emc230x 0.8.0

An async driver for the EMC230x family of fan controllers
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113

// Copyright (c) 2026 Jake Swensen
// SPDX-License-Identifier: MPL-2.0
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

use core::fmt;

use crate::constants::EMC230X_ADDRESSES;
use crate::error::Error;

/// The set of I2C addresses at which EMC230x devices were discovered during a bus probe.
///
/// Returned by [`crate::Emc230x::probe`]. Iterating yields only addresses where a device was found.
#[derive(Copy, Clone, Debug, Default)]
pub struct ProbeResult(pub(crate) [bool; 6]);

impl ProbeResult {
    /// Returns an iterator over found device addresses.
    pub fn iter(&self) -> impl Iterator<Item = u8> + '_ {
        EMC230X_ADDRESSES
            .iter()
            .zip(self.0.iter())
            .filter_map(|(&addr, &found)| found.then_some(addr))
    }

    /// Returns `true` if no devices were found.
    pub fn is_empty(&self) -> bool {
        self.0.iter().all(|&x| !x)
    }

    /// Returns the number of devices found.
    pub fn len(&self) -> usize {
        self.0.iter().filter(|&&x| x).count()
    }

    /// Returns whether a device was found at the given address.
    ///
    /// Returns an error if the address is not a valid EMC230x I2C address.
    pub fn contains(&self, address: u8) -> Result<bool, Error> {
        let index = EMC230X_ADDRESSES
            .iter()
            .position(|&a| a == address)
            .ok_or(Error::InvalidI2cAddress)?;
        Ok(self.0[index])
    }
}

impl fmt::Display for ProbeResult {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "0x2C: {}; 0x2D: {}; 0x2E: {}; 0x2F: {}; 0x4C: {}; 0x4D: {}",
            self.0[0], self.0[1], self.0[2], self.0[3], self.0[4], self.0[5]
        )
    }
}

#[cfg(feature = "defmt")]
impl defmt::Format for ProbeResult {
    fn format(&self, f: defmt::Formatter) {
        defmt::write!(
            f,
            "0x2C: {}; 0x2D: {}; 0x2E: {}; 0x2F: {}; 0x4C: {}; 0x4D: {}",
            self.0[0],
            self.0[1],
            self.0[2],
            self.0[3],
            self.0[4],
            self.0[5]
        )
    }
}

impl IntoIterator for ProbeResult {
    type Item = u8;
    type IntoIter = core::iter::FilterMap<
        core::iter::Zip<core::array::IntoIter<u8, 6>, core::array::IntoIter<bool, 6>>,
        fn((u8, bool)) -> Option<u8>,
    >;

    fn into_iter(self) -> Self::IntoIter {
        EMC230X_ADDRESSES
            .into_iter()
            .zip(self.0)
            .filter_map((|(addr, found)| found.then_some(addr)) as fn((u8, bool)) -> Option<u8>)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::*;

    #[test]
    fn contains_found_address() {
        let result = ProbeResult([false, false, false, true, false, false]);
        assert!(result.contains(EMC230X_I2C_ADDR_3).unwrap());
    }

    #[test]
    fn contains_not_found_address() {
        let result = ProbeResult([false, false, false, true, false, false]);
        assert!(!result.contains(EMC230X_I2C_ADDR_0).unwrap());
    }

    #[test]
    fn contains_invalid_address() {
        let result = ProbeResult::default();
        assert!(result.contains(0xFF).is_err());
    }
}