bluetooth serdev driver for wi2wi w2cbw003?

["H. Nikolaus Schaller" <hns@goldelico.com>]

Hi,
what is the best strategy to support the above mentioned
bluetooth (+ wlan combo) chip by a serdev driver?

We have the chip up and running for long time with using
hciattach on the serial port (and no vendor specific
functions like firmware download). And our own out-of-tree
driver to control the power on/off.

But we now want to be able to use hcicontrol hci0 up/down
to control a regulator like the hci_ll.c driver is doing
with a gpio.

Which means we would like to use this DT:

&uart1 {
	pinctrl-names = "default";
	pinctrl-0 = <&uart1_pins>;

	bluetooth: bluetooth {
		compatible = "wi2wi,w2cbw003-bt";
		vdd-supply = <&vaux4>;
	};
};

Does such a driver already exist so that we just have to add
.compatible = "wi2wi,w2cbw003-bt" or should we start to
make one based on by hci_ll.c by removing firmware download
and special ti protocol handling?

Other maybe relevant information from the w2cbw003 data sheet:
- Bluetooth technology based on CSR BC04-ROM
- Data rate up to 3 Mbps for Bluetooth EDR
- It uses a standard HCI interface – any commercial stack or profile supporting the standard interface will work with W2CBW003.

Any directions are welcome.

BR and thanks,
Nikolaus