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>

2 files changed, 26 insertions, 0 deletions

diff --git a/src/device/device_util.c b/src/device/device_util.c
index a64b63ae23..aad3b4ba26 100644
--- a/src/device/device_util.c
+++ b/src/device/device_util.c
@@ -256,6 +256,9 @@ u32 dev_path_encode(const struct device *dev)
 	case DEVICE_PATH_SPI:
 		ret |= dev->path.spi.cs;
 		break;
+	case DEVICE_PATH_USB:
+		ret |= dev->path.usb.port_type << 8 || dev->path.usb.port_id;
+		break;
 	case DEVICE_PATH_NONE:
 	case DEVICE_PATH_MMIO:  /* don't care */
 	default:
@@ -333,6 +336,10 @@ const char *dev_path(const struct device *dev)
 			snprintf(buffer, sizeof (buffer), "SPI: %02x",
 				 dev->path.spi.cs);
 			break;
+		case DEVICE_PATH_USB:
+			snprintf(buffer, sizeof (buffer), "USB%u port %u",
+				 dev->path.usb.port_type, dev->path.usb.port_id);
+			break;
 		case DEVICE_PATH_MMIO:
 			snprintf(buffer, sizeof (buffer), "MMIO: %08x",
 				 dev->path.mmio.addr);
@@ -411,6 +418,10 @@ int path_eq(struct device_path *path1, struct device_path *path2)
 	case DEVICE_PATH_SPI:
 		equal = (path1->spi.cs == path2->spi.cs);
 		break;
+	case DEVICE_PATH_USB:
+		equal = (path1->usb.port_type == path2->usb.port_type) &&
+			(path1->usb.port_id == path2->usb.port_id);
+		break;
 	case DEVICE_PATH_MMIO:
 		equal = (path1->mmio.addr == path2->mmio.addr);
 		break;
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;