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/*
* BK Id: SCCS/s.pci.c 1.6 05/18/01 15:17:06 cort
*/
/* Stand alone funtions for QSpan Tundra support.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <asm/mpc8xx.h>
/* To map PCI devices, you first write 0xffffffff into the device
* base address registers. When the register is read back, the
* number of most significant '1' bits describes the amount of address
* space needed for mapping. If the most significant bit is not set,
* either the device does not use that address register, or it has
* a fixed address that we can't change. After the address is assigned,
* the command register has to be written to enable the card.
*/
typedef struct {
u_char pci_bus;
u_char pci_devfn;
ushort pci_command;
uint pci_addrs[6];
} pci_map_t;
/* We should probably dynamically allocate these structures.
*/
#define MAX_PCI_DEVS 32
int pci_dev_cnt;
pci_map_t pci_map[MAX_PCI_DEVS];
void pci_conf_write(int bus, int device, int func, int reg, uint writeval);
void pci_conf_read(int bus, int device, int func, int reg, void *readval);
void probe_addresses(int bus, int devfn);
void map_pci_addrs(void);
/* This is a really stripped version of PCI bus scan. All we are
* looking for are devices that exist.
*/
pci_scanner(int addr_probe)
{
unsigned int devfn, l, max, class, bus_number;
unsigned char cmd, irq, tmp, hdr_type, is_multi;
int reg;
is_multi = 0;
bus_number = 0;
for (devfn = 0; devfn < 0xff; ++devfn) {
/* The device numbers are comprised of upper 5 bits of
* device number and lower 3 bits of multi-function number.
*/
if ((devfn & 7) && !is_multi) {
/* Don't scan multifunction addresses if this is
* not a multifunction device.
*/
continue;
}
/* Read the header to determine card type.
*/
qs_pci_read_config_byte(bus_number, devfn, PCI_HEADER_TYPE,
&hdr_type);
/* If this is a base device number, check the header to
* determine if it is mulifunction.
*/
if ((devfn & 7) == 0)
is_multi = hdr_type & 0x80;
/* Check to see if the board is really in the slot.
*/
qs_pci_read_config_dword(bus_number, devfn, PCI_VENDOR_ID, &l);
/* some broken boards return 0 if a slot is empty: */
if (l == 0xffffffff || l == 0x00000000 || l == 0x0000ffff ||
l == 0xffff0000) {
/* Nothing there.
*/
is_multi = 0;
continue;
}
/* If we are not performing an address probe,
* just simply print out some information.
*/
if (!addr_probe) {
qs_pci_read_config_dword(bus_number, devfn,
PCI_CLASS_REVISION, &class);
class >>= 8; /* upper 3 bytes */
#if 0
printf("Found (%3d:%d): vendor 0x%04x, device 0x%04x, class 0x%06x\n",
(devfn >> 3), (devfn & 7),
(l & 0xffff), (l >> 16) & 0xffff, class);
#else
puts("Found ("); puthex(devfn >> 3);
puts(":"); puthex(devfn & 7);
puts("): vendor "); puthex(l & 0xffff);
puts(", device "); puthex((l >> 16) & 0xffff);
puts(", class "); puthex(class); puts("\n");
#endif
}
else {
/* If this is a "normal" device, build address list.
*/
if ((hdr_type & 0x7f) == PCI_HEADER_TYPE_NORMAL)
probe_addresses(bus_number, devfn);
}
}
/* Now map the boards.
*/
if (addr_probe)
map_pci_addrs();
}
/* Probe addresses for the specified device. This is a destructive
* operation because it writes the registers.
*/
void
probe_addresses(bus, devfn)
{
int i;
uint pciaddr;
ushort pcicmd;
pci_map_t *pm;
if (pci_dev_cnt >= MAX_PCI_DEVS) {
puts("Too many PCI devices\n");
return;
}
pm = &pci_map[pci_dev_cnt++];
pm->pci_bus = bus;
pm->pci_devfn = devfn;
for (i=0; i<6; i++) {
qs_pci_write_config_dword(bus, devfn, PCI_BASE_ADDRESS_0 + (i * 4), -1);
qs_pci_read_config_dword(bus, devfn, PCI_BASE_ADDRESS_0 + (i * 4),
&pciaddr);
pm->pci_addrs[i] = pciaddr;
qs_pci_read_config_word(bus, devfn, PCI_COMMAND, &pcicmd);
pm->pci_command = pcicmd;
}
}
/* Map the cards into the PCI space. The PCI has separate memory
* and I/O spaces. In addition, some memory devices require mapping
* below 1M. The least significant 4 bits of the address register
* provide information. If this is an I/O device, only the LS bit
* is used to indicate that, so I/O devices can be mapped to a two byte
* boundard. Memory addresses can be mapped to a 32 byte boundary.
* The QSpan implementations usually have a 1Gbyte space for each
* memory and I/O spaces.
*
* This isn't a terribly fancy algorithm. I just map the spaces from
* the top starting with the largest address space. When finished,
* the registers are written and the card enabled.
*
* While the Tundra can map a large address space on most boards, we
* need to be careful because it may overlap other devices (like IMMR).
*/
#define MEMORY_SPACE_SIZE 0x20000000
#define IO_SPACE_SIZE 0x20000000
void
map_pci_addrs()
{
uint pci_mem_top, pci_mem_low;
uint pci_io_top;
uint addr_mask, reg_addr, space;
int i, j;
pci_map_t *pm;
pci_mem_top = MEMORY_SPACE_SIZE;
pci_io_top = IO_SPACE_SIZE;
pci_mem_low = (1 * 1024 * 1024); /* Below one meg addresses */
/* We can't map anything more than the maximum space, but test
* for it anyway to catch devices out of range.
*/
addr_mask = 0x80000000;
do {
space = (~addr_mask) + 1; /* Size of the space */
for (i=0; i<pci_dev_cnt; i++) {
pm = &pci_map[i];
for (j=0; j<6; j++) {
/* If the MS bit is not set, this has either
* already been mapped, or is not used.
*/
reg_addr = pm->pci_addrs[j];
if ((reg_addr & 0x80000000) == 0)
continue;
if (reg_addr & PCI_BASE_ADDRESS_SPACE_IO) {
if ((reg_addr & PCI_BASE_ADDRESS_IO_MASK) != addr_mask)
continue;
if (pci_io_top < space) {
puts("Out of PCI I/O space\n");
}
else {
pci_io_top -= space;
pm->pci_addrs[j] = pci_io_top;
pm->pci_command |= PCI_COMMAND_IO;
}
}
else {
if ((reg_addr & PCI_BASE_ADDRESS_MEM_MASK) != addr_mask)
continue;
/* Memory space. Test if below 1M.
*/
if (reg_addr & PCI_BASE_ADDRESS_MEM_TYPE_1M) {
if (pci_mem_low < space) {
puts("Out of PCI 1M space\n");
}
else {
pci_mem_low -= space;
pm->pci_addrs[j] = pci_mem_low;
}
}
else {
if (pci_mem_top < space) {
puts("Out of PCI Mem space\n");
}
else {
pci_mem_top -= space;
pm->pci_addrs[j] = pci_mem_top;
}
}
pm->pci_command |= PCI_COMMAND_MEMORY;
}
}
}
addr_mask >>= 1;
addr_mask |= 0x80000000;
} while (addr_mask != 0xfffffffe);
/* Now, run the list one more time and map everything.
*/
for (i=0; i<pci_dev_cnt; i++) {
pm = &pci_map[i];
for (j=0; j<6; j++) {
qs_pci_write_config_dword(pm->pci_bus, pm->pci_devfn,
PCI_BASE_ADDRESS_0 + (j * 4), pm->pci_addrs[j]);
}
/* Enable memory or address mapping.
*/
qs_pci_write_config_word(pm->pci_bus, pm->pci_devfn, PCI_COMMAND,
pm->pci_command);
}
}
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