mbox series

[v5,0/3] Add support for MaxLinear/Exar USB to serial converters

Message ID 20201122170822.21715-1-mani@kernel.org
Headers show
Series Add support for MaxLinear/Exar USB to serial converters | expand

Message

Manivannan Sadhasivam Nov. 22, 2020, 5:08 p.m. UTC
From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>


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.

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

Comments

Manivannan Sadhasivam Dec. 8, 2020, 10:51 a.m. UTC | #1
On Sun, Nov 22, 2020 at 10:38:19PM +0530, Manivannan Sadhasivam wrote:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

> 

> 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

>
Johan Hovold Dec. 14, 2020, 9:51 a.m. UTC | #2
On Tue, Dec 08, 2020 at 04:21:28PM +0530, Manivannan Sadhasivam wrote:
> On Sun, Nov 22, 2020 at 10:38:19PM +0530, Manivannan Sadhasivam wrote:

> > From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

> > 

> > 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?


No, sorry, reviewing this one again will be at the top of my list after
the merge window opens. Hopefully we'll have reached some conclusions
regarding the line names by then too.

Johan