device/root_device: Consolidate common _scan_bus() functions

scan_usb_bus() and root_dev_scan_bus() had the very same implementation.
So rename the latter to scan_static_bus() and use that for both cases.

Change-Id: If0aba9c690b23e3716f2d47ff7a8c3e8f6d82679
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31901
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/device/root_device.c

@@ -65,21 +65,6 @@ void scan_lpc_bus(struct device *bus)
 	printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
 }
 
-void scan_usb_bus(struct device *bus)
-{
-	struct bus *link;
-
-	printk(BIOS_SPEW, "%s for %s\n", __func__, dev_path(bus));
-
-	enable_static_devices(bus);
-
-	/* Scan bridges in case this device is a hub */
-	for (link = bus->link_list; link; link = link->next)
-		scan_bridges(link);
-
-	printk(BIOS_SPEW, "%s for %s done\n", __func__, dev_path(bus));
-}
-
 void scan_generic_bus(struct device *bus)
 {
 	struct device *child;
@@ -116,14 +101,17 @@ void scan_smbus(struct device *bus)
 	scan_generic_bus(bus);
 }
 
-/**
- * Scan root bus for generic systems.
+/*
+ * Default scan_bus() implementation
  *
- * This function is the default scan_bus() method of the root device.
+ * This is the default implementation for buses that can't
+ * be probed at runtime. It simply walks through the topology
+ * given by the mainboard's `devicetree.cb`.
  *
- * @param root The root device structure.
+ * First, all direct descendants of the given device are
+ * enabled. Then, downstream buses are scanned.
  */
-static void root_dev_scan_bus(struct device *bus)
+void scan_static_bus(struct device *bus)
 {
 	struct bus *link;
 
@@ -162,7 +150,7 @@ struct device_operations default_dev_ops_root = {
 	.set_resources    = DEVICE_NOOP,
 	.enable_resources = DEVICE_NOOP,
 	.init             = DEVICE_NOOP,
-	.scan_bus         = root_dev_scan_bus,
+	.scan_bus         = scan_static_bus,
 	.reset_bus        = root_dev_reset,
 #if CONFIG(HAVE_ACPI_TABLES)
 	.acpi_name        = root_dev_acpi_name,

src/drivers/usb/acpi/usb_acpi.c

@@ -85,7 +85,7 @@ static struct device_operations usb_acpi_ops = {
 	.read_resources			= DEVICE_NOOP,
 	.set_resources			= DEVICE_NOOP,
 	.enable_resources		= DEVICE_NOOP,
-	.scan_bus			= scan_usb_bus,
+	.scan_bus			= scan_static_bus,
 	.acpi_fill_ssdt_generator	= usb_acpi_fill_ssdt_generator,
 };
 

src/include/device/device.h

@@ -331,7 +331,7 @@ void enable_static_devices(struct device *bus);
 void scan_smbus(struct device *bus);
 void scan_generic_bus(struct device *bus);
 void scan_lpc_bus(struct device *bus);
-void scan_usb_bus(struct device *bus);
+void scan_static_bus(struct device *bus);
 
 #endif /* !defined(__ROMCC__) */
 

src/soc/amd/picasso/usb.c

@@ -60,7 +60,7 @@ static struct device_operations usb_ops = {
 	.set_resources = pci_dev_set_resources,
 	.enable_resources = pci_dev_enable_resources,
 	.init = set_usb_over_current,
-	.scan_bus = scan_usb_bus,
+	.scan_bus = scan_static_bus,
 	.acpi_name = soc_acpi_name,
 	.ops_pci = &lops_pci,
 };

src/soc/amd/stoneyridge/usb.c

@@ -63,7 +63,7 @@ static struct device_operations usb_ops = {
 	.set_resources = pci_dev_set_resources,
 	.enable_resources = pci_dev_enable_resources,
 	.init = set_usb_over_current,
-	.scan_bus = scan_usb_bus,
+	.scan_bus = scan_static_bus,
 	.acpi_name = soc_acpi_name,
 	.ops_pci = &lops_pci,
 };

src/soc/intel/common/block/xhci/xhci.c

@@ -113,7 +113,7 @@ static struct device_operations usb_xhci_ops = {
 	.enable_resources	= pci_dev_enable_resources,
 	.init			= soc_xhci_init,
 	.ops_pci		= &pci_dev_ops_pci,
-	.scan_bus		= scan_usb_bus,
+	.scan_bus		= scan_static_bus,
 #if CONFIG(HAVE_ACPI_TABLES)
 	.acpi_name		= soc_acpi_name,
 #endif