arch/mips/pci/pci-ar724x.c - kernel/msm-4.9 - Gitiles

 /*
  *  Atheros AR724X PCI host controller driver
  *
  *  Copyright (C) 2011 René Bolldorf <xsecute@googlemail.com>
  *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
  *
  *  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/irq.h>
 #include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <asm/mach-ath79/ath79.h>
 #include <asm/mach-ath79/ar71xx_regs.h>

 #define AR724X_PCI_REG_RESET		0x18
 #define AR724X_PCI_REG_INT_STATUS	0x4c
 #define AR724X_PCI_REG_INT_MASK		0x50

 #define AR724X_PCI_RESET_LINK_UP	BIT(0)

 #define AR724X_PCI_INT_DEV0		BIT(14)

 #define AR724X_PCI_IRQ_COUNT		1

 #define AR7240_BAR0_WAR_VALUE	0xffff

 #define AR724X_PCI_CMD_INIT	(PCI_COMMAND_MEMORY |		\
 				 PCI_COMMAND_MASTER |		\
 				 PCI_COMMAND_INVALIDATE |	\
 				 PCI_COMMAND_PARITY |		\
 				 PCI_COMMAND_SERR |		\
 				 PCI_COMMAND_FAST_BACK)

 struct ar724x_pci_controller {
 	void __iomem *devcfg_base;
 	void __iomem *ctrl_base;
 	void __iomem *crp_base;

 	int irq;
 	int irq_base;

 	bool link_up;
 	bool bar0_is_cached;
 	u32  bar0_value;

 	struct pci_controller pci_controller;
 	struct resource io_res;
 	struct resource mem_res;
 };

 static inline bool ar724x_pci_check_link(struct ar724x_pci_controller *apc)
 {
 	u32 reset;

 	reset = __raw_readl(apc->ctrl_base + AR724X_PCI_REG_RESET);
 	return reset & AR724X_PCI_RESET_LINK_UP;
 }

 static inline struct ar724x_pci_controller *
 pci_bus_to_ar724x_controller(struct pci_bus *bus)
 {
 	struct pci_controller *hose;

 	hose = (struct pci_controller *) bus->sysdata;
 	return container_of(hose, struct ar724x_pci_controller, pci_controller);
 }

 static int ar724x_pci_local_write(struct ar724x_pci_controller *apc,
 				  int where, int size, u32 value)
 {
 	void __iomem *base;
 	u32 data;
 	int s;

 	WARN_ON(where & (size - 1));

 	if (!apc->link_up)
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	base = apc->crp_base;
 	data = __raw_readl(base + (where & ~3));

 	switch (size) {
 	case 1:
 		s = ((where & 3) * 8);
 		data &= ~(0xff << s);
 		data |= ((value & 0xff) << s);
 		break;
 	case 2:
 		s = ((where & 2) * 8);
 		data &= ~(0xffff << s);
 		data |= ((value & 0xffff) << s);
 		break;
 	case 4:
 		data = value;
 		break;
 	default:
 		return PCIBIOS_BAD_REGISTER_NUMBER;
 	}

 	__raw_writel(data, base + (where & ~3));
 	/* flush write */
 	__raw_readl(base + (where & ~3));

 	return PCIBIOS_SUCCESSFUL;
 }

 static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
 			    int size, uint32_t *value)
 {
 	struct ar724x_pci_controller *apc;
 	void __iomem *base;
 	u32 data;

 	apc = pci_bus_to_ar724x_controller(bus);
 	if (!apc->link_up)
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	if (devfn)
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	base = apc->devcfg_base;
 	data = __raw_readl(base + (where & ~3));

 	switch (size) {
 	case 1:
 		if (where & 1)
 			data >>= 8;
 		if (where & 2)
 			data >>= 16;
 		data &= 0xff;
 		break;
 	case 2:
 		if (where & 2)
 			data >>= 16;
 		data &= 0xffff;
 		break;
 	case 4:
 		break;
 	default:
 		return PCIBIOS_BAD_REGISTER_NUMBER;
 	}

 	if (where == PCI_BASE_ADDRESS_0 && size == 4 &&
 	    apc->bar0_is_cached) {
 		/* use the cached value */
 		*value = apc->bar0_value;
 	} else {
 		*value = data;
 	}

 	return PCIBIOS_SUCCESSFUL;
 }

 static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
 			     int size, uint32_t value)
 {
 	struct ar724x_pci_controller *apc;
 	void __iomem *base;
 	u32 data;
 	int s;

 	apc = pci_bus_to_ar724x_controller(bus);
 	if (!apc->link_up)
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	if (devfn)
 		return PCIBIOS_DEVICE_NOT_FOUND;

 	if (soc_is_ar7240() && where == PCI_BASE_ADDRESS_0 && size == 4) {
 		if (value != 0xffffffff) {
 			/*
 			 * WAR for a hw issue. If the BAR0 register of the
 			 * device is set to the proper base address, the
 			 * memory space of the device is not accessible.
 			 *
 			 * Cache the intended value so it can be read back,
 			 * and write a SoC specific constant value to the
 			 * BAR0 register in order to make the device memory
 			 * accessible.
 			 */
 			apc->bar0_is_cached = true;
 			apc->bar0_value = value;

 			value = AR7240_BAR0_WAR_VALUE;
 		} else {
 			apc->bar0_is_cached = false;
 		}
 	}

 	base = apc->devcfg_base;
 	data = __raw_readl(base + (where & ~3));

 	switch (size) {
 	case 1:
 		s = ((where & 3) * 8);
 		data &= ~(0xff << s);
 		data |= ((value & 0xff) << s);
 		break;
 	case 2:
 		s = ((where & 2) * 8);
 		data &= ~(0xffff << s);
 		data |= ((value & 0xffff) << s);
 		break;
 	case 4:
 		data = value;
 		break;
 	default:
 		return PCIBIOS_BAD_REGISTER_NUMBER;
 	}

 	__raw_writel(data, base + (where & ~3));
 	/* flush write */
 	__raw_readl(base + (where & ~3));

 	return PCIBIOS_SUCCESSFUL;
 }

 static struct pci_ops ar724x_pci_ops = {
 	.read	= ar724x_pci_read,
 	.write	= ar724x_pci_write,
 };

 static void ar724x_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
 {
 	struct ar724x_pci_controller *apc;
 	void __iomem *base;
 	u32 pending;

 	apc = irq_desc_get_handler_data(desc);
 	base = apc->ctrl_base;

 	pending = __raw_readl(base + AR724X_PCI_REG_INT_STATUS) &
 		  __raw_readl(base + AR724X_PCI_REG_INT_MASK);

 	if (pending & AR724X_PCI_INT_DEV0)
 		generic_handle_irq(apc->irq_base + 0);

 	else
 		spurious_interrupt();
 }

 static void ar724x_pci_irq_unmask(struct irq_data *d)
 {
 	struct ar724x_pci_controller *apc;
 	void __iomem *base;
 	int offset;
 	u32 t;

 	apc = irq_data_get_irq_chip_data(d);
 	base = apc->ctrl_base;
 	offset = apc->irq_base - d->irq;

 	switch (offset) {
 	case 0:
 		t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
 		__raw_writel(t | AR724X_PCI_INT_DEV0,
 			     base + AR724X_PCI_REG_INT_MASK);
 		/* flush write */
 		__raw_readl(base + AR724X_PCI_REG_INT_MASK);
 	}
 }

 static void ar724x_pci_irq_mask(struct irq_data *d)
 {
 	struct ar724x_pci_controller *apc;
 	void __iomem *base;
 	int offset;
 	u32 t;

 	apc = irq_data_get_irq_chip_data(d);
 	base = apc->ctrl_base;
 	offset = apc->irq_base - d->irq;

 	switch (offset) {
 	case 0:
 		t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
 		__raw_writel(t & ~AR724X_PCI_INT_DEV0,
 			     base + AR724X_PCI_REG_INT_MASK);

 		/* flush write */
 		__raw_readl(base + AR724X_PCI_REG_INT_MASK);

 		t = __raw_readl(base + AR724X_PCI_REG_INT_STATUS);
 		__raw_writel(t | AR724X_PCI_INT_DEV0,
 			     base + AR724X_PCI_REG_INT_STATUS);

 		/* flush write */
 		__raw_readl(base + AR724X_PCI_REG_INT_STATUS);
 	}
 }

 static struct irq_chip ar724x_pci_irq_chip = {
 	.name		= "AR724X PCI ",
 	.irq_mask	= ar724x_pci_irq_mask,
 	.irq_unmask	= ar724x_pci_irq_unmask,
 	.irq_mask_ack	= ar724x_pci_irq_mask,
 };

 static void ar724x_pci_irq_init(struct ar724x_pci_controller *apc,
 				int id)
 {
 	void __iomem *base;
 	int i;

 	base = apc->ctrl_base;

 	__raw_writel(0, base + AR724X_PCI_REG_INT_MASK);
 	__raw_writel(0, base + AR724X_PCI_REG_INT_STATUS);

 	apc->irq_base = ATH79_PCI_IRQ_BASE + (id * AR724X_PCI_IRQ_COUNT);

 	for (i = apc->irq_base;
 	     i < apc->irq_base + AR724X_PCI_IRQ_COUNT; i++) {
 		irq_set_chip_and_handler(i, &ar724x_pci_irq_chip,
 					 handle_level_irq);
 		irq_set_chip_data(i, apc);
 	}

 	irq_set_chained_handler_and_data(apc->irq, ar724x_pci_irq_handler,
 					 apc);
 }

 static int ar724x_pci_probe(struct platform_device *pdev)
 {
 	struct ar724x_pci_controller *apc;
 	struct resource *res;
 	int id;

 	id = pdev->id;
 	if (id == -1)
 		id = 0;

 	apc = devm_kzalloc(&pdev->dev, sizeof(struct ar724x_pci_controller),
 			    GFP_KERNEL);
 	if (!apc)
 		return -ENOMEM;

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl_base");
 	apc->ctrl_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(apc->ctrl_base))
 		return PTR_ERR(apc->ctrl_base);

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg_base");
 	apc->devcfg_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(apc->devcfg_base))
 		return PTR_ERR(apc->devcfg_base);

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "crp_base");
 	apc->crp_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(apc->crp_base))
 		return PTR_ERR(apc->crp_base);

 	apc->irq = platform_get_irq(pdev, 0);
 	if (apc->irq < 0)
 		return -EINVAL;

 	res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base");
 	if (!res)
 		return -EINVAL;

 	apc->io_res.parent = res;
 	apc->io_res.name = "PCI IO space";
 	apc->io_res.start = res->start;
 	apc->io_res.end = res->end;
 	apc->io_res.flags = IORESOURCE_IO;

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base");
 	if (!res)
 		return -EINVAL;

 	apc->mem_res.parent = res;
 	apc->mem_res.name = "PCI memory space";
 	apc->mem_res.start = res->start;
 	apc->mem_res.end = res->end;
 	apc->mem_res.flags = IORESOURCE_MEM;

 	apc->pci_controller.pci_ops = &ar724x_pci_ops;
 	apc->pci_controller.io_resource = &apc->io_res;
 	apc->pci_controller.mem_resource = &apc->mem_res;

 	apc->link_up = ar724x_pci_check_link(apc);
 	if (!apc->link_up)
 		dev_warn(&pdev->dev, "PCIe link is down\n");

 	ar724x_pci_irq_init(apc, id);

 	ar724x_pci_local_write(apc, PCI_COMMAND, 4, AR724X_PCI_CMD_INIT);

 	register_pci_controller(&apc->pci_controller);

 	return 0;
 }

 static struct platform_driver ar724x_pci_driver = {
 	.probe = ar724x_pci_probe,
 	.driver = {
 		.name = "ar724x-pci",
 	},
 };

 static int __init ar724x_pci_init(void)
 {
 	return platform_driver_register(&ar724x_pci_driver);
 }

 postcore_initcall(ar724x_pci_init);
	/*
	* Atheros AR724X PCI host controller driver
	*
	* Copyright (C) 2011 René Bolldorf <xsecute@googlemail.com>
	* Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
	*
	* 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/irq.h>
	#include <linux/pci.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <asm/mach-ath79/ath79.h>
	#include <asm/mach-ath79/ar71xx_regs.h>

	#define AR724X_PCI_REG_RESET 0x18
	#define AR724X_PCI_REG_INT_STATUS 0x4c
	#define AR724X_PCI_REG_INT_MASK 0x50

	#define AR724X_PCI_RESET_LINK_UP BIT(0)

	#define AR724X_PCI_INT_DEV0 BIT(14)

	#define AR724X_PCI_IRQ_COUNT 1

	#define AR7240_BAR0_WAR_VALUE 0xffff

	#define AR724X_PCI_CMD_INIT (PCI_COMMAND_MEMORY \| \
	PCI_COMMAND_MASTER \| \
	PCI_COMMAND_INVALIDATE \| \
	PCI_COMMAND_PARITY \| \
	PCI_COMMAND_SERR \| \
	PCI_COMMAND_FAST_BACK)

	struct ar724x_pci_controller {
	void __iomem *devcfg_base;
	void __iomem *ctrl_base;
	void __iomem *crp_base;

	int irq;
	int irq_base;

	bool link_up;
	bool bar0_is_cached;
	u32 bar0_value;

	struct pci_controller pci_controller;
	struct resource io_res;
	struct resource mem_res;
	};

	static inline bool ar724x_pci_check_link(struct ar724x_pci_controller *apc)
	{
	u32 reset;

	reset = __raw_readl(apc->ctrl_base + AR724X_PCI_REG_RESET);
	return reset & AR724X_PCI_RESET_LINK_UP;
	}

	static inline struct ar724x_pci_controller *
	pci_bus_to_ar724x_controller(struct pci_bus *bus)
	{
	struct pci_controller *hose;

	hose = (struct pci_controller *) bus->sysdata;
	return container_of(hose, struct ar724x_pci_controller, pci_controller);
	}

	static int ar724x_pci_local_write(struct ar724x_pci_controller *apc,
	int where, int size, u32 value)
	{
	void __iomem *base;
	u32 data;
	int s;

	WARN_ON(where & (size - 1));

	if (!apc->link_up)
	return PCIBIOS_DEVICE_NOT_FOUND;

	base = apc->crp_base;
	data = __raw_readl(base + (where & ~3));

	switch (size) {
	case 1:
	s = ((where & 3) * 8);
	data &= ~(0xff << s);
	data \|= ((value & 0xff) << s);
	break;
	case 2:
	s = ((where & 2) * 8);
	data &= ~(0xffff << s);
	data \|= ((value & 0xffff) << s);
	break;
	case 4:
	data = value;
	break;
	default:
	return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	__raw_writel(data, base + (where & ~3));
	/* flush write */
	__raw_readl(base + (where & ~3));

	return PCIBIOS_SUCCESSFUL;
	}

	static int ar724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
	int size, uint32_t *value)
	{
	struct ar724x_pci_controller *apc;
	void __iomem *base;
	u32 data;

	apc = pci_bus_to_ar724x_controller(bus);
	if (!apc->link_up)
	return PCIBIOS_DEVICE_NOT_FOUND;

	if (devfn)
	return PCIBIOS_DEVICE_NOT_FOUND;

	base = apc->devcfg_base;
	data = __raw_readl(base + (where & ~3));

	switch (size) {
	case 1:
	if (where & 1)
	data >>= 8;
	if (where & 2)
	data >>= 16;
	data &= 0xff;
	break;
	case 2:
	if (where & 2)
	data >>= 16;
	data &= 0xffff;
	break;
	case 4:
	break;
	default:
	return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	if (where == PCI_BASE_ADDRESS_0 && size == 4 &&
	apc->bar0_is_cached) {
	/* use the cached value */
	*value = apc->bar0_value;
	} else {
	*value = data;
	}

	return PCIBIOS_SUCCESSFUL;
	}

	static int ar724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
	int size, uint32_t value)
	{
	struct ar724x_pci_controller *apc;
	void __iomem *base;
	u32 data;
	int s;

	apc = pci_bus_to_ar724x_controller(bus);
	if (!apc->link_up)
	return PCIBIOS_DEVICE_NOT_FOUND;

	if (devfn)
	return PCIBIOS_DEVICE_NOT_FOUND;

	if (soc_is_ar7240() && where == PCI_BASE_ADDRESS_0 && size == 4) {
	if (value != 0xffffffff) {
	/*
	* WAR for a hw issue. If the BAR0 register of the
	* device is set to the proper base address, the
	* memory space of the device is not accessible.
	*
	* Cache the intended value so it can be read back,
	* and write a SoC specific constant value to the
	* BAR0 register in order to make the device memory
	* accessible.
	*/
	apc->bar0_is_cached = true;
	apc->bar0_value = value;

	value = AR7240_BAR0_WAR_VALUE;
	} else {
	apc->bar0_is_cached = false;
	}
	}

	base = apc->devcfg_base;
	data = __raw_readl(base + (where & ~3));

	switch (size) {
	case 1:
	s = ((where & 3) * 8);
	data &= ~(0xff << s);
	data \|= ((value & 0xff) << s);
	break;
	case 2:
	s = ((where & 2) * 8);
	data &= ~(0xffff << s);
	data \|= ((value & 0xffff) << s);
	break;
	case 4:
	data = value;
	break;
	default:
	return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	__raw_writel(data, base + (where & ~3));
	/* flush write */
	__raw_readl(base + (where & ~3));

	return PCIBIOS_SUCCESSFUL;
	}

	static struct pci_ops ar724x_pci_ops = {
	.read = ar724x_pci_read,
	.write = ar724x_pci_write,
	};

	static void ar724x_pci_irq_handler(unsigned int irq, struct irq_desc *desc)
	{
	struct ar724x_pci_controller *apc;
	void __iomem *base;
	u32 pending;

	apc = irq_desc_get_handler_data(desc);
	base = apc->ctrl_base;

	pending = __raw_readl(base + AR724X_PCI_REG_INT_STATUS) &
	__raw_readl(base + AR724X_PCI_REG_INT_MASK);

	if (pending & AR724X_PCI_INT_DEV0)
	generic_handle_irq(apc->irq_base + 0);

	else
	spurious_interrupt();
	}

	static void ar724x_pci_irq_unmask(struct irq_data *d)
	{
	struct ar724x_pci_controller *apc;
	void __iomem *base;
	int offset;
	u32 t;

	apc = irq_data_get_irq_chip_data(d);
	base = apc->ctrl_base;
	offset = apc->irq_base - d->irq;

	switch (offset) {
	case 0:
	t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
	__raw_writel(t \| AR724X_PCI_INT_DEV0,
	base + AR724X_PCI_REG_INT_MASK);
	/* flush write */
	__raw_readl(base + AR724X_PCI_REG_INT_MASK);
	}
	}

	static void ar724x_pci_irq_mask(struct irq_data *d)
	{
	struct ar724x_pci_controller *apc;
	void __iomem *base;
	int offset;
	u32 t;

	apc = irq_data_get_irq_chip_data(d);
	base = apc->ctrl_base;
	offset = apc->irq_base - d->irq;

	switch (offset) {
	case 0:
	t = __raw_readl(base + AR724X_PCI_REG_INT_MASK);
	__raw_writel(t & ~AR724X_PCI_INT_DEV0,
	base + AR724X_PCI_REG_INT_MASK);

	/* flush write */
	__raw_readl(base + AR724X_PCI_REG_INT_MASK);

	t = __raw_readl(base + AR724X_PCI_REG_INT_STATUS);
	__raw_writel(t \| AR724X_PCI_INT_DEV0,
	base + AR724X_PCI_REG_INT_STATUS);

	/* flush write */
	__raw_readl(base + AR724X_PCI_REG_INT_STATUS);
	}
	}

	static struct irq_chip ar724x_pci_irq_chip = {
	.name = "AR724X PCI ",
	.irq_mask = ar724x_pci_irq_mask,
	.irq_unmask = ar724x_pci_irq_unmask,
	.irq_mask_ack = ar724x_pci_irq_mask,
	};

	static void ar724x_pci_irq_init(struct ar724x_pci_controller *apc,
	int id)
	{
	void __iomem *base;
	int i;

	base = apc->ctrl_base;

	__raw_writel(0, base + AR724X_PCI_REG_INT_MASK);
	__raw_writel(0, base + AR724X_PCI_REG_INT_STATUS);

	apc->irq_base = ATH79_PCI_IRQ_BASE + (id * AR724X_PCI_IRQ_COUNT);

	for (i = apc->irq_base;
	i < apc->irq_base + AR724X_PCI_IRQ_COUNT; i++) {
	irq_set_chip_and_handler(i, &ar724x_pci_irq_chip,
	handle_level_irq);
	irq_set_chip_data(i, apc);
	}

	irq_set_chained_handler_and_data(apc->irq, ar724x_pci_irq_handler,
	apc);
	}

	static int ar724x_pci_probe(struct platform_device *pdev)
	{
	struct ar724x_pci_controller *apc;
	struct resource *res;
	int id;

	id = pdev->id;
	if (id == -1)
	id = 0;

	apc = devm_kzalloc(&pdev->dev, sizeof(struct ar724x_pci_controller),
	GFP_KERNEL);
	if (!apc)
	return -ENOMEM;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl_base");
	apc->ctrl_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(apc->ctrl_base))
	return PTR_ERR(apc->ctrl_base);

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg_base");
	apc->devcfg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(apc->devcfg_base))
	return PTR_ERR(apc->devcfg_base);

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "crp_base");
	apc->crp_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(apc->crp_base))
	return PTR_ERR(apc->crp_base);

	apc->irq = platform_get_irq(pdev, 0);
	if (apc->irq < 0)
	return -EINVAL;

	res = platform_get_resource_byname(pdev, IORESOURCE_IO, "io_base");
	if (!res)
	return -EINVAL;

	apc->io_res.parent = res;
	apc->io_res.name = "PCI IO space";
	apc->io_res.start = res->start;
	apc->io_res.end = res->end;
	apc->io_res.flags = IORESOURCE_IO;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem_base");
	if (!res)
	return -EINVAL;

	apc->mem_res.parent = res;
	apc->mem_res.name = "PCI memory space";
	apc->mem_res.start = res->start;
	apc->mem_res.end = res->end;
	apc->mem_res.flags = IORESOURCE_MEM;

	apc->pci_controller.pci_ops = &ar724x_pci_ops;
	apc->pci_controller.io_resource = &apc->io_res;
	apc->pci_controller.mem_resource = &apc->mem_res;

	apc->link_up = ar724x_pci_check_link(apc);
	if (!apc->link_up)
	dev_warn(&pdev->dev, "PCIe link is down\n");

	ar724x_pci_irq_init(apc, id);

	ar724x_pci_local_write(apc, PCI_COMMAND, 4, AR724X_PCI_CMD_INIT);

	register_pci_controller(&apc->pci_controller);

	return 0;
	}

	static struct platform_driver ar724x_pci_driver = {
	.probe = ar724x_pci_probe,
	.driver = {
	.name = "ar724x-pci",
	},
	};

	static int __init ar724x_pci_init(void)
	{
	return platform_driver_register(&ar724x_pci_driver);
	}

	postcore_initcall(ar724x_pci_init);