On 27/01/17 22:09, Peter Rosin wrote: > On 2017-01-27 20:50, Rob Herring wrote: >> On Wed, Jan 18, 2017 at 04:57:12PM +0100, Peter Rosin wrote: >>> Analog Devices ADG792A/G is a triple 4:1 mux. >>> >>> Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx> >>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx> >>> --- >>> .../devicetree/bindings/mux/mux-adg792a.txt | 79 ++++++++++++++++++++++ >>> 1 file changed, 79 insertions(+) >>> create mode 100644 Documentation/devicetree/bindings/mux/mux-adg792a.txt >>> >>> diff --git a/Documentation/devicetree/bindings/mux/mux-adg792a.txt b/Documentation/devicetree/bindings/mux/mux-adg792a.txt >>> new file mode 100644 >>> index 000000000000..0b26dd11f070 >>> --- /dev/null >>> +++ b/Documentation/devicetree/bindings/mux/mux-adg792a.txt >>> @@ -0,0 +1,79 @@ >>> +Bindings for Analog Devices ADG792A/G Triple 4:1 Multiplexers >>> + >>> +Required properties: >>> +- compatible : "adi,adg792a" or "adi,adg792g" >>> +- #mux-control-cells : <0> if parallel, or <1> if not. >>> +* Standard mux-controller bindings as decribed in mux-controller.txt >>> + >>> +Optional properties for ADG792G: >>> +- gpio-controller : if present, #gpio-cells below is required. >>> +- #gpio-cells : should be <2> >>> + - First cell is the GPO line number, i.e. 0 or 1 >>> + - Second cell is used to specify active high (0) >>> + or active low (1) >>> + >>> +Optional properties: >>> +- adi,parallel : if present, the three muxes are bound together with a single >>> + mux controller, controlling all three muxes in parallel. >> >> Can't this be implied by #mux-control-cells == 0? > > Right, good point! I'll drop adi,parallel. > >>> +- adi,idle-state : if present, array of 2-tuples with mux controller number >>> + and state that mux controllers will have when idle. States 0 through 3 >>> + correspond to signals A through D in the datasheet. >>> +- adi,idle-high-impedance : if present, array of mux controller numbers that >>> + should be in the disconnected high-impedance state when idle. >> >> Perhaps combine these 2 to a common idle-state with the index being the >> mux controller number and a value of -1 (or 4) being hi-Z. > > At one point [1] I had a straight array for the mux controllers with state 4 > being hi-Z and state 5 being the default "leave mux as-is on release", but > Jonathan didn't like magic numbers. Can you please read the follow-ups to the > referenced mail for some background, and then pick out the most suitable color > for me to paint with? :-) Hohum. Given it can be cleanly represented as two properties rather than a single property with a single magic value alongside the obvious ones I asked Peter to split it. Not all that fussed though as I don't have to maintain this ;) *ducks* Jonathan > > [1] https://lkml.org/lkml/2016/11/30/110 > >>> + >>> +Mux controller states 0 through 3 correspond to signals A through D in the >>> +datasheet. If a mux controller is mentioned in neither adi,idle-state nor >>> +adi,idle-high-impedance it is left in its previously selected state when idle. >>> + >>> +Example: >>> + >>> + /* >>> + * Three independent mux controllers (of which one is used). >>> + * Mux 0 is disconnected when idle, mux 1 idles with signal C >>> + * and mux 2 idles with signal A. >>> + */ >>> + &i2c0 { >>> + mux: adg792a@50 { >> >> mux-controller@50 > > Yep. Hmm, where have I seen that before? :-) > > Cheers, > peda > >>> + compatible = "adi,adg792a"; >>> + reg = <0x50>; >>> + #mux-control-cells = <1>; >>> + >>> + adi,idle-high-impedance = <0>; >>> + adi,idle-state = <1 2>, <2 0>; >>> + }; >>> + }; >>> + >>> + adc-mux { >>> + compatible = "io-channel-mux"; >>> + io-channels = <&adc 0>; >>> + io-channel-names = "parent"; >>> + >>> + mux-controls = <&mux 1>; >>> + >>> + channels = "sync-1", "", "out"; >>> + }; >>> + >>> + >>> + /* >>> + * Three parallel muxes with one mux controller, useful e.g. if >>> + * the adc is differential, thus needing two signals to be muxed >>> + * simultaneously for correct operation. >>> + */ >>> + &i2c0 { >>> + pmux: adg792a@50 { >>> + compatible = "adi,adg792a"; >>> + reg = <0x50>; >>> + #mux-control-cells = <0>; >>> + adi,parallel; >>> + }; >>> + }; >>> + >>> + diff-adc-mux { >>> + compatible = "io-channel-mux"; >>> + io-channels = <&adc 0>; >>> + io-channel-names = "parent"; >>> + >>> + mux-controls = <&pmux>; >>> + >>> + channels = "sync-1", "", "out"; >>> + }; >>> -- >>> 2.1.4 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe devicetree" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
