Re: [PATCH v2 0/1] Add remote I2C device to support external I2C device

[Corey Minyard]

On Mon, Aug 02, 2021 at 11:03:22PM +0000, Shengtan Mao wrote:
> This patch implements the remote I2C device.
> The remote I2C device allows an external I2C device to communicate with the 
> I2C controller in QEMU through the remote I2C protocol.
> Users no longer have to directly modify QEMU to add new I2C devices and can 
> instead implement the emulated device externally and connect it to the remote 
> I2C device.

I apologise, I haven't had time to look at this, and I'm going to be
really busy for a little while.

I looked it over a bit, and is there some description of the protocol?
Could you add a reference to it in the code?

-corey

> 
> Previous work by Wolfram Sang 
> (https://git.kernel.org/pub/scm/virt/qemu/wsa/qemu.git/commit/?h=i2c-passthrough)
>  was referenced.
> It shares the similar idea of redirecting the actual I2C device 
> functionalities, but Sang focuses on physical devices, and we focus on 
> emulated devices.
> The work by Sang mainly utilizes file descriptors while ours utilizes 
> character devices, which offers better support for emulated devices.
> The work by Sang is not meant to offer full I2C device support; it only 
> implements the receive functionality.
> Our work implements full support for I2C devices: send, recv, and event 
> (match_and_add is not applicable for external devices).
> 
> Shengtan Mao (1):
>   hw/i2c: add remote I2C device
> 
>  hw/arm/Kconfig                |   1 +
>  hw/i2c/Kconfig                |   4 +
>  hw/i2c/meson.build            |   1 +
>  hw/i2c/remote-i2c.c           | 117 ++++++++++++++++++
>  tests/qtest/meson.build       |   1 +
>  tests/qtest/remote-i2c-test.c | 216 ++++++++++++++++++++++++++++++++++
>  6 files changed, 340 insertions(+)
>  create mode 100644 hw/i2c/remote-i2c.c
>  create mode 100644 tests/qtest/remote-i2c-test.c
> 
> -- 
> 2.32.0.554.ge1b32706d8-goog
>