stm32ral/stm32f0/instances/
stk.rs

1#![allow(non_snake_case, non_upper_case_globals)]
2#![allow(non_camel_case_types)]
3//! SysTick timer
4//!
5//! Used by: stm32f0x0, stm32f0x1, stm32f0x2, stm32f0x8
6
7#[cfg(not(feature = "nosync"))]
8pub use crate::stm32f0::peripherals::stk::Instance;
9pub use crate::stm32f0::peripherals::stk::{RegisterBlock, ResetValues};
10pub use crate::stm32f0::peripherals::stk::{CALIB, CSR, CVR, RVR};
11
12/// Access functions for the STK peripheral instance
13pub mod STK {
14    use super::ResetValues;
15
16    #[cfg(not(feature = "nosync"))]
17    use super::Instance;
18
19    #[cfg(not(feature = "nosync"))]
20    const INSTANCE: Instance = Instance {
21        addr: 0xe000e010,
22        _marker: ::core::marker::PhantomData,
23    };
24
25    /// Reset values for each field in STK
26    pub const reset: ResetValues = ResetValues {
27        CSR: 0x00000000,
28        RVR: 0x00000000,
29        CVR: 0x00000000,
30        CALIB: 0x00000000,
31    };
32
33    #[cfg(not(feature = "nosync"))]
34    #[allow(renamed_and_removed_lints)]
35    #[allow(private_no_mangle_statics)]
36    #[no_mangle]
37    static mut STK_TAKEN: bool = false;
38
39    /// Safe access to STK
40    ///
41    /// This function returns `Some(Instance)` if this instance is not
42    /// currently taken, and `None` if it is. This ensures that if you
43    /// do get `Some(Instance)`, you are ensured unique access to
44    /// the peripheral and there cannot be data races (unless other
45    /// code uses `unsafe`, of course). You can then pass the
46    /// `Instance` around to other functions as required. When you're
47    /// done with it, you can call `release(instance)` to return it.
48    ///
49    /// `Instance` itself dereferences to a `RegisterBlock`, which
50    /// provides access to the peripheral's registers.
51    #[cfg(not(feature = "nosync"))]
52    #[inline]
53    pub fn take() -> Option<Instance> {
54        external_cortex_m::interrupt::free(|_| unsafe {
55            if STK_TAKEN {
56                None
57            } else {
58                STK_TAKEN = true;
59                Some(INSTANCE)
60            }
61        })
62    }
63
64    /// Release exclusive access to STK
65    ///
66    /// This function allows you to return an `Instance` so that it
67    /// is available to `take()` again. This function will panic if
68    /// you return a different `Instance` or if this instance is not
69    /// already taken.
70    #[cfg(not(feature = "nosync"))]
71    #[inline]
72    pub fn release(inst: Instance) {
73        external_cortex_m::interrupt::free(|_| unsafe {
74            if STK_TAKEN && inst.addr == INSTANCE.addr {
75                STK_TAKEN = false;
76            } else {
77                panic!("Released a peripheral which was not taken");
78            }
79        });
80    }
81
82    /// Unsafely steal STK
83    ///
84    /// This function is similar to take() but forcibly takes the
85    /// Instance, marking it as taken irregardless of its previous
86    /// state.
87    #[cfg(not(feature = "nosync"))]
88    #[inline]
89    pub unsafe fn steal() -> Instance {
90        STK_TAKEN = true;
91        INSTANCE
92    }
93}
94
95/// Raw pointer to STK
96///
97/// Dereferencing this is unsafe because you are not ensured unique
98/// access to the peripheral, so you may encounter data races with
99/// other users of this peripheral. It is up to you to ensure you
100/// will not cause data races.
101///
102/// This constant is provided for ease of use in unsafe code: you can
103/// simply call for example `write_reg!(gpio, GPIOA, ODR, 1);`.
104pub const STK: *const RegisterBlock = 0xe000e010 as *const _;