Re: [PATCH v3 1/3] dt-bindings: iio: adc: Add Xilinx AMS binding documentation

From: Rob Herring
Date: Tue Oct 30 2018 - 16:43:01 EST


On Mon, Oct 29, 2018 at 05:40:24PM +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..1635576
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/xilinx-ams.txt
> @@ -0,0 +1,183 @@
> +Xilinx AMS controller
> +`````````````````````
> +The AMS includes an ADC as well as on-chip sensors that can be used to

AMS stands for?

> +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
> +
> + AMS sub-nodes:
> + - ams_ps : Used as PS-SYSMON node
> + - ams_pl : Used as PL-SYSMON node

Don't use '_' in node or property names.

> +
> +
> +
> +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.
> +
> + 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.
> +
> + 'reg' value Channel Name Channel Number
> + ----------- ------------ --------------
> + 0 VP/VN 30
> + 1 VUSER0 31
> + 2 VUSER1 32
> + 3 VUSER3 33
> + 4 VUSER4 34
> + 5 VAUXP[0]/VAUXN[0] 35
> + 6 VAUXP[1]/VAUXN[1] 36
> + ...
> + 20 VAUXP[15]/VAUXN[15] 50

Why this reg to channel mapping? Just use channel numbers for reg. I'm
confused by this table and the one below.

> +
> + 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.
> +
> +
> +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 0x400
> + 1 0 0xffa50c00 0x400>;

This doesn't work. This is mapping child addresses 0 and 1, but both
child nodes are at address 0. I believe you want the length to be 0x800
and drop the 2nd entry.

> +
> + ams_ps: ams_ps@0,0 {
> + compatible = "xlnx,zynqmp-ams-ps";
> + reg = <0 0x400>;
> + };
> +
> + ams_pl: ams_pl@1,0 {
> + compatible = "xlnx,zynqmp-ams-pl";
> + reg = <0 0x400>;

And then this should be address 0x400.

> + xlnx,ext-channels {
> + channel@0 {
> + reg = <0>;
> + xlnx,bipolar;
> + };
> + channel@1 {
> + reg = <1>;
> + };
> + channel@8 {
> + reg = <8>;
> + 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
>