it8172_pci.c

一个2.4.21版本的嵌入式linux内核

/*
 *
 * BRIEF MODULE DESCRIPTION
 *	IT8172 system controller specific pci support.
 *
 * Copyright 2000 MontaVista Software Inc.
 * Author: MontaVista Software, Inc.
 *         	[e-mail] or [e-mail]
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/config.h>

#ifdef CONFIG_PCI

#include <linux/types.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/init.h>

#include <asm/pci_channel.h>
#include <asm/it8172/it8172.h>
#include <asm/it8172/it8172_pci.h>

#define PCI_ACCESS_READ  0
#define PCI_ACCESS_WRITE 1

#undef DEBUG
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

static struct resource pci_mem_resource_1;

static struct resource pci_io_resource = {
	"io pci IO space", 
	0x14000000,
	0x17FFFFFF,
	IORESOURCE_IO
};

static struct resource pci_mem_resource_0 = {
	"ext pci memory space 0/1", 
	0x0C000000,
	0x13FFFFFF,
	IORESOURCE_MEM,
	&pci_mem_resource_0,
	NULL,
	&pci_mem_resource_1
};

static struct resource pci_mem_resource_1 = {
	"ext pci memory space 2/3", 
	0x1A000000,
	0x1FBFFFFF,
	IORESOURCE_MEM,
	&pci_mem_resource_0,
	NULL,
	NULL
};

extern struct pci_ops it8172_pci_ops;

struct pci_channel mips_pci_channels[] = {
	{ &it8172_pci_ops, &pci_io_resource, &pci_mem_resource_0, 0, 0xff },
	{ NULL, NULL, NULL, NULL, NULL}
};

static int
it8172_pcibios_config_access(unsigned char access_type, struct pci_dev *dev,
                           unsigned char where, u32 *data)
{
	/* 
	 * config cycles are on 4 byte boundary only
	 */
	unsigned char bus = dev->bus->number;
	unsigned char dev_fn = dev->devfn;

	DBG("it config: type %d dev %x bus %d dev_fn %x data %x\n",
			access_type, dev, bus, dev_fn, *data);

	/* Setup address */
	IT_WRITE(IT_CONFADDR, (bus << IT_BUSNUM_SHF) | 
			(dev_fn << IT_FUNCNUM_SHF) | (where & ~0x3));


	if (access_type == PCI_ACCESS_WRITE) {
		IT_WRITE(IT_CONFDATA, *data);
	} 
	else {
		IT_READ(IT_CONFDATA, *data);
	}

	/*
	 * Revisit: check for master or target abort.
	 */
	return 0;


}


/*
 * We can't address 8 and 16 bit words directly.  Instead we have to
 * read/write a 32bit word and mask/modify the data we actually want.
 */
static int
read_config_byte (struct pci_dev *dev, int where, u8 *val)
{
	u32 data = 0;

	if (it8172_pcibios_config_access(PCI_ACCESS_READ, dev, where, &data))
		return -1;

	*val = (data >> ((where & 3) << 3)) & 0xff;
        DBG("cfg read byte: bus %d dev_fn %x where %x: val %x\n", 
                dev->bus->number, dev->devfn, where, *val);

	return PCIBIOS_SUCCESSFUL;
}


static int
read_config_word (struct pci_dev *dev, int where, u16 *val)
{
	u32 data = 0;

	if (where & 1)
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (it8172_pcibios_config_access(PCI_ACCESS_READ, dev, where, &data))
	       return -1;

	*val = (data >> ((where & 3) << 3)) & 0xffff;
        DBG("cfg read word: bus %d dev_fn %x where %x: val %x\n", 
                dev->bus->number, dev->devfn, where, *val);

	return PCIBIOS_SUCCESSFUL;
}

static int
read_config_dword (struct pci_dev *dev, int where, u32 *val)
{
	u32 data = 0;

	if (where & 3)
		return PCIBIOS_BAD_REGISTER_NUMBER;
	
	if (it8172_pcibios_config_access(PCI_ACCESS_READ, dev, where, &data))
		return -1;

	*val = data;
        DBG("cfg read dword: bus %d dev_fn %x where %x: val %x\n", 
                dev->bus->number, dev->devfn, where, *val);

	return PCIBIOS_SUCCESSFUL;
}


static int
write_config_byte (struct pci_dev *dev, int where, u8 val)
{
	u32 data = 0;
       
	if (it8172_pcibios_config_access(PCI_ACCESS_READ, dev, where, &data))
		return -1;

	data = (data & ~(0xff << ((where & 3) << 3))) |
	       (val << ((where & 3) << 3));

	if (it8172_pcibios_config_access(PCI_ACCESS_WRITE, dev, where, &data))
		return -1;

	return PCIBIOS_SUCCESSFUL;
}

static int
write_config_word (struct pci_dev *dev, int where, u16 val)
{
        u32 data = 0;

	if (where & 1)
		return PCIBIOS_BAD_REGISTER_NUMBER;
       
        if (it8172_pcibios_config_access(PCI_ACCESS_READ, dev, where, &data))
	       return -1;

	data = (data & ~(0xffff << ((where & 3) << 3))) | 
	       (val << ((where & 3) << 3));

	if (it8172_pcibios_config_access(PCI_ACCESS_WRITE, dev, where, &data))
	       return -1;


	return PCIBIOS_SUCCESSFUL;
}

static int
write_config_dword(struct pci_dev *dev, int where, u32 val)
{
	if (where & 3)
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (it8172_pcibios_config_access(PCI_ACCESS_WRITE, dev, where, &val))
	       return -1;

	return PCIBIOS_SUCCESSFUL;
}

struct pci_ops it8172_pci_ops = {
	read_config_byte,
        read_config_word,
	read_config_dword,
	write_config_byte,
	write_config_word,
	write_config_dword
};

unsigned __init int pcibios_assign_all_busses(void)
{
       return 1;
}
#endif /* CONFIG_PCI */