Re: [PATCH v4 1/3] dt-bindings: iio: adc: Add Xilinx AMS binding documentation

From: Jonathan Cameron
Date: Sat Apr 27 2019 - 08:05:22 EST


On Fri, 26 Apr 2019 14:33:09 -0500
Rob Herring <robh@xxxxxxxxxx> wrote:

> On Mon, Apr 22, 2019 at 08:07:48PM +0530, Manish Narani wrote:
> > Xilinx AMS have several ADC channels that can be used for measurement of
> > different voltages and temperatures. Document the same in the bindings.
> >
> > Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
> > ---
> > .../devicetree/bindings/iio/adc/xilinx-ams.txt | 183 +++++++++++++++++++++
> > 1 file changed, 183 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/iio/adc/xilinx-ams.txt
> >
> > diff --git a/Documentation/devicetree/bindings/iio/adc/xilinx-ams.txt b/Documentation/devicetree/bindings/iio/adc/xilinx-ams.txt
> > new file mode 100644
> > index 0000000..cacb6d4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/xilinx-ams.txt
> > @@ -0,0 +1,183 @@
> > +Xilinx AMS controller
> > +`````````````````````
> > +The AMS (Analog Monitoring System) includes an ADC as well as on-chip sensors
> > +that can be used to sample external voltages and monitor on-die operating
> > +conditions, such as temperature and supply voltage levels.
> > +The AMS has two SYSMON blocks which are PL (Programmable Logic) SYSMON and
> > +PS (Processing System) SYSMON.
> > +All designs should have AMS registers, but PS and PL are optional. The
> > +AMS controller can work with only PS, only PL and both PS and PL
> > +configurations. Please specify registers according to your design. Devicetree
> > +should always have AMS module property. Providing PS & PL module is optional.
> > +
> > +Required properties:
> > + - compatible: Should be "xlnx,zynqmp-ams"
> > + - reg: Should specify AMS register space
> > + - interrupts: Interrupt number for the AMS control interface
> > + - interrupt-names: Interrupt name, must be "ams-irq"
> > + - clocks: Should contain a clock specifier for the device
> > + - ranges: keep the property empty to map child address space
> > + (for PS and/or PL) nodes 1:1 onto the parent address
> > + space
>
> empty is not what you've done in the example. Non-empty is preferred.
>
> > +
> > + AMS sub-nodes:
> > + - ams-ps : Used as PS-SYSMON node
> > + - ams-pl : Used as PL-SYSMON node
> > +
> > +
> > +
> > +AMS PS-SYSMON
> > +`````````````
> > +PS (Processing System) SYSMON is memory mapped to PS. This block has built-in
> > +alarm generation logic that is used to interrupt the processor based on
> > +condition set.
> > +
> > +Required properties:
> > + - compatible: Should be "xlnx,zynqmp-ams-ps"
> > + - reg: Register space for PS-SYSMON
> > +
> > +
> > +
> > +AMS PL-SYSMON
> > +`````````````
> > +PL-SYSMON is capable of monitoring off chip voltage and temperature. PL-SYSMON
> > +block has DRP, JTAG and I2C interface to enable monitoring from external master.
> > +Out of this interface currently only DRP is supported. This block has alarm
> > +generation logic that is used to interrupt the processor based on condition set.
> > +
> > +Required properties:
> > + - compatible: Should be "xlnx,zynqmp-ams-pl"
> > + - reg: Register space for PL-SYSMON
> > +
> > +PL-SYSMON optional sub-nodes:
> > + - xlnx,ext-channels: List of external channels that are connected to the
> > + AMS PL module.
>
> Why not just get rid of this and move 'channel' nodes up a level?
>
> > +
> > + The child nodes of PL-SYSMON represent the external channels which are
> > + connected to this Module. If the property is not present
> > + no external channels will be assumed to be connected.
> > +
> > + Each child node represents one channel and has the following
> > + properties:
> > +
> > + Required properties:
> > + * reg: Pair of pins the channel is connected to. This value is
> > + same as Channel Number for particular channel.
> > +
> > + 'reg' value Channel Name
> > + ----------- ------------
> > + 30 VP/VN
> > + 31 VUSER0
> > + 32 VUSER1
> > + 33 VUSER3
> > + 34 VUSER4
> > + 35 VAUXP[0]/VAUXN[0]
> > + 36 VAUXP[1]/VAUXN[1]
> > + ...
> > + 50 VAUXP[15]/VAUXN[15]
> > +
> > + Each channel number should only be used at most once. For
> > + more details on channels, refer to the table given at the end.
> > +
> > + Optional properties:
> > + * xlnx,bipolar: If set the channel is used in bipolar
> > + mode.
>
> I think we have a standard property for this now.
Yes, in the meantime we introduced a standard binding for
child channels, including bipolar.

Documentation/devicetree/bindings/iio/adc/adc.txt

I haven't totally thought through how it maps to this particular device
but from a quick glance, it should be possible.

You will need to be more explicit with the pair of channels, rather
than basically using an enum though.
Have a go and let's see how it looks before concluding if that
binding perhaps needs further extension.

Thanks,

Jonathan


>
> > +
> > +
> > +Example:
> > + xilinx_ams: ams@ffa50000 {
> > + compatible = "xlnx,zynqmp-ams";
> > + interrupt-parent = <&gic>;
> > + interrupts = <0 56 4>;
> > + interrupt-names = "ams-irq";
> > + reg = <0x0 0xffa50000 0x0 0x800>;
> > + reg-names = "ams-base";
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + #io-channel-cells = <1>;
> > + ranges = <0 0 0xffa50800 0x800>;
> > +
> > + ams_ps: ams-ps@0,0 {
>
> unit address should be '0'
>
> > + compatible = "xlnx,zynqmp-ams-ps";
> > + reg = <0 0x400>;
> > + };
> > +
> > + ams_pl: ams-pl@1,0 {
>
> unit address should be '400'
>
> > + compatible = "xlnx,zynqmp-ams-pl";
> > + reg = <0x400 0x400>;
> > + xlnx,ext-channels {
>
> Needs #address-cells and #size-cells. dtc should complain here.
>
> > + channel@30 {
> > + reg = <30>;
> > + xlnx,bipolar;
> > + };
> > + channel@31 {
> > + reg = <31>;
> > + };
> > + channel@38 {
> > + reg = <38>;
> > + xlnx,bipolar;
> > + };
> > + };
> > + };
> > + };
> > +
> > +
> > +AMS Channel Details
> > +```````````````````
> > +Sysmon Block |Channel| Details |Measurement
> > + |Number | |Type
> > +---------------------------------------------------------------------------------------------------------
> > +AMS CTRL |0 |System PLLs voltage measurement, VCC_PSPLL. |Voltage
> > + |1 |Battery voltage measurement, VCC_PSBATT. |Voltage
> > + |2 |PL Internal voltage measurement, VCCINT. |Voltage
> > + |3 |Block RAM voltage measurement, VCCBRAM. |Voltage
> > + |4 |PL Aux voltage measurement, VCCAUX. |Voltage
> > + |5 |Voltage measurement for six DDR I/O PLLs, VCC_PSDDR_PLL. |Voltage
> > + |6 |VCC_PSINTFP_DDR voltage measurement. |Voltage
> > +---------------------------------------------------------------------------------------------------------
> > +PS Sysmon |7 |LPD temperature measurement. |Temperature
> > + |8 |FPD temperature measurement (REMOTE). |Temperature
> > + |9 |VCC PS LPD voltage measurement (supply1). |Voltage
> > + |10 |VCC PS FPD voltage measurement (supply2). |Voltage
> > + |11 |PS Aux voltage reference (supply3). |Voltage
> > + |12 |DDR I/O VCC voltage measurement. |Voltage
> > + |13 |PS IO Bank 503 voltage measurement (supply5). |Voltage
> > + |14 |PS IO Bank 500 voltage measurement (supply6). |Voltage
> > + |15 |VCCO_PSIO1 voltage measurement. |Voltage
> > + |16 |VCCO_PSIO2 voltage measurement. |Voltage
> > + |17 |VCC_PS_GTR voltage measurement (VPS_MGTRAVCC). |Voltage
> > + |18 |VTT_PS_GTR voltage measurement (VPS_MGTRAVTT). |Voltage
> > + |19 |VCC_PSADC voltage measurement. |Voltage
> > +---------------------------------------------------------------------------------------------------------
> > +PL Sysmon |20 |PL temperature measurement. |Temperature
> > + |21 |PL Internal voltage measurement, VCCINT. |Voltage
> > + |22 |PL Auxiliary voltage measurement, VCCAUX. |Voltage
> > + |23 |ADC Reference P+ voltage measurement. |Voltage
> > + |24 |ADC Reference N- voltage measurement. |Voltage
> > + |25 |PL Block RAM voltage measurement, VCCBRAM. |Voltage
> > + |26 |LPD Internal voltage measurement, VCC_PSINTLP (supply4). |Voltage
> > + |27 |FPD Internal voltage measurement, VCC_PSINTFP (supply5). |Voltage
> > + |28 |PS Auxiliary voltage measurement (supply6). |Voltage
> > + |29 |PL VCCADC voltage measurement (vccams). |Voltage
> > + |30 |Differential analog input signal voltage measurment. |Voltage
> > + |31 |VUser0 voltage measurement (supply7). |Voltage
> > + |32 |VUser1 voltage measurement (supply8). |Voltage
> > + |33 |VUser2 voltage measurement (supply9). |Voltage
> > + |34 |VUser3 voltage measurement (supply10). |Voltage
> > + |35 |Auxiliary ch 0 voltage measurement (VAux0). |Voltage
> > + |36 |Auxiliary ch 1 voltage measurement (VAux1). |Voltage
> > + |37 |Auxiliary ch 2 voltage measurement (VAux2). |Voltage
> > + |38 |Auxiliary ch 3 voltage measurement (VAux3). |Voltage
> > + |39 |Auxiliary ch 4 voltage measurement (VAux4). |Voltage
> > + |40 |Auxiliary ch 5 voltage measurement (VAux5). |Voltage
> > + |41 |Auxiliary ch 6 voltage measurement (VAux6). |Voltage
> > + |42 |Auxiliary ch 7 voltage measurement (VAux7). |Voltage
> > + |43 |Auxiliary ch 8 voltage measurement (VAux8). |Voltage
> > + |44 |Auxiliary ch 9 voltage measurement (VAux9). |Voltage
> > + |45 |Auxiliary ch 10 voltage measurement (VAux10). |Voltage
> > + |46 |Auxiliary ch 11 voltage measurement (VAux11). |Voltage
> > + |47 |Auxiliary ch 12 voltage measurement (VAux12). |Voltage
> > + |48 |Auxiliary ch 13 voltage measurement (VAux13). |Voltage
> > + |49 |Auxiliary ch 14 voltage measurement (VAux14). |Voltage
> > + |50 |Auxiliary ch 15 voltage measurement (VAux15). |Voltage
> > +---------------------------------------------------------------------------------------------------------
> > --
> > 2.1.1
> >