Skip to content

analog: add comp enable/disable ioctl and STM32 support - #20149

Open
daniel-p-carvalho wants to merge 4 commits into
apache:masterfrom
daniel-p-carvalho:feat/stm32-comp-ioctl
Open

analog: add comp enable/disable ioctl and STM32 support#20149
daniel-p-carvalho wants to merge 4 commits into
apache:masterfrom
daniel-p-carvalho:feat/stm32-comp-ioctl

Conversation

@daniel-p-carvalho

@daniel-p-carvalho daniel-p-carvalho commented Sep 15, 2026

Copy link
Copy Markdown
Contributor

Summary

This PR adds standard IOCTL commands to control analog comparator devices and implements them for STM32 (M3/M4 v2 architecture).

  1. include/nuttx/analog/ioctl.h:

    • Adds ANIOC_COMP_ENABLE and ANIOC_COMP_DISABLE commands.
    • Bumps AN_NCMDS to 14.

  2. arch/arm/src/common/stm32/stm32_comp_m3m4_v2.c:

    • Implements ao_ioctl to handle enable and disable requests via ANIOC_COMP_ENABLE and ANIOC_COMP_DISABLE.
    • Adds CONFIG_STM32_COMP_INIT_DISABLED in Kconfig.comp to optionally keep the comparator disabled during driver setup until explicitly requested.
    • Cleans up coding style alignment.

  3. boards/arm/stm32g4/nucleo-g431kb/configs/comp/defconfig:

    • Enables CONFIG_EXAMPLES_COMP=y and sets default DAC path to /dev/dac5 for comparator verification.

Impact

  • Allows user-space applications to dynamically control the comparator state via standard IOCTL.
  • Backward compatible with existing comparator lower-half drivers (unknown commands return -ENOTTY).

Testing

  • Host OS: Linux x86_64
  • Target Board: STMicroelectronics NUCLEO-G431KB (STM32G431KB)
  • Configuration: nucleo-g431kb:comp
  • Toolchain: arm-none-eabi-gcc 13.2.1

Execution Logs on Physical Hardware:

nsh> comp
Running comparator test on /dev/comp0...
  1. Initial output state: 0
  2. ANIOC_COMP_DISABLE: OK
  3. Output state when disabled: 0
  4. ANIOC_COMP_ENABLE: OK
  5. Output state when enabled: 1
Comparator test PASSED on /dev/comp0

Individual commands:

nsh> comp disable
/dev/comp0: Comparator disabled successfully

nsh> comp read
/dev/comp0: output = 0

nsh> comp enable
/dev/comp0: Comparator enabled successfully

nsh> comp read
/dev/comp0: output = 1
  • Verified with checkpatch.sh: 0 errors, 0 warnings.

@daniel-p-carvalho
analog: add ANIOC_COMP_ENABLE and ANIOC_COMP_DISABLE commands
05d0378 
Define standard IOCTL commands to enable and disable analog comparator
devices from user-space applications.

Assisted-by: Gemini:gemini-2.5-pro
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>
@daniel-p-carvalho
stm32: implement comp ioctl and update nucleo-g431kb defconfig
df62e9a 
Implement ao_ioctl in stm32_comp_m3m4_v2.c to handle ANIOC_COMP_ENABLE and
ANIOC_COMP_DISABLE commands. Also add CONFIG_STM32_COMP_INIT_DISABLED to
allow keeping the comparator disabled after driver initialization until
explicitly enabled.

Update nucleo-g431kb:comp defconfig to enable CONFIG_EXAMPLES_COMP and
set default DAC path for comparator ramp verification.

Assisted-by: Gemini:gemini-2.5-pro
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>
@daniel-p-carvalho

daniel-p-carvalho commented Sep 15, 2026

Copy link
Copy Markdown
Contributor Author

Companion example tool PR in apps: apache/nuttx-apps#3783

@github-actions github-actions Bot added Arch: arm Issues related to ARM (32-bit) architecture Area: Drivers Drivers issues Size: M The size of the change in this PR is medium Board: arm labels Sep 15, 2026
@daniel-p-carvalho daniel-p-carvalho mentioned this pull request Sep 15, 2026
Merged
@github-actions

github-actions Bot commented Sep 15, 2026 •
edited
Loading

Copy link
Copy Markdown

MemBrowse Memory Report

qemu-armv8a

  • Code: .rodata +464 B, .text.init_service_check +24 B, .text.ostest_main +52 B, .text.tester +68 B, .text.verifier +148 B, .text.wqueue_priority_test -240 B, .text.wqueue_test -184 B (+2.2%, 344,288 B)

qemu-intel64

jerpelea
jerpelea previously approved these changes Sep 15, 2026
View reviewed changes
@daniel-p-carvalho
boards: stm32g4: regenerate nucleo-g431kb comp defconfig
0e83d97 
CONFIG_EXAMPLES_COMP_DACPATH matched its Kconfig default value, which
make savedefconfig drops as redundant. The stale explicit line made
the committed defconfig differ from what a clean savedefconfig
produces, failing CI's defconfig-completeness check even though the
board builds fine either way.

Assisted-by: Claude:claude-sonnet-5
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>
jerpelea
jerpelea previously approved these changes Sep 15, 2026
View reviewed changes
acassis
acassis previously approved these changes Sep 15, 2026
View reviewed changes
michallenc
michallenc requested changes Sep 15, 2026
View reviewed changes
Comment thread arch/arm/src/common/stm32/stm32_comp_m3m4_v2.c Outdated
@daniel-p-carvalho
stm32/comp: propagate enable error and handle lock in ioctl
5adfc8e 
In comp_ioctl(), propagate the return code of comp_enable() to caller so
failures (such as when the comparator CSR register is locked) return -EPERM.
Also call comp_lock_set() if the comparator was configured with locking,
handling cases where initialization was delayed.

Assisted-by: Gemini:gemini-2.5-pro
Signed-off-by: Daniel P. Carvalho <danieloak@gmail.com>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@michallenc michallenc michallenc approved these changes
@acassis acassis acassis left review comments
@jerpelea jerpelea jerpelea left review comments
@xiaoxiang781216 xiaoxiang781216 xiaoxiang781216 left review comments
@GUIDINGLI GUIDINGLI Awaiting requested review from GUIDINGLI GUIDINGLI is a code owner
@Donny9 Donny9 Awaiting requested review from Donny9 Donny9 is a code owner
@raiden00pl raiden00pl Awaiting requested review from raiden00pl raiden00pl is a code owner

At least 2 approving reviews are required to merge this pull request.

Assignees

No one assigned

Labels

Arch: arm Issues related to ARM (32-bit) architecture Area: Drivers Drivers issues Board: arm Size: M The size of the change in this PR is medium

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

5 participants

@daniel-p-carvalho @acassis @jerpelea @xiaoxiang781216 @michallenc