/*
 * leon_pci.c: LEON Host PCI support
 *
 * Copyright (C) 2011 Aeroflex Gaisler AB, Daniel Hellstrom
 *
 * Code is partially derived from pcic.c
 */

#include <linux/of_device.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/export.h>
#include <asm/leon.h>
#include <asm/leon_pci.h>

/* The LEON architecture does not rely on a BIOS or bootloader to setup
 * PCI for us. The Linux generic routines are used to setup resources,
 * reset values of confuration-space registers settings ae preseved.
 */
void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
{
	struct pci_bus *root_bus;

	root_bus = pci_scan_bus_parented(&ofdev->dev, 0, info->ops, info);
	if (root_bus) {
		root_bus->resource[0] = &info->io_space;
		root_bus->resource[1] = &info->mem_space;
		root_bus->resource[2] = NULL;

		/* Init all PCI devices into PCI tree */
		pci_bus_add_devices(root_bus);

		/* Setup IRQs of all devices using custom routines */
		pci_fixup_irqs(pci_common_swizzle, info->map_irq);

		/* Assign devices with resources */
		pci_assign_unassigned_resources();
	}
}

/* PCI Memory and Prefetchable Memory is direct-mapped. However I/O Space is
 * accessed through a Window which is translated to low 64KB in PCI space, the
 * first 4KB is not used so 60KB is available.
 *
 * This function is used by generic code to translate resource addresses into
 * PCI addresses.
 */
void pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
			     struct resource *res)
{
	struct leon_pci_info *info = dev->bus->sysdata;

	region->start = res->start;
	region->end = res->end;

	if (res->flags & IORESOURCE_IO) {
		region->start -= (info->io_space.start - 0x1000);
		region->end -= (info->io_space.start - 0x1000);
	}
}
EXPORT_SYMBOL(pcibios_resource_to_bus);

/* see pcibios_resource_to_bus() comment */
void pcibios_bus_to_resource(struct pci_dev *dev, struct resource *res,
			     struct pci_bus_region *region)
{
	struct leon_pci_info *info = dev->bus->sysdata;

	res->start = region->start;
	res->end = region->end;

	if (res->flags & IORESOURCE_IO) {
		res->start += (info->io_space.start - 0x1000);
		res->end += (info->io_space.start - 0x1000);
	}
}
EXPORT_SYMBOL(pcibios_bus_to_resource);

void __devinit pcibios_fixup_bus(struct pci_bus *pbus)
{
	struct leon_pci_info *info = pbus->sysdata;
	struct pci_dev *dev;
	int i, has_io, has_mem;
	u16 cmd;

	/* Generic PCI bus probing sets these to point at
	 * &io{port,mem}_resouce which is wrong for us.
	 */
	if (pbus->self == NULL) {
		pbus->resource[0] = &info->io_space;
		pbus->resource[1] = &info->mem_space;
		pbus->resource[2] = NULL;
	}

	list_for_each_entry(dev, &pbus->devices, bus_list) {
		/*
		 * We can not rely on that the bootloader has enabled I/O
		 * or memory access to PCI devices. Instead we enable it here
		 * if the device has BARs of respective type.
		 */
		has_io = has_mem = 0;
		for (i = 0; i < PCI_ROM_RESOURCE; i++) {
			unsigned long f = dev->resource[i].flags;
			if (f & IORESOURCE_IO)
				has_io = 1;
			else if (f & IORESOURCE_MEM)
				has_mem = 1;
		}
		/* ROM BARs are mapped into 32-bit memory space */
		if (dev->resource[PCI_ROM_RESOURCE].end != 0) {
			dev->resource[PCI_ROM_RESOURCE].flags |=
							IORESOURCE_ROM_ENABLE;
			has_mem = 1;
		}
		pci_bus_read_config_word(pbus, dev->devfn, PCI_COMMAND, &cmd);
		if (has_io && !(cmd & PCI_COMMAND_IO)) {
#ifdef CONFIG_PCI_DEBUG
			printk(KERN_INFO "LEONPCI: Enabling I/O for dev %s\n",
					 pci_name(dev));
#endif
			cmd |= PCI_COMMAND_IO;
			pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
									cmd);
		}
		if (has_mem && !(cmd & PCI_COMMAND_MEMORY)) {
#ifdef CONFIG_PCI_DEBUG
			printk(KERN_INFO "LEONPCI: Enabling MEMORY for dev"
					 "%s\n", pci_name(dev));
#endif
			cmd |= PCI_COMMAND_MEMORY;
			pci_bus_write_config_word(pbus, dev->devfn, PCI_COMMAND,
									cmd);
		}
	}
}

/*
 * Other archs parse arguments here.
 */
char * __devinit pcibios_setup(char *str)
{
	return str;
}

resource_size_t pcibios_align_resource(void *data, const struct resource *res,
				resource_size_t size, resource_size_t align)
{
	return res->start;
}

int pcibios_enable_device(struct pci_dev *dev, int mask)
{
	return pci_enable_resources(dev, mask);
}

struct device_node *pci_device_to_OF_node(struct pci_dev *pdev)
{
	/*
	 * Currently the OpenBoot nodes are not connected with the PCI device,
	 * this is because the LEON PROM does not create PCI nodes. Eventually
	 * this will change and the same approach as pcic.c can be used to
	 * match PROM nodes with pci devices.
	 */
	return NULL;
}
EXPORT_SYMBOL(pci_device_to_OF_node);

void __devinit pcibios_update_irq(struct pci_dev *dev, int irq)
{
#ifdef CONFIG_PCI_DEBUG
	printk(KERN_DEBUG "LEONPCI: Assigning IRQ %02d to %s\n", irq,
		pci_name(dev));
#endif
	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}

/* in/out routines taken from pcic.c
 *
 * This probably belongs here rather than ioport.c because
 * we do not want this crud linked into SBus kernels.
 * Also, think for a moment about likes of floppy.c that
 * include architecture specific parts. They may want to redefine ins/outs.
 *
 * We do not use horrible macros here because we want to
 * advance pointer by sizeof(size).
 */
void outsb(unsigned long addr, const void *src, unsigned long count)
{
	while (count) {
		count -= 1;
		outb(*(const char *)src, addr);
		src += 1;
		/* addr += 1; */
	}
}
EXPORT_SYMBOL(outsb);

void outsw(unsigned long addr, const void *src, unsigned long count)
{
	while (count) {
		count -= 2;
		outw(*(const short *)src, addr);
		src += 2;
		/* addr += 2; */
	}
}
EXPORT_SYMBOL(outsw);

void outsl(unsigned long addr, const void *src, unsigned long count)
{
	while (count) {
		count -= 4;
		outl(*(const long *)src, addr);
		src += 4;
		/* addr += 4; */
	}
}
EXPORT_SYMBOL(outsl);

void insb(unsigned long addr, void *dst, unsigned long count)
{
	while (count) {
		count -= 1;
		*(unsigned char *)dst = inb(addr);
		dst += 1;
		/* addr += 1; */
	}
}
EXPORT_SYMBOL(insb);

void insw(unsigned long addr, void *dst, unsigned long count)
{
	while (count) {
		count -= 2;
		*(unsigned short *)dst = inw(addr);
		dst += 2;
		/* addr += 2; */
	}
}
EXPORT_SYMBOL(insw);

void insl(unsigned long addr, void *dst, unsigned long count)
{
	while (count) {
		count -= 4;
		/*
		 * XXX I am sure we are in for an unaligned trap here.
		 */
		*(unsigned long *)dst = inl(addr);
		dst += 4;
		/* addr += 4; */
	}
}
EXPORT_SYMBOL(insl);