espressif/rmt: replace rmtchar with arch-specific lirc adapter

[PiyushPatle26]

Note: Please adhere to Contributing Guidelines.

Summary

Replace the ESP-specific rmtchar upper-half with arch-local esp_lirc adapters for Xtensa and RISC-V.

This moves the RMT upper-half out of drivers/rmt, registers LIRC
devices from the ESP board bring-up paths, and removes the old common
rmtchar driver and headers.

Also update the ESP Kconfig and build wiring to build esp_lirc when
ESP_RMT and DRIVERS_RC are enabled.

Impact

• Moves ESP-specific RMT support from common drivers/rmt into arch-local esp_lirc, aligning with NuttX layering.
• Replaces the legacy rmtchar interface with the standard LIRC framework and removes obsolete code.
• Registers LIRC devices from board bring-up, fixing RX/TX device conflicts and improving stability.
• Limited to ESP targets; out-of-tree users must migrate to /dev/lircX

Testing

Tested on: ESP32-DEVKITC (Chip v1.0)
booted with CONFIG_ESP32_IGNORE_CHIP_REVISION_CHECK=y for local validation only

• flashed and booted successfully to NSH
• confirmed device registration:
  • /dev/lirc0
  • /dev/lirc1
  • /dev/leds0
• confirmed the previous TX registration collision was fixed
  • before fix: board_rmt_txinitialize() failed: -17
  • after fix: both /dev/lirc0 and /dev/lirc1 register
• confirmed the RX worker thread crash was fixed
  • before fix: opening the RX side triggered a kernel panic in esp_lirc_rx_thread
  • after fix: devices open successfully

Fixes discovered during hardware validation:

• register TX as /dev/lirc1 so RX and TX do not collide
• parse the RX worker thread argument from the correct argv slot
• keep RX devices from advertising TX capability

Test logs:

Irtest seems struck so need guidance on what must be changed to validate completely

[acassis]

@PiyushPatle26 I liked the idea, however ESP32 RMT is use not only for RC, it is used as signal "generator" to control WS8212 RGB LEDs for example. Similar how people use I2S to emulate other protocols.

@fdcavalcanti @tmedicci @eren-terzioglu please take a look

[acassis]

@xiaoxiang781216 who from Xiaomi could help him: "Irtest seems struck so need guidance on what must be changed to validate completely" ?

[acassis]

@PiyushPatle26 nice work! Kudos!!!
You didn't submit a Documentation about this driver, so searching further I noticed we even don't have basic documentation about RC: https://nuttx.apache.org/docs/latest/components/drivers/character/rc.html#remote-control-devices

Could you please help us to improve it?

[raiden00pl]

related issue: #15431

[tmedicci]

@PiyushPatle26 I liked the idea, however ESP32 RMT is use not only for RC, it is used as signal "generator" to control WS8212 RGB LEDs for example. Similar how people use I2S to emulate other protocols.

@fdcavalcanti @tmedicci @eren-terzioglu please take a look

Thanks for submitting it, @PiyushPatle26 . We are testing on our internal CI. Please don't merge it yet.

As Alan pointed, @PiyushPatle26 , the RMT driver is used to drive the WS2812 (on-board LED for some of the Espressif's boards). Did you test it?

[PiyushPatle26]

@xiaoxiang781216 have removed the files you asked for
@acassis Added the documentation as asked
@tmedicci not yet, my ESP32-devkitc doesn't have a WS2812 on board LED , can use a external ws2812 with jumper wires for proper testing

[xiaoxiang781216]

@xiaoxiang781216 have removed the files you asked for @acassis Added the documentation as asked @tmedicci not yet, my ESP32-devkitc doesn't have a WS2812 on board LED , can use a external ws2812 with jumper wires for proper testing

need fix:

    1: .codespellrc
Warning: /home/runner/work/nuttx/nuttx/nuttx/arch/risc-v/src/common/espressif/esp_lirc.h:26:1: warning: #include outside of 'Included Files' section
Warning: /home/runner/work/nuttx/nuttx/nuttx/arch/risc-v/src/common/espressif/esp_lirc.h:28:1: warning: #include outside of 'Included Files' section
Some checks failed. For contributing guidelines, see:

[PiyushPatle26]

@xiaoxiang781216, I have made the changes you asked.

[linguini1]

Please read the contributing guide and update the PR description to match the requirements :)

[PiyushPatle26]

@linguini1 I have made all the changes according to contributing.md

[linguini1]

@linguini1 I have made all the changes according to contributing.md

Your PR description should follow the template with a clear summary, impact and test section. I think you have all these components but just need the headers

[PiyushPatle26]

@linguini1 I have updated the description as you mentioned

[acassis]

@PiyushPatle26 as @tmedicci you need to test it with existing usage case: i.e. to control WS8212 RGB LED matrix. Otherwise you will broke an existing feature

[acassis]

@xiaoxiang781216 is there some board where LIRC was tested?

alan@dev:~/nuttxspace/nuttx/boards$ git grep LIRC_
alan@dev:~/nuttxspace/nuttx/boards$

I found a low cost board that I think we can use to validate it:
https://aliexpress.com/item/1005010805058390.html

[eren-terzioglu]

@PiyushPatle26 as @tmedicci you need to test it with existing usage case: i.e. to control WS8212 RGB LED matrix. Otherwise you will broke an existing feature

Hi,
Tested internal RGB led using rmt defconfig with ws2812 example. C6 and S3 is working fine

[eren-terzioglu]

Please check CI errors

[acassis]

@PiyushPatle26 as @tmedicci you need to test it with existing usage case: i.e. to control WS8212 RGB LED matrix. Otherwise you will broke an existing feature

Hi, Tested internal RGB led using rmt defconfig with ws2812 example. C6 and S3 is working fine

So the snake and shift game still working? That is the most important thing to save! :-D

[eren-terzioglu]

@PiyushPatle26 as @tmedicci you need to test it with existing usage case: i.e. to control WS8212 RGB LED matrix. Otherwise you will broke an existing feature

Hi, Tested internal RGB led using rmt defconfig with ws2812 example. C6 and S3 is working fine

So the snake and shift game still working? That is the most important thing to save! :-D

I have to find the demo board but even if it doesn't; it would be somehow different, no worries. :)

[PiyushPatle26]

Please check CI errors

Hey @eren-terzioglu, i think CI errors should be fixed now
@acassis I was not able to test as I just have a ESP32-devkitC which doesn't have WS8212, But i think @eren-terzioglu have already tested, right?

[linguini1]

Ideally you should have a way to test your changes in some capacity. Also, the CI is failing because of config files which aren't normalized. You can use tools/refresh.sh to normalize them :)

[PiyushPatle26]

Ideally you should have a way to test your changes in some capacity. Also, the CI is failing because of config files which aren't normalized. You can use tools/refresh.sh to normalize them :)

Sorry for not being able to test properly, Thanks for helping for CI, now i have normalized the configs