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Subject: Re: [PATCH v5] Bluetooth: Add hci_nxp to hci_uart module to support
 NXP BT chipsets
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <20221216094350.1121354-1-neeraj.sanjaykale@nxp.com>
Date:   Fri, 16 Dec 2022 21:15:03 +0100
Cc:     Johan Hedberg <johan.hedberg@gmail.com>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
        Paul Menzel <pmenzel@molgen.mpg.de>, amitkumar.karwar@nxp.com,
        rohit.fule@nxp.com, sherry.sun@nxp.com,
        linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org
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Message-Id: <85D2AE3F-97A5-4C88-8FC4-1684F3FD4438@holtmann.org>
References: <20221216094350.1121354-1-neeraj.sanjaykale@nxp.com>
To:     Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Precedence: bulk

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@nxp.com>
> ---
> 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.

Regards

Marcel