Messages in this thread | | | Subject | Re: [linux-sunxi] PATH[1/3] ARM: axp20x_usb_power.c add device tree configuration options for REG 30H: VBUS-IPSOUT | From | Hans de Goede <> | Date | Fri, 10 Jun 2016 11:56:25 +0200 |
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Hi,
On 17-05-16 19:41, Ene Alexandru wrote: > The AXP20X chips have a configuration register "REG 30H: VBUS-IPSOUT Power Path Management" that provide USB power supply protection. > The current axp20x_usb_power.c provides support only for reading those values. > > From the datasheet: > In order not to affect the USB communication, VBUS is always working under Voltage-Limit mode by default. In this mode, AXP209 ensures that VBUS voltage remains above a configurable reference voltage VHOLD which can meet the USB specification. The default VHOLD is 4.4V, adjustable in Reg30H [5:3] register. If the system has limit on current obtained from USB VBUS, a current-limit mode is provided (See REG30H[1] register), with 900mA/500mA/100mA (Reg30H [0]) selectable. > > The following entries are added in the axp209.dtsi file: vhold-enable, vhold-set and ibus-limit > The chosen default values are the AXP20X reset values, as described in the data sheet. > > Signed-off-by: Ene Alexandru <ene.alexandru@gmail.com> > > > --- > diff -uprN -X linux-sunxi-original/Documentation/dontdiff linux-sunxi-original/arch/arm/boot/dts/axp209.dtsi linux-sunxi/arch/arm/boot/dts/axp209.dtsi > --- linux-sunxi-original/arch/arm/boot/dts/axp209.dtsi 2016-05-11 09:21:47.470923679 +0200 > +++ linux-sunxi/arch/arm/boot/dts/axp209.dtsi 2016-05-10 18:45:32.795158651 +0200 > @@ -98,5 +98,8 @@ > usb_power_supply: usb_power_supply { > compatible = "x-powers,axp202-usb-power-supply"; > status = "disabled"; > + vhold-enable = <0x01>; > + vhold-set = <0x04>; > + ibus-limit = <0x01>; > }; > };
Please do not use raw register values like this, instead make the device-tree property take microvolts / microamps like e.g. the regulator bindings do, and translate these in the driver.
Regards,
Hans
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