[Bluetooth] Add UART driver for Texas Instruments' BRF63xx chips

Add support for Texas Instruments' HCI Low Level (HCILL) Bluetooth
protocol, which is a power management extension to H4. The HCILL is
widely used by TI's BRF63xx Bluetooth chips.

Signed-off-by: Ohad Ben-Cohen <ohad@bencohen.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/Kconfig

@@ -55,6 +55,17 @@ config BT_HCIUART_BCSP
 
 	  Say Y here to compile support for HCI BCSP protocol.
 
+config BT_HCIUART_LL
+	bool "HCILL protocol support"
+	depends on BT_HCIUART
+	help
+	  HCILL (HCI Low Level) is a serial protocol for communication
+	  between Bluetooth device and host. This protocol is required for
+	  serial Bluetooth devices that are based on Texas Instruments'
+	  BRF chips.
+
+	  Say Y here to compile support for HCILL protocol.
+
 config BT_HCIBCM203X
 	tristate "HCI BCM203x USB driver"
 	depends on USB

drivers/bluetooth/Makefile

@@ -16,4 +16,5 @@ obj-$(CONFIG_BT_HCIBTUART)	+= btuart_cs.o
 hci_uart-y				:= hci_ldisc.o
 hci_uart-$(CONFIG_BT_HCIUART_H4)	+= hci_h4.o
 hci_uart-$(CONFIG_BT_HCIUART_BCSP)	+= hci_bcsp.o
+hci_uart-$(CONFIG_BT_HCIUART_LL)	+= hci_ll.o
 hci_uart-objs				:= $(hci_uart-y)

drivers/bluetooth/hci_ldisc.c

@@ -549,7 +549,10 @@ static int __init hci_uart_init(void)
 #ifdef CONFIG_BT_HCIUART_BCSP
 	bcsp_init();
 #endif
-
+#ifdef CONFIG_BT_HCIUART_LL
+	ll_init();
+#endif
+
 	return 0;
 }
 
@@ -563,6 +566,9 @@ static void __exit hci_uart_exit(void)
 #ifdef CONFIG_BT_HCIUART_BCSP
 	bcsp_deinit();
 #endif
+#ifdef CONFIG_BT_HCIUART_LL
+	ll_deinit();
+#endif
 
 	/* Release tty registration of line discipline */
 	if ((err = tty_unregister_ldisc(N_HCI)))