/*
 *  Atheros 724x PCI support
 *
 *  Copyright (C) 2011 René Bolldorf <xsecute@googlemail.com>
 *
 *  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/pci.h>
#include <asm/mach-ath79/pci-ath724x.h>

#define reg_read(_phys)		(*(unsigned int *) KSEG1ADDR(_phys))
#define reg_write(_phys, _val)	((*(unsigned int *) KSEG1ADDR(_phys)) = (_val))

#define ATH724X_PCI_DEV_BASE	0x14000000
#define ATH724X_PCI_MEM_BASE	0x10000000
#define ATH724X_PCI_MEM_SIZE	0x08000000

static DEFINE_SPINLOCK(ath724x_pci_lock);
static struct ath724x_pci_data *pci_data;
static int pci_data_size;

static int ath724x_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
			    int size, uint32_t *value)
{
	unsigned long flags, addr, tval, mask;

	if (devfn)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (where & (size - 1))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	spin_lock_irqsave(&ath724x_pci_lock, flags);

	switch (size) {
	case 1:
		addr = where & ~3;
		mask = 0xff000000 >> ((where % 4) * 8);
		tval = reg_read(ATH724X_PCI_DEV_BASE + addr);
		tval = tval & ~mask;
		*value = (tval >> ((4 - (where % 4))*8));
		break;
	case 2:
		addr = where & ~3;
		mask = 0xffff0000 >> ((where % 4)*8);
		tval = reg_read(ATH724X_PCI_DEV_BASE + addr);
		tval = tval & ~mask;
		*value = (tval >> ((4 - (where % 4))*8));
		break;
	case 4:
		*value = reg_read(ATH724X_PCI_DEV_BASE + where);
		break;
	default:
		spin_unlock_irqrestore(&ath724x_pci_lock, flags);

		return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	spin_unlock_irqrestore(&ath724x_pci_lock, flags);

	return PCIBIOS_SUCCESSFUL;
}

static int ath724x_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
			     int size, uint32_t value)
{
	unsigned long flags, tval, addr, mask;

	if (devfn)
		return PCIBIOS_DEVICE_NOT_FOUND;

	if (where & (size - 1))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	spin_lock_irqsave(&ath724x_pci_lock, flags);

	switch (size) {
	case 1:
		addr = (ATH724X_PCI_DEV_BASE + where) & ~3;
		mask = 0xff000000 >> ((where % 4)*8);
		tval = reg_read(addr);
		tval = tval & ~mask;
		tval |= (value << ((4 - (where % 4))*8)) & mask;
		reg_write(addr, tval);
		break;
	case 2:
		addr = (ATH724X_PCI_DEV_BASE + where) & ~3;
		mask = 0xffff0000 >> ((where % 4)*8);
		tval = reg_read(addr);
		tval = tval & ~mask;
		tval |= (value << ((4 - (where % 4))*8)) & mask;
		reg_write(addr, tval);
		break;
	case 4:
		reg_write((ATH724X_PCI_DEV_BASE + where), value);
		break;
	default:
		spin_unlock_irqrestore(&ath724x_pci_lock, flags);

		return PCIBIOS_BAD_REGISTER_NUMBER;
	}

	spin_unlock_irqrestore(&ath724x_pci_lock, flags);

	return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops ath724x_pci_ops = {
	.read	= ath724x_pci_read,
	.write	= ath724x_pci_write,
};

static struct resource ath724x_io_resource = {
	.name   = "PCI IO space",
	.start  = 0,
	.end    = 0,
	.flags  = IORESOURCE_IO,
};

static struct resource ath724x_mem_resource = {
	.name   = "PCI memory space",
	.start  = ATH724X_PCI_MEM_BASE,
	.end    = ATH724X_PCI_MEM_BASE + ATH724X_PCI_MEM_SIZE - 1,
	.flags  = IORESOURCE_MEM,
};

static struct pci_controller ath724x_pci_controller = {
	.pci_ops        = &ath724x_pci_ops,
	.io_resource    = &ath724x_io_resource,
	.mem_resource	= &ath724x_mem_resource,
};

void ath724x_pci_add_data(struct ath724x_pci_data *data, int size)
{
	pci_data	= data;
	pci_data_size	= size;
}

int __init pcibios_map_irq(const struct pci_dev *dev, uint8_t slot, uint8_t pin)
{
	unsigned int devfn = dev->devfn;
	int irq = -1;

	if (devfn > pci_data_size - 1)
		return irq;

	irq = pci_data[devfn].irq;

	return irq;
}

int pcibios_plat_dev_init(struct pci_dev *dev)
{
	unsigned int devfn = dev->devfn;

	if (devfn > pci_data_size - 1)
		return PCIBIOS_DEVICE_NOT_FOUND;

	dev->dev.platform_data = pci_data[devfn].pdata;

	return PCIBIOS_SUCCESSFUL;
}

static int __init ath724x_pcibios_init(void)
{
	register_pci_controller(&ath724x_pci_controller);

	return PCIBIOS_SUCCESSFUL;
}

arch_initcall(ath724x_pcibios_init);