Add power management support to the gpio-qdec driver.
This is a bit complicated by the fact that the driver has two modes of
operation and the interrupt, timer and idle work ineract with each
other.
The suspend sequence is:
- set the suspended bit (inhibits the poll timer so that it does not
resubmit the idle work)
- cancel the idle work (so that it does not schedule and re-set the
interrupt or timers)
- disable interrupts (if used)
- stop the sampling timer
- disconnect the pins
The resume sequence is more or less the opposite.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Change the gpio_qdec driver to support optical encoders.
Add a property to use for defining an arbitrary number of GPIOs for the
sensing devices (typically infrared LEDs, but could also be the
biasing for the phototransistor), and one for adding a delay between
turning those on and reading the pin status.
The infrared LEDs typically consume a non negligible amount of power, so
there's also a new idle-poll-time-us property that enables two possible
modes of operation:
- if idle-poll-time-us is zero (default) the LEDs are enabled all the
time and the driver enters polling mode using the GPIO interrupt as
with mechanical encoders. This is usable for mains powered devices and
has the lowest overhead on the CPU.
- if idle-poll-time-us is non zero, then the driver polls the encoder
all the time, turning on the LEDs just before reading the state and
shutting them off immediately after, but when the encoder is idle it
switches the polling rate to idle-poll-time-us to save power, and only
polls at sample-time-us when some movement is detected.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Fix few instances of delayable work handlers using the k_work pointer
directly in a CONTAINER_OF pointing to a k_work_delayable.
This is harmless since the k_work is the first element in
k_work_delayable, but using k_work_delayable_from_work is the right way
of handling it.
Change a couple of explicit CONTAINER_OF doing the same work as the
macro in the process.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Add few missing check on gpio_add_callback and gpio_add_callback_dt
calls, fixes a coverity warning.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Add a GPIO based quadrature decoder driver that reports relative axes
movements using the input subsystem.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
