embedded_hal_bus/i2c/
rc.rs

1extern crate alloc;
2use alloc::rc::Rc;
3
4use core::cell::RefCell;
5use embedded_hal::i2c::{ErrorType, I2c};
6
7/// `Rc<RefCell<T>>`-based shared bus [`I2c`] implementation.
8/// This is the reference-counting equivalent of [`RefCellDevice`](super::RefCellDevice).
9///
10/// Sharing is implemented with a [`RefCell`] and ownership is managed by [`Rc`].
11/// Like [`RefCellDevice`](super::RefCellDevice), `RcDevice` instances are not [`Send`],
12/// so they can only be shared within a single thread (interrupt priority level).
13///
14/// When this `RcDevice` is dropped, the reference count of the I2C bus will be decremented.
15/// Once that reference count hits zero, it will be cleaned up.
16#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
17pub struct RcDevice<Bus> {
18    bus: Rc<RefCell<Bus>>,
19}
20
21impl<Bus> RcDevice<Bus> {
22    /// Creates a new `RcDevice`.
23    ///
24    /// This function does not increment the reference count for the bus:
25    /// you will need to call `Rc::clone(&bus)` if you only have a `&Rc<RefCell<Bus>>`.
26    #[inline]
27    pub fn new(bus: Rc<RefCell<Bus>>) -> Self {
28        Self { bus }
29    }
30}
31
32impl<Bus> ErrorType for RcDevice<Bus>
33where
34    Bus: ErrorType,
35{
36    type Error = Bus::Error;
37}
38
39impl<Bus> I2c for RcDevice<Bus>
40where
41    Bus: I2c,
42{
43    #[inline]
44    fn read(&mut self, address: u8, read: &mut [u8]) -> Result<(), Self::Error> {
45        let bus = &mut *self.bus.borrow_mut();
46        bus.read(address, read)
47    }
48
49    #[inline]
50    fn write(&mut self, address: u8, write: &[u8]) -> Result<(), Self::Error> {
51        let bus = &mut *self.bus.borrow_mut();
52        bus.write(address, write)
53    }
54
55    #[inline]
56    fn write_read(
57        &mut self,
58        address: u8,
59        write: &[u8],
60        read: &mut [u8],
61    ) -> Result<(), Self::Error> {
62        let bus = &mut *self.bus.borrow_mut();
63        bus.write_read(address, write, read)
64    }
65
66    #[inline]
67    fn transaction(
68        &mut self,
69        address: u8,
70        operations: &mut [embedded_hal::i2c::Operation<'_>],
71    ) -> Result<(), Self::Error> {
72        let bus = &mut *self.bus.borrow_mut();
73        bus.transaction(address, operations)
74    }
75}
embedded_hal_bus/i2c/rc.rs

embedded_hal_bus/i2c/
rc.rs
