On Saturday 19 September 2015 01:36:43 Constantine Shulyupin wrote:
>
> I am designing DT support for a hwmon chip.
> It has some sensors, each of them can be:
> - "disabled"
> - "thermal diode"
> - "thermistor"
> - "voltage"
>
> Four possible options for DT properties format.
>
> Option 1: Separated property for each sensor.
>
> Example nct7802 node:
>
> nct7802 {
> compatible = "nuvoton,nct7802";
> reg = <0x2a>;
> nuvoton,sensor1-type = "thermistor";
> nuvoton,sensor2-type = "disabled";
> nuvoton,sensor3-type = "voltage";
> };
>
> Option 2: Array of strings for all sensors.
>
> nct7802 {
> compatible = "nuvoton,nct7802";
> reg = <0x2a>;
> nuvoton,sensors-types = "thermistor", "disabled", "voltage";
> };
>
> Option 3: Sets of 4 cells.
>
> Borrowed from marvell,reg-init and broadcom,c45-reg-init.
>
> The first cell is the page address,
> the second a register address within the page,
> the third cell contains a mask to be ANDed with the existing register
> value, and the fourth cell is ORed with the result to yield the
> new register value. If the third cell has a value of zero,
> no read of the existing value is performed.
>
> Example nct7802 node:
>
> nct7802 {
> compatible = "nuvoton,nct7802";
> reg = <0x2a>;
> nct7802,reg-init =
> <0 0x21 0 0x01 > // START = 1
> <0 0x22 0x03 0x02>; // RTD1_MD = 2
> };
>
I would strongly prefer Option 1 or 2 over option 3.
Between 1 and 2, I'd probably go for 1. Another option might
be to have a subnode per sensor:
nct7802@2a {
compatible = "nuvoton,nct7802";
reg = <0x2a>;
#address-cells=<1>;
#size-cells=<0>;
sensor@1 {
compatible = "nuvoton,nct7802-thermistor";
further-properties;
};
sensor@3 {
compatible = "nuvoton,nct7802-voltage";
for-example-range-mv = <0 5000>;
};
};
In either case, I'd say that disabled sensors should not need to
be listed.
Arnd
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