/*
 * arch/arm/mach-ixp4xx/include/mach/io.h
 *
 * Author: Deepak Saxena <dsaxena@plexity.net>
 *
 * Copyright (C) 2002-2005  MontaVista Software, Inc.
 *
 * 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.
 */

#ifndef __ASM_ARM_ARCH_IO_H
#define __ASM_ARM_ARCH_IO_H

#include <linux/bitops.h>

#include <mach/hardware.h>

extern int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data);
extern int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data);


/*
 * IXP4xx provides two methods of accessing PCI memory space:
 *
 * 1) A direct mapped window from 0x48000000 to 0x4BFFFFFF (64MB).
 *    To access PCI via this space, we simply ioremap() the BAR
 *    into the kernel and we can use the standard read[bwl]/write[bwl]
 *    macros. This is the preffered method due to speed but it
 *    limits the system to just 64MB of PCI memory. This can be
 *    problematic if using video cards and other memory-heavy targets.
 *
 * 2) If > 64MB of memory space is required, the IXP4xx can use indirect
 *    registers to access the whole 4 GB of PCI memory space (as we do below
 *    for I/O transactions). This allows currently for up to 1 GB (0x10000000
 *    to 0x4FFFFFFF) of memory on the bus. The disadvantage of this is that
 *    every PCI access requires three local register accesses plus a spinlock,
 *    but in some cases the performance hit is acceptable. In addition, you
 *    cannot mmap() PCI devices in this case.
 */
#ifdef	CONFIG_IXP4XX_INDIRECT_PCI

/*
 * In the case of using indirect PCI, we simply return the actual PCI
 * address and our read/write implementation use that to drive the 
 * access registers. If something outside of PCI is ioremap'd, we
 * fallback to the default.
 */

static inline int is_pci_memory(u32 addr)
{
	return (addr >= PCIBIOS_MIN_MEM) && (addr <= 0x4FFFFFFF);
}

#define writeb(v, p)			__indirect_writeb(v, p)
#define writew(v, p)			__indirect_writew(v, p)
#define writel(v, p)			__indirect_writel(v, p)

#define writesb(p, v, l)		__indirect_writesb(p, v, l)
#define writesw(p, v, l)		__indirect_writesw(p, v, l)
#define writesl(p, v, l)		__indirect_writesl(p, v, l)

#define readb(p)			__indirect_readb(p)
#define readw(p)			__indirect_readw(p)
#define readl(p)			__indirect_readl(p)

#define readsb(p, v, l)			__indirect_readsb(p, v, l)
#define readsw(p, v, l)			__indirect_readsw(p, v, l)
#define readsl(p, v, l)			__indirect_readsl(p, v, l)

static inline void __indirect_writeb(u8 value, volatile void __iomem *p)
{
	u32 addr = (u32)p;
	u32 n, byte_enables, data;

	if (!is_pci_memory(addr)) {
		__raw_writeb(value, addr);
		return;
	}

	n = addr % 4;
	byte_enables = (0xf & ~BIT(n)) << IXP4XX_PCI_NP_CBE_BESL;
	data = value << (8*n);
	ixp4xx_pci_write(addr, byte_enables | NP_CMD_MEMWRITE, data);
}

static inline void __indirect_writesb(volatile void __iomem *bus_addr,
				      const u8 *vaddr, int count)
{
	while (count--)
		writeb(*vaddr++, bus_addr);
}

static inline void __indirect_writew(u16 value, volatile void __iomem *p)
{
	u32 addr = (u32)p;
	u32 n, byte_enables, data;

	if (!is_pci_memory(addr)) {
		__raw_writew(value, addr);
		return;
	}

	n = addr % 4;
	byte_enables = (0xf & ~(BIT(n) | BIT(n+1))) << IXP4XX_PCI_NP_CBE_BESL;
	data = value << (8*n);
	ixp4xx_pci_write(addr, byte_enables | NP_CMD_MEMWRITE, data);
}

static inline void __indirect_writesw(volatile void __iomem *bus_addr,
				      const u16 *vaddr, int count)
{
	while (count--)
		writew(*vaddr++, bus_addr);
}

static inline void __indirect_writel(u32 value, volatile void __iomem *p)
{
	u32 addr = (__force u32)p;

	if (!is_pci_memory(addr)) {
		__raw_writel(value, p);
		return;
	}

	ixp4xx_pci_write(addr, NP_CMD_MEMWRITE, value);
}

static inline void __indirect_writesl(volatile void __iomem *bus_addr,
				      const u32 *vaddr, int count)
{
	while (count--)
		writel(*vaddr++, bus_addr);
}

static inline unsigned char __indirect_readb(const volatile void __iomem *p)
{
	u32 addr = (u32)p;
	u32 n, byte_enables, data;

	if (!is_pci_memory(addr))
		return __raw_readb(addr);

	n = addr % 4;
	byte_enables = (0xf & ~BIT(n)) << IXP4XX_PCI_NP_CBE_BESL;
	if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_MEMREAD, &data))
		return 0xff;

	return data >> (8*n);
}

static inline void __indirect_readsb(const volatile void __iomem *bus_addr,
				     u8 *vaddr, u32 count)
{
	while (count--)
		*vaddr++ = readb(bus_addr);
}

static inline unsigned short __indirect_readw(const volatile void __iomem *p)
{
	u32 addr = (u32)p;
	u32 n, byte_enables, data;

	if (!is_pci_memory(addr))
		return __raw_readw(addr);

	n = addr % 4;
	byte_enables = (0xf & ~(BIT(n) | BIT(n+1))) << IXP4XX_PCI_NP_CBE_BESL;
	if (ixp4xx_pci_read(addr, byte_enables | NP_CMD_MEMREAD, &data))
		return 0xffff;

	return data>>(8*n);
}

static inline void __indirect_readsw(const volatile void __iomem *bus_addr,
				     u16 *vaddr, u32 count)
{
	while (count--)
		*vaddr++ = readw(bus_addr);
}

static inline unsigned long __indirect_readl(const volatile void __iomem *p)
{
	u32 addr = (__force u32)p;
	u32 data;

	if (!is_pci_memory(addr))
		return __raw_readl(p);

	if (ixp4xx_pci_read(addr, NP_CMD_MEMREAD, &data))
		return 0xffffffff;

	return data;
}

static inline void __indirect_readsl(const volatile void __iomem *bus_addr,
				     u32 *vaddr, u32 count)
{
	while (count--)
		*vaddr++ = readl(bus_addr);
}


/*
 * We can use the built-in functions b/c they end up calling writeb/readb
 */