dm: pci: Add a function to find the regions for a PCI bus

This function looks up the controller and returns a pointer to each region
type.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

drivers/pci/pci-uclass.c

@@ -974,6 +974,36 @@ ulong pci_conv_size_to_32(ulong old, ulong value, uint offset,
 	return value;
 }
 
+int pci_get_regions(struct udevice *dev, struct pci_region **iop,
+		    struct pci_region **memp, struct pci_region **prefp)
+{
+	struct udevice *bus = pci_get_controller(dev);
+	struct pci_controller *hose = dev_get_uclass_priv(bus);
+	int i;
+
+	*iop = NULL;
+	*memp = NULL;
+	*prefp = NULL;
+	for (i = 0; i < hose->region_count; i++) {
+		switch (hose->regions[i].flags) {
+		case PCI_REGION_IO:
+			if (!*iop || (*iop)->size < hose->regions[i].size)
+				*iop = hose->regions + i;
+			break;
+		case PCI_REGION_MEM:
+			if (!*memp || (*memp)->size < hose->regions[i].size)
+				*memp = hose->regions + i;
+			break;
+		case (PCI_REGION_MEM | PCI_REGION_PREFETCH):
+			if (!*prefp || (*prefp)->size < hose->regions[i].size)
+				*prefp = hose->regions + i;
+			break;
+		}
+	}
+
+	return (*iop != NULL) + (*memp != NULL) + (*prefp != NULL);
+}
+
 UCLASS_DRIVER(pci) = {
 	.id		= UCLASS_PCI,
 	.name		= "pci",

include/pci.h

@@ -1131,6 +1131,18 @@ ulong pci_conv_size_to_32(ulong old, ulong value, uint offset,
 struct udevice *pci_get_controller(struct udevice *dev);
 
 /**
+ * pci_get_regions() - obtain pointers to all the region types
+ *
+ * @dev:	Device to check
+ * @iop:	Returns a pointer to the I/O region, or NULL if none
+ * @memp:	Returns a pointer to the memory region, or NULL if none
+ * @prefp:	Returns a pointer to the pre-fetch region, or NULL if none
+ * @return the number of non-NULL regions returned, normally 3
+ */
+int pci_get_regions(struct udevice *dev, struct pci_region **iop,
+		    struct pci_region **memp, struct pci_region **prefp);
+
+/**
  * struct dm_pci_emul_ops - PCI device emulator operations
  */
 struct dm_pci_emul_ops {