| Message ID | 20180712110240.3006-2-m.felsch@pengutronix.de |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | Re-Enable support to disable switch regulators | expand |
On Thu, Jul 12, 2018 at 8:02 AM, Marco Felsch <m.felsch@pengutronix.de> wrote: > +Optional properties: > +- pfuze-disable-sw: Disable all unused switch regulators to save power > + consumption. Attention, some platforms are using the switch regulators as DDR > + ref or supply voltage. Mark these regulators as "regulator-always-on" to skip > + disabling these regulators. If not specified, the driver simualtes the s/simualtes/simulates/ Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jul 12, 2018 at 01:02:39PM +0200, Marco Felsch wrote: > +Optional properties: > +- pfuze-disable-sw: Disable all unused switch regulators to save power > + consumption. Attention, some platforms are using the switch regulators as DDR > + ref or supply voltage. Mark these regulators as "regulator-always-on" to skip > + disabling these regulators. If not specified, the driver simualtes the > + disabling. This means the state of the regulator is set to 'disabled' but the > + driver don't disable the regulator. This is a bit of a confused way of specifying things that depends on the Linux implementation, and the property sounds like a double negative too. I'd say something like "pfuze-support-disable" and then explicitly say that this is a workaround for backwards compatibility. I'd also recommend changing the implementation patch to just register a different version of the desc and ops that just doesn't have the disable operation so that the framework knows what's going on. While the current implementation works now there's the possibility that at some point in the future we might start relying on the disable actually having taken effect somehow and will get confused. There's some existing drivers that optimize their resume paths if they know power wasn't removed.
Hi Fabio, On 18-07-12 12:19, Fabio Estevam wrote: > On Thu, Jul 12, 2018 at 8:02 AM, Marco Felsch <m.felsch@pengutronix.de> wrote: > > > +Optional properties: > > +- pfuze-disable-sw: Disable all unused switch regulators to save power > > + consumption. Attention, some platforms are using the switch regulators as DDR > > + ref or supply voltage. Mark these regulators as "regulator-always-on" to skip > > + disabling these regulators. If not specified, the driver simualtes the > > s/simualtes/simulates/ > > Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> Thanks for the feedback, I'll fix it in v2.
Hi Mark, On 18-07-12 16:31, Mark Brown wrote: > On Thu, Jul 12, 2018 at 01:02:39PM +0200, Marco Felsch wrote: > > > +Optional properties: > > +- pfuze-disable-sw: Disable all unused switch regulators to save power > > + consumption. Attention, some platforms are using the switch regulators as DDR > > + ref or supply voltage. Mark these regulators as "regulator-always-on" to skip > > + disabling these regulators. If not specified, the driver simualtes the > > + disabling. This means the state of the regulator is set to 'disabled' but the > > + driver don't disable the regulator. > > This is a bit of a confused way of specifying things that depends on the > Linux implementation, and the property sounds like a double negative > too. I'd say something like "pfuze-support-disable" and then explicitly > say that this is a workaround for backwards compatibility. I can't find the double negative. Anyway your binding sounds better. So I will use yours. Should we add a vendor prefix too to be clear? I will also add some more informations to mark it as workaround. > I'd also recommend changing the implementation patch to just register a > different version of the desc and ops that just doesn't have the disable > operation so that the framework knows what's going on. While the > current implementation works now there's the possibility that at some > point in the future we might start relying on the disable actually > having taken effect somehow and will get confused. There's some > existing drivers that optimize their resume paths if they know power > wasn't removed. Okay I will change that too. I didn't know that there are drivers with optimized resume paths. Thanks for your feedback. Regards, Marco -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jul 13, 2018 at 10:30:39AM +0200, Marco Felsch wrote: > On 18-07-12 16:31, Mark Brown wrote: > > On Thu, Jul 12, 2018 at 01:02:39PM +0200, Marco Felsch wrote: > > > +Optional properties: > > > +- pfuze-disable-sw: Disable all unused switch regulators to save power > > This is a bit of a confused way of specifying things that depends on the > > Linux implementation, and the property sounds like a double negative > > too. I'd say something like "pfuze-support-disable" and then explicitly > > say that this is a workaround for backwards compatibility. > I can't find the double negative. Anyway your binding sounds better. So > I will use yours. Should we add a vendor prefix too to be clear? I will > also add some more informations to mark it as workaround. The property doesn't disable the use of switch regulators, it enables their disabling. A vendor prefix is probably required but I can't entirely follow the DT rules there, it certainly shouldn't hurt anyway.
diff --git a/Documentation/devicetree/bindings/regulator/pfuze100.txt b/Documentation/devicetree/bindings/regulator/pfuze100.txt index 672c939045ff..1f17ab7c7123 100644 --- a/Documentation/devicetree/bindings/regulator/pfuze100.txt +++ b/Documentation/devicetree/bindings/regulator/pfuze100.txt @@ -4,6 +4,14 @@ Required properties: - compatible: "fsl,pfuze100", "fsl,pfuze200", "fsl,pfuze3000", "fsl,pfuze3001" - reg: I2C slave address +Optional properties: +- pfuze-disable-sw: Disable all unused switch regulators to save power + consumption. Attention, some platforms are using the switch regulators as DDR + ref or supply voltage. Mark these regulators as "regulator-always-on" to skip + disabling these regulators. If not specified, the driver simualtes the + disabling. This means the state of the regulator is set to 'disabled' but the + driver don't disable the regulator. + Required child node: - regulators: This is the list of child nodes that specify the regulator initialization data for defined regulators. Please refer to below doc
This binding is used to keep the backward compatibility with the current dtb's [1]. The binding informs the driver that the unused switch regulators can be disabled. If it is not specified, the driver doesn't disable the switch regulators. [1] https://patchwork.kernel.org/patch/10490381/ Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> --- Documentation/devicetree/bindings/regulator/pfuze100.txt | 8 ++++++++ 1 file changed, 8 insertions(+)