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
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161

//! Asynchronous shared I2C bus
//!
//! # Example (nrf52)
//!
//! ```rust,ignore
//! use embassy_embedded_hal::shared_bus::asynch::i2c::I2cDevice;
//! use embassy_sync::mutex::Mutex;
//! use embassy_sync::blocking_mutex::raw::NoopRawMutex;
//!
//! static I2C_BUS: StaticCell<Mutex<NoopRawMutex, Twim<TWISPI0>>> = StaticCell::new();
//! let config = twim::Config::default();
//! let i2c = Twim::new(p.TWISPI0, Irqs, p.P0_03, p.P0_04, config);
//! let i2c_bus = Mutex::new(i2c);
//! let i2c_bus = I2C_BUS.init(i2c_bus);
//!
//! // Device 1, using embedded-hal-async compatible driver for QMC5883L compass
//! let i2c_dev1 = I2cDevice::new(i2c_bus);
//! let compass = QMC5883L::new(i2c_dev1).await.unwrap();
//!
//! // Device 2, using embedded-hal-async compatible driver for Mpu6050 accelerometer
//! let i2c_dev2 = I2cDevice::new(i2c_bus);
//! let mpu = Mpu6050::new(i2c_dev2);
//! ```

use embassy_sync::blocking_mutex::raw::RawMutex;
use embassy_sync::mutex::Mutex;
use embedded_hal_async::i2c;

use crate::shared_bus::I2cDeviceError;
use crate::SetConfig;

/// I2C device on a shared bus.
pub struct I2cDevice<'a, M: RawMutex, BUS> {
    bus: &'a Mutex<M, BUS>,
}

impl<'a, M: RawMutex, BUS> I2cDevice<'a, M, BUS> {
    /// Create a new `I2cDevice`.
    pub fn new(bus: &'a Mutex<M, BUS>) -> Self {
        Self { bus }
    }
}

impl<'a, M: RawMutex, BUS> i2c::ErrorType for I2cDevice<'a, M, BUS>
where
    BUS: i2c::ErrorType,
{
    type Error = I2cDeviceError<BUS::Error>;
}

impl<M, BUS> i2c::I2c for I2cDevice<'_, M, BUS>
where
    M: RawMutex + 'static,
    BUS: i2c::I2c + 'static,
{
    async fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.read(address, read).await.map_err(I2cDeviceError::I2c)?;
        Ok(())
    }

    async fn write(&mut self, address: u8, write: &[u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.write(address, write).await.map_err(I2cDeviceError::I2c)?;
        Ok(())
    }

    async fn write_read(
        &mut self,
        address: u8,
        write: &[u8],
        read: &mut [u8],
    ) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.write_read(address, write, read)
            .await
            .map_err(I2cDeviceError::I2c)?;
        Ok(())
    }

    async fn transaction(
        &mut self,
        address: u8,
        operations: &mut [embedded_hal_async::i2c::Operation<'_>],
    ) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.transaction(address, operations)
            .await
            .map_err(I2cDeviceError::I2c)?;
        Ok(())
    }
}

/// I2C device on a shared bus, with its own configuration.
///
/// This is like [`I2cDevice`], with an additional bus configuration that's applied
/// to the bus before each use using [`SetConfig`]. This allows different
/// devices on the same bus to use different communication settings.
pub struct I2cDeviceWithConfig<'a, M: RawMutex, BUS: SetConfig> {
    bus: &'a Mutex<M, BUS>,
    config: BUS::Config,
}

impl<'a, M: RawMutex, BUS: SetConfig> I2cDeviceWithConfig<'a, M, BUS> {
    /// Create a new `I2cDeviceWithConfig`.
    pub fn new(bus: &'a Mutex<M, BUS>, config: BUS::Config) -> Self {
        Self { bus, config }
    }
}

impl<'a, M, BUS> i2c::ErrorType for I2cDeviceWithConfig<'a, M, BUS>
where
    BUS: i2c::ErrorType,
    M: RawMutex,
    BUS: SetConfig,
{
    type Error = I2cDeviceError<BUS::Error>;
}

impl<M, BUS> i2c::I2c for I2cDeviceWithConfig<'_, M, BUS>
where
    M: RawMutex + 'static,
    BUS: i2c::I2c + SetConfig + 'static,
{
    async fn read(&mut self, address: u8, buffer: &mut [u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
        bus.read(address, buffer).await.map_err(I2cDeviceError::I2c)?;
        Ok(())
    }

    async fn write(&mut self, address: u8, bytes: &[u8]) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
        bus.write(address, bytes).await.map_err(I2cDeviceError::I2c)?;
        Ok(())
    }

    async fn write_read(
        &mut self,
        address: u8,
        wr_buffer: &[u8],
        rd_buffer: &mut [u8],
    ) -> Result<(), I2cDeviceError<BUS::Error>> {
        let mut bus = self.bus.lock().await;
        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
        bus.write_read(address, wr_buffer, rd_buffer)
            .await
            .map_err(I2cDeviceError::I2c)?;
        Ok(())
    }

    async fn transaction(&mut self, address: u8, operations: &mut [i2c::Operation<'_>]) -> Result<(), Self::Error> {
        let mut bus = self.bus.lock().await;
        bus.set_config(&self.config).map_err(|_| I2cDeviceError::Config)?;
        bus.transaction(address, operations)
            .await
            .map_err(I2cDeviceError::I2c)?;
        Ok(())
    }
}