drivers: gpio: mcp23xxx: fix drive mode validation for input pins #100759
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Without this fix, I get the following error when trying to use the MCP23018 IOs as inputs:
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Tested on an MCP23018 chip with IOs configured as both input and output. |
The drive mode validation added in commit ede19a4 was rejecting valid configurations for input pins. The validation ensures that GPIO_SINGLE_ENDED and GPIO_LINE_OPEN_DRAIN flags match the hardware capabilities of each MCP23xxx variant (push-pull vs open-drain). However, this validation was applied to all pin configurations, including input pins. Input pins do not have a drive mode, so applications typically configure them without setting drive mode flags. This caused the validation to incorrectly reject input pin configurations with -ENOTSUP. Fix by only validating drive mode flags when GPIO_OUTPUT is set. Input pins now configure successfully, while output pins still receive proper validation to ensure the requested drive mode matches the hardware capabilities. Fixes: ede19a4 ("drivers: mcp23xxx: add support for open-drain ...") Signed-off-by: Cliff Brake <[email protected]>
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The drive mode validation added in commit ede19a4 was rejecting valid configurations for input pins. The validation ensures that GPIO_SINGLE_ENDED and GPIO_LINE_OPEN_DRAIN flags match the hardware capabilities of each MCP23xxx variant (push-pull vs open-drain).
However, this validation was applied to all pin configurations, including input pins. Input pins do not have a drive mode, so applications typically configure them without setting drive mode flags. This caused the validation to incorrectly reject input pin configurations with -ENOTSUP.
Fix by only validating drive mode flags when GPIO_OUTPUT is set. Input pins now configure successfully, while output pins still receive proper validation to ensure the requested drive mode matches the hardware capabilities.
Fixes: ede19a4 ("drivers: mcp23xxx: add support for open-drain chip variants")