dm: pci: Add a driver-model version of pci_find_class()

Add a function which scans the driver model device information rather
than scanning the PCI bus again.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

drivers/pci/pci-uclass.c

@@ -234,6 +234,26 @@ int dm_pci_find_device(unsigned int vendor, unsigned int device, int index,
 	return -ENODEV;
 }
 
+int dm_pci_find_class(uint find_class, int index, struct udevice **devp)
+{
+	struct udevice *dev;
+
+	/* Scan all known buses */
+	for (pci_find_first_device(&dev);
+	     dev;
+	     pci_find_next_device(&dev)) {
+		struct pci_child_platdata *pplat = dev_get_parent_platdata(dev);
+
+		if (pplat->class == find_class && !index--) {
+			*devp = dev;
+			return device_probe(*devp);
+		}
+	}
+	*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)
 {

include/pci.h

@@ -1179,6 +1179,16 @@ int dm_pci_find_device(unsigned int vendor, unsigned int device, int index,
 		       struct udevice **devp);
 
 /**
+ * dm_pci_find_class() - find a device by class
+ *
+ * @find_class: 3-byte (24-bit) class value to find
+ * @index:	0 to find the first match, 1 for second, etc.
+ * @devp:	Returns pointer to the device, if found
+ * @return 0 if found, -ve on error
+ */
+int dm_pci_find_class(uint find_class, int index, struct udevice **devp);
+
+/**
  * struct dm_pci_emul_ops - PCI device emulator operations
  */
 struct dm_pci_emul_ops {