Re: [PATCH v5 0/3] Add support for MaxLinear/Exar USB to serial converters
From: Manivannan Sadhasivam
Date: Tue Dec 08 2020 - 05:52:24 EST
On Sun, Nov 22, 2020 at 10:38:19PM +0530, Manivannan Sadhasivam wrote:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
>
> Hello,
>
> This series adds support for MaxLinear/Exar USB to serial converters.
> This driver only supports XR21V141X series but it can easily be extended
> to other series in future.
>
> This driver is inspired from the initial one submitted by Patong Yang:
> https://lore.kernel.org/linux-usb/20180404070634.nhspvmxcjwfgjkcv@advantechmxl-desktop
>
> While the initial driver was a custom tty USB driver exposing whole
> new serial interface ttyXRUSBn, this version is completely based on USB
> serial core thus exposing the interfaces as ttyUSBn. This will avoid
> the overhead of exposing a new USB serial interface which the userspace
> tools are unaware of.
>
> This series has been tested with Hikey970 board hosting XR21V141X chip.
>
> NOTE: I've removed all reviews and tested-by tags as the code has gone
> through substantial rework. Greg, Linus, Mauro please consider reviewing
> again.
>
Any chance to get this series into v5.11?
Thanks,
Mani
> Thanks,
> Mani
>
> Changes in v5:
>
> * Incorporated review comments from Johan. Noticeable ones are:
> - Made serial and gpiolib support exclusive and used mutex to avoid
> race. The gpio requests from gpiolib will be rejected when serial
> port is in use.
> - The driver only binds to data interface but claims both control and
> data interface.
> - Handled B0 request
> - Removed all reviews as the code has gone through substantial rework.
>
> Changes in v4:
>
> * Multiple improvements based on Johan's review. Noticeable ones are:
> - Now the driver claims both control and data interfaces but only registers
> tty device for data interface.
> - GPIO pin status is now shared between the console and gpiolib
> implementations. This is done to avoid changing the lines spuriously.
> - A separate port_open flag is added to reject GPIO requests while the tty
> port is open.
> - Removed padding PID to gpio device.
> * Added Greg and Mauro's review and tested tags.
> * Included a patch from Mauro to avoid the CDC-ACM driver to claim this device
> when this driver is built.
>
> Changes in v3:
>
> * Dropped the check for PID and also the reg_width property.
>
> Changes in v2:
>
> * Dropped the code related to handling variable register size. It's all u8 now.
> * Dropped the header file and moved the contents to driver itself.
> * Added Linus's reviewed-by tag for gpiochip patch.
> * Added PID to gpiochip label
> * Dropped gpiochip for interface 0
>
> Manivannan Sadhasivam (2):
> usb: serial: Add MaxLinear/Exar USB to Serial driver
> usb: serial: xr_serial: Add gpiochip support
>
> Mauro Carvalho Chehab (1):
> usb: cdc-acm: Ignore Exar XR21V141X when serial driver is built
>
> drivers/usb/class/cdc-acm.c | 6 +
> drivers/usb/serial/Kconfig | 9 +
> drivers/usb/serial/Makefile | 1 +
> drivers/usb/serial/xr_serial.c | 854 +++++++++++++++++++++++++++++++++
> 4 files changed, 870 insertions(+)
> create mode 100644 drivers/usb/serial/xr_serial.c
>
> --
> 2.25.1
>