dm: pci: Add an inline API to test if a device is on a PCI bus

Introduce device_is_on_pci_bus() which can be utilized by driver
to test if a device is on a PCI bus.

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

2 files changed, 13 insertions, 2 deletions

diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index ea70853da2..0756bbe8f1 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -238,7 +238,7 @@ int dm_pci_write_config(struct udevice *dev, int offset, unsigned long value,
 {
 	struct udevice *bus;
 
-	for (bus = dev; device_get_uclass_id(bus->parent) == UCLASS_PCI;)
+	for (bus = dev; device_is_on_pci_bus(bus);)
 		bus = bus->parent;
 	return pci_bus_write_config(bus, pci_get_bdf(dev), offset, value, size);
 }
@@ -303,7 +303,7 @@ int dm_pci_read_config(struct udevice *dev, int offset, unsigned long *valuep,
 {
 	struct udevice *bus;
 
-	for (bus = dev; device_get_uclass_id(bus->parent) == UCLASS_PCI;)
+	for (bus = dev; device_is_on_pci_bus(bus);)
 		bus = bus->parent;
 	return pci_bus_read_config(bus, pci_get_bdf(dev), offset, valuep,
 				   size);
diff --git a/include/dm/device.h b/include/dm/device.h
index a239be6469..85196124b4 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -485,6 +485,17 @@ bool device_is_last_sibling(struct udevice *dev);
  */
 int device_set_name(struct udevice *dev, const char *name);
 
+/**
+ * device_is_on_pci_bus - Test if a device is on a PCI bus
+ *
+ * @dev:	device to test
+ * @return:	true if it is on a PCI bus, false otherwise
+ */
+static inline bool device_is_on_pci_bus(struct udevice *dev)
+{
+	return device_get_uclass_id(dev->parent) == UCLASS_PCI;
+}
+
 /* device resource management */
 typedef void (*dr_release_t)(struct udevice *dev, void *res);
 typedef int (*dr_match_t)(struct udevice *dev, void *res, void *match_data);