From mboxrd@z Thu Jan 1 00:00:00 1970 From: megous@megous.com (=?UTF-8?Q?Ond=C5=99ej?= Jirman) Date: Wed, 26 Jul 2017 12:23:48 +0200 Subject: [linux-sunxi] [PATCH 10/10] ARM: dts: sun8i: Add SY8106A regulator to Orange Pi PC In-Reply-To: <82507f40a1ddba8517cf09f51d3afa33@aosc.io> References: <20170723102749.17323-1-icenowy@aosc.io> <20170723102749.17323-11-icenowy@aosc.io> <25C8A89C-8495-4787-934C-8E9667CD70BF@aosc.io> <82507f40a1ddba8517cf09f51d3afa33@aosc.io> Message-ID: <1501064628.14577.1.camel@megous.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, icenowy at aosc.io p??e v St 26. 07. 2017 v 15:36 +0800: > > > > > > > > > Otherwse > > > > > > > > > + regulator-max-microvolt = <1400000>; > > > > > + regulator-ramp-delay = <200>; > > > > > > > > Is this an actual constraint of the SoC? Or is it a characteristic > > > > of the regulator? If it is the latter, it belongs in the driver. > > > > AFAIK the regulator supports varying the ramp delay (slew rate). > > I don't know... > > Maybe I should ask Ondrej? It is probably neither. It is used to calculate a delay inserted by the kernel between setting a new target voltage over I2C and changing the frequency of the CPU. The actual delay is calculated by the difference between previous and the new voltage. I don't remember seeing anything in the datasheet of the regulator. This is just some low value that works. It would probably be dependent on the capacitance on the output of the regulator, actual load (which varies), etc. So it is a board specific value. One could measure it with an oscilloscope if there's a need to optimize this. regards, o. > > > > > > > > ChenYu > > > > > > > > > + regulator-boot-on; > > > > > + regulator-always-on; > > > > > + }; > > > > > +}; > > > > > + > > > > > &r_pio { > > > > > leds_r_opc: led_pins at 0 { > > > > > pins = "PL10"; > > > > > -- > > > > > 2.13.0 > > > > > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: This is a digitally signed message part URL: