On Tue, Sep 14, 2021 at 08:41:36AM -0400, Oskar Senft wrote: > Hi Guenter > > > https://lore.kernel.org/linux-hwmon/cover.1631021349.git.krzysztof.adamski@xxxxxxxxx/ > > > > That specifically includes the ability to enable or disable channels > > using the standard 'status' property. While that series is primarily > > for the n-factor property supported by the tmp421, the same approach > > can be used for [temperature] sensor properties on other chips as well. > > Good pointer! I should be able to replicate that for the LTD (@0) and > RTDs (1, 2, 3) in a similar way. > > > I put [temperature] in [] because we'd need to find a means to express > > if the sub-nodes are for temperature, voltage, or something else, but > > I think the basic principle is sound. > Following the example from tmp421, this could then be like this: > Something like that, only we'll need something to distinguish temperature sensors from other sensor types, eg voltage or current. Maybe a "type" property. I'd suggest "sensor-type", but we have non-sensor attributes such as fan count and pwm values which should be covered as well. But it looks like a good start for a set of generic sensor properties. > i2c { > #address-cells = <1>; > #size-cells = <0>; > > nct7802@28 { > compatible = "nuvoton,nct7802"; > reg = <0x28>; > #address-cells = <1>; > #size-cells = <0>; > > /* LTD */ > input@0 { > reg = <0x0>; > status = "okay"; Not sure what the default is here ('okay' or 'disabled'). We'd also need to define what to do if there is no data for a given sensor. > /* No "mode" attribute here*/ > label = "local temp"; > }; > > /* RTD1 */ > input@1 { > reg = <0x1>; > mode = <0x2>; /* 3904 transistor */ > label = "voltage mode"; That isn't the idea for "label", as "label" would be expected to show up as tempX_label (and a label of "voltage mode" would be odd). The label should indicate where the sensor is located on a board, such as "inlet" or "outlet". > }; > > input@2 { > reg = <0x2>; > mode = <0x4>; /* thermistor */ > label = "thermistor mode"; > }; > > /* RTD3 */ > input@3 { > reg = <0x3>; > mode = <0x3>; /* thermal diode */ > label = "current mode"; > status = "disabled"; > }; > }; > }; > > I noticed that "nct7802_temp_is_visible" only allows the temperature > sensor to be visible for current and thermistor but not voltage. Is > that right? > No, that is a bug. > Before I go and change the driver further, I'd like to make sure we > agree on the interface. > > Also: Is nct7802_temp_is_visible called again after temp_type_store > was called (I didn't try it)? > No. That would not be the idea. If enabling / disabling a sensor is supposed with the _enable attribute (and/or with devicetree), the affected sensor should always be instantiated, and reading sensor data should return -ENODATA if the sensor is disabled. Thanks, Guenter
