* regulator: Policy for setting current limits
@ 2012-08-05 23:27 Heiko Stübner
2012-08-06 11:56 ` Mark Brown
0 siblings, 1 reply; 4+ messages in thread
From: Heiko Stübner @ 2012-08-05 23:27 UTC (permalink / raw)
To: Mark Brown; +Cc: Liam Girdwood, linux-kernel, Axel Lin
Hi,
I hit a problem when setting a current limit and am not sure whose fault it is
(i.e. which component to change). Therefore I'd appreciate a pointer in the
right direction.
After the recent changes the gpio-regulator always selects the minimal value
to set. The gpio-vbus driver sets it's current limits as 0 - x mA (x = 100,
500). Therefore if 500mA are the upper limit but the regulator also supports
lower values, these lower values always get selected (100mA in my case).
In contrast pda_power sets the target current as both lower and upper limit.
So the question is, what is the correct way to handle this:
(a) let the gpio-regulator select the max current (in contrast to the minimum
voltage)
(b) change gpio-vbus to also use the target current as min and max value
(c) something else
Thanks
Heiko
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: regulator: Policy for setting current limits
2012-08-05 23:27 regulator: Policy for setting current limits Heiko Stübner
@ 2012-08-06 11:56 ` Mark Brown
2012-08-06 23:19 ` Heiko Stübner
0 siblings, 1 reply; 4+ messages in thread
From: Mark Brown @ 2012-08-06 11:56 UTC (permalink / raw)
To: Heiko Stübner; +Cc: Liam Girdwood, linux-kernel, Axel Lin
On Mon, Aug 06, 2012 at 01:27:56AM +0200, Heiko Stübner wrote:
> 500). Therefore if 500mA are the upper limit but the regulator also supports
> lower values, these lower values always get selected (100mA in my case).
> In contrast pda_power sets the target current as both lower and upper limit.
This isn't good, it means that the regulator has to be able to deliver
exactly the limit requested.
> (a) let the gpio-regulator select the max current (in contrast to the minimum
> voltage)
> (b) change gpio-vbus to also use the target current as min and max value
> (c) something else
Regulators should be tending to the maximum in the available range and
consumers should specify the widest range possible so both a and b.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: regulator: Policy for setting current limits
2012-08-06 11:56 ` Mark Brown
@ 2012-08-06 23:19 ` Heiko Stübner
2012-08-07 17:06 ` Mark Brown
0 siblings, 1 reply; 4+ messages in thread
From: Heiko Stübner @ 2012-08-06 23:19 UTC (permalink / raw)
To: Mark Brown; +Cc: Liam Girdwood, linux-kernel, Axel Lin
Am Montag, 6. August 2012, 13:56:33 schrieb Mark Brown:
> On Mon, Aug 06, 2012 at 01:27:56AM +0200, Heiko Stübner wrote:
> > 500). Therefore if 500mA are the upper limit but the regulator also
> > supports lower values, these lower values always get selected (100mA in
> > my case). In contrast pda_power sets the target current as both lower
> > and upper limit.
>
> This isn't good, it means that the regulator has to be able to deliver
> exactly the limit requested.
>
> > (a) let the gpio-regulator select the max current (in contrast to the
> > minimum voltage)
> > (b) change gpio-vbus to also use the target current as min and max value
> > (c) something else
>
> Regulators should be tending to the maximum in the available range and
> consumers should specify the widest range possible so both a and b.
Is this true for all regulators (i.e. voltage and currency regulators)?
Because 4dbd8f63f07a (regulator: gpio-regulator: Set the smallest
voltage/current in the specified range) implemented the exact oposite.
Thanks
Heiko
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: regulator: Policy for setting current limits
2012-08-06 23:19 ` Heiko Stübner
@ 2012-08-07 17:06 ` Mark Brown
0 siblings, 0 replies; 4+ messages in thread
From: Mark Brown @ 2012-08-07 17:06 UTC (permalink / raw)
To: Heiko Stübner; +Cc: Liam Girdwood, linux-kernel, Axel Lin
On Tue, Aug 07, 2012 at 01:19:34AM +0200, Heiko Stübner wrote:
> Am Montag, 6. August 2012, 13:56:33 schrieb Mark Brown:
> > Regulators should be tending to the maximum in the available range and
> > consumers should specify the widest range possible so both a and b.
> Is this true for all regulators (i.e. voltage and currency regulators)?
No, voltage regualtors should tend to the lowest voltage.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-08-07 17:06 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2012-08-05 23:27 regulator: Policy for setting current limits Heiko Stübner
2012-08-06 11:56 ` Mark Brown
2012-08-06 23:19 ` Heiko Stübner
2012-08-07 17:06 ` Mark Brown
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