Re: [PATCH 4/5] regulator: pwm: Add support for voltage linear equal steps

From: Laxman Dewangan
Date: Sun Mar 13 2016 - 09:19:38 EST



On Saturday 12 March 2016 11:39 AM, Mark Brown wrote:
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On Tue, Mar 08, 2016 at 04:23:24PM +0530, Laxman Dewangan wrote:

There is a use cases where entire voltage ranges from minimum
to maximum is divided into n equal steps and just providing the
steps count, the voltage table with duty cycles is linearly
calculated.
I can't see any reason why this would ever be preferable to just using
the flat linear range (you certainly haven't articulated one, you're
just stating it). This seems like you are bodging around a limited
consumer driver, you should fix the consumer to cope with regulators
with lots of voltages - PWM regulators aren't the only ones with high
resolution steps.

The requirement is to have perfect linear steps interms of the period/pulse time of PWM without loosing any voltage.
Continuous mode is pretty much near to what you said but here we are loosing the perfect step as this divides the periods to 100 parts and then set voltage.

If new mode is not accpetable then need to enhance the existing continuous mode like before scaling for 100% of period, first look if we get the perfect pulse time of of PWM period and if it is there then use this direct instead of converting required voltage to 100% scale and then back calculating duty time.