drivers/pci/host/pci-versatile.c - linux - Git at Google

 /*
  * Copyright 2004 Koninklijke Philips Electronics NV
  *
  * Conversion to platform driver and DT:
  * Copyright 2014 Linaro Ltd.
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * 14/04/2005 Initial version, colin.king@philips.com
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>

 static void __iomem *versatile_pci_base;
 static void __iomem *versatile_cfg_base[2];

 #define PCI_IMAP(m)		(versatile_pci_base + ((m) * 4))
 #define PCI_SMAP(m)		(versatile_pci_base + 0x14 + ((m) * 4))
 #define PCI_SELFID		(versatile_pci_base + 0xc)

 #define VP_PCI_DEVICE_ID		0x030010ee
 #define VP_PCI_CLASS_ID			0x0b400000

 static u32 pci_slot_ignore;

 static int __init versatile_pci_slot_ignore(char *str)
 {
 	int retval;
 	int slot;

 	while ((retval = get_option(&str, &slot))) {
 		if ((slot < 0) || (slot > 31))
 			pr_err("Illegal slot value: %d\n", slot);
 		else
 			pci_slot_ignore |= (1 << slot);
 	}
 	return 1;
 }
 __setup("pci_slot_ignore=", versatile_pci_slot_ignore);


 static void __iomem *versatile_map_bus(struct pci_bus *bus,
 				       unsigned int devfn, int offset)
 {
 	unsigned int busnr = bus->number;

 	if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
 		return NULL;

 	return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
 }

 static struct pci_ops pci_versatile_ops = {
 	.map_bus = versatile_map_bus,
 	.read	= pci_generic_config_read32,
 	.write	= pci_generic_config_write,
 };

 static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
 						     struct list_head *res)
 {
 	int err, mem = 1, res_valid = 0;
 	struct device_node *np = dev->of_node;
 	resource_size_t iobase;
 	struct resource_entry *win;

 	err = of_pci_get_host_bridge_resources(np, 0, 0xff, res, &iobase);
 	if (err)
 		return err;

 	err = devm_request_pci_bus_resources(dev, res);
 	if (err)
 		goto out_release_res;

 	resource_list_for_each_entry(win, res) {
 		struct resource *res = win->res;

 		switch (resource_type(res)) {
 		case IORESOURCE_IO:
 			err = pci_remap_iospace(res, iobase);
 			if (err)
 				dev_warn(dev, "error %d: failed to map resource %pR\n",
 					 err, res);
 			break;
 		case IORESOURCE_MEM:
 			res_valid |= !(res->flags & IORESOURCE_PREFETCH);

 			writel(res->start >> 28, PCI_IMAP(mem));
 			writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
 			mem++;

 			break;
 		}
 	}

 	if (res_valid)
 		return 0;

 	dev_err(dev, "non-prefetchable memory resource required\n");
 	err = -EINVAL;

 out_release_res:
 	pci_free_resource_list(res);
 	return err;
 }

 static int versatile_pci_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	int ret, i, myslot = -1;
 	u32 val;
 	void __iomem *local_pci_cfg_base;
 	struct pci_bus *bus;
 	LIST_HEAD(pci_res);

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	versatile_pci_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(versatile_pci_base))
 		return PTR_ERR(versatile_pci_base);

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 	versatile_cfg_base[0] = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(versatile_cfg_base[0]))
 		return PTR_ERR(versatile_cfg_base[0]);

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 	versatile_cfg_base[1] = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(versatile_cfg_base[1]))
 		return PTR_ERR(versatile_cfg_base[1]);

 	ret = versatile_pci_parse_request_of_pci_ranges(&pdev->dev, &pci_res);
 	if (ret)
 		return ret;

 	/*
 	 * We need to discover the PCI core first to configure itself
 	 * before the main PCI probing is performed
 	 */
 	for (i = 0; i < 32; i++) {
 		if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
 		    (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
 			myslot = i;
 			break;
 		}
 	}
 	if (myslot == -1) {
 		dev_err(&pdev->dev, "Cannot find PCI core!\n");
 		return -EIO;
 	}
 	/*
 	 * Do not to map Versatile FPGA PCI device into memory space
 	 */
 	pci_slot_ignore |= (1 << myslot);

 	dev_info(&pdev->dev, "PCI core found (slot %d)\n", myslot);

 	writel(myslot, PCI_SELFID);
 	local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);

 	val = readl(local_pci_cfg_base + PCI_COMMAND);
 	val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
 	writel(val, local_pci_cfg_base + PCI_COMMAND);

 	/*
 	 * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
 	 */
 	writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
 	writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
 	writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);

 	/*
 	 * For many years the kernel and QEMU were symbiotically buggy
 	 * in that they both assumed the same broken IRQ mapping.
 	 * QEMU therefore attempts to auto-detect old broken kernels
 	 * so that they still work on newer QEMU as they did on old
 	 * QEMU. Since we now use the correct (ie matching-hardware)
 	 * IRQ mapping we write a definitely different value to a
 	 * PCI_INTERRUPT_LINE register to tell QEMU that we expect
 	 * real hardware behaviour and it need not be backwards
 	 * compatible for us. This write is harmless on real hardware.
 	 */
 	writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);

 	pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
 	pci_add_flags(PCI_REASSIGN_ALL_BUS | PCI_REASSIGN_ALL_RSRC);

 	bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, NULL, &pci_res);
 	if (!bus)
 		return -ENOMEM;

 	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 	pci_assign_unassigned_bus_resources(bus);
 	pci_bus_add_devices(bus);

 	return 0;
 }

 static const struct of_device_id versatile_pci_of_match[] = {
 	{ .compatible = "arm,versatile-pci", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, versatile_pci_of_match);

 static struct platform_driver versatile_pci_driver = {
 	.driver = {
 		.name = "versatile-pci",
 		.of_match_table = versatile_pci_of_match,
 	},
 	.probe = versatile_pci_probe,
 };
 module_platform_driver(versatile_pci_driver);

 MODULE_DESCRIPTION("Versatile PCI driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright 2004 Koninklijke Philips Electronics NV
	*
	* Conversion to platform driver and DT:
	* Copyright 2014 Linaro Ltd.
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* 14/04/2005 Initial version, colin.king@philips.com
	*/
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of_address.h>
	#include <linux/of_pci.h>
	#include <linux/of_platform.h>
	#include <linux/pci.h>
	#include <linux/platform_device.h>

	static void __iomem *versatile_pci_base;
	static void __iomem *versatile_cfg_base[2];

	#define PCI_IMAP(m) (versatile_pci_base + ((m) * 4))
	#define PCI_SMAP(m) (versatile_pci_base + 0x14 + ((m) * 4))
	#define PCI_SELFID (versatile_pci_base + 0xc)

	#define VP_PCI_DEVICE_ID 0x030010ee
	#define VP_PCI_CLASS_ID 0x0b400000

	static u32 pci_slot_ignore;

	static int __init versatile_pci_slot_ignore(char *str)
	{
	int retval;
	int slot;

	while ((retval = get_option(&str, &slot))) {
	if ((slot < 0) \|\| (slot > 31))
	pr_err("Illegal slot value: %d\n", slot);
	else
	pci_slot_ignore \|= (1 << slot);
	}
	return 1;
	}
	__setup("pci_slot_ignore=", versatile_pci_slot_ignore);


	static void __iomem versatile_map_bus(struct pci_bus bus,
	unsigned int devfn, int offset)
	{
	unsigned int busnr = bus->number;

	if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
	return NULL;

	return versatile_cfg_base[1] + ((busnr << 16) \| (devfn << 8) \| offset);
	}

	static struct pci_ops pci_versatile_ops = {
	.map_bus = versatile_map_bus,
	.read = pci_generic_config_read32,
	.write = pci_generic_config_write,
	};

	static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
	struct list_head *res)
	{
	int err, mem = 1, res_valid = 0;
	struct device_node *np = dev->of_node;
	resource_size_t iobase;
	struct resource_entry *win;

	err = of_pci_get_host_bridge_resources(np, 0, 0xff, res, &iobase);
	if (err)
	return err;

	err = devm_request_pci_bus_resources(dev, res);
	if (err)
	goto out_release_res;

	resource_list_for_each_entry(win, res) {
	struct resource *res = win->res;

	switch (resource_type(res)) {
	case IORESOURCE_IO:
	err = pci_remap_iospace(res, iobase);
	if (err)
	dev_warn(dev, "error %d: failed to map resource %pR\n",
	err, res);
	break;
	case IORESOURCE_MEM:
	res_valid \|= !(res->flags & IORESOURCE_PREFETCH);

	writel(res->start >> 28, PCI_IMAP(mem));
	writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
	mem++;

	break;
	}
	}

	if (res_valid)
	return 0;

	dev_err(dev, "non-prefetchable memory resource required\n");
	err = -EINVAL;

	out_release_res:
	pci_free_resource_list(res);
	return err;
	}

	static int versatile_pci_probe(struct platform_device *pdev)
	{
	struct resource *res;
	int ret, i, myslot = -1;
	u32 val;
	void __iomem *local_pci_cfg_base;
	struct pci_bus *bus;
	LIST_HEAD(pci_res);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	versatile_pci_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(versatile_pci_base))
	return PTR_ERR(versatile_pci_base);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	versatile_cfg_base[0] = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(versatile_cfg_base[0]))
	return PTR_ERR(versatile_cfg_base[0]);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
	versatile_cfg_base[1] = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(versatile_cfg_base[1]))
	return PTR_ERR(versatile_cfg_base[1]);

	ret = versatile_pci_parse_request_of_pci_ranges(&pdev->dev, &pci_res);
	if (ret)
	return ret;

	/*
	* We need to discover the PCI core first to configure itself
	* before the main PCI probing is performed
	*/
	for (i = 0; i < 32; i++) {
	if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
	(readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
	myslot = i;
	break;
	}
	}
	if (myslot == -1) {
	dev_err(&pdev->dev, "Cannot find PCI core!\n");
	return -EIO;
	}
	/*
	* Do not to map Versatile FPGA PCI device into memory space
	*/
	pci_slot_ignore \|= (1 << myslot);

	dev_info(&pdev->dev, "PCI core found (slot %d)\n", myslot);

	writel(myslot, PCI_SELFID);
	local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);

	val = readl(local_pci_cfg_base + PCI_COMMAND);
	val \|= PCI_COMMAND_MEMORY \| PCI_COMMAND_MASTER \| PCI_COMMAND_INVALIDATE;
	writel(val, local_pci_cfg_base + PCI_COMMAND);

	/*
	* Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
	*/
	writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
	writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
	writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);

	/*
	* For many years the kernel and QEMU were symbiotically buggy
	* in that they both assumed the same broken IRQ mapping.
	* QEMU therefore attempts to auto-detect old broken kernels
	* so that they still work on newer QEMU as they did on old
	* QEMU. Since we now use the correct (ie matching-hardware)
	* IRQ mapping we write a definitely different value to a
	* PCI_INTERRUPT_LINE register to tell QEMU that we expect
	* real hardware behaviour and it need not be backwards
	* compatible for us. This write is harmless on real hardware.
	*/
	writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);

	pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
	pci_add_flags(PCI_REASSIGN_ALL_BUS \| PCI_REASSIGN_ALL_RSRC);

	bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, NULL, &pci_res);
	if (!bus)
	return -ENOMEM;

	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
	pci_assign_unassigned_bus_resources(bus);
	pci_bus_add_devices(bus);

	return 0;
	}

	static const struct of_device_id versatile_pci_of_match[] = {
	{ .compatible = "arm,versatile-pci", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, versatile_pci_of_match);

	static struct platform_driver versatile_pci_driver = {
	.driver = {
	.name = "versatile-pci",
	.of_match_table = versatile_pci_of_match,
	},
	.probe = versatile_pci_probe,
	};
	module_platform_driver(versatile_pci_driver);

	MODULE_DESCRIPTION("Versatile PCI driver");
	MODULE_LICENSE("GPL v2");