stm32: support GLOBAL ADC DMA signals

[lennlouisgeek]

Some STM32 metadata, including STM32C5, describes ADC DMA channels using the GLOBAL signal name.

The embassy-stm32 build script previously recognized ADC, ADC1, ADC2, and ADC3, but ignored GLOBAL. Therefore, valid STM32C5 ADC DMA metadata did not generate the required RxDma<ADCx> implementations.

This change maps ADC GLOBAL signals to adc::RxDma and adds an STM32C5 ADC DMA example as compile-time coverage.

Tested with:

cargo build --manifest-path examples/stm32c5/Cargo.toml --bin adc_dma

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[Dirbaio]

is there a real difference between C5 ADC and others that justifies the different naming? If not, this is an inconsistency that should be fixed in stm32-data, not workarounded in embassy-stm32.

[lennlouisgeek]

Thanks, I checked the generated metadata against STM32U3. There does not appear to be a hardware difference that requires the C5 ADC DMA signal to be named `GLOBAL` . STM32U3 emits `ADC1` for the equivalent ADC DMA request, while C5 currently emits `GLOBAL`. The C5 package DMA parser takes `signal_id` directly from the source package, which appears to be where the inconsistency is introduced. I agree this should be fixed in stm32-data instead of add a workaround to embassy-stm32. I'll prepare a stm32-data fix and update this PR accordingly.

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On Mon, Aug 24, 2026 at 4:46 PM Dario Nieuwenhuis ***@***.***> wrote: *Dirbaio* left a comment (embassy-rs/embassy#6822) <#6822 (comment)> is there a real difference between C5 ADC and others that justifies the different naming? If not, this is an inconsistency that should be fixed in stm32-data, not workarounded in embassy-stm32. — Reply to this email directly, view it on GitHub <#6822?email_source=notifications&email_token=B5YIR4SVYB7QA5NHMGXGCTL5LP6FZA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMZZGI3TSNZYGQ32M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-5392797847>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B5YIR4UU4IDMHMMXMIW25R35LP6FZAVCNFSNUABFKJSXA33TNF2G64TZHMZDSNZXGAYTIOBRHNEXG43VMU5TKMRTGI3DMMJTHE42C5QC> . You are receiving this because you were mentioned.Message ID: ***@***.***>