Re: [PATCH 4/5] regulator: pwm: Add support for voltage linear equal steps
From: Mark Brown
Date: Mon Mar 14 2016 - 12:28:59 EST
On Sun, Mar 13, 2016 at 06:36:06PM +0530, Laxman Dewangan wrote:
> On Saturday 12 March 2016 11:39 AM, Mark Brown wrote:
> >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
Could you be more specific about what the issue is? We've hopefully got
errors of less than 1% in the values here...
> 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.
That seems a lot better, what you're proposing is changing the ABI to
fudge things for a client specific requirement where both the client
requirement and the change you're proposing are specific to the current
Linux implementation. That doesn't sound like a DT thing.
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