src/device: Get device structure by path type

Add helper function to find a device by path type
in the device tree.

Change-Id: I8846f63bd2488788ea3c7ab5154e7cf431a252bc
Credits-to: Aaron Durbin <adurbin@chromium.org>
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Signed-off-by: Dhaval V Sharma <dhaval.v.sharma@intel.com>
Reviewed-on: https://review.coreboot.org/17731
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)

src/device/device_util.c

@@ -130,6 +130,31 @@ device_t dev_find_lapic(unsigned apic_id)
 	return result;
 }
 
+/**
+ * Given a Device Path Type, find the device structure.
+ *
+ * @param prev_match The previously matched device instance.
+ * @param path_type The Device Path Type.
+ * @return Pointer to the device structure (if found), 0 otherwise.
+ */
+device_t dev_find_path(device_t prev_match, enum device_path_type path_type)
+{
+	device_t dev, result = NULL;
+
+	if (prev_match == NULL)
+		prev_match = all_devices;
+	else
+		prev_match = prev_match->next;
+
+	for (dev = prev_match; dev; dev = dev->next) {
+		if (dev->path.type == path_type) {
+			result = dev;
+			break;
+		}
+	}
+	return result;
+}
+
 /**
  * Find a device of a given vendor and type.
  *

src/include/device/device.h

@@ -195,6 +195,7 @@ device_t find_dev_path(struct bus *parent, struct device_path *path);
 device_t alloc_find_dev(struct bus *parent, struct device_path *path);
 device_t dev_find_device (u16 vendor, u16 device, device_t from);
 device_t dev_find_class (unsigned int class, device_t from);
+device_t dev_find_path(device_t prev_match, enum device_path_type path_type);
 device_t dev_find_slot (unsigned int bus, unsigned int devfn);
 device_t dev_find_slot_on_smbus (unsigned int bus, unsigned int addr);
 device_t dev_find_slot_pnp(u16 port, u16 device);