[usualtreee]

Problem

The AB32 ADC driver maps the requested channel for the HAL conversion, but then uses the original unchecked channel to index the ADC data registers. Values outside 0 through 15 therefore select memory outside the sixteen-register window. The callback channel types also do not match struct rt_adc_ops.

Fixes #11948.

Changes

• Match both ADC callback signatures to the public rt_adc_ops interface.
• Return -RT_EINVAL for channels without a defined AB32 ADC mapping instead of silently falling back to channel 0.
• Validate the mapping before starting a conversion or indexing the data registers.
• Reject invalid channels in the enable callback without calling the HAL.

Valid channel mappings and the existing conversion polling behavior are unchanged.

Verification

• A host test includes the real driver source, mocks only the HAL and the sixteen data registers, and uses the real public ADC interface header.
• Before the fix, channel = 16 produced an AddressSanitizer global-buffer-overflow at the original register access.
• After the fix, ASAN+UBSAN regression tests pass for all valid channels 0 through 15 and invalid channels -128, -3, -2, -1, 16, and 127.
• Invalid conversions return -RT_EINVAL, do not call the HAL, and leave the output value unchanged. Invalid enable requests are also rejected without calling the HAL.
• The modified driver compiles against the real RT-Thread and AB32 headers with incompatible callback pointer types treated as errors.
• Cross-compilation with riscv64-unknown-elf-gcc 14.2.0 and the AB32 rv32imc/ilp32 flags produces a 32-bit RISC-V relocatable object for the driver.
• git diff --check and changed-line checks with clang-format 22.1.8 pass locally.

Not tested on physical AB32 hardware. Only the driver object was cross-compiled; a complete firmware image was not built or linked.

[github-actions]

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