MIPS: Add driver for the built-in PCI controller of the RT3883 SoC

The Ralink RT3883 SoCs have a built-in PCI Host Controller
device. The patch adds a platform driver and device tree
binding documentation for that.

The patch also enables the HW_HAS_PCI config option. This
is required in order to be able to enable the PCI support.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Acked-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5758/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 638 insertions, 0 deletions

diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
index c382042911dd..719e4557e22e 100644
--- a/arch/mips/pci/Makefile
+++ b/arch/mips/pci/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_SIBYTE_BCM1x80)	+= pci-bcm1480.o pci-bcm1480ht.o
 obj-$(CONFIG_SNI_RM)            += fixup-sni.o ops-sni.o
 obj-$(CONFIG_LANTIQ)            += fixup-lantiq.o
 obj-$(CONFIG_PCI_LANTIQ)        += pci-lantiq.o ops-lantiq.o
+obj-$(CONFIG_SOC_RT3883)        += pci-rt3883.o
 obj-$(CONFIG_TANBAC_TB0219)     += fixup-tb0219.o
 obj-$(CONFIG_TANBAC_TB0226)     += fixup-tb0226.o
 obj-$(CONFIG_TANBAC_TB0287)     += fixup-tb0287.o
diff --git a/arch/mips/pci/pci-rt3883.c b/arch/mips/pci/pci-rt3883.c
new file mode 100644
index 000000000000..95c9d41382e7
--- /dev/null
+++ b/arch/mips/pci/pci-rt3883.c
@@ -0,0 +1,636 @@
+/*
+ *  Ralink RT3662/RT3883 SoC PCI support
+ *
+ *  Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  Parts of this file are based on Ralink's 2.6.21 BSP
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/platform_device.h>
+
+#include <asm/mach-ralink/rt3883.h>
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define RT3883_MEMORY_BASE              0x00000000
+#define RT3883_MEMORY_SIZE              0x02000000
+
+#define RT3883_PCI_REG_PCICFG           0x00
+#define   RT3883_PCICFG_P2P_BR_DEVNUM_M 0xf
+#define   RT3883_PCICFG_P2P_BR_DEVNUM_S 16
+#define   RT3883_PCICFG_PCIRST          BIT(1)
+#define RT3883_PCI_REG_PCIRAW           0x04
+#define RT3883_PCI_REG_PCIINT           0x08
+#define RT3883_PCI_REG_PCIENA           0x0c
+
+#define RT3883_PCI_REG_CFGADDR          0x20
+#define RT3883_PCI_REG_CFGDATA          0x24
+#define RT3883_PCI_REG_MEMBASE          0x28
+#define RT3883_PCI_REG_IOBASE           0x2c
+#define RT3883_PCI_REG_ARBCTL           0x80
+
+#define RT3883_PCI_REG_BASE(_x)         (0x1000 + (_x) * 0x1000)
+#define RT3883_PCI_REG_BAR0SETUP(_x)    (RT3883_PCI_REG_BASE((_x)) + 0x10)
+#define RT3883_PCI_REG_IMBASEBAR0(_x)   (RT3883_PCI_REG_BASE((_x)) + 0x18)
+#define RT3883_PCI_REG_ID(_x)           (RT3883_PCI_REG_BASE((_x)) + 0x30)
+#define RT3883_PCI_REG_CLASS(_x)        (RT3883_PCI_REG_BASE((_x)) + 0x34)
+#define RT3883_PCI_REG_SUBID(_x)        (RT3883_PCI_REG_BASE((_x)) + 0x38)
+#define RT3883_PCI_REG_STATUS(_x)       (RT3883_PCI_REG_BASE((_x)) + 0x50)
+
+#define RT3883_PCI_MODE_NONE    0
+#define RT3883_PCI_MODE_PCI     BIT(0)
+#define RT3883_PCI_MODE_PCIE    BIT(1)
+#define RT3883_PCI_MODE_BOTH    (RT3883_PCI_MODE_PCI | RT3883_PCI_MODE_PCIE)
+
+#define RT3883_PCI_IRQ_COUNT    32
+
+#define RT3883_P2P_BR_DEVNUM    1
+
+struct rt3883_pci_controller {
+        void __iomem *base;
+        spinlock_t lock;
+
+        struct device_node *intc_of_node;
+        struct irq_domain *irq_domain;
+
+        struct pci_controller pci_controller;
+        struct resource io_res;
+        struct resource mem_res;
+
+        bool pcie_ready;
+};
+
+static inline struct rt3883_pci_controller *
+pci_bus_to_rt3883_controller(struct pci_bus *bus)
+{
+        struct pci_controller *hose;
+
+        hose = (struct pci_controller *) bus->sysdata;
+        return container_of(hose, struct rt3883_pci_controller, pci_controller);
+}
+
+static inline u32 rt3883_pci_r32(struct rt3883_pci_controller *rpc,
+                                 unsigned reg)
+{
+        return ioread32(rpc->base + reg);
+}
+
+static inline void rt3883_pci_w32(struct rt3883_pci_controller *rpc,
+                                  u32 val, unsigned reg)
+{
+        iowrite32(val, rpc->base + reg);
+}
+
+static inline u32 rt3883_pci_get_cfgaddr(unsigned int bus, unsigned int slot,
+                                         unsigned int func, unsigned int where)
+{
+        return (bus << 16) | (slot << 11) | (func << 8) | (where & 0xfc) |
+               0x80000000;
+}
+
+static u32 rt3883_pci_read_cfg32(struct rt3883_pci_controller *rpc,
+                               unsigned bus, unsigned slot,
+                               unsigned func, unsigned reg)
+{
+        unsigned long flags;
+        u32 address;
+        u32 ret;
+
+        address = rt3883_pci_get_cfgaddr(bus, slot, func, reg);
+
+        spin_lock_irqsave(&rpc->lock, flags);
+        rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
+        ret = rt3883_pci_r32(rpc, RT3883_PCI_REG_CFGDATA);
+        spin_unlock_irqrestore(&rpc->lock, flags);
+
+        return ret;
+}
+
+static void rt3883_pci_write_cfg32(struct rt3883_pci_controller *rpc,
+                                 unsigned bus, unsigned slot,
+                                 unsigned func, unsigned reg, u32 val)
+{
+        unsigned long flags;
+        u32 address;
+
+        address = rt3883_pci_get_cfgaddr(bus, slot, func, reg);
+
+        spin_lock_irqsave(&rpc->lock, flags);
+        rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
+        rt3883_pci_w32(rpc, val, RT3883_PCI_REG_CFGDATA);
+        spin_unlock_irqrestore(&rpc->lock, flags);
+}
+
+static void rt3883_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+        struct rt3883_pci_controller *rpc;
+        u32 pending;
+
+        rpc = irq_get_handler_data(irq);
+
+        pending = rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIINT) &
+                  rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
+
+        if (!pending) {
+                spurious_interrupt();
+                return;
+        }
+
+        while (pending) {
+                unsigned bit = __ffs(pending);
+
+                irq = irq_find_mapping(rpc->irq_domain, bit);
+                generic_handle_irq(irq);
+
+                pending &= ~BIT(bit);
+        }
+}
+
+static void rt3883_pci_irq_unmask(struct irq_data *d)
+{
+        struct rt3883_pci_controller *rpc;
+        u32 t;
+
+        rpc = irq_data_get_irq_chip_data(d);
+
+        t = rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
+        rt3883_pci_w32(rpc, t | BIT(d->hwirq), RT3883_PCI_REG_PCIENA);
+        /* flush write */
+        rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
+}
+
+static void rt3883_pci_irq_mask(struct irq_data *d)
+{
+        struct rt3883_pci_controller *rpc;
+        u32 t;
+
+        rpc = irq_data_get_irq_chip_data(d);
+
+        t = rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
+        rt3883_pci_w32(rpc, t & ~BIT(d->hwirq), RT3883_PCI_REG_PCIENA);
+        /* flush write */
+        rt3883_pci_r32(rpc, RT3883_PCI_REG_PCIENA);
+}
+
+static struct irq_chip rt3883_pci_irq_chip = {
+        .name           = "RT3883 PCI",
+        .irq_mask       = rt3883_pci_irq_mask,
+        .irq_unmask     = rt3883_pci_irq_unmask,
+        .irq_mask_ack   = rt3883_pci_irq_mask,
+};
+
+static int rt3883_pci_irq_map(struct irq_domain *d, unsigned int irq,
+                              irq_hw_number_t hw)
+{
+        irq_set_chip_and_handler(irq, &rt3883_pci_irq_chip, handle_level_irq);
+        irq_set_chip_data(irq, d->host_data);
+
+        return 0;
+}
+
+static const struct irq_domain_ops rt3883_pci_irq_domain_ops = {
+        .map = rt3883_pci_irq_map,
+        .xlate = irq_domain_xlate_onecell,
+};
+
+static int rt3883_pci_irq_init(struct device *dev,
+                               struct rt3883_pci_controller *rpc)
+{
+        int irq;
+
+        irq = irq_of_parse_and_map(rpc->intc_of_node, 0);
+        if (irq == 0) {
+                dev_err(dev, "%s has no IRQ",
+                        of_node_full_name(rpc->intc_of_node));
+                return -EINVAL;
+        }
+
+        /* disable all interrupts */
+        rt3883_pci_w32(rpc, 0, RT3883_PCI_REG_PCIENA);
+
+        rpc->irq_domain =
+                irq_domain_add_linear(rpc->intc_of_node, RT3883_PCI_IRQ_COUNT,
+                                      &rt3883_pci_irq_domain_ops,
+                                      rpc);
+        if (!rpc->irq_domain) {
+                dev_err(dev, "unable to add IRQ domain\n");
+                return -ENODEV;
+        }
+
+        irq_set_handler_data(irq, rpc);
+        irq_set_chained_handler(irq, rt3883_pci_irq_handler);
+
+        return 0;
+}
+
+static int rt3883_pci_config_read(struct pci_bus *bus, unsigned int devfn,
+                                  int where, int size, u32 *val)
+{
+        struct rt3883_pci_controller *rpc;
+        unsigned long flags;
+        u32 address;
+        u32 data;
+
+        rpc = pci_bus_to_rt3883_controller(bus);
+
+        if (!rpc->pcie_ready && bus->number == 1)
+                return PCIBIOS_DEVICE_NOT_FOUND;
+
+        address = rt3883_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
+                                         PCI_FUNC(devfn), where);
+
+        spin_lock_irqsave(&rpc->lock, flags);
+        rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
+        data = rt3883_pci_r32(rpc, RT3883_PCI_REG_CFGDATA);
+        spin_unlock_irqrestore(&rpc->lock, flags);
+
+        switch (size) {
+        case 1:
+                *val = (data >> ((where & 3) << 3)) & 0xff;
+                break;
+        case 2:
+                *val = (data >> ((where & 3) << 3)) & 0xffff;
+                break;
+        case 4:
+                *val = data;
+                break;
+        }
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static int rt3883_pci_config_write(struct pci_bus *bus, unsigned int devfn,
+                                   int where, int size, u32 val)
+{
+        struct rt3883_pci_controller *rpc;
+        unsigned long flags;
+        u32 address;
+        u32 data;
+
+        rpc = pci_bus_to_rt3883_controller(bus);
+
+        if (!rpc->pcie_ready && bus->number == 1)
+                return PCIBIOS_DEVICE_NOT_FOUND;
+
+        address = rt3883_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
+                                         PCI_FUNC(devfn), where);
+
+        spin_lock_irqsave(&rpc->lock, flags);
+        rt3883_pci_w32(rpc, address, RT3883_PCI_REG_CFGADDR);
+        data = rt3883_pci_r32(rpc, RT3883_PCI_REG_CFGDATA);
+
+        switch (size) {
+        case 1:
+                data = (data & ~(0xff << ((where & 3) << 3))) |
+                       (val << ((where & 3) << 3));
+                break;
+        case 2:
+                data = (data & ~(0xffff << ((where & 3) << 3))) |
+                       (val << ((where & 3) << 3));
+                break;
+        case 4:
+                data = val;
+                break;
+        }
+
+        rt3883_pci_w32(rpc, data, RT3883_PCI_REG_CFGDATA);
+        spin_unlock_irqrestore(&rpc->lock, flags);
+
+        return PCIBIOS_SUCCESSFUL;
+}
+
+static struct pci_ops rt3883_pci_ops = {
+        .read   = rt3883_pci_config_read,
+        .write  = rt3883_pci_config_write,
+};
+
+static void rt3883_pci_preinit(struct rt3883_pci_controller *rpc, unsigned mode)
+{
+        u32 syscfg1;
+        u32 rstctrl;
+        u32 clkcfg1;
+        u32 t;
+
+        rstctrl = rt_sysc_r32(RT3883_SYSC_REG_RSTCTRL);
+        syscfg1 = rt_sysc_r32(RT3883_SYSC_REG_SYSCFG1);
+        clkcfg1 = rt_sysc_r32(RT3883_SYSC_REG_CLKCFG1);
+
+        if (mode & RT3883_PCI_MODE_PCIE) {
+                rstctrl |= RT3883_RSTCTRL_PCIE;
+                rt_sysc_w32(rstctrl, RT3883_SYSC_REG_RSTCTRL);
+
+                /* setup PCI PAD drive mode */
+                syscfg1 &= ~(0x30);
+                syscfg1 |= (2 << 4);
+                rt_sysc_w32(syscfg1, RT3883_SYSC_REG_SYSCFG1);
+
+                t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN0);
+                t &= ~BIT(31);
+                rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN0);
+
+                t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN1);
+                t &= 0x80ffffff;
+                rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN1);
+
+                t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN1);
+                t |= 0xa << 24;
+                rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN1);
+
+                t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN0);
+                t |= BIT(31);
+                rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN0);
+
+                msleep(50);
+
+                rstctrl &= ~RT3883_RSTCTRL_PCIE;
+                rt_sysc_w32(rstctrl, RT3883_SYSC_REG_RSTCTRL);
+        }
+
+        syscfg1 |= (RT3883_SYSCFG1_PCIE_RC_MODE | RT3883_SYSCFG1_PCI_HOST_MODE);
+
+        clkcfg1 &= ~(RT3883_CLKCFG1_PCI_CLK_EN | RT3883_CLKCFG1_PCIE_CLK_EN);
+
+        if (mode & RT3883_PCI_MODE_PCI) {
+                clkcfg1 |= RT3883_CLKCFG1_PCI_CLK_EN;
+                rstctrl &= ~RT3883_RSTCTRL_PCI;
+        }
+
+        if (mode & RT3883_PCI_MODE_PCIE) {
+                clkcfg1 |= RT3883_CLKCFG1_PCIE_CLK_EN;
+                rstctrl &= ~RT3883_RSTCTRL_PCIE;
+        }
+
+        rt_sysc_w32(syscfg1, RT3883_SYSC_REG_SYSCFG1);
+        rt_sysc_w32(rstctrl, RT3883_SYSC_REG_RSTCTRL);
+        rt_sysc_w32(clkcfg1, RT3883_SYSC_REG_CLKCFG1);
+
+        msleep(500);
+
+        /*
+         * setup the device number of the P2P bridge
+         * and de-assert the reset line
+         */
+        t = (RT3883_P2P_BR_DEVNUM << RT3883_PCICFG_P2P_BR_DEVNUM_S);
+        rt3883_pci_w32(rpc, t, RT3883_PCI_REG_PCICFG);
+
+        /* flush write */
+        rt3883_pci_r32(rpc, RT3883_PCI_REG_PCICFG);
+        msleep(500);
+
+        if (mode & RT3883_PCI_MODE_PCIE) {
+                msleep(500);
+
+                t = rt3883_pci_r32(rpc, RT3883_PCI_REG_STATUS(1));
+
+                rpc->pcie_ready = t & BIT(0);
+
+                if (!rpc->pcie_ready) {
+                        /* reset the PCIe block */
+                        t = rt_sysc_r32(RT3883_SYSC_REG_RSTCTRL);
+                        t |= RT3883_RSTCTRL_PCIE;
+                        rt_sysc_w32(t, RT3883_SYSC_REG_RSTCTRL);
+                        t &= ~RT3883_RSTCTRL_PCIE;
+                        rt_sysc_w32(t, RT3883_SYSC_REG_RSTCTRL);
+
+                        /* turn off PCIe clock */
+                        t = rt_sysc_r32(RT3883_SYSC_REG_CLKCFG1);
+                        t &= ~RT3883_CLKCFG1_PCIE_CLK_EN;
+                        rt_sysc_w32(t, RT3883_SYSC_REG_CLKCFG1);
+
+                        t = rt_sysc_r32(RT3883_SYSC_REG_PCIE_CLK_GEN0);
+                        t &= ~0xf000c080;
+                        rt_sysc_w32(t, RT3883_SYSC_REG_PCIE_CLK_GEN0);
+                }
+        }
+
+        /* enable PCI arbiter */
+        rt3883_pci_w32(rpc, 0x79, RT3883_PCI_REG_ARBCTL);
+}
+
+static int rt3883_pci_probe(struct platform_device *pdev)
+{
+        struct rt3883_pci_controller *rpc;
+        struct device *dev = &pdev->dev;
+        struct device_node *np = dev->of_node;
+        struct resource *res;
+        struct device_node *child;
+        u32 val;
+        int err;
+        int mode;
+
+        rpc = devm_kzalloc(dev, sizeof(*rpc), GFP_KERNEL);
+        if (!rpc)
+                return -ENOMEM;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -EINVAL;
+
+        rpc->base = devm_ioremap_resource(dev, res);
+        if (IS_ERR(rpc->base))
+                return PTR_ERR(rpc->base);
+
+        /* find the interrupt controller child node */
+        for_each_child_of_node(np, child) {
+                if (of_get_property(child, "interrupt-controller", NULL) &&
+                    of_node_get(child)) {
+                        rpc->intc_of_node = child;
+                        break;
+                }
+        }
+
+        if (!rpc->intc_of_node) {
+                dev_err(dev, "%s has no %s child node",
+                        of_node_full_name(rpc->intc_of_node),
+                        "interrupt controller");
+                return -EINVAL;
+        }
+
+        /* find the PCI host bridge child node */
+        for_each_child_of_node(np, child) {
+                if (child->type &&
+                    of_node_cmp(child->type, "pci") == 0 &&
+                    of_node_get(child)) {
+                        rpc->pci_controller.of_node = child;
+                        break;
+                }
+        }
+
+        if (!rpc->pci_controller.of_node) {
+                dev_err(dev, "%s has no %s child node",
+                        of_node_full_name(rpc->intc_of_node),
+                        "PCI host bridge");
+                err = -EINVAL;
+                goto err_put_intc_node;
+        }
+
+        mode = RT3883_PCI_MODE_NONE;
+        for_each_available_child_of_node(rpc->pci_controller.of_node, child) {
+                int devfn;
+
+                if (!child->type ||
+                    of_node_cmp(child->type, "pci") != 0)
+                        continue;
+
+                devfn = of_pci_get_devfn(child);
+                if (devfn < 0)
+                        continue;
+
+                switch (PCI_SLOT(devfn)) {
+                case 1:
+                        mode |= RT3883_PCI_MODE_PCIE;
+                        break;
+
+                case 17:
+                case 18:
+                        mode |= RT3883_PCI_MODE_PCI;
+                        break;
+                }
+        }
+
+        if (mode == RT3883_PCI_MODE_NONE) {
+                dev_err(dev, "unable to determine PCI mode\n");
+                err = -EINVAL;
+                goto err_put_hb_node;
+        }
+
+        dev_info(dev, "mode:%s%s\n",
+                 (mode & RT3883_PCI_MODE_PCI) ? " PCI" : "",
+                 (mode & RT3883_PCI_MODE_PCIE) ? " PCIe" : "");
+
+        rt3883_pci_preinit(rpc, mode);
+
+        rpc->pci_controller.pci_ops = &rt3883_pci_ops;
+        rpc->pci_controller.io_resource = &rpc->io_res;
+        rpc->pci_controller.mem_resource = &rpc->mem_res;
+
+        /* Load PCI I/O and memory resources from DT */
+        pci_load_of_ranges(&rpc->pci_controller,
+                           rpc->pci_controller.of_node);
+
+        rt3883_pci_w32(rpc, rpc->mem_res.start, RT3883_PCI_REG_MEMBASE);
+        rt3883_pci_w32(rpc, rpc->io_res.start, RT3883_PCI_REG_IOBASE);
+
+        ioport_resource.start = rpc->io_res.start;
+        ioport_resource.end = rpc->io_res.end;
+
+        /* PCI */
+        rt3883_pci_w32(rpc, 0x03ff0000, RT3883_PCI_REG_BAR0SETUP(0));
+        rt3883_pci_w32(rpc, RT3883_MEMORY_BASE, RT3883_PCI_REG_IMBASEBAR0(0));
+        rt3883_pci_w32(rpc, 0x08021814, RT3883_PCI_REG_ID(0));
+        rt3883_pci_w32(rpc, 0x00800001, RT3883_PCI_REG_CLASS(0));
+        rt3883_pci_w32(rpc, 0x28801814, RT3883_PCI_REG_SUBID(0));
+
+        /* PCIe */
+        rt3883_pci_w32(rpc, 0x03ff0000, RT3883_PCI_REG_BAR0SETUP(1));
+        rt3883_pci_w32(rpc, RT3883_MEMORY_BASE, RT3883_PCI_REG_IMBASEBAR0(1));
+        rt3883_pci_w32(rpc, 0x08021814, RT3883_PCI_REG_ID(1));
+        rt3883_pci_w32(rpc, 0x06040001, RT3883_PCI_REG_CLASS(1));
+        rt3883_pci_w32(rpc, 0x28801814, RT3883_PCI_REG_SUBID(1));
+
+        err = rt3883_pci_irq_init(dev, rpc);
+        if (err)
+                goto err_put_hb_node;
+
+        /* PCIe */
+        val = rt3883_pci_read_cfg32(rpc, 0, 0x01, 0, PCI_COMMAND);
+        val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
+        rt3883_pci_write_cfg32(rpc, 0, 0x01, 0, PCI_COMMAND, val);
+
+        /* PCI */
+        val = rt3883_pci_read_cfg32(rpc, 0, 0x00, 0, PCI_COMMAND);
+        val |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
+        rt3883_pci_write_cfg32(rpc, 0, 0x00, 0, PCI_COMMAND, val);
+
+        if (mode == RT3883_PCI_MODE_PCIE) {
+                rt3883_pci_w32(rpc, 0x03ff0001, RT3883_PCI_REG_BAR0SETUP(0));
+                rt3883_pci_w32(rpc, 0x03ff0001, RT3883_PCI_REG_BAR0SETUP(1));
+
+                rt3883_pci_write_cfg32(rpc, 0, RT3883_P2P_BR_DEVNUM, 0,
+                                       PCI_BASE_ADDRESS_0,
+                                       RT3883_MEMORY_BASE);
+                /* flush write */
+                rt3883_pci_read_cfg32(rpc, 0, RT3883_P2P_BR_DEVNUM, 0,
+                                      PCI_BASE_ADDRESS_0);
+        } else {
+                rt3883_pci_write_cfg32(rpc, 0, RT3883_P2P_BR_DEVNUM, 0,
+                                       PCI_IO_BASE, 0x00000101);
+        }
+
+        register_pci_controller(&rpc->pci_controller);
+
+        return 0;
+
+err_put_hb_node:
+        of_node_put(rpc->pci_controller.of_node);
+err_put_intc_node:
+        of_node_put(rpc->intc_of_node);
+        return err;
+}
+
+int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+        struct of_irq dev_irq;
+        int err;
+        int irq;
+
+        err = of_irq_map_pci(dev, &dev_irq);
+        if (err) {
+                pr_err("pci %s: unable to get irq map, err=%d\n",
+                       pci_name((struct pci_dev *) dev), err);
+                return 0;
+        }
+
+        irq = irq_create_of_mapping(dev_irq.controller,
+                                    dev_irq.specifier,
+                                    dev_irq.size);
+
+        if (irq == 0)
+                pr_crit("pci %s: no irq found for pin %u\n",
+                        pci_name((struct pci_dev *) dev), pin);
+        else
+                pr_info("pci %s: using irq %d for pin %u\n",
+                        pci_name((struct pci_dev *) dev), irq, pin);
+
+        return irq;
+}
+
+int pcibios_plat_dev_init(struct pci_dev *dev)
+{
+        return 0;
+}
+
+static const struct of_device_id rt3883_pci_ids[] = {
+        { .compatible = "ralink,rt3883-pci" },
+        {},
+};
+MODULE_DEVICE_TABLE(of, rt3883_pci_ids);
+
+static struct platform_driver rt3883_pci_driver = {
+        .probe = rt3883_pci_probe,
+        .driver = {
+                .name = "rt3883-pci",
+                .owner = THIS_MODULE,
+                .of_match_table = of_match_ptr(rt3883_pci_ids),
+        },
+};
+
+static int __init rt3883_pci_init(void)
+{
+        return platform_driver_register(&rt3883_pci_driver);
+}
+
+postcore_initcall(rt3883_pci_init);
diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
index 5f5dad26c13d..424f03496d14 100644
--- a/arch/mips/ralink/Kconfig
+++ b/arch/mips/ralink/Kconfig
@@ -26,6 +26,7 @@ choice
                 bool "RT3883"
                 select USB_ARCH_HAS_OHCI
                 select USB_ARCH_HAS_EHCI
+                select HW_HAS_PCI
 
         config SOC_MT7620
                 bool "MT7620"