version 3: - try to provide better description of parent_trigger usages - add one channel to get counter raw value
version 2: - Do not automatically set parent_trigger attribute on all triggers. Let driver decide to use it. - Improve documentation of parent_trigger - Improve slave modes documentation
Thoses patches add parent_trigger attribute to IIO triggers. Parent trigger edges or levels could be used to control current trigger. For example current trigger could be started on parent rising edges or be enabled only when parent trigger level is high.
Since there is many ways to use parent edges and levels to control current trigger behavoir an additional custom sysfs attribute may be needed to describe those control modes.
Similary to what already exist to validate a device, a new (optional) validate_trigger function is added in iio_trigger structure and should be filled by drivers.
For STM32 triggers parent trigger edges or levels could used in various ways. To be able to select them "in_count0_count_mode" attribute is added to STM32 triggers.
When setting a parent trigger on STM32 trigger "trigger_rising_edges" mode is automatically set so current trigger is clock by the rising edges of it parent.
Benjamin Gaignard (2): iio: Allow triggers to be used as parent of others triggers iio: stm32 trigger: Implement parent trigger feature
.../ABI/testing/sysfs-bus-iio-timer-stm32 | 63 +++++ .../ABI/testing/sysfs-bus-iio-trigger-sysfs | 15 ++ drivers/iio/industrialio-trigger.c | 69 ++++++ drivers/iio/trigger/stm32-timer-trigger.c | 256 ++++++++++++++++++++- include/linux/iio/trigger.h | 7 +- include/linux/mfd/stm32-timers.h | 2 + 6 files changed, 405 insertions(+), 7 deletions(-)