On Tue, Aug 30, 2016 at 09:21:15PM -0700, Douglas Anderson wrote:

A change of the duty cycle doesn't necessarily cause an immediate switch
to the target voltage.  On many PWM regulators there is a fixed "settle
time" (irrespective of the jump size) that we need to wait after an
upward jump.  This change introduces the device tree property
"settle-time-up-us" which allows us to specify a fixed delay after a
voltage increase.

Why is this specific to regulators implemented with PWM controllers?
Most DCDCs have a PWM element and the concept of a hard time limit for
transition rather than a ramp rate doesn't seem like it'd be unique.