ComponentExt: Add document to Linux details.

src/traits.rs

@@ -1486,6 +1486,11 @@ pub trait ComponentExt: Debug {
  /// println!("{}°C", component.temperature());
  /// }
  /// ```
+ ///
+ /// ## Linux hwmon
+ ///
+ /// Last temperature reading in case of an errors,
+ /// returns `f32::NAN`.
  fn temperature(&self) -> f32;
 
  /// Returns the maximum temperature of the component (in celsius degree).
@@ -1498,6 +1503,11 @@ pub trait ComponentExt: Debug {
  /// println!("{}°C", component.max());
  /// }
  /// ```
+ ///
+ /// ## Linux hwmon
+ ///
+ /// Read current Maximum value encountered may be computed by sysinfo
+ /// or from kernel in case of an errors, returns `f32::NAN`.
  fn max(&self) -> f32;
 
  /// Returns the highest temperature before the component halts (in celsius degree).
@@ -1510,6 +1520,13 @@ pub trait ComponentExt: Debug {
  /// println!("{:?}°C", component.critical());
  /// }
  /// ```
+ ///
+ /// ## Linux hwmon
+ ///
+ /// Critical threshold defined by chip or kernel may be defined or not.
+ /// Implementation detail:
+ ///
+ /// `thresold_critical` is >= `thresold_max`.
  fn critical(&self) -> Option<f32>;
 
  /// Returns the label of the component.
@@ -1522,6 +1539,17 @@ pub trait ComponentExt: Debug {
  /// println!("{}", component.label());
  /// }
  /// ```
+ ///
+ /// ## Linux hwmon label formating
+ ///
+ /// It may change. Inspired by `sensors` own formating.
+ ///
+ /// | name | label | device_model | id_sensor | Computed label by `sysinfo` |
+ /// |:----:|:-----:|:------------:|:----------|:-----------------------------------------:|
+ /// | ✓ | ✓ | ✓ | ✓ | `"{name} {label} {device_model} temp{id}"` |
+ /// | ✓ | ✓ | ✗ | ✓ | `"{name} {label} {id}"` |
+ /// | ✓ | ✗ | ✓ | ✓ | `"{name} {device_model}"` |
+ /// | ✓ | ✗ | ✗ | ✓ | `"{name} temp{id}"` |
  fn label(&self) -> &str;
 
  /// Refreshes component.
@@ -1534,6 +1562,12 @@ pub trait ComponentExt: Debug {
  /// component.refresh();
  /// }
  /// ```
+ ///
+ /// ## Linux
+ ///
+ /// - `temperature` is always read out form `hwmon`.
+ /// - `max` may kernel provided from `temp*-highest` or computed if
+ /// `current_temperature` > `max`.
  fn refresh(&mut self);
 }