/arch/frv/mb93090-mb00/pci-frv.c
https://bitbucket.org/evzijst/gittest · C · 288 lines · 188 code · 26 blank · 74 comment · 54 complexity · 5b4ac5afdd33223bc09a9390e3ca5e03 MD5 · raw file
- /* pci-frv.c: low-level PCI access routines
- *
- * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- * - Derived from the i386 equivalent stuff
- *
- * 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.
- */
- #include <linux/types.h>
- #include <linux/kernel.h>
- #include <linux/pci.h>
- #include <linux/init.h>
- #include <linux/ioport.h>
- #include <linux/errno.h>
- #include "pci-frv.h"
- #if 0
- void
- pcibios_update_resource(struct pci_dev *dev, struct resource *root,
- struct resource *res, int resource)
- {
- u32 new, check;
- int reg;
- new = res->start | (res->flags & PCI_REGION_FLAG_MASK);
- if (resource < 6) {
- reg = PCI_BASE_ADDRESS_0 + 4*resource;
- } else if (resource == PCI_ROM_RESOURCE) {
- res->flags |= IORESOURCE_ROM_ENABLE;
- new |= PCI_ROM_ADDRESS_ENABLE;
- reg = dev->rom_base_reg;
- } else {
- /* Somebody might have asked allocation of a non-standard resource */
- return;
- }
- pci_write_config_dword(dev, reg, new);
- pci_read_config_dword(dev, reg, &check);
- if ((new ^ check) & ((new & PCI_BASE_ADDRESS_SPACE_IO) ? PCI_BASE_ADDRESS_IO_MASK : PCI_BASE_ADDRESS_MEM_MASK)) {
- printk(KERN_ERR "PCI: Error while updating region "
- "%s/%d (%08x != %08x)\n", pci_name(dev), resource,
- new, check);
- }
- }
- #endif
- /*
- * We need to avoid collisions with `mirrored' VGA ports
- * and other strange ISA hardware, so we always want the
- * addresses to be allocated in the 0x000-0x0ff region
- * modulo 0x400.
- *
- * Why? Because some silly external IO cards only decode
- * the low 10 bits of the IO address. The 0x00-0xff region
- * is reserved for motherboard devices that decode all 16
- * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
- * but we want to try to avoid allocating at 0x2900-0x2bff
- * which might have be mirrored at 0x0100-0x03ff..
- */
- void
- pcibios_align_resource(void *data, struct resource *res,
- unsigned long size, unsigned long align)
- {
- if (res->flags & IORESOURCE_IO) {
- unsigned long start = res->start;
- if (start & 0x300) {
- start = (start + 0x3ff) & ~0x3ff;
- res->start = start;
- }
- }
- }
- /*
- * Handle resources of PCI devices. If the world were perfect, we could
- * just allocate all the resource regions and do nothing more. It isn't.
- * On the other hand, we cannot just re-allocate all devices, as it would
- * require us to know lots of host bridge internals. So we attempt to
- * keep as much of the original configuration as possible, but tweak it
- * when it's found to be wrong.
- *
- * Known BIOS problems we have to work around:
- * - I/O or memory regions not configured
- * - regions configured, but not enabled in the command register
- * - bogus I/O addresses above 64K used
- * - expansion ROMs left enabled (this may sound harmless, but given
- * the fact the PCI specs explicitly allow address decoders to be
- * shared between expansion ROMs and other resource regions, it's
- * at least dangerous)
- *
- * Our solution:
- * (1) Allocate resources for all buses behind PCI-to-PCI bridges.
- * This gives us fixed barriers on where we can allocate.
- * (2) Allocate resources for all enabled devices. If there is
- * a collision, just mark the resource as unallocated. Also
- * disable expansion ROMs during this step.
- * (3) Try to allocate resources for disabled devices. If the
- * resources were assigned correctly, everything goes well,
- * if they weren't, they won't disturb allocation of other
- * resources.
- * (4) Assign new addresses to resources which were either
- * not configured at all or misconfigured. If explicitly
- * requested by the user, configure expansion ROM address
- * as well.
- */
- static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
- {
- struct list_head *ln;
- struct pci_bus *bus;
- struct pci_dev *dev;
- int idx;
- struct resource *r, *pr;
- /* Depth-First Search on bus tree */
- for (ln=bus_list->next; ln != bus_list; ln=ln->next) {
- bus = pci_bus_b(ln);
- if ((dev = bus->self)) {
- for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
- r = &dev->resource[idx];
- if (!r->start)
- continue;
- pr = pci_find_parent_resource(dev, r);
- if (!pr || request_resource(pr, r) < 0)
- printk(KERN_ERR "PCI: Cannot allocate resource region %d of bridge %s\n", idx, pci_name(dev));
- }
- }
- pcibios_allocate_bus_resources(&bus->children);
- }
- }
- static void __init pcibios_allocate_resources(int pass)
- {
- struct pci_dev *dev = NULL;
- int idx, disabled;
- u16 command;
- struct resource *r, *pr;
- while (dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev),
- dev != NULL
- ) {
- pci_read_config_word(dev, PCI_COMMAND, &command);
- for(idx = 0; idx < 6; idx++) {
- r = &dev->resource[idx];
- if (r->parent) /* Already allocated */
- continue;
- if (!r->start) /* Address not assigned at all */
- continue;
- if (r->flags & IORESOURCE_IO)
- disabled = !(command & PCI_COMMAND_IO);
- else
- disabled = !(command & PCI_COMMAND_MEMORY);
- if (pass == disabled) {
- DBG("PCI: Resource %08lx-%08lx (f=%lx, d=%d, p=%d)\n",
- r->start, r->end, r->flags, disabled, pass);
- pr = pci_find_parent_resource(dev, r);
- if (!pr || request_resource(pr, r) < 0) {
- printk(KERN_ERR "PCI: Cannot allocate resource region %d of device %s\n", idx, pci_name(dev));
- /* We'll assign a new address later */
- r->end -= r->start;
- r->start = 0;
- }
- }
- }
- if (!pass) {
- r = &dev->resource[PCI_ROM_RESOURCE];
- if (r->flags & IORESOURCE_ROM_ENABLE) {
- /* Turn the ROM off, leave the resource region, but keep it unregistered. */
- u32 reg;
- DBG("PCI: Switching off ROM of %s\n", pci_name(dev));
- r->flags &= ~IORESOURCE_ROM_ENABLE;
- pci_read_config_dword(dev, dev->rom_base_reg, ®);
- pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE);
- }
- }
- }
- }
- static void __init pcibios_assign_resources(void)
- {
- struct pci_dev *dev = NULL;
- int idx;
- struct resource *r;
- while (dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev),
- dev != NULL
- ) {
- int class = dev->class >> 8;
- /* Don't touch classless devices and host bridges */
- if (!class || class == PCI_CLASS_BRIDGE_HOST)
- continue;
- for(idx=0; idx<6; idx++) {
- r = &dev->resource[idx];
- /*
- * Don't touch IDE controllers and I/O ports of video cards!
- */
- if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) ||
- (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO)))
- continue;
- /*
- * We shall assign a new address to this resource, either because
- * the BIOS forgot to do so or because we have decided the old
- * address was unusable for some reason.
- */
- if (!r->start && r->end)
- pci_assign_resource(dev, idx);
- }
- if (pci_probe & PCI_ASSIGN_ROMS) {
- r = &dev->resource[PCI_ROM_RESOURCE];
- r->end -= r->start;
- r->start = 0;
- if (r->end)
- pci_assign_resource(dev, PCI_ROM_RESOURCE);
- }
- }
- }
- void __init pcibios_resource_survey(void)
- {
- DBG("PCI: Allocating resources\n");
- pcibios_allocate_bus_resources(&pci_root_buses);
- pcibios_allocate_resources(0);
- pcibios_allocate_resources(1);
- pcibios_assign_resources();
- }
- int pcibios_enable_resources(struct pci_dev *dev, int mask)
- {
- u16 cmd, old_cmd;
- int idx;
- struct resource *r;
- pci_read_config_word(dev, PCI_COMMAND, &cmd);
- old_cmd = cmd;
- for(idx=0; idx<6; idx++) {
- /* Only set up the requested stuff */
- if (!(mask & (1<<idx)))
- continue;
- r = &dev->resource[idx];
- if (!r->start && r->end) {
- printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev));
- return -EINVAL;
- }
- if (r->flags & IORESOURCE_IO)
- cmd |= PCI_COMMAND_IO;
- if (r->flags & IORESOURCE_MEM)
- cmd |= PCI_COMMAND_MEMORY;
- }
- if (dev->resource[PCI_ROM_RESOURCE].start)
- cmd |= PCI_COMMAND_MEMORY;
- if (cmd != old_cmd) {
- printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd);
- pci_write_config_word(dev, PCI_COMMAND, cmd);
- }
- return 0;
- }
- /*
- * If we set up a device for bus mastering, we need to check the latency
- * timer as certain crappy BIOSes forget to set it properly.
- */
- unsigned int pcibios_max_latency = 255;
- void pcibios_set_master(struct pci_dev *dev)
- {
- u8 lat;
- pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
- if (lat < 16)
- lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
- else if (lat > pcibios_max_latency)
- lat = pcibios_max_latency;
- else
- return;
- printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n", pci_name(dev), lat);
- pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
- }