i2c_master.h for ESP8266 RTOS SDK (IDFGH-13827)

[trombik]

Is your feature request related to a problem?

We are maintaining device drivers for esp-idf and ESP8266 RTOS SDK at https://github.com/UncleRus/esp-idf-lib/. Recently, users asked for updating our libraries to newer I2C driver introduced in esp-idf 5.2. We are willing to do so but the issue is ESP8266 support. As i2c_master.h is completely different from i2c.h, it is not practically possible to maintain two versions of each i2c drivers. Our options are:

1. Wrapping our i2c device driver so that the device drivers supports both i2c.h and i2c_master.h
2. Supporting both i2c.h and i2c_master.h by creating two versions of the drivers
3. Dropping ESP8266 support

It seems that 1st and 2nd are not practically possible. We do want to avoid 3rd.

Do you have any plan to add i2c_master.h and its friends to ESP8266 RTOS SDK? If you do, we can continue to support ESP8266.

I do know that this repository is for esp-idf, but the maintainers of ESP8266 RTOS SDK repository rarely reply to issues or PRs, I am asking here.

See also: UncleRus/esp-idf-lib#655

Describe the solution you'd like.

Update ESP8266 RTOS SDK with i2c_master.h and its friends.

Describe alternatives you've considered.

See above.

Additional context.

Thanks to the common I2C component and the interface, we have been able to support ESP8266 and ESP32. We do know Espressif has few reasons to update ESP8266 RTOS SDK, but I saw some ESP8266 support is still in some tools, like the latest toolchains. We don't have numbers, but there are users who still want to use ESP8266 RTOS SDK and our drivers.