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#include "io.h"
#include "pci.h"
#define PCI_CONF_TYPE_NONE 0
#define PCI_CONF_TYPE_1 1
#define PCI_CONF_TYPE_2 2
static unsigned char pci_conf_type = PCI_CONF_TYPE_NONE;
#define PCI_CONF1_ADDRESS(bus, dev, fn, reg) \
(0x80000000 | (bus << 16) | (dev << 11) | (fn << 8) | (reg & ~3))
#define PCI_CONF2_ADDRESS(dev, reg) (unsigned short)(0xC000 | (dev << 8) | reg)
int pci_conf_read(unsigned bus, unsigned dev, unsigned fn, unsigned reg, unsigned len, unsigned long *value)
{
int result;
if (!value || (bus > 255) || (dev > 31) || (fn > 7) || (reg > 255))
return -1;
result = -1;
switch(pci_conf_type) {
case PCI_CONF_TYPE_1:
outl(PCI_CONF1_ADDRESS(bus, dev, fn, reg), 0xCF8);
switch(len) {
case 1: *value = inb(0xCFC + (reg & 3)); result = 0; break;
case 2: *value = inw(0xCFC + (reg & 2)); result = 0; break;
case 4: *value = inl(0xCFC); result = 0; break;
}
break;
case PCI_CONF_TYPE_2:
outb(0xF0 | (fn << 1), 0xCF8);
outb(bus, 0xCFA);
switch(len) {
case 1: *value = inb(PCI_CONF2_ADDRESS(dev, reg)); result = 0; break;
case 2: *value = inw(PCI_CONF2_ADDRESS(dev, reg)); result = 0; break;
case 4: *value = inl(PCI_CONF2_ADDRESS(dev, reg)); result = 0; break;
}
outb(0, 0xCF8);
break;
}
return result;
}
int pci_conf_write(unsigned bus, unsigned dev, unsigned fn, unsigned reg, unsigned len, unsigned long value)
{
int result;
if ((bus > 255) || (dev > 31) || (fn > 7) || (reg > 255))
return -1;
result = -1;
switch(pci_conf_type) {
case PCI_CONF_TYPE_1:
outl(PCI_CONF1_ADDRESS(bus, dev, fn, reg), 0xCF8);
switch(len) {
case 1: outb(value, 0xCFC + (reg & 3)); result = 0; break;
case 2: outw(value, 0xCFC + (reg & 2)); result = 0; break;
case 4: outl(value, 0xCFC); result = 0; break;
}
break;
case PCI_CONF_TYPE_2:
outb(0xF0 | (fn << 1), 0xCF8);
outb(bus, 0xCFA);
switch(len) {
case 1: outb(value, PCI_CONF2_ADDRESS(dev, reg)); result = 0; break;
case 2: outw(value, PCI_CONF2_ADDRESS(dev, reg)); result = 0; break;
case 4: outl(value, PCI_CONF2_ADDRESS(dev, reg)); result = 0; break;
}
outb(0, 0xCF8);
break;
}
return result;
}
static int pci_sanity_check(void)
{
unsigned long value;
int result;
/* Do a trivial check to make certain we can see a host bridge.
* There are reportedly some buggy chipsets from intel and
* compaq where this test does not work, I will worry about
* that when we support them.
*/
result = pci_conf_read(0, 0, 0, PCI_CLASS_DEVICE, 2, &value);
if (result == 0) {
result = -1;
if (value == PCI_CLASS_BRIDGE_HOST) {
result = 0;
}
}
return result;
}
static int pci_check_direct(void)
{
unsigned int tmp;
/* Check if configuration type 1 works. */
pci_conf_type = PCI_CONF_TYPE_1;
outb(0x01, 0xCFB);
tmp = inl(0xCF8);
outl(0x80000000, 0xCF8);
if ((inl(0xCF8) == 0x80000000) && (pci_sanity_check() == 0)) {
outl(tmp, 0xCF8);
return 0;
}
outl(tmp, 0xCF8);
/* Check if configuration type 2 works. */
pci_conf_type = PCI_CONF_TYPE_2;
outb(0x00, 0xCFB);
outb(0x00, 0xCF8);
outb(0x00, 0xCFA);
if (inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00 && (pci_sanity_check() == 0)) {
return 0;
}
/* Nothing worked return an error */
pci_conf_type = PCI_CONF_TYPE_NONE;
return -1;
}
int pci_init(void)
{
int result;
/* For now just make certain we can directly
* use the pci functions.
*/
result = pci_check_direct();
return result;
}
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