This scan code set is more advanced than the basic scan code set 1, and
is required to be supported for some bare metal hardware that might not
properly enable the PS2 first port translation in the i8042 controller.
LibWeb can now also generate bindings for keyboard events like the Pause
key, as well as other function keys (such as Right Alt, etc).
The logic for handling scan code sets is implemented by the PS2 keyboard
driver and is abstracted from the main HID KeyboardDevice code which
only handles "standard" KeyEvent(s).
This scan code set is more advanced than the basic scan code set 1, and
is required to be supported for some bare metal hardware that might not
properly enable the PS2 first port translation in the i8042 controller.
LibWeb can now also generate bindings for keyboard events like the Pause
key, as well as other function keys (such as Right Alt, etc).
The logic for handling scan code sets is implemented by the PS2 keyboard
driver and is abstracted from the main HID KeyboardDevice code which
only handles "standard" KeyEvent(s).
To ensure actual PS2 code is not tied to the i8042 code, we make them
separated in the following ways:
- PS2KeyboardDevice and PS2MouseDevice classes are no longer inheriting
from the IRQHandler class. Instead we have specific IRQHandler derived
class for the i8042 controller implementation, which is used to ensure
that we don't end up mixing PS2 code with low-level interrupt handling
functionality. In the future this means that we could add a driver for
other PS2 controllers that might have only one interrupt handler but
multiple PS2 devices are attached, therefore, making it easier to put
the right propagation flow from the controller driver all the way to
the HID core code.
- A simple abstraction layer is added between the PS2 command set which
devices could use and the actual implementation low-level commands.
This means that the code in PS2MouseDevice and PS2KeyboardDevice
classes is no longer tied to i8042 implementation-specific commands,
so now these objects could send PS2 commands to their PS2 controller
and get a PS2Response which abstracts the given response too.
For a very long time, the kernel had only support for basic PS/2 devices
such as the PS2 AT keyboard and regular PS2 mouse (with a scroll wheel).
To adapt to this, we had very simple abstractions in place, essentially,
the PS2 devices were registered as IRQ handlers (IRQ 1 and 12), and when
an interrupt was triggered, we simply had to tell the I8042Controller to
fetch a byte for us, then send it back to the appropriate device for
further processing and queueing of either a key event, or a mouse packet
so userspace can do something meaningful about it.
When we added the VMWare mouse integration feature it was easily adapted
to this paradigm, requiring small changes across the handling code for
these devices.
This patch is a major cleanup for any future advancements in the HID
subsystem.
It ensures we do things in a much more sane manner:
- We stop using LockRefPtrs. Currently, after the initialization of the
i8042 controller, we never have to change RefPtrs in that class, as we
simply don't support PS2 hotplugging currently.
Also, we remove the unnecessary getters for keyboard and mouse devices
which also returned a LockRefPtr.
- There's a clear separation between PS2 devices and the actual device
nodes that normally exist in /dev. PS2 devices are not polled, because
when the user uses these devices, they will trigger an IRQ which when
is handled, could produce either a MousePacket or KeyEvent, depending
on the device state.
The separation is crucial for buses that are polled, for example - USB
is a polled bus and will not generate an IRQ for HID devices.
- There's a clear separation in roles of each structure. The PS2 devices
which are attached to a I8042Controller object are managing the device
state, while the generic MouseDevice and KeyboardDevice manage all
related tasks of a CharacterDevice, as well as interpreting scan code
events and mouse relative/absolute coordinates.
Use the new class in HID code, because all other HID device controllers
will be using this class as their parent class.
Hence, we no longer keep a reference to any PS/2 device in HIDManagement
and rely on HIDController derived classes to do this for us.
It also means that we removed another instance of a LockRefPtr, which
is designated to be removed and is replaced by the better pattern of
SpinlockProtected<RefPtr<>> instead.
This seems to work perfectly OK on my ICH7 test machine and also it
works on QEMU, so it is probably OK to restore this.
This will ensure we always get scan code set 1 input, because we enable
scan code set 2 and PS/2 translation on the first (keyboard) port.
The setting of scan code set sequence is removed, as it's buggy and
could lead the controller to fail immediately when doing self-test
afterwards. We will restore it when we understand how to do so safely.
Allow the user to determine a preferred detection path with a new kernel
command line argument. The defualt option is to check i8042 presence
with an ACPI check and if necessary - an "aggressive" test to determine
i8042 existence in the system.
Also, keep the i8042 controller pointer on the stack, so don't assign
m_i8042_controller member pointer if it does not exist.
