/*
* QSpan pci routines.
* Most 8xx boards use the QSpan PCI bridge. The config address register
* is located 0x500 from the base of the bridge control/status registers.
* The data register is located at 0x504.
* This is a two step operation. First, the address register is written,
* then the data register is read/written as required.
* I don't know what to do about interrupts (yet).
*
* The RPX Classic implementation shares a chip select for normal
* PCI access and QSpan control register addresses. The selection is
* further selected by a bit setting in a board control register.
* Although it should happen, we disable interrupts during this operation
* to make sure some driver doesn't accidentally access the PCI while
* we have switched the chip select.
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/mpc8xx.h>
#include <asm/system.h>
#include <asm/machdep.h>
#include <asm/pci-bridge.h>
/*
* This blows......
* When reading the configuration space, if something does not respond
* the bus times out and we get a machine check interrupt. So, the
* good ol' exception tables come to mind to trap it and return some
* value.
*
* On an error we just return a -1, since that is what the caller wants
* returned if nothing is present. I copied this from __get_user_asm,
* with the only difference of returning -1 instead of EFAULT.
* There is an associated hack in the machine check trap code.
*
* The QSPAN is also a big endian device, that is it makes the PCI
* look big endian to us. This presents a problem for the Linux PCI
* functions, which assume little endian. For example, we see the
* first 32-bit word like this:
* ------------------------
* | Device ID | Vendor ID |
* ------------------------
* If we read/write as a double word, that's OK. But in our world,
* when read as a word, device ID is at location 0, not location 2 as
* the little endian PCI would believe. We have to switch bits in
* the PCI addresses given to us to get the data to/from the correct
* byte lanes.
*
* The QSPAN only supports 4 bits of "slot" in the dev_fn instead of 5.
* It always forces the MS bit to zero. Therefore, dev_fn values
* greater than 128 are returned as "no device found" errors.
*
* The QSPAN can only perform long word (32-bit) configuration cycles.
* The "offset" must have the two LS bits set to zero. Read operations
* require we read the entire word and then sort out what should be
* returned. Write operations other than long word require that we
* read the long word, update the proper word or byte, then write the
* entire long word back.
*
* PCI Bridge hack. We assume (correctly) that bus 0 is the primary
* PCI bus from the QSPAN. If we are called with a bus number other
* than zero, we create a Type 1 configuration access that a downstream
* PCI bridge will interpret.
*/
#define __get_qspan_pci_config(x, addr, op) \
__asm__ __volatile__( \
"1: "op" %0,0(%1)\n" \
" eieio\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,-1\n" \
" b 2b\n" \
".section __ex_table,\"a\"\n" \
" .align 2\n" \
" .long 1b,3b\n" \
".text" \
: "=r"(x) : "r"(addr) : " %0")
#define QS_CONFIG_ADDR ((volatile uint *)(PCI_CSR_ADDR + 0x500))
#define QS_CONFIG_DATA ((volatile uint *)(PCI_CSR_ADDR + 0x504))
#define mk_config_addr(bus, dev, offset) \
(((bus)<<16) | ((dev)<<8) | (offset & 0xfc))
#define mk_config_type1(bus, dev, offset) \
mk_config_addr(bus, dev, offset) | 1;
static DEFINE_SPINLOCK(pcibios_lock);
int qspan_pcibios_read_config_byte(unsigned char bus, unsigned char dev_fn,
unsigned char offset, unsigned char *val)
{
uint temp;
u_char *cp;
#ifdef CONFIG_RPXCLASSIC
unsigned long flags;
#endif
if ((bus > 7) || (dev_fn > 127)) {
*val = 0xff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
#ifdef CONFIG_RPXCLASSIC
/* disable interrupts */
spin_lock_irqsave(&pcibios_lock, flags);
*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
eieio();
#endif
if (bus == 0)
*QS_CONFIG_ADDR = mk_config_addr(bus, dev_fn, offset);
else
*QS_CONFIG_ADDR = mk_config_type1(bus, dev_fn, offset);
__get_qspan_pci_config(temp, QS_CONFIG_DATA, "lwz");
#ifdef CONFIG_RPXCLASSIC
*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
eieio();
spin_unlock_irqrestore(&pcibios_lock, flags);
#endif
offset ^= 0x03;
cp = ((u_char *)&temp) + (offset & 0x03);
*val = *cp;
return PCIBIOS_SUCCESSFUL;
}
int qspan_pcibios_read_config_word(unsigned char bus, unsigned char dev_fn,
unsigned char offset, unsigned short *val)
{
uint temp;
ushort *sp;
#ifdef CONFIG_RPXCLASSIC
unsigned long flags;
#endif
if ((bus > 7) || (dev_fn > 127)) {
*val = 0xffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
#ifdef CONFIG_RPXCLASSIC
/* disable interrupts */
spin_lock_irqsave(&pcibios_lock, flags);
*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
eieio();
#endif
if (bus == 0)
*QS_CONFIG_ADDR = mk_config_addr(bus, dev_fn, offset);
else
*QS_CONFIG_ADDR = mk_config_type1(bus, dev_fn, offset);
__get_qspan_pci_config(temp, QS_CONFIG_DATA, "lwz");
offset ^= 0x02;
#ifdef CONFIG_RPXCLASSIC
*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
eieio();
spin_unlock_irqrestore(&pcibios_lock, flags);
#endif
sp = ((ushort *)&temp) + ((offset >> 1) & 1);
*val = *sp;
return PCIBIOS_SUCCESSFUL;
}
int qspan_pcibios_read_config_dword(unsigned char bus, unsigned char dev_fn,
unsigned char offset, unsigned int *val)
{
#ifdef CONFIG_RPXCLASSIC
unsigned long flags;
#endif
if ((bus > 7) || (dev_fn > 127)) {
*val = 0xffffffff;
return PCIBIOS_DEVICE_NOT_FOUND;
}
#ifdef CONFIG_RPXCLASSIC
/* disable interrupts */
spin_lock_irqsave(&pcibios_lock, flags);
*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
eieio();
#endif
if (bus == 0)
*QS_CONFIG_ADDR = mk_config_addr(bus, dev_fn, offset);
else
*QS_CONFIG_ADDR = mk_config_type1(bus, dev_fn, offset);
__get_qspan_pci_config(*val, QS_CONFIG_DATA, "lwz");
#ifdef CONFIG_RPXCLASSIC
*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
eieio();
spin_unlock_irqrestore(&pcibios_lock, flags);
#endif
return PCIBIOS_SUCCESSFUL;
}
int qspan_pcibios_write_config_byte(unsigned char bus, unsigned char dev_fn,
unsigned char offset, unsigned char val)
{
uint temp;
u_char *cp;
#ifdef CONFIG_RPXCLASSIC
unsigned long flags;
#endif
if ((bus > 7) || (dev_fn > 127))
return PCIBIOS_DEVICE_NOT_FOUND;
qspan_pcibios_read_config_dword(bus, dev_fn, offset, &temp);
offset ^= 0x03;
cp = ((u_char *)&temp) + (offset & 0x03);
*cp = val;
#ifdef CONFIG_RPXCLASSIC
/* disable interrupts */
spin_lock_irqsave(&pcibios_lock, flags);
*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
eieio();
#endif
if (bus == 0)
*QS_CONFIG_ADDR = mk_config_addr(bus, dev_fn, offset);
else
*QS_CONFIG_ADDR = mk_config_type1(bus, dev_fn, offset);
*QS_CONFIG_DATA = temp;
#ifdef CONFIG_RPXCLASSIC
*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
eieio();
spin_unlock_irqrestore(&pcibios_lock, flags);
#endif
return PCIBIOS_SUCCESSFUL;
}
int qspan_pcibios_write_config_word(unsigned char bus, unsigned char dev_fn,
unsigned char offset, unsigned short val)
{
uint temp;
ushort *sp;
#ifdef CONFIG_RPXCLASSIC
unsigned long flags;
#endif
if ((bus > 7) || (dev_fn > 127))
return PCIBIOS_DEVICE_NOT_FOUND;
qspan_pcibios_read_config_dword(bus, dev_fn, offset, &temp);
offset ^= 0x02;
sp = ((ushort *)&temp) + ((offset >> 1) & 1);
*sp = val;
#ifdef CONFIG_RPXCLASSIC
/* disable interrupts */
spin_lock_irqsave(&pcibios_lock, flags);
*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
eieio();
#endif
if (bus == 0)
*QS_CONFIG_ADDR = mk_config_addr(bus, dev_fn, offset);
else
*QS_CONFIG_ADDR = mk_config_type1(bus, dev_fn, offset);
*QS_CONFIG_DATA = temp;
#ifdef CONFIG_RPXCLASSIC
*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
eieio();
spin_unlock_irqrestore(&pcibios_lock, flags);
#endif
return PCIBIOS_SUCCESSFUL;
}
int qspan_pcibios_write_config_dword(unsigned char bus, unsigned char dev_fn,
unsigned char offset, unsigned int val)
{
#ifdef CONFIG_RPXCLASSIC
unsigned long flags;
#endif
if ((bus > 7) || (dev_fn > 127))
return PCIBIOS_DEVICE_NOT_FOUND;
#ifdef CONFIG_RPXCLASSIC
/* disable interrupts */
spin_lock_irqsave(&pcibios_lock, flags);
*((uint *)RPX_CSR_ADDR) &= ~BCSR2_QSPACESEL;
eieio();
#endif
if (bus == 0)
*QS_CONFIG_ADDR = mk_config_addr(bus, dev_fn, offset);
else
*QS_CONFIG_ADDR = mk_config_type1(bus, dev_fn, offset);
*(unsigned int *)QS_CONFIG_DATA = val;
#ifdef CONFIG_RPXCLASSIC
*((uint *)RPX_CSR_ADDR) |= BCSR2_QSPACESEL;
eieio();
spin_unlock_irqrestore(&pcibios_lock, flags);
#endif
return PCIBIOS_SUCCESSFUL;
}
int qspan_pcibios_find_device(unsigned short vendor, unsigned short dev_id,
unsigned short index, unsigned char *bus_ptr,
unsigned char *dev_fn_ptr)
{
int num, devfn;
unsigned int x, vendev;
if (vendor == 0xffff)
return PCIBIOS_BAD_VENDOR_ID;
vendev = (dev_id << 16) + vendor;
num = 0;
for (devfn = 0; devfn < 32; devfn++) {
qspan_pcibios_read_config_dword(0, devfn<<3, PCI_VENDOR_ID, &x);
if (x == vendev) {
if (index == num) {
*bus_ptr = 0;
*dev_fn_ptr = devfn<<3;
return PCIBIOS_SUCCESSFUL;
}
++num;
}
}
return PCIBIOS_DEVICE_NOT_FOUND;
}
int qspan_pcibios_find_class(unsigned int class_code, unsigned short index,
unsigned char *bus_ptr, unsigned char *dev_fn_ptr)
{
int devnr, x, num;
num = 0;
for (devnr = 0; devnr < 32; devnr++) {
qspan_pcibios_read_config_dword(0, devnr<<3, PCI_CLASS_REVISION, &x);
if ((x>>8) == class_code) {
if (index == num) {
*bus_ptr = 0;
*dev_fn_ptr = devnr<<3;
return PCIBIOS_SUCCESSFUL;
}
++num;
}
}
return PCIBIOS_DEVICE_NOT_FOUND;
}
void __init
m8xx_pcibios_fixup(void)
{
/* Lots to do here, all board and configuration specific. */
}
void __init
m8xx_setup_pci_ptrs(void)
{
set_config_access_method(qspan);
ppc_md.pcibios_fixup = m8xx_pcibios_fixup;
}
