Currently, there are 3 helper macros in iio/events.h to create event identifiers: - IIO_EVENT_CODE : create generic event identifier for differential and non differential channels - IIO_MOD_EVENT_CODE : create event identifier for modified (non differential) channels - IIO_UNMOD_EVENT_CODE : create event identifier for unmodified (non differential) channels For differential channels, drivers are expected to use IIO_EVENT_CODE. However, only one driver in drivers/iio currently uses it correctly, leading to inconsistent event identifiers for differential channels that don’t match the intended attributes (such as max1363.c that supports differential channels, but only uses IIO_UNMOD_EVENT_CODE). To prevent such issues in future drivers, a new helper macro, IIO_DIFF_EVENT_CODE, is introduced to specifically create event identifiers for differential channels. Only one helper is needed for differential channels since they cannot have modifiers. Additionally, the descriptions for IIO_MOD_EVENT_CODE and IIO_UNMOD_EVENT_CODE have been updated to clarify that they are intended for non-differential channels, Signed-off-by: Julien Stephan <jstephan@xxxxxxxxxxxx> --- include/linux/iio/events.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/include/linux/iio/events.h b/include/linux/iio/events.h index a4558c45a548834e33702927609ca9ad447c67de..eeaba5e1525e44fd3b51985ffa99837efc6cdd00 100644 --- a/include/linux/iio/events.h +++ b/include/linux/iio/events.h @@ -30,7 +30,8 @@ /** - * IIO_MOD_EVENT_CODE() - create event identifier for modified channels + * IIO_MOD_EVENT_CODE() - create event identifier for modified (non + * differential) channels * @chan_type: Type of the channel. Should be one of enum iio_chan_type. * @number: Channel number. * @modifier: Modifier for the channel. Should be one of enum iio_modifier. @@ -43,7 +44,8 @@ IIO_EVENT_CODE(chan_type, 0, modifier, direction, type, number, 0, 0) /** - * IIO_UNMOD_EVENT_CODE() - create event identifier for unmodified channels + * IIO_UNMOD_EVENT_CODE() - create event identifier for unmodified (non + * differential) channels * @chan_type: Type of the channel. Should be one of enum iio_chan_type. * @number: Channel number. * @type: Type of the event. Should be one of enum iio_event_type. @@ -53,4 +55,16 @@ #define IIO_UNMOD_EVENT_CODE(chan_type, number, type, direction) \ IIO_EVENT_CODE(chan_type, 0, 0, direction, type, number, 0, 0) +/** + * IIO_DIFF_EVENT_CODE() - create event identifier for differential channels + * @chan_type: Type of the channel. Should be one of enum iio_chan_type. + * @chan1: First channel number for differential channels. + * @chan2: Second channel number for differential channels. + * @type: Type of the event. Should be one of enum iio_event_type. + * @direction: Direction of the event. One of enum iio_event_direction. + */ + +#define IIO_DIFF_EVENT_CODE(chan_type, chan1, chan2, type, direction) \ + IIO_EVENT_CODE(chan_type, 1, 0, direction, type, 0, chan1, chan2) + #endif -- 2.47.0
