devicetree: Add USB device type

This commit adds support for describing USB ports in devicetree.cb.
It allows a USB port location to be described in the tree with
configuration information, and ACPI code to be generated that
provides this information to the OS.

A new scan_usb_bus() is added that will scan bridges for devices so
a tree of ports and hubs can be created.

The device address is computed with a 'port type' and a 'port id'
which is flexible for SOC to handle depending on their specific USB
setup and allows USB2 and USB3 ports to be described separately.

For example a board may have devices on two ports, one with a USB2
device and one with a USB3 device, both of which are connected to an
xHCI controller with a root hub:

     xHCI
       |
    RootHub
    |     |
USB2[0]  USB3[2]

device pci 14.0 on
  chip drivers/usb/acpi
    register "name" = ""Root Hub""
    device usb 0.0 on
      chip drivers/usb/acpi
        register "name" = ""USB 2.0 Port 0""
        device usb 2.0 on end
      end
      chip drivers/usb/acpi
        register "name" = ""USB 3.0 Port 2""
        device usb 3.2 on end
      end
    end
  end
end

Change-Id: I64e6eba503cdab49be393465b535e139a8c90ef4
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/26169
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/device/root_device.c b/src/device/root_device.c
index a19028d43d..b0b6712ebb 100644
--- a/src/device/root_device.c
+++ b/src/device/root_device.c
@@ -72,6 +72,21 @@ 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));
+
+	scan_static_bus(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;