drivers/pci/pci-uclass.c - platform/external/u-boot - Gitiles

 /*
  * Copyright (c) 2014 Google, Inc
  * Written by Simon Glass <sjg@chromium.org>
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 #include <common.h>
 #include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>
 #include <inttypes.h>
 #include <pci.h>
 #include <dm/lists.h>
 #include <dm/root.h>
 #include <dm/device-internal.h>

 DECLARE_GLOBAL_DATA_PTR;

 struct pci_controller *pci_bus_to_hose(int busnum)
 {
 	struct udevice *bus;
 	int ret;

 	ret = uclass_get_device_by_seq(UCLASS_PCI, busnum, &bus);
 	if (ret) {
 		debug("%s: Cannot get bus %d: ret=%d\n", __func__, busnum, ret);
 		return NULL;
 	}
 	return dev_get_uclass_priv(bus);
 }

 pci_dev_t pci_get_bdf(struct udevice *dev)
 {
 	struct pci_child_platdata *pplat = dev_get_parent_platdata(dev);
 	struct udevice *bus = dev->parent;

 	return PCI_ADD_BUS(bus->seq, pplat->devfn);
 }

 /**
  * pci_get_bus_max() - returns the bus number of the last active bus
  *
  * @return last bus number, or -1 if no active buses
  */
 static int pci_get_bus_max(void)
 {
 	struct udevice *bus;
 	struct uclass *uc;
 	int ret = -1;

 	ret = uclass_get(UCLASS_PCI, &uc);
 	uclass_foreach_dev(bus, uc) {
 		if (bus->seq > ret)
 			ret = bus->seq;
 	}

 	debug("%s: ret=%d\n", __func__, ret);

 	return ret;
 }

 int pci_last_busno(void)
 {
 	struct pci_controller *hose;
 	struct udevice *bus;
 	struct uclass *uc;
 	int ret;

 	debug("pci_last_busno\n");
 	ret = uclass_get(UCLASS_PCI, &uc);
 	if (ret || list_empty(&uc->dev_head))
 		return -1;

 	/* Probe the last bus */
 	bus = list_entry(uc->dev_head.prev, struct udevice, uclass_node);
 	debug("bus = %p, %s\n", bus, bus->name);
 	assert(bus);
 	ret = device_probe(bus);
 	if (ret)
 		return ret;

 	/* If that bus has bridges, we may have new buses now. Get the last */
 	bus = list_entry(uc->dev_head.prev, struct udevice, uclass_node);
 	hose = dev_get_uclass_priv(bus);
 	debug("bus = %s, hose = %p\n", bus->name, hose);

 	return hose->last_busno;
 }

 int pci_get_ff(enum pci_size_t size)
 {
 	switch (size) {
 	case PCI_SIZE_8:
 		return 0xff;
 	case PCI_SIZE_16:
 		return 0xffff;
 	default:
 		return 0xffffffff;
 	}
 }

 int pci_bus_find_devfn(struct udevice *bus, pci_dev_t find_devfn,
 		       struct udevice **devp)
 {
 	struct udevice *dev;

 	for (device_find_first_child(bus, &dev);
 	     dev;
 	     device_find_next_child(&dev)) {
 		struct pci_child_platdata *pplat;

 		pplat = dev_get_parent_platdata(dev);
 		if (pplat && pplat->devfn == find_devfn) {
 			*devp = dev;
 			return 0;
 		}
 	}

 	return -ENODEV;
 }

 int pci_bus_find_bdf(pci_dev_t bdf, struct udevice **devp)
 {
 	struct udevice *bus;
 	int ret;

 	ret = uclass_get_device_by_seq(UCLASS_PCI, PCI_BUS(bdf), &bus);
 	if (ret)
 		return ret;
 	return pci_bus_find_devfn(bus, PCI_MASK_BUS(bdf), devp);
 }

 static int pci_device_matches_ids(struct udevice *dev,
 				  struct pci_device_id *ids)
 {
 	struct pci_child_platdata *pplat;
 	int i;

 	pplat = dev_get_parent_platdata(dev);
 	if (!pplat)
 		return -EINVAL;
 	for (i = 0; ids[i].vendor != 0; i++) {
 		if (pplat->vendor == ids[i].vendor &&
 		    pplat->device == ids[i].device)
 			return i;
 	}

 	return -EINVAL;
 }

 int pci_bus_find_devices(struct udevice *bus, struct pci_device_id *ids,
 			 int *indexp, struct udevice **devp)
 {
 	struct udevice *dev;

 	/* Scan all devices on this bus */
 	for (device_find_first_child(bus, &dev);
 	     dev;
 	     device_find_next_child(&dev)) {
 		if (pci_device_matches_ids(dev, ids) >= 0) {
 			if ((*indexp)-- <= 0) {
 				*devp = dev;
 				return 0;
 			}
 		}
 	}

 	return -ENODEV;
 }

 int pci_find_device_id(struct pci_device_id *ids, int index,
 		       struct udevice **devp)
 {
 	struct udevice *bus;

 	/* Scan all known buses */
 	for (uclass_first_device(UCLASS_PCI, &bus);
 	     bus;
 	     uclass_next_device(&bus)) {
 		if (!pci_bus_find_devices(bus, ids, &index, devp))
 			return 0;
 	}
 	*devp = NULL;

 	return -ENODEV;
 }

 int pci_bus_write_config(struct udevice *bus, pci_dev_t bdf, int offset,
 			 unsigned long value, enum pci_size_t size)
 {
 	struct dm_pci_ops *ops;

 	ops = pci_get_ops(bus);
 	if (!ops->write_config)
 		return -ENOSYS;
 	return ops->write_config(bus, bdf, offset, value, size);
 }

 int pci_write_config(pci_dev_t bdf, int offset, unsigned long value,
 		     enum pci_size_t size)
 {
 	struct udevice *bus;
 	int ret;

 	ret = uclass_get_device_by_seq(UCLASS_PCI, PCI_BUS(bdf), &bus);
 	if (ret)
 		return ret;

 	return pci_bus_write_config(bus, bdf, offset, value, size);
 }

 int pci_write_config32(pci_dev_t bdf, int offset, u32 value)
 {
 	return pci_write_config(bdf, offset, value, PCI_SIZE_32);
 }

 int pci_write_config16(pci_dev_t bdf, int offset, u16 value)
 {
 	return pci_write_config(bdf, offset, value, PCI_SIZE_16);
 }

 int pci_write_config8(pci_dev_t bdf, int offset, u8 value)
 {
 	return pci_write_config(bdf, offset, value, PCI_SIZE_8);
 }

 int pci_bus_read_config(struct udevice *bus, pci_dev_t bdf, int offset,
 			unsigned long *valuep, enum pci_size_t size)
 {
 	struct dm_pci_ops *ops;

 	ops = pci_get_ops(bus);
 	if (!ops->read_config)
 		return -ENOSYS;
 	return ops->read_config(bus, bdf, offset, valuep, size);
 }

 int pci_read_config(pci_dev_t bdf, int offset, unsigned long *valuep,
 		    enum pci_size_t size)
 {
 	struct udevice *bus;
 	int ret;

 	ret = uclass_get_device_by_seq(UCLASS_PCI, PCI_BUS(bdf), &bus);
 	if (ret)
 		return ret;

 	return pci_bus_read_config(bus, bdf, offset, valuep, size);
 }

 int pci_read_config32(pci_dev_t bdf, int offset, u32 *valuep)
 {
 	unsigned long value;
 	int ret;

 	ret = pci_read_config(bdf, offset, &value, PCI_SIZE_32);
 	if (ret)
 		return ret;
 	*valuep = value;

 	return 0;
 }

 int pci_read_config16(pci_dev_t bdf, int offset, u16 *valuep)
 {
 	unsigned long value;
 	int ret;

 	ret = pci_read_config(bdf, offset, &value, PCI_SIZE_16);
 	if (ret)
 		return ret;
 	*valuep = value;

 	return 0;
 }

 int pci_read_config8(pci_dev_t bdf, int offset, u8 *valuep)
 {
 	unsigned long value;
 	int ret;

 	ret = pci_read_config(bdf, offset, &value, PCI_SIZE_8);
 	if (ret)
 		return ret;
 	*valuep = value;

 	return 0;
 }

 int pci_auto_config_devices(struct udevice *bus)
 {
 	struct pci_controller *hose = bus->uclass_priv;
 	unsigned int sub_bus;
 	struct udevice *dev;
 	int ret;

 	sub_bus = bus->seq;
 	debug("%s: start\n", __func__);
 	pciauto_config_init(hose);
 	for (ret = device_find_first_child(bus, &dev);
 	     !ret && dev;
 	     ret = device_find_next_child(&dev)) {
 		struct pci_controller *ctlr_hose;
 		unsigned int max_bus;

 		debug("%s: device %s\n", __func__, dev->name);

 		/* The root controller has the region information */
 		ctlr_hose = hose->ctlr->uclass_priv;
 		max_bus = pciauto_config_device(ctlr_hose, pci_get_bdf(dev));
 		sub_bus = max(sub_bus, max_bus);
 	}
 	debug("%s: done\n", __func__);

 	return sub_bus;
 }

 int dm_pci_hose_probe_bus(struct pci_controller *hose, pci_dev_t bdf)
 {
 	struct udevice *parent, *bus;
 	int sub_bus;
 	int ret;

 	debug("%s\n", __func__);
 	parent = hose->bus;

 	/* Find the bus within the parent */
 	ret = pci_bus_find_devfn(parent, bdf, &bus);
 	if (ret) {
 		debug("%s: Cannot find device %x on bus %s: %d\n", __func__,
 		      bdf, parent->name, ret);
 		return ret;
 	}

 	sub_bus = pci_get_bus_max() + 1;
 	debug("%s: bus = %d/%s\n", __func__, sub_bus, bus->name);
 	pciauto_prescan_setup_bridge(hose, bdf, sub_bus);

 	ret = device_probe(bus);
 	if (ret) {
 		debug("%s: Cannot probe bus bus %s: %d\n", __func__, bus->name,
 		      ret);
 		return ret;
 	}
 	if (sub_bus != bus->seq) {
 		printf("%s: Internal error, bus '%s' got seq %d, expected %d\n",
 		       __func__, bus->name, bus->seq, sub_bus);
 		return -EPIPE;
 	}
 	sub_bus = pci_get_bus_max();
 	pciauto_postscan_setup_bridge(hose, bdf, sub_bus);

 	return sub_bus;
 }

 /**
  * pci_match_one_device - Tell if a PCI device structure has a matching
  *                        PCI device id structure
  * @id: single PCI device id structure to match
  * @dev: the PCI device structure to match against
  *
  * Returns the matching pci_device_id structure or %NULL if there is no match.
  */
 static bool pci_match_one_id(const struct pci_device_id *id,
 			     const struct pci_device_id *find)
 {
 	if ((id->vendor == PCI_ANY_ID || id->vendor == find->vendor) &&
 	    (id->device == PCI_ANY_ID || id->device == find->device) &&
 	    (id->subvendor == PCI_ANY_ID || id->subvendor == find->subvendor) &&
 	    (id->subdevice == PCI_ANY_ID || id->subdevice == find->subdevice) &&
 	    !((id->class ^ find->class) & id->class_mask))
 		return true;

 	return false;
 }

 /**
  * pci_find_and_bind_driver() - Find and bind the right PCI driver
  *
  * This only looks at certain fields in the descriptor.
  */
 static int pci_find_and_bind_driver(struct udevice *parent,
 				    struct pci_device_id *find_id, pci_dev_t bdf,
 				    struct udevice **devp)
 {
 	struct pci_driver_entry *start, *entry;
 	const char *drv;
 	int n_ents;
 	int ret;
 	char name[30], *str;

 	*devp = NULL;

 	debug("%s: Searching for driver: vendor=%x, device=%x\n", __func__,
 	      find_id->vendor, find_id->device);
 	start = ll_entry_start(struct pci_driver_entry, pci_driver_entry);
 	n_ents = ll_entry_count(struct pci_driver_entry, pci_driver_entry);
 	for (entry = start; entry != start + n_ents; entry++) {
 		const struct pci_device_id *id;
 		struct udevice *dev;
 		const struct driver *drv;

 		for (id = entry->match;
 		     id->vendor || id->subvendor || id->class_mask;
 		     id++) {
 			if (!pci_match_one_id(id, find_id))
 				continue;

 			drv = entry->driver;
 			/*
 			 * We could pass the descriptor to the driver as
 			 * platdata (instead of NULL) and allow its bind()
 			 * method to return -ENOENT if it doesn't support this
 			 * device. That way we could continue the search to
 			 * find another driver. For now this doesn't seem
 			 * necesssary, so just bind the first match.
 			 */
 			ret = device_bind(parent, drv, drv->name, NULL, -1,
 					  &dev);
 			if (ret)
 				goto error;
 			debug("%s: Match found: %s\n", __func__, drv->name);
 			dev->driver_data = find_id->driver_data;
 			*devp = dev;
 			return 0;
 		}
 	}

 	/* Bind a generic driver so that the device can be used */
 	sprintf(name, "pci_%x:%x.%x", parent->seq, PCI_DEV(bdf),
 		PCI_FUNC(bdf));
 	str = strdup(name);
 	if (!str)
 		return -ENOMEM;
 	drv = (find_id->class >> 8) == PCI_CLASS_BRIDGE_PCI ? "pci_bridge_drv" :
 			"pci_generic_drv";
 	ret = device_bind_driver(parent, drv, str, devp);
 	if (ret) {
 		debug("%s: Failed to bind generic driver: %d", __func__, ret);
 		return ret;
 	}
 	debug("%s: No match found: bound generic driver instead\n", __func__);

 	return 0;

 error:
 	debug("%s: No match found: error %d\n", __func__, ret);
 	return ret;
 }

 int pci_bind_bus_devices(struct udevice *bus)
 {
 	ulong vendor, device;
 	ulong header_type;
 	pci_dev_t bdf, end;
 	bool found_multi;
 	int ret;

 	found_multi = false;
 	end = PCI_BDF(bus->seq, PCI_MAX_PCI_DEVICES - 1,
 		      PCI_MAX_PCI_FUNCTIONS - 1);
 	for (bdf = PCI_BDF(bus->seq, 0, 0); bdf < end;
 	     bdf += PCI_BDF(0, 0, 1)) {
 		struct pci_child_platdata *pplat;
 		struct udevice *dev;
 		ulong class;

 		if (PCI_FUNC(bdf) && !found_multi)
 			continue;
 		/* Check only the first access, we don't expect problems */
 		ret = pci_bus_read_config(bus, bdf, PCI_HEADER_TYPE,
 					  &header_type, PCI_SIZE_8);
 		if (ret)
 			goto error;
 		pci_bus_read_config(bus, bdf, PCI_VENDOR_ID, &vendor,
 				    PCI_SIZE_16);
 		if (vendor == 0xffff || vendor == 0x0000)
 			continue;

 		if (!PCI_FUNC(bdf))
 			found_multi = header_type & 0x80;

 		debug("%s: bus %d/%s: found device %x, function %d\n", __func__,
 		      bus->seq, bus->name, PCI_DEV(bdf), PCI_FUNC(bdf));
 		pci_bus_read_config(bus, bdf, PCI_DEVICE_ID, &device,
 				    PCI_SIZE_16);
 		pci_bus_read_config(bus, bdf, PCI_CLASS_REVISION, &class,
 				    PCI_SIZE_32);
 		class >>= 8;

 		/* Find this device in the device tree */
 		ret = pci_bus_find_devfn(bus, PCI_MASK_BUS(bdf), &dev);

 		/* Search for a driver */

 		/* If nothing in the device tree, bind a generic device */
 		if (ret == -ENODEV) {
 			struct pci_device_id find_id;
 			ulong val;

 			memset(&find_id, '\0', sizeof(find_id));
 			find_id.vendor = vendor;
 			find_id.device = device;
 			find_id.class = class;
 			if ((header_type & 0x7f) == PCI_HEADER_TYPE_NORMAL) {
 				pci_bus_read_config(bus, bdf,
 						    PCI_SUBSYSTEM_VENDOR_ID,
 						    &val, PCI_SIZE_32);
 				find_id.subvendor = val & 0xffff;
 				find_id.subdevice = val >> 16;
 			}
 			ret = pci_find_and_bind_driver(bus, &find_id, bdf,
 						       &dev);
 		}
 		if (ret)
 			return ret;

 		/* Update the platform data */
 		pplat = dev_get_parent_platdata(dev);
 		pplat->devfn = PCI_MASK_BUS(bdf);
 		pplat->vendor = vendor;
 		pplat->device = device;
 		pplat->class = class;
 	}

 	return 0;
 error:
 	printf("Cannot read bus configuration: %d\n", ret);

 	return ret;
 }

 static int pci_uclass_post_bind(struct udevice *bus)
 {
 	/*
 	 * Scan the device tree for devices. This does not probe the PCI bus,
 	 * as this is not permitted while binding. It just finds devices
 	 * mentioned in the device tree.
 	 *
 	 * Before relocation, only bind devices marked for pre-relocation
 	 * use.
 	 */
 	return dm_scan_fdt_node(bus, gd->fdt_blob, bus->of_offset,
 				gd->flags & GD_FLG_RELOC ? false : true);
 }

 static int decode_regions(struct pci_controller *hose, const void *blob,
 			  int parent_node, int node)
 {
 	int pci_addr_cells, addr_cells, size_cells;
 	int cells_per_record;
 	phys_addr_t addr;
 	const u32 *prop;
 	int len;
 	int i;

 	prop = fdt_getprop(blob, node, "ranges", &len);
 	if (!prop)
 		return -EINVAL;
 	pci_addr_cells = fdt_address_cells(blob, node);
 	addr_cells = fdt_address_cells(blob, parent_node);
 	size_cells = fdt_size_cells(blob, node);

 	/* PCI addresses are always 3-cells */
 	len /= sizeof(u32);
 	cells_per_record = pci_addr_cells + addr_cells + size_cells;
 	hose->region_count = 0;
 	debug("%s: len=%d, cells_per_record=%d\n", __func__, len,
 	      cells_per_record);
 	for (i = 0; i < MAX_PCI_REGIONS; i++, len -= cells_per_record) {
 		u64 pci_addr, addr, size;
 		int space_code;
 		u32 flags;
 		int type;

 		if (len < cells_per_record)
 			break;
 		flags = fdt32_to_cpu(prop[0]);
 		space_code = (flags >> 24) & 3;
 		pci_addr = fdtdec_get_number(prop + 1, 2);
 		prop += pci_addr_cells;
 		addr = fdtdec_get_number(prop, addr_cells);
 		prop += addr_cells;
 		size = fdtdec_get_number(prop, size_cells);
 		prop += size_cells;
 		debug("%s: region %d, pci_addr=%" PRIx64 ", addr=%" PRIx64
 		      ", size=%" PRIx64 ", space_code=%d\n", __func__,
 		      hose->region_count, pci_addr, addr, size, space_code);
 		if (space_code & 2) {
 			type = flags & (1U << 30) ? PCI_REGION_PREFETCH :
 					PCI_REGION_MEM;
 		} else if (space_code & 1) {
 			type = PCI_REGION_IO;
 		} else {
 			continue;
 		}
 		debug(" - type=%d\n", type);
 		pci_set_region(hose->regions + hose->region_count++, pci_addr,
 			       addr, size, type);
 	}

 	/* Add a region for our local memory */
 	addr = gd->ram_size;
 	if (gd->pci_ram_top && gd->pci_ram_top < addr)
 		addr = gd->pci_ram_top;
 	pci_set_region(hose->regions + hose->region_count++, 0, 0, addr,
 		       PCI_REGION_MEM | PCI_REGION_SYS_MEMORY);

 	return 0;
 }

 static int pci_uclass_pre_probe(struct udevice *bus)
 {
 	struct pci_controller *hose;
 	int ret;

 	debug("%s, bus=%d/%s, parent=%s\n", __func__, bus->seq, bus->name,
 	      bus->parent->name);
 	hose = bus->uclass_priv;

 	/* For bridges, use the top-level PCI controller */
 	if (device_get_uclass_id(bus->parent) == UCLASS_ROOT) {
 		hose->ctlr = bus;
 		ret = decode_regions(hose, gd->fdt_blob, bus->parent->of_offset,
 				bus->of_offset);
 		if (ret) {
 			debug("%s: Cannot decode regions\n", __func__);
 			return ret;
 		}
 	} else {
 		struct pci_controller *parent_hose;

 		parent_hose = dev_get_uclass_priv(bus->parent);
 		hose->ctlr = parent_hose->bus;
 	}
 	hose->bus = bus;
 	hose->first_busno = bus->seq;
 	hose->last_busno = bus->seq;

 	return 0;
 }

 static int pci_uclass_post_probe(struct udevice *bus)
 {
 	int ret;

 	/* Don't scan buses before relocation */
 	if (!(gd->flags & GD_FLG_RELOC))
 		return 0;

 	debug("%s: probing bus %d\n", __func__, bus->seq);
 	ret = pci_bind_bus_devices(bus);
 	if (ret)
 		return ret;

 #ifdef CONFIG_PCI_PNP
 	ret = pci_auto_config_devices(bus);
 #endif

 	return ret < 0 ? ret : 0;
 }

 static int pci_uclass_child_post_bind(struct udevice *dev)
 {
 	struct pci_child_platdata *pplat;
 	struct fdt_pci_addr addr;
 	int ret;

 	if (dev->of_offset == -1)
 		return 0;

 	/*
 	 * We could read vendor, device, class if available. But for now we
 	 * just check the address.
 	 */
 	pplat = dev_get_parent_platdata(dev);
 	ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
 				  FDT_PCI_SPACE_CONFIG, "reg", &addr);

 	if (ret) {
 		if (ret != -ENOENT)
 			return -EINVAL;
 	} else {
 		/* extract the bdf from fdt_pci_addr */
 		pplat->devfn = addr.phys_hi & 0xffff00;
 	}

 	return 0;
 }

 static int pci_bridge_read_config(struct udevice *bus, pci_dev_t bdf,
 				  uint offset, ulong *valuep,
 				  enum pci_size_t size)
 {
 	struct pci_controller *hose = bus->uclass_priv;

 	return pci_bus_read_config(hose->ctlr, bdf, offset, valuep, size);
 }

 static int pci_bridge_write_config(struct udevice *bus, pci_dev_t bdf,
 				   uint offset, ulong value,
 				   enum pci_size_t size)
 {
 	struct pci_controller *hose = bus->uclass_priv;

 	return pci_bus_write_config(hose->ctlr, bdf, offset, value, size);
 }

 UCLASS_DRIVER(pci) = {
 	.id		= UCLASS_PCI,
 	.name		= "pci",
 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
 	.post_bind	= pci_uclass_post_bind,
 	.pre_probe	= pci_uclass_pre_probe,
 	.post_probe	= pci_uclass_post_probe,
 	.child_post_bind = pci_uclass_child_post_bind,
 	.per_device_auto_alloc_size = sizeof(struct pci_controller),
 	.per_child_platdata_auto_alloc_size =
 			sizeof(struct pci_child_platdata),
 };

 static const struct dm_pci_ops pci_bridge_ops = {
 	.read_config	= pci_bridge_read_config,
 	.write_config	= pci_bridge_write_config,
 };

 static const struct udevice_id pci_bridge_ids[] = {
 	{ .compatible = "pci-bridge" },
 	{ }
 };

 U_BOOT_DRIVER(pci_bridge_drv) = {
 	.name		= "pci_bridge_drv",
 	.id		= UCLASS_PCI,
 	.of_match	= pci_bridge_ids,
 	.ops		= &pci_bridge_ops,
 };

 UCLASS_DRIVER(pci_generic) = {
 	.id		= UCLASS_PCI_GENERIC,
 	.name		= "pci_generic",
 };

 static const struct udevice_id pci_generic_ids[] = {
 	{ .compatible = "pci-generic" },
 	{ }
 };

 U_BOOT_DRIVER(pci_generic_drv) = {
 	.name		= "pci_generic_drv",
 	.id		= UCLASS_PCI_GENERIC,
 	.of_match	= pci_generic_ids,
 };
	/*
	* Copyright (c) 2014 Google, Inc
	* Written by Simon Glass <sjg@chromium.org>
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	#include <common.h>
	#include <dm.h>
	#include <errno.h>
	#include <fdtdec.h>
	#include <inttypes.h>
	#include <pci.h>
	#include <dm/lists.h>
	#include <dm/root.h>
	#include <dm/device-internal.h>

	DECLARE_GLOBAL_DATA_PTR;

	struct pci_controller *pci_bus_to_hose(int busnum)
	{
	struct udevice *bus;
	int ret;

	ret = uclass_get_device_by_seq(UCLASS_PCI, busnum, &bus);
	if (ret) {
	debug("%s: Cannot get bus %d: ret=%d\n", __func__, busnum, ret);
	return NULL;
	}
	return dev_get_uclass_priv(bus);
	}

	pci_dev_t pci_get_bdf(struct udevice *dev)
	{
	struct pci_child_platdata *pplat = dev_get_parent_platdata(dev);
	struct udevice *bus = dev->parent;

	return PCI_ADD_BUS(bus->seq, pplat->devfn);
	}

	/**
	* pci_get_bus_max() - returns the bus number of the last active bus
	*
	* @return last bus number, or -1 if no active buses
	*/
	static int pci_get_bus_max(void)
	{
	struct udevice *bus;
	struct uclass *uc;
	int ret = -1;

	ret = uclass_get(UCLASS_PCI, &uc);
	uclass_foreach_dev(bus, uc) {
	if (bus->seq > ret)
	ret = bus->seq;
	}

	debug("%s: ret=%d\n", __func__, ret);

	return ret;
	}

	int pci_last_busno(void)
	{
	struct pci_controller *hose;
	struct udevice *bus;
	struct uclass *uc;
	int ret;

	debug("pci_last_busno\n");
	ret = uclass_get(UCLASS_PCI, &uc);
	if (ret \|\| list_empty(&uc->dev_head))
	return -1;

	/* Probe the last bus */
	bus = list_entry(uc->dev_head.prev, struct udevice, uclass_node);
	debug("bus = %p, %s\n", bus, bus->name);
	assert(bus);
	ret = device_probe(bus);
	if (ret)
	return ret;

	/* If that bus has bridges, we may have new buses now. Get the last */
	bus = list_entry(uc->dev_head.prev, struct udevice, uclass_node);
	hose = dev_get_uclass_priv(bus);
	debug("bus = %s, hose = %p\n", bus->name, hose);

	return hose->last_busno;
	}

	int pci_get_ff(enum pci_size_t size)
	{
	switch (size) {
	case PCI_SIZE_8:
	return 0xff;
	case PCI_SIZE_16:
	return 0xffff;
	default:
	return 0xffffffff;
	}
	}

	int pci_bus_find_devfn(struct udevice *bus, pci_dev_t find_devfn,
	struct udevice **devp)
	{
	struct udevice *dev;

	for (device_find_first_child(bus, &dev);
	dev;
	device_find_next_child(&dev)) {
	struct pci_child_platdata *pplat;

	pplat = dev_get_parent_platdata(dev);
	if (pplat && pplat->devfn == find_devfn) {
	*devp = dev;
	return 0;
	}
	}

	return -ENODEV;
	}

	int pci_bus_find_bdf(pci_dev_t bdf, struct udevice **devp)
	{
	struct udevice *bus;
	int ret;

	ret = uclass_get_device_by_seq(UCLASS_PCI, PCI_BUS(bdf), &bus);
	if (ret)
	return ret;
	return pci_bus_find_devfn(bus, PCI_MASK_BUS(bdf), devp);
	}

	static int pci_device_matches_ids(struct udevice *dev,
	struct pci_device_id *ids)
	{
	struct pci_child_platdata *pplat;
	int i;

	pplat = dev_get_parent_platdata(dev);
	if (!pplat)
	return -EINVAL;
	for (i = 0; ids[i].vendor != 0; i++) {
	if (pplat->vendor == ids[i].vendor &&
	pplat->device == ids[i].device)
	return i;
	}

	return -EINVAL;
	}

	int pci_bus_find_devices(struct udevice bus, struct pci_device_id ids,
	int indexp, struct udevice *devp)
	{
	struct udevice *dev;

	/* Scan all devices on this bus */
	for (device_find_first_child(bus, &dev);
	dev;
	device_find_next_child(&dev)) {
	if (pci_device_matches_ids(dev, ids) >= 0) {
	if ((*indexp)-- <= 0) {
	*devp = dev;
	return 0;
	}
	}
	}

	return -ENODEV;
	}

	int pci_find_device_id(struct pci_device_id *ids, int index,
	struct udevice **devp)
	{
	struct udevice *bus;

	/* Scan all known buses */
	for (uclass_first_device(UCLASS_PCI, &bus);
	bus;
	uclass_next_device(&bus)) {
	if (!pci_bus_find_devices(bus, ids, &index, devp))
	return 0;
	}
	*devp = NULL;

	return -ENODEV;
	}

	int pci_bus_write_config(struct udevice *bus, pci_dev_t bdf, int offset,
	unsigned long value, enum pci_size_t size)
	{
	struct dm_pci_ops *ops;

	ops = pci_get_ops(bus);
	if (!ops->write_config)
	return -ENOSYS;
	return ops->write_config(bus, bdf, offset, value, size);
	}

	int pci_write_config(pci_dev_t bdf, int offset, unsigned long value,
	enum pci_size_t size)
	{
	struct udevice *bus;
	int ret;

	ret = uclass_get_device_by_seq(UCLASS_PCI, PCI_BUS(bdf), &bus);
	if (ret)
	return ret;

	return pci_bus_write_config(bus, bdf, offset, value, size);
	}

	int pci_write_config32(pci_dev_t bdf, int offset, u32 value)
	{
	return pci_write_config(bdf, offset, value, PCI_SIZE_32);
	}

	int pci_write_config16(pci_dev_t bdf, int offset, u16 value)
	{
	return pci_write_config(bdf, offset, value, PCI_SIZE_16);
	}

	int pci_write_config8(pci_dev_t bdf, int offset, u8 value)
	{
	return pci_write_config(bdf, offset, value, PCI_SIZE_8);
	}

	int pci_bus_read_config(struct udevice *bus, pci_dev_t bdf, int offset,
	unsigned long *valuep, enum pci_size_t size)
	{
	struct dm_pci_ops *ops;

	ops = pci_get_ops(bus);
	if (!ops->read_config)
	return -ENOSYS;
	return ops->read_config(bus, bdf, offset, valuep, size);
	}

	int pci_read_config(pci_dev_t bdf, int offset, unsigned long *valuep,
	enum pci_size_t size)
	{
	struct udevice *bus;
	int ret;

	ret = uclass_get_device_by_seq(UCLASS_PCI, PCI_BUS(bdf), &bus);
	if (ret)
	return ret;

	return pci_bus_read_config(bus, bdf, offset, valuep, size);
	}

	int pci_read_config32(pci_dev_t bdf, int offset, u32 *valuep)
	{
	unsigned long value;
	int ret;

	ret = pci_read_config(bdf, offset, &value, PCI_SIZE_32);
	if (ret)
	return ret;
	*valuep = value;

	return 0;
	}

	int pci_read_config16(pci_dev_t bdf, int offset, u16 *valuep)
	{
	unsigned long value;
	int ret;

	ret = pci_read_config(bdf, offset, &value, PCI_SIZE_16);
	if (ret)
	return ret;
	*valuep = value;

	return 0;
	}

	int pci_read_config8(pci_dev_t bdf, int offset, u8 *valuep)
	{
	unsigned long value;
	int ret;

	ret = pci_read_config(bdf, offset, &value, PCI_SIZE_8);
	if (ret)
	return ret;
	*valuep = value;

	return 0;
	}

	int pci_auto_config_devices(struct udevice *bus)
	{
	struct pci_controller *hose = bus->uclass_priv;
	unsigned int sub_bus;
	struct udevice *dev;
	int ret;

	sub_bus = bus->seq;
	debug("%s: start\n", __func__);
	pciauto_config_init(hose);
	for (ret = device_find_first_child(bus, &dev);
	!ret && dev;
	ret = device_find_next_child(&dev)) {
	struct pci_controller *ctlr_hose;
	unsigned int max_bus;

	debug("%s: device %s\n", __func__, dev->name);

	/* The root controller has the region information */
	ctlr_hose = hose->ctlr->uclass_priv;
	max_bus = pciauto_config_device(ctlr_hose, pci_get_bdf(dev));
	sub_bus = max(sub_bus, max_bus);
	}
	debug("%s: done\n", __func__);

	return sub_bus;
	}

	int dm_pci_hose_probe_bus(struct pci_controller *hose, pci_dev_t bdf)
	{
	struct udevice parent, bus;
	int sub_bus;
	int ret;

	debug("%s\n", __func__);
	parent = hose->bus;

	/* Find the bus within the parent */
	ret = pci_bus_find_devfn(parent, bdf, &bus);
	if (ret) {
	debug("%s: Cannot find device %x on bus %s: %d\n", __func__,
	bdf, parent->name, ret);
	return ret;
	}

	sub_bus = pci_get_bus_max() + 1;
	debug("%s: bus = %d/%s\n", __func__, sub_bus, bus->name);
	pciauto_prescan_setup_bridge(hose, bdf, sub_bus);

	ret = device_probe(bus);
	if (ret) {
	debug("%s: Cannot probe bus bus %s: %d\n", __func__, bus->name,
	ret);
	return ret;
	}
	if (sub_bus != bus->seq) {
	printf("%s: Internal error, bus '%s' got seq %d, expected %d\n",
	__func__, bus->name, bus->seq, sub_bus);
	return -EPIPE;
	}
	sub_bus = pci_get_bus_max();
	pciauto_postscan_setup_bridge(hose, bdf, sub_bus);

	return sub_bus;
	}

	/**
	* pci_match_one_device - Tell if a PCI device structure has a matching
	* PCI device id structure
	* @id: single PCI device id structure to match
	* @dev: the PCI device structure to match against
	*
	* Returns the matching pci_device_id structure or %NULL if there is no match.
	*/
	static bool pci_match_one_id(const struct pci_device_id *id,
	const struct pci_device_id *find)
	{
	if ((id->vendor == PCI_ANY_ID \|\| id->vendor == find->vendor) &&
	(id->device == PCI_ANY_ID \|\| id->device == find->device) &&
	(id->subvendor == PCI_ANY_ID \|\| id->subvendor == find->subvendor) &&
	(id->subdevice == PCI_ANY_ID \|\| id->subdevice == find->subdevice) &&
	!((id->class ^ find->class) & id->class_mask))
	return true;

	return false;
	}

	/**
	* pci_find_and_bind_driver() - Find and bind the right PCI driver
	*
	* This only looks at certain fields in the descriptor.
	*/
	static int pci_find_and_bind_driver(struct udevice *parent,
	struct pci_device_id *find_id, pci_dev_t bdf,
	struct udevice **devp)
	{
	struct pci_driver_entry start, entry;
	const char *drv;
	int n_ents;
	int ret;
	char name[30], *str;

	*devp = NULL;

	debug("%s: Searching for driver: vendor=%x, device=%x\n", __func__,
	find_id->vendor, find_id->device);
	start = ll_entry_start(struct pci_driver_entry, pci_driver_entry);
	n_ents = ll_entry_count(struct pci_driver_entry, pci_driver_entry);
	for (entry = start; entry != start + n_ents; entry++) {
	const struct pci_device_id *id;
	struct udevice *dev;
	const struct driver *drv;

	for (id = entry->match;
	id->vendor \|\| id->subvendor \|\| id->class_mask;
	id++) {
	if (!pci_match_one_id(id, find_id))
	continue;

	drv = entry->driver;
	/*
	* We could pass the descriptor to the driver as
	* platdata (instead of NULL) and allow its bind()
	* method to return -ENOENT if it doesn't support this
	* device. That way we could continue the search to
	* find another driver. For now this doesn't seem
	* necesssary, so just bind the first match.
	*/
	ret = device_bind(parent, drv, drv->name, NULL, -1,
	&dev);
	if (ret)
	goto error;
	debug("%s: Match found: %s\n", __func__, drv->name);
	dev->driver_data = find_id->driver_data;
	*devp = dev;
	return 0;
	}
	}

	/* Bind a generic driver so that the device can be used */
	sprintf(name, "pci_%x:%x.%x", parent->seq, PCI_DEV(bdf),
	PCI_FUNC(bdf));
	str = strdup(name);
	if (!str)
	return -ENOMEM;
	drv = (find_id->class >> 8) == PCI_CLASS_BRIDGE_PCI ? "pci_bridge_drv" :
	"pci_generic_drv";
	ret = device_bind_driver(parent, drv, str, devp);
	if (ret) {
	debug("%s: Failed to bind generic driver: %d", __func__, ret);
	return ret;
	}
	debug("%s: No match found: bound generic driver instead\n", __func__);

	return 0;

	error:
	debug("%s: No match found: error %d\n", __func__, ret);
	return ret;
	}

	int pci_bind_bus_devices(struct udevice *bus)
	{
	ulong vendor, device;
	ulong header_type;
	pci_dev_t bdf, end;
	bool found_multi;
	int ret;

	found_multi = false;
	end = PCI_BDF(bus->seq, PCI_MAX_PCI_DEVICES - 1,
	PCI_MAX_PCI_FUNCTIONS - 1);
	for (bdf = PCI_BDF(bus->seq, 0, 0); bdf < end;
	bdf += PCI_BDF(0, 0, 1)) {
	struct pci_child_platdata *pplat;
	struct udevice *dev;
	ulong class;

	if (PCI_FUNC(bdf) && !found_multi)
	continue;
	/* Check only the first access, we don't expect problems */
	ret = pci_bus_read_config(bus, bdf, PCI_HEADER_TYPE,
	&header_type, PCI_SIZE_8);
	if (ret)
	goto error;
	pci_bus_read_config(bus, bdf, PCI_VENDOR_ID, &vendor,
	PCI_SIZE_16);
	if (vendor == 0xffff \|\| vendor == 0x0000)
	continue;

	if (!PCI_FUNC(bdf))
	found_multi = header_type & 0x80;

	debug("%s: bus %d/%s: found device %x, function %d\n", __func__,
	bus->seq, bus->name, PCI_DEV(bdf), PCI_FUNC(bdf));
	pci_bus_read_config(bus, bdf, PCI_DEVICE_ID, &device,
	PCI_SIZE_16);
	pci_bus_read_config(bus, bdf, PCI_CLASS_REVISION, &class,
	PCI_SIZE_32);
	class >>= 8;

	/* Find this device in the device tree */
	ret = pci_bus_find_devfn(bus, PCI_MASK_BUS(bdf), &dev);

	/* Search for a driver */

	/* If nothing in the device tree, bind a generic device */
	if (ret == -ENODEV) {
	struct pci_device_id find_id;
	ulong val;

	memset(&find_id, '\0', sizeof(find_id));
	find_id.vendor = vendor;
	find_id.device = device;
	find_id.class = class;
	if ((header_type & 0x7f) == PCI_HEADER_TYPE_NORMAL) {
	pci_bus_read_config(bus, bdf,
	PCI_SUBSYSTEM_VENDOR_ID,
	&val, PCI_SIZE_32);
	find_id.subvendor = val & 0xffff;
	find_id.subdevice = val >> 16;
	}
	ret = pci_find_and_bind_driver(bus, &find_id, bdf,
	&dev);
	}
	if (ret)
	return ret;

	/* Update the platform data */
	pplat = dev_get_parent_platdata(dev);
	pplat->devfn = PCI_MASK_BUS(bdf);
	pplat->vendor = vendor;
	pplat->device = device;
	pplat->class = class;
	}

	return 0;
	error:
	printf("Cannot read bus configuration: %d\n", ret);

	return ret;
	}

	static int pci_uclass_post_bind(struct udevice *bus)
	{
	/*
	* Scan the device tree for devices. This does not probe the PCI bus,
	* as this is not permitted while binding. It just finds devices
	* mentioned in the device tree.
	*
	* Before relocation, only bind devices marked for pre-relocation
	* use.
	*/
	return dm_scan_fdt_node(bus, gd->fdt_blob, bus->of_offset,
	gd->flags & GD_FLG_RELOC ? false : true);
	}

	static int decode_regions(struct pci_controller hose, const void blob,
	int parent_node, int node)
	{
	int pci_addr_cells, addr_cells, size_cells;
	int cells_per_record;
	phys_addr_t addr;
	const u32 *prop;
	int len;
	int i;

	prop = fdt_getprop(blob, node, "ranges", &len);
	if (!prop)
	return -EINVAL;
	pci_addr_cells = fdt_address_cells(blob, node);
	addr_cells = fdt_address_cells(blob, parent_node);
	size_cells = fdt_size_cells(blob, node);

	/* PCI addresses are always 3-cells */
	len /= sizeof(u32);
	cells_per_record = pci_addr_cells + addr_cells + size_cells;
	hose->region_count = 0;
	debug("%s: len=%d, cells_per_record=%d\n", __func__, len,
	cells_per_record);
	for (i = 0; i < MAX_PCI_REGIONS; i++, len -= cells_per_record) {
	u64 pci_addr, addr, size;
	int space_code;
	u32 flags;
	int type;

	if (len < cells_per_record)
	break;
	flags = fdt32_to_cpu(prop[0]);
	space_code = (flags >> 24) & 3;
	pci_addr = fdtdec_get_number(prop + 1, 2);
	prop += pci_addr_cells;
	addr = fdtdec_get_number(prop, addr_cells);
	prop += addr_cells;
	size = fdtdec_get_number(prop, size_cells);
	prop += size_cells;
	debug("%s: region %d, pci_addr=%" PRIx64 ", addr=%" PRIx64
	", size=%" PRIx64 ", space_code=%d\n", __func__,
	hose->region_count, pci_addr, addr, size, space_code);
	if (space_code & 2) {
	type = flags & (1U << 30) ? PCI_REGION_PREFETCH :
	PCI_REGION_MEM;
	} else if (space_code & 1) {
	type = PCI_REGION_IO;
	} else {
	continue;
	}
	debug(" - type=%d\n", type);
	pci_set_region(hose->regions + hose->region_count++, pci_addr,
	addr, size, type);
	}

	/* Add a region for our local memory */
	addr = gd->ram_size;
	if (gd->pci_ram_top && gd->pci_ram_top < addr)
	addr = gd->pci_ram_top;
	pci_set_region(hose->regions + hose->region_count++, 0, 0, addr,
	PCI_REGION_MEM \| PCI_REGION_SYS_MEMORY);

	return 0;
	}

	static int pci_uclass_pre_probe(struct udevice *bus)
	{
	struct pci_controller *hose;
	int ret;

	debug("%s, bus=%d/%s, parent=%s\n", __func__, bus->seq, bus->name,
	bus->parent->name);
	hose = bus->uclass_priv;

	/* For bridges, use the top-level PCI controller */
	if (device_get_uclass_id(bus->parent) == UCLASS_ROOT) {
	hose->ctlr = bus;
	ret = decode_regions(hose, gd->fdt_blob, bus->parent->of_offset,
	bus->of_offset);
	if (ret) {
	debug("%s: Cannot decode regions\n", __func__);
	return ret;
	}
	} else {
	struct pci_controller *parent_hose;

	parent_hose = dev_get_uclass_priv(bus->parent);
	hose->ctlr = parent_hose->bus;
	}
	hose->bus = bus;
	hose->first_busno = bus->seq;
	hose->last_busno = bus->seq;

	return 0;
	}

	static int pci_uclass_post_probe(struct udevice *bus)
	{
	int ret;

	/* Don't scan buses before relocation */
	if (!(gd->flags & GD_FLG_RELOC))
	return 0;

	debug("%s: probing bus %d\n", __func__, bus->seq);
	ret = pci_bind_bus_devices(bus);
	if (ret)
	return ret;

	#ifdef CONFIG_PCI_PNP
	ret = pci_auto_config_devices(bus);
	#endif

	return ret < 0 ? ret : 0;
	}

	static int pci_uclass_child_post_bind(struct udevice *dev)
	{
	struct pci_child_platdata *pplat;
	struct fdt_pci_addr addr;
	int ret;

	if (dev->of_offset == -1)
	return 0;

	/*
	* We could read vendor, device, class if available. But for now we
	* just check the address.
	*/
	pplat = dev_get_parent_platdata(dev);
	ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
	FDT_PCI_SPACE_CONFIG, "reg", &addr);

	if (ret) {
	if (ret != -ENOENT)
	return -EINVAL;
	} else {
	/* extract the bdf from fdt_pci_addr */
	pplat->devfn = addr.phys_hi & 0xffff00;
	}

	return 0;
	}

	static int pci_bridge_read_config(struct udevice *bus, pci_dev_t bdf,
	uint offset, ulong *valuep,
	enum pci_size_t size)
	{
	struct pci_controller *hose = bus->uclass_priv;

	return pci_bus_read_config(hose->ctlr, bdf, offset, valuep, size);
	}

	static int pci_bridge_write_config(struct udevice *bus, pci_dev_t bdf,
	uint offset, ulong value,
	enum pci_size_t size)
	{
	struct pci_controller *hose = bus->uclass_priv;

	return pci_bus_write_config(hose->ctlr, bdf, offset, value, size);
	}

	UCLASS_DRIVER(pci) = {
	.id = UCLASS_PCI,
	.name = "pci",
	.flags = DM_UC_FLAG_SEQ_ALIAS,
	.post_bind = pci_uclass_post_bind,
	.pre_probe = pci_uclass_pre_probe,
	.post_probe = pci_uclass_post_probe,
	.child_post_bind = pci_uclass_child_post_bind,
	.per_device_auto_alloc_size = sizeof(struct pci_controller),
	.per_child_platdata_auto_alloc_size =
	sizeof(struct pci_child_platdata),
	};

	static const struct dm_pci_ops pci_bridge_ops = {
	.read_config = pci_bridge_read_config,
	.write_config = pci_bridge_write_config,
	};

	static const struct udevice_id pci_bridge_ids[] = {
	{ .compatible = "pci-bridge" },
	{ }
	};

	U_BOOT_DRIVER(pci_bridge_drv) = {
	.name = "pci_bridge_drv",
	.id = UCLASS_PCI,
	.of_match = pci_bridge_ids,
	.ops = &pci_bridge_ops,
	};

	UCLASS_DRIVER(pci_generic) = {
	.id = UCLASS_PCI_GENERIC,
	.name = "pci_generic",
	};

	static const struct udevice_id pci_generic_ids[] = {
	{ .compatible = "pci-generic" },
	{ }
	};

	U_BOOT_DRIVER(pci_generic_drv) = {
	.name = "pci_generic_drv",
	.id = UCLASS_PCI_GENERIC,
	.of_match = pci_generic_ids,
	};