> In order to accommodate in a logical manner for the premuxed channels > in PM8921 and the similarly addressed channels in later PMICs, we > need a twocell arrangement with premux and analog mux setting as > a tuple to uniquely identify a hardware channel. > > These bindings are not yet in use, so it should be fine to augment > them before we actually start using it in drivers and device trees. nitpicking below > This scheme came out of lengthy discussions and reverse-engineering > and reading of the few information sources we have. > > Cc: devicetree@xxxxxxxxxxxxxxx > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Suggested-by: Björn Andersson <bjorn.andersson@xxxxxxxxxx> > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > --- > ChangeLog v2->v3: > - Drop leading zeroes on unit addresses. > ChangeLog v1->v2: > - Name nodes with <01 02> in a foo@0102 pattern. > - Minor spelling nits. > - Delete flimsy leftover docs from an interrim development path. > --- > .../bindings/iio/adc/qcom,pm8xxx-xoadc.txt | 76 ++++++++++++---------- > 1 file changed, 42 insertions(+), 34 deletions(-) > > diff --git a/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt b/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt > index 53cd146d8096..69c404112df1 100644 > --- a/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt > +++ b/Documentation/devicetree/bindings/iio/adc/qcom,pm8xxx-xoadc.txt > @@ -19,32 +19,42 @@ Required properties: > with PMIC variant but is typically something like 2.2 or 1.8V. > > The following required properties are standard for IO channels, see > -iio-bindings.txt for more details: > +iio-bindings.txt for more details, but noitice that this particular notice > +ADC has a special adressing scheme that require two cells for addressing > +identifying each ADC channel: > > -- #address-cells: should be set to <1> > +- #address-cells: should be set to <2>, the first cell is the > + prescaler (on PM8058) or premux (on PM8921) with two valid bits > + so legal values are 0x00, 0x01 or 0x02. The second cell > + is the main analog mux setting (0x00..0x0f). The combination > + of prescaler/premux and analog mux uniquely addresses a hardware > + channel on all systems. > > - #size-cells: should be set to <0> > > -- #io-channel-cells: should be set to <1> > +- #io-channel-cells: should be set to <2>, again the cells are > + precaler or premux followed by the analog muxing line. > > - interrupts: should refer to the parent PMIC interrupt controller > and reference the proper ADC interrupt. > > Required subnodes: > > -The ADC channels are configured as subnodes of the ADC. Since some of > -them are used for calibrating the ADC, these nodes are compulsory: > +The ADC channels are configured as subnodes of the ADC. > + > +Since some of them are used for calibrating the ADC, these nodes are > +compulsory: > > adc-channel@c { > - reg = <0x0c>; > + reg = <0x00 0x0c>; > }; > > adc-channel@d { > - reg = <0x0d>; > + reg = <0x00 0x0d>; > }; > > adc-channel@f { > - reg = <0x0f>; > + reg = <0x00 0x0f>; > }; > > These three nodes are used for absolute and ratiometric calibration > @@ -52,13 +62,13 @@ and only need to have these reg values: they are by hardware definition > 1:1 ratio converters that sample 625, 1250 and 0 milliV and create > an interpolation calibration for all other ADCs. > > -Optional subnodes: any channels other than channel 0x0c, 0x0d and > -0x0f are optional. > +Optional subnodes: any channels other than channels [0x00 0x0c], > +[0x00 0x0d] and [0x00 0x0f] are optional. > > Required channel node properties: > > - reg: should contain the hardware channel number in the range > - 0 .. 0x0f (4 bits). The hardware only supports 16 channels. > + 0 .. 0xff (8 bits). > > Optional channel node properties: > > @@ -94,56 +104,54 @@ Example: > xoadc: xoadc@197 { > compatible = "qcom,pm8058-adc"; > reg = <0x197>; > - interrupt-parent = <&pm8058>; > - interrupts = <76 1>; > - #address-cells = <1>; > + interrupts-extended = <&pm8058 76 IRQ_TYPE_EDGE_RISING>; > + #address-cells = <2>; > #size-cells = <0>; > - #io-channel-cells = <1>; > + #io-channel-cells = <2>; > > vcoin: adc-channel@0 { > - reg = <0x00>; > + reg = <0x00 0x00>; > }; > vbat: adc-channel@1 { > - reg = <0x01>; > + reg = <0x00 0x01>; > }; > dcin: adc-channel@2 { > - reg = <0x02>; > + reg = <0x00 0x02>; > }; > ichg: adc-channel@3 { > - reg = <0x03>; > + reg = <0x00 0x03>; > }; > vph_pwr: adc-channel@4 { > - reg = <0x04>; > + reg = <0x00 0x04>; > }; > usb_vbus: adc-channel@a { > - reg = <0x0a>; > + reg = <0x00 0x0a>; > }; > die_temp: adc-channel@b { > - reg = <0x0b>; > + reg = <0x00 0x0b>; > }; > ref_625mv: adc-channel@c { > - reg = <0x0c>; > + reg = <0x00 0x0c>; > }; > ref_1250mv: adc-channel@d { > - reg = <0x0d>; > + reg = <0x00 0x0d>; > }; > ref_325mv: adc-channel@e { > - reg = <0x0e>; > + reg = <0x00 0x0e>; > }; > ref_muxoff: adc-channel@f { > - reg = <0x0f>; > + reg = <0x00 0x0f>; > }; > }; > > - > /* IIO client node */ > iio-hwmon { > compatible = "iio-hwmon"; > - io-channels = <&xoadc 0x01>, /* Battery */ > - <&xoadc 0x02>, /* DC in (charger) */ > - <&xoadc 0x04>, /* VPH the main system voltage */ > - <&xoadc 0x0b>, /* Die temperature */ > - <&xoadc 0x0c>, /* Reference voltage 1.25V */ > - <&xoadc 0x0d>, /* Reference voltage 0.625V */ > - <&xoadc 0x0e>; /* Reference voltage 0.325V */ > + io-channels = <&xoadc 0x00 0x01>, /* Battery */ > + <&xoadc 0x00 0x02>, /* DC in (charger) */ > + <&xoadc 0x00 0x04>, /* VPH the main system voltage */ > + <&xoadc 0x00 0x0b>, /* Die temperature */ > + <&xoadc 0x00 0x0c>, /* Reference voltage 1.25V */ > + <&xoadc 0x00 0x0d>, /* Reference voltage 0.625V */ > + <&xoadc 0x00 0x0e>; /* Reference voltage 0.325V */ > }; > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418