Kernel/USB: Replace PortNumber enum with a raw u8

A hub can technically have up to 255 ports, given that bNbrPorts is a
u8 and the DeviceRemovable field is a VLA to support up to 255 ports.

Source: USB 2.0 Specification Section 11.23.2.1

That means this enum is not going to scale well in terms of size.
Replacing it with a raw u8 allows me to remove the two port assumption
and a cast.

Kernel/Bus/USB/USBDevice.cpp

@@ -16,7 +16,7 @@
 
 namespace Kernel::USB {
 
-KResultOr<NonnullRefPtr<Device>> Device::try_create(USBController const& controller, PortNumber port, DeviceSpeed speed)
+KResultOr<NonnullRefPtr<Device>> Device::try_create(USBController const& controller, u8 port, DeviceSpeed speed)
 {
     auto pipe_or_error = Pipe::try_create_pipe(controller, Pipe::Type::Control, Pipe::Direction::Bidirectional, 0, 8, 0);
     if (pipe_or_error.is_error())
@@ -33,7 +33,7 @@ KResultOr<NonnullRefPtr<Device>> Device::try_create(USBController const& control
     return device.release_nonnull();
 }
 
-Device::Device(USBController const& controller, PortNumber port, DeviceSpeed speed, NonnullOwnPtr<Pipe> default_pipe)
+Device::Device(USBController const& controller, u8 port, DeviceSpeed speed, NonnullOwnPtr<Pipe> default_pipe)
     : m_device_port(port)
     , m_device_speed(speed)
     , m_address(0)
@@ -42,7 +42,7 @@ Device::Device(USBController const& controller, PortNumber port, DeviceSpeed spe
 {
 }
 
-Device::Device(NonnullRefPtr<USBController> controller, u8 address, PortNumber port, DeviceSpeed speed, NonnullOwnPtr<Pipe> default_pipe)
+Device::Device(NonnullRefPtr<USBController> controller, u8 address, u8 port, DeviceSpeed speed, NonnullOwnPtr<Pipe> default_pipe)
     : m_device_port(port)
     , m_device_speed(speed)
     , m_address(address)

Kernel/Bus/USB/USBDevice.h

@@ -21,26 +21,21 @@ class USBController;
 // https://www.ftdichip.com/Support/Documents/TechnicalNotes/TN_113_Simplified%20Description%20of%20USB%20Device%20Enumeration.pdf
 class Device : public RefCounted<Device> {
 public:
-    enum class PortNumber : u8 {
-        Port1 = 0,
-        Port2
-    };
-
     enum class DeviceSpeed : u8 {
         FullSpeed = 0,
         LowSpeed
     };
 
 public:
-    static KResultOr<NonnullRefPtr<Device>> try_create(USBController const&, PortNumber, DeviceSpeed);
+    static KResultOr<NonnullRefPtr<Device>> try_create(USBController const&, u8, DeviceSpeed);
 
-    Device(USBController const&, PortNumber, DeviceSpeed, NonnullOwnPtr<Pipe> default_pipe);
+    Device(USBController const&, u8, DeviceSpeed, NonnullOwnPtr<Pipe> default_pipe);
     Device(Device const& device, NonnullOwnPtr<Pipe> default_pipe);
     virtual ~Device();
 
     KResult enumerate_device();
 
-    PortNumber port() const { return m_device_port; }
+    u8 port() const { return m_device_port; }
     DeviceSpeed speed() const { return m_device_speed; }
 
     u8 address() const { return m_address; }
@@ -51,9 +46,9 @@ public:
     USBController const& controller() const { return *m_controller; }
 
 protected:
-    Device(NonnullRefPtr<USBController> controller, u8 address, PortNumber port, DeviceSpeed speed, NonnullOwnPtr<Pipe> default_pipe);
+    Device(NonnullRefPtr<USBController> controller, u8 address, u8 port, DeviceSpeed speed, NonnullOwnPtr<Pipe> default_pipe);
 
-    PortNumber m_device_port;   // What port is this device attached to
+    u8 m_device_port { 0 };     // What port is this device attached to. NOTE: This is 1-based.
     DeviceSpeed m_device_speed; // What speed is this device running at
     u8 m_address { 0 };         // USB address assigned to this device
 

Kernel/Bus/USB/USBHub.cpp

@@ -45,7 +45,7 @@ KResultOr<NonnullRefPtr<Hub>> Hub::try_create_from_device(Device const& device)
 }
 
 Hub::Hub(NonnullRefPtr<USBController> controller, DeviceSpeed device_speed, NonnullOwnPtr<Pipe> default_pipe)
-    : Device(move(controller), PortNumber::Port1, device_speed, move(default_pipe))
+    : Device(move(controller), 1 /* Port 1 */, device_speed, move(default_pipe))
 {
 }
 
@@ -260,8 +260,7 @@ void Hub::check_for_port_updates()
                 // FIXME: Check for high speed.
                 auto speed = port_status.status & PORT_STATUS_LOW_SPEED_DEVICE_ATTACHED ? USB::Device::DeviceSpeed::LowSpeed : USB::Device::DeviceSpeed::FullSpeed;
 
-                // FIXME: This only assumes two ports.
-                auto device_or_error = USB::Device::try_create(m_controller, port_number == 1 ? PortNumber::Port1 : PortNumber::Port2, speed);
+                auto device_or_error = USB::Device::try_create(m_controller, port_number, speed);
                 if (device_or_error.is_error()) {
                     dbgln("USB Hub: Failed to create device for port {}: {}", port_number, device_or_error.error());
                     return;
@@ -290,8 +289,7 @@ void Hub::check_for_port_updates()
 
                 Device* device_to_remove = nullptr;
                 for (auto& child : m_children) {
-                    // FIXME: This kinda sucks.
-                    if (port_number - 1 == (u8)child.port()) {
+                    if (port_number == child.port()) {
                         device_to_remove = &child;
                         break;
                     }