drivers: pwm_nrfx: Fix handling of zero length periods
When the driver was called to set the period length for a channel
to 0, it set the COUNTERTOP register in the PWM peripheral to 0,
what resulted in an undefined behavior of the peripheral (and lack
of the STOPPED event sometimes).
The PWM API does not precise how should a zero length period be
handled; some drivers return the -EINVAL error in such case, some
do not. This patch fixes the pwm_nrfx driver so that it does not
change the previously used COUNTERTOP register value when the period
length is set to 0, and because the pulse cycles are always limited
by the driver to period cycles (so 0 in this case), in result the
relevant channel is simply deactivated. This allows users to switch
off a channel by requesting the pulse width to be set to 0 without
providing a non-zero period in such call.
Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
1 file changed
