stat, reg, i;
+
+	faraday_pci_read_config(p->bus, 0, FARADAY_PCI_CTRL2, 4, &reg);
+	irq_stat = reg >> PCI_CTRL2_INTSTS_SHIFT;
+
+	chained_irq_enter(irqchip, desc);
+
+	for (i = 0; i < 4; i++) {
+		if ((irq_stat & BIT(i)) == 0)
+			continue;
+		generic_handle_irq(irq_find_mapping(p->irqdomain, i));
+	}
+
+	chained_irq_exit(irqchip, desc);
+}
+
+static struct irq_chip faraday_pci_irq_chip = {
+	.name = "PCI",
+	.irq_ack = faraday_pci_ack_irq,
+	.irq_mask = faraday_pci_mask_irq,
+	.irq_unmask = faraday_pci_unmask_irq,
+};
+
+static int faraday_pci_irq_map(struct irq_domain *domain, unsigned int irq,
+			      irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &faraday_pci_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops faraday_pci_irqdomain_ops = {
+	.map = faraday_pci_irq_map,
+};
+
+static int faraday_pci_setup_cascaded_irq(struct faraday_pci *p)
+{
+	struct device_node *intc = of_get_next_child(p->dev->of_node, NULL);
+	int irq;
+	int i;
+
+	if (!intc) {
+		dev_err(p->dev, "missing child interrupt-controller node\n");
+		return -EINVAL;
+	}
+
+	/* All PCI IRQs cascade off this one */
+	irq = of_irq_get(intc, 0);
+	if (!irq) {
+		dev_err(p->dev, "failed to get parent IRQ\n");
+		return -EINVAL;
+	}
+
+	p->irqdomain = irq_domain_add_linear(intc, 4,
+					     &faraday_pci_irqdomain_ops,
+					     p);
+	if (!p->irqdomain) {
+		dev_err(p->dev, "failed to create Gemini PCI IRQ domain\n");
+		return -EINVAL;
+	}
+
+	irq_set_chained_handler_and_data(irq, faraday_pci_irq_handler, p);
+
+	for (i = 0; i < 4; i++)
+		irq_create_mapping(p->irqdomain, i);
+
+	return 0;
+}
+
+static int faraday_pci_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct faraday_pci_variant *variant =
+		of_device_get_match_data(dev);
+	struct resource *regs;
+	resource_size_t io_base;
+	struct resource_entry *win;
+	struct faraday_pci *p;
+	struct resource *mem;
+	struct resource *io;
+	struct pci_bus *bus;
+	int ret;
+	u32 val;
+	LIST_HEAD(res);
+
+	p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	p->dev = dev;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	p->base = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(p->base))
+		return PTR_ERR(p->base);
+
+	ret = of_pci_get_host_bridge_resources(dev->of_node, 0, 0xff,
+					       &res, &io_base);
+	if (ret)
+		return ret;
+
+	ret = devm_request_pci_bus_resources(dev, &res);
+	if (ret)
+		return ret;
+
+	/* Get the I/O and memory ranges from DT */
+	resource_list_for_each_entry(win, &res) {
+		switch (resource_type(win->res)) {
+		case IORESOURCE_IO:
+			io = win->res;
+			io->name = "Gemini PCI I/O";
+			if (resource_size(io) == SZ_1M) {
+				/* setup I/O space to 1MB size */
+				writel(FARADAY_PCI_IOSIZE_1M,
+				       p->base + PCI_IOSIZE);
+			} else {
+				dev_err(dev,
+					"illegal IO mem size, must be 1 MiB\n");
+			}
+			ret = pci_remap_iospace(io, io_base);
+			if (ret) {
+				dev_warn(dev, "error %d: failed to map resource %pR\n",
+					 ret, io);
+				continue;
+			}
+			break;
+		case IORESOURCE_MEM:
+			mem = win->res;
+			mem->name = "Gemini PCI MEM";
+			break;
+		case IORESOURCE_BUS:
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* Setup hostbridge */
+	val = readl(p->base + PCI_CTRL);
+	val |= PCI_COMMAND_IO;
+	val |= PCI_COMMAND_MEMORY;
+	val |= PCI_COMMAND_MASTER;
+	writel(val, p->base + PCI_CTRL);
+
+	bus = pci_scan_root_bus(&pdev->dev, 0, &faraday_pci_ops, p, &res);
+	if (!bus)
+		return -ENOMEM;
+	p->bus = bus;
+
+	dev_info(dev, "clear all IRQs\n");
+
+	/* Mask and clear all interrupts */
+	faraday_pci_write_config(bus, 0, FARADAY_PCI_CTRL2 + 2, 2, 0xF000);
+
+	if (variant->cascaded_irq) {
+		ret = faraday_pci_setup_cascaded_irq(p);
+		if (ret) {
+			dev_err(dev, "failed to setup cascaded IRQ\n");
+			return ret;
+		}
+	}
+
+	dev_info(dev, "setting up PCI DMA\n");
+	val = (FARADAY_PCI_DMA_MEM1_BASE & FARADAY_PCI_DMA_MASK)
+		| (FARADAY_PCI_DMA_MEM1_SIZE << 16);
+	faraday_pci_write_config(bus, 0, FARADAY_PCI_MEM1_BASE_SIZE, 4, val);
+	val = (FARADAY_PCI_DMA_MEM2_BASE & FARADAY_PCI_DMA_MASK)
+		| (FARADAY_PCI_DMA_MEM2_SIZE << 16);
+	faraday_pci_write_config(bus, 0, FARADAY_PCI_MEM2_BASE_SIZE, 4, val);
+	val = (FARADAY_PCI_DMA_MEM3_BASE & FARADAY_PCI_DMA_MASK)
+		| (FARADAY_PCI_DMA_MEM3_SIZE << 16);
+	faraday_pci_write_config(bus, 0, FARADAY_PCI_MEM3_BASE_SIZE, 4, val);
+
+	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+	pci_bus_assign_resources(bus);
+	pci_assign_unassigned_bus_resources(bus);
+	pci_bus_add_devices(bus);
+	pci_free_resource_list(&res);
+
+	return 0;
+}
+
+/*
+ * We encode bridge variants here, we have at least two so it doesn't
+ * hurt to have infrastructure to encompass future variants as well.
+ */
+const struct faraday_pci_variant faraday_regular = {
+	.cascaded_irq = true,
+};
+
+const struct faraday_pci_variant faraday_dual = {
+	.cascaded_irq = false,
+};
+
+static const struct of_device_id faraday_pci_of_match[] = {
+	{
+		.compatible = "faraday,pci",
+		.data = &faraday_regular,
+	},
+	{
+		.compatible = "faraday,pci-dual",
+		.data = &faraday_dual,
+	},
+	{},
+};
+
+static struct platform_driver faraday_pci_driver = {
+	.driver = {
+		.name = "gemini-pci",
+		.of_match_table = of_match_ptr(faraday_pci_of_match),
+	},
+	.probe  = faraday_pci_probe,
+};
+builtin_platform_driver(faraday_pci_driver);