Hi Neeraj, >>>>> Add hci_nxp to the hci_uart module which adds support for the NXP BT >>>>> chips. This driver has Power Save feature that will put the NXP >>>>> bluetooth chip into sleep state, whenever there is no activity for >>>>> certain duration of time (2000ms), and will be woken up when any >>>>> activity is to be initiated. >>>>> >>>>> The Power Save feature can be configured with the following set of >>>>> commands (optional): >>>>> hcitool -i hci0 cmd 3F 23 02 00 00 (enable Power Save) >>>>> hcitool -i hci0 cmd 3F 23 03 00 00 (disable Power Save) >>>>> where, >>>>> OGF = 0x3F (vendor specific command) OCF = 0x23 (command to set >>>>> Power Save state) arg[0] = 0x02 (disable Power Save) arg[0] = 0x03 >>>>> (enable Power Save) arg[1,2,...] = XX (don't care) >>>>> >>>>> The sleep/wake-up source can be configured with the following set of >>>>> commands (optional): >>>>> hcitool -i hci0 cmd 3F 53 03 14 01 FF (set UART break method) >>>>> hcitool -i hci0 cmd 3F 53 03 14 00 FF (set UART DSR method) >>>>> where, >>>>> OGF = 0x3F (vendor specific command) OCF = 0x53 (command to set >>>>> sleep and wake-up source) arg[0] = 0x00 (Chip to host method NONE) >>>>> arg[0] = 0x01 (Chip to host method UART DTR) arg[0] = 0x02 (Chip to >>>>> host method UART BREAK) arg[0] = 0x03 (Chip to host method GPIO) >>>>> arg[1] = 0x14 (Chip to host GPIO[20] if arg[0] is 0x03, else 0xFF) >>>>> arg[2] = 0x00 (Host to chip method UART DSR) arg[2] = 0x01 (Host to >>>>> chip method UART BREAK) arg[3] = 0xXX (Reserved for future use) >>>>> >>>>> By default, the hci_nxp sets power save enable, chip to host wake-up >>>>> source as GPIO and host to chip sleep and wake-up source as UART >>>>> break during driver initialization, by sending the respective >>>>> commands to the chip. >>>>> >>>>> Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@xxxxxxx> >>>>> --- >>>>> v2: Changed the subject/summary lines and added more details in the >>>>> description. (Paul Menzel) >>>>> v3: Made internal functions static, optimized the code, added few >>>>> comments. (Sherry Sun) >>>>> v4: Reworked entire code to send vendor commands cmd23 and cmd53 >> by >>>>> using __hci_cmd_sync. (Luiz Augusto von Dentz) >>>>> v5: Used hci_command_hdr and combined OGF+OCF into a single >> opcode. >>>>> (Luiz Augusto von Dentz) >>>>> --- >>>>> MAINTAINERS | 6 + >>>>> drivers/bluetooth/Kconfig | 10 + >>>>> drivers/bluetooth/Makefile | 1 + >>>>> drivers/bluetooth/hci_ldisc.c | 6 + >>>>> drivers/bluetooth/hci_nxp.c | 592 >> ++++++++++++++++++++++++++++++++++ >>>>> drivers/bluetooth/hci_nxp.h | 94 ++++++ >>>>> drivers/bluetooth/hci_uart.h | 8 +- >>>>> 7 files changed, 716 insertions(+), 1 deletion(-) create mode 100644 >>>>> drivers/bluetooth/hci_nxp.c create mode 100644 >>>>> drivers/bluetooth/hci_nxp.h >>>> >>>> so this is a clear NAK. Add this as serdev driver and not hook >>>> further into the mess that is the HCI line discipline. >>> >>> I wonder if we should make it more clear somehow, perhaps include a >>> text on the likes of BT_HCIUART that is deprecated and new drivers >>> shall use BT_HCIUART_SERDEV instead. >> >> not even that. They need to be separate drivers. A long time ago I posted the >> skeleton for btuart.ko and bt3wire.ko and that is where this has to go. >> >> Regards >> >> Marcel > > Thanks for your comment. > Based on your comment, I re-worked the entire driver with reference to following patches: > https://www.spinics.net/lists/linux-bluetooth/msg74918.html > https://elixir.bootlin.com/linux/v6.1-rc4/source/drivers/bluetooth/btmtkuart.c > > I am able to create a standalone btnxp.ko which is able to run basic BT operations along with FW download with NXP chipsets. > > However I have now hit a blocker. The NXP chipsets require support for break signal, by which the host can put the chip into sleep, and wake it up. > > However, it seems that the serdev API's in https://elixir.bootlin.com/linux/v6.1-rc8/source/include/linux/serdev.h do not support break assertion over serial TX line. > > Is there any plan for serdev to support break signaling? > > Any help on this blocker would be highly appreciated. I recall some posts about that. Either on LKML or some other mailing list. Don’t remember what the outcome was though. Regards Marcel
