diff options
Diffstat (limited to 'arch/ppc/syslib/qspan_pci.c')
| -rw-r--r-- | arch/ppc/syslib/qspan_pci.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/arch/ppc/syslib/qspan_pci.c b/arch/ppc/syslib/qspan_pci.c new file mode 100644 index 00000000000..57f4ed5e5ae --- /dev/null +++ b/arch/ppc/syslib/qspan_pci.c @@ -0,0 +1,381 @@ +/* + * 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/config.h> +#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 spinlock_t pcibios_lock = SPIN_LOCK_UNLOCKED; + +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; +} + |