1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2c07158..ed113bf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -722,3 +722,68 @@ void pci_init(void)
 	/* now call board specific pci_init()... */
 	pci_init_board();
 }
+
+/* Returns the address of the requested capability structure within the
+ * device's PCI configuration space or 0 in case the device does not
+ * support it.
+ * */
+int pci_hose_find_capability(struct pci_controller *hose, pci_dev_t dev,
+			     int cap)
+{
+	int pos;
+	u8 hdr_type;
+
+	pci_hose_read_config_byte(hose, dev, PCI_HEADER_TYPE, &hdr_type);
+
+	pos = pci_hose_find_cap_start(hose, dev, hdr_type & 0x7F);
+
+	if (pos)
+		pos = pci_find_cap(hose, dev, pos, cap);
+
+	return pos;
+}
+
+/* Find the header pointer to the Capabilities*/
+int pci_hose_find_cap_start(struct pci_controller *hose, pci_dev_t dev,
+			    u8 hdr_type)
+{
+	u16 status;
+
+	pci_hose_read_config_word(hose, dev, PCI_STATUS, &status);
+
+	if (!(status & PCI_STATUS_CAP_LIST))
+		return 0;
+
+	switch (hdr_type) {
+	case PCI_HEADER_TYPE_NORMAL:
+	case PCI_HEADER_TYPE_BRIDGE:
+		return PCI_CAPABILITY_LIST;
+	case PCI_HEADER_TYPE_CARDBUS:
+		return PCI_CB_CAPABILITY_LIST;
+	default:
+		return 0;
+	}
+}
+
+int pci_find_cap(struct pci_controller *hose, pci_dev_t dev, int pos, int cap)
+{
+	int ttl = PCI_FIND_CAP_TTL;
+	u8 id;
+	u8 next_pos;
+
+	while (ttl--) {
+		pci_hose_read_config_byte(hose, dev, pos, &next_pos);
+		if (next_pos < CAP_START_POS)
+			break;
+		next_pos &= ~3;
+		pos = (int) next_pos;
+		pci_hose_read_config_byte(hose, dev,
+					  pos + PCI_CAP_LIST_ID, &id);
+		if (id == 0xff)
+			break;
+		if (id == cap)
+			return pos;
+		pos += PCI_CAP_LIST_NEXT;
+	}
+	return 0;
+}