Redo ESP32-C2 clocktree, remove ESP_HAL_CONFIG_XTAL_FREQUENCY

[bugadani]

cc #4502

[bugadani]

/hil full

[github-actions]

Triggered full HIL run for #4517.

Run: https://github.com/esp-rs/esp-hal/actions/runs/19533125842

Status update: ❌ HIL (full) run failed (conclusion: failure).

[bugadani]

/hil full

[github-actions]

Triggered full HIL run for #4517.

Run: https://github.com/esp-rs/esp-hal/actions/runs/19533561326

Status update: ✅ HIL (full) run succeeded.

[Copilot]

Pull Request Overview

This PR refactors the ESP32-C2 clock tree implementation and removes the ESP_HAL_CONFIG_XTAL_FREQUENCY configuration option. The changes introduce a comprehensive clock tree structure for ESP32-C2 with proper clock node definitions, multiplexers, and dividers. The clock frequency is now automatically detected at runtime rather than configured at compile time.

• Introduces a complete clock tree definition for ESP32-C2 including all clock sources, multiplexers, and dividers
• Removes the ESP_HAL_CONFIG_XTAL_FREQUENCY build-time configuration in favor of runtime detection
• Cleans up ESP32 peripheral clock handling by removing redundant TIMG0/1_PERIPHERAL_CLOCK nodes

Reviewed Changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
esp-metadata/devices/esp32c2.toml	Adds comprehensive clock tree definition with system clocks, peripheral clocks, and timer-specific clock configurations
esp-metadata/devices/esp32.toml	Removes TIMG peripheral clock definitions and adds TODO comment about APB clock tracking
esp-metadata-generated/src/_generated_esp32c2.rs	Generates clock tree types, configuration structs, and management functions for ESP32-C2
esp-metadata-generated/src/_generated_esp32.rs	Removes generated code for TIMG peripheral clocks
esp-metadata-generated/src/_build_script_utils.rs	Updates build script configuration flags for new clock nodes
esp-hal/src/timer/timg.rs	Adds clock configuration for TIMG0 function clock
esp-hal/src/soc/esp32c2/mod.rs	Adds public clocks module
esp-hal/src/soc/esp32c2/clocks.rs	New implementation file with clock detection, PLL configuration, and clock tree management
esp-hal/src/soc/esp32/clocks.rs	Removes peripheral clock handling and updates crystal frequency detection logic
esp-hal/src/rtc_cntl/rtc/esp32c2.rs	Comments out RTC clock configuration (marked for future work)
esp-hal/src/clock/mod.rs	Removes ESP_HAL_CONFIG_XTAL_FREQUENCY handling and simplifies XTAL frequency measurement
esp-hal/src/clock/clocks_ll/esp32c2.rs	Removes old clock configuration functions (moved to new implementation)
esp-hal/esp_config.yml	Removes xtal-frequency configuration option
esp-hal/CHANGELOG.md	Documents removal of ESP_HAL_CONFIG_XTAL_FREQUENCY option

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[bugadani]

Current status: scanner example fails to print any devices, I presume one of the clocks aren't started.

[bugadani]

Ok, so the issue wasn't that a clock wasn't running. Instead the problem was caused by trying to store the XTAL frequency in Hz instead of in MHz in RTC_CNTL_STORE4, which ended up setting the DISABLE_ROM_LOG bit, which disabled the serial output.