On Monday 21 November 2016 09:47 PM, Rob Herring wrote:
On Fri, Nov 18, 2016 at 08:05:55PM +0530, Laxman Dewangan wrote:
Some PWM regulator has the exponential transition in voltage change as
opposite to fixed slew-rate linear transition on other regulators.
For such PWM regulators, add the property to tell that voltage change
is exponential and having fixed delay for any level of change.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
CC: Douglas Anderson <dianders@xxxxxxxxxxxx>
CC: Aleksandr Frid <afrid@xxxxxxxxxx>
---
This patch is continuation of discussion on patch
regulator: pwm: Fix regulator ramp delay for continuous mode
https://patchwork.kernel.org/patch/9216857/
where is it discussed to have separate property for PWM which has
exponential voltage transition.
Changes from V1:
- Pass the flag to tell that voltage ramp is exponential instead of
providing delay.
---
.../devicetree/bindings/regulator/pwm-regulator.txt | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
index 3aeba9f..2d9ef3a 100644
--- a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
+++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt
@@ -54,6 +54,18 @@ Optional properties:
--------------------
- enable-gpios: GPIO to use to enable/disable the regulator
+- voltage-ramp-exponential: Boolean, Some of PWM regulator has the exponential
+ transition in voltage ramp as opposite to fixed
+ slew-rate linear transition on other regulators.
+ For such PWM regulator, presence of this property will
+ tell that value of the regulator ramp delay provided by
+ DT property "regulator-ramp-delay" is exponential and
+ fixed delay for any voltage level change.
+ If PWM regulator supports the fixed linear slew rate
+ then this property should be absent from DT node and
+ property "regulator-ramp-delay" is used as linear slew
+ rate.
Sorry, but on further thought, I don't think we should mix different
units for the same property. Also, the fact that the ramp is exponential
is irrelevant. You just want an absolute delay time rather than a rate,
right? So instead, how about just "regulator-ramp-time-us". Roughly what
you had in v1, but not PWM specific.
Can we say "regulator-settling-time-us" and make it generic i.e. part of
the regulator core instead of PWM regulator specific?
So no change for "regulator-ramp-delay".
new property "regulator-settling-time-us" for fixed settling time in any
voltage level change.
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