zephyr: add rmt support

[joelguittet]

Add expected source files to CMakeLists.txt for each relevant targets.

[wmrsouza]

@joelguittet I think you must also:

• fill the following files with the corresponding RMT pincfg information (from datasheets and TRMs)
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32.yml
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32c3.yml
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32c6.yml
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32h2.yml
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32s2.yml
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32s3.yml
  • https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/port/pincfgs/esp32s3.yml
• read https://github.com/zephyrproject-rtos/hal_espressif/blob/main/zephyr/scripts/pinctrl/README.md
• and follow the instructions in order to provide pinctrl definitions for SoCs supporting RMT on Zephyr

[joelguittet]

@wmrsouza thanks for the inputs, however, I'm not sure how the pinctrl should be done for such driver. Actually the pin is configured when creating a channel. It's configured at runtime and can change depending on application behavior. How to set pins in the device tree in the rmt node and then reuse them when creating channels in the application? Do you have a similar example in mind?

[wmrsouza]

@joelguittet pincfgs will permit to apply different states to the peripheral pins according to the Zephyr's power management state. At least you should define rmt pincfg in device tree for the default state and then:

int err = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);

during peripheral instance initialization or configuration

for instance, rmt initialization and channel configuration is very similar to i2s

[wmrsouza]

@joelguittet for pincfgs, take a look in the PR#282 where i2s was suported on esp32s3 and esp32c3 (and related pins entry were inserted)
zephyr/port/pincfgs/esp32s3.yml

i2s0:
  mclk:
    sigo: i2s0_mclk_out
    gpio: [[0, 21], [26, 48]]
  i_bck:
    sigi: i2s0i_bck_in
    sigo: i2s0i_bck_out
    gpio: [[0, 21], [26, 48]]
  i_ws:
    sigi: i2s0i_ws_in
    sigo: i2s0i_ws_out
    gpio: [[0, 21], [26, 48]]
  i_sd:
    sigi: i2s0i_sd_in
    gpio: [[0, 21], [26, 48]]
  o_bck:
    sigi: i2s0o_bck_in
    sigo: i2s0o_bck_out
    gpio: [[0, 21], [26, 48]]
  o_ws:
    sigi: i2s0o_ws_in
    sigo: i2s0o_ws_out
    gpio: [[0, 21], [26, 48]]
  o_sd:
    sigo: i2s0o_sd_out
    gpio: [[0, 21], [26, 48]]

rmt case will be, probably:

...
rmt0
rx:
    sigi: rmt0_rx
    gpio: [[range0], [range1], ...]
tx:
    sigo: rmt0_out
    gpio: [[range0], [range1], ...]
...

consult TRM and datasheet to get pin ranges

[wmrsouza]

LGTM

Changes applied in subsequent commit. Dismissing review.

[wmrsouza]

@sylvioalves , @marekmatej , @LucasTambor , @raffarost , PTAL

[sylvioalves]

@joelguittet I suggest you to re-work rmt.h entries to adapt to Zephyr-like, i.e., removing freertos calls, converting to Zephyr locks, add kernel.h and so. This way you can use hal_espressif headers in Zephyr driver directly.

[joelguittet]

@joelguittet I suggest you to re-work rmt.h entries to adapt to Zephyr-like, i.e., removing freertos calls, converting to Zephyr locks, add kernel.h and so. This way you can use hal_espressif headers in Zephyr driver directly.

Hello @sylvioalves
I suspect you speak of the files:

• components/driver/deprecated/driver/rmt.h
• components/driver/include/esp_private/rmt.h
  Correct? However I don't really understand what should I do with those files... Actually not used, should I simply delete them ? What do you suggest to move here, some stuff from the zephyr repo in the other PR ?

[sylvioalves]

Would you mind moving this to common include section at the top? I know it is global includes and eventually will improve this..

[joelguittet]

No problem, will do

[joelguittet]

Done