stm32/rcc: change family-specific code from dirs to single files.

Consistent with how other peripherals handle their versions.

1 files changed, 234 insertions, 0 deletions

diff --git a/embassy-stm32/src/rcc/g0.rs b/embassy-stm32/src/rcc/g0.rs
new file mode 100644
index 000000000..df11ff36d
--- /dev/null
+++ b/embassy-stm32/src/rcc/g0.rs
@@ -0,0 +1,234 @@
+use crate::pac;
+use crate::peripherals::{self, RCC};
+use crate::rcc::{get_freqs, set_freqs, Clocks};
+use crate::time::Hertz;
+use crate::time::U32Ext;
+use core::marker::PhantomData;
+use embassy::util::Unborrow;
+use embassy_hal_common::unborrow;
+
+/// HSI speed
+pub const HSI_FREQ: u32 = 16_000_000;
+
+/// LSI speed
+pub const LSI_FREQ: u32 = 32_000;
+
+/// System clock mux source
+#[derive(Clone, Copy)]
+pub enum ClockSrc {
+    HSE(Hertz),
+    HSI16(HSI16Prescaler),
+    LSI,
+}
+
+#[derive(Clone, Copy)]
+pub enum HSI16Prescaler {
+    NotDivided,
+    Div2,
+    Div4,
+    Div8,
+    Div16,
+    Div32,
+    Div64,
+    Div128,
+}
+
+impl Into<u8> for HSI16Prescaler {
+    fn into(self) -> u8 {
+        match self {
+            HSI16Prescaler::NotDivided => 0x00,
+            HSI16Prescaler::Div2 => 0x01,
+            HSI16Prescaler::Div4 => 0x02,
+            HSI16Prescaler::Div8 => 0x03,
+            HSI16Prescaler::Div16 => 0x04,
+            HSI16Prescaler::Div32 => 0x05,
+            HSI16Prescaler::Div64 => 0x06,
+            HSI16Prescaler::Div128 => 0x07,
+        }
+    }
+}
+
+/// AHB prescaler
+#[derive(Clone, Copy, PartialEq)]
+pub enum AHBPrescaler {
+    NotDivided,
+    Div2,
+    Div4,
+    Div8,
+    Div16,
+    Div64,
+    Div128,
+    Div256,
+    Div512,
+}
+
+/// APB prescaler
+#[derive(Clone, Copy)]
+pub enum APBPrescaler {
+    NotDivided,
+    Div2,
+    Div4,
+    Div8,
+    Div16,
+}
+
+impl Into<u8> for APBPrescaler {
+    fn into(self) -> u8 {
+        match self {
+            APBPrescaler::NotDivided => 1,
+            APBPrescaler::Div2 => 0x04,
+            APBPrescaler::Div4 => 0x05,
+            APBPrescaler::Div8 => 0x06,
+            APBPrescaler::Div16 => 0x07,
+        }
+    }
+}
+
+impl Into<u8> for AHBPrescaler {
+    fn into(self) -> u8 {
+        match self {
+            AHBPrescaler::NotDivided => 1,
+            AHBPrescaler::Div2 => 0x08,
+            AHBPrescaler::Div4 => 0x09,
+            AHBPrescaler::Div8 => 0x0a,
+            AHBPrescaler::Div16 => 0x0b,
+            AHBPrescaler::Div64 => 0x0c,
+            AHBPrescaler::Div128 => 0x0d,
+            AHBPrescaler::Div256 => 0x0e,
+            AHBPrescaler::Div512 => 0x0f,
+        }
+    }
+}
+
+/// Clocks configutation
+pub struct Config {
+    pub mux: ClockSrc,
+    pub ahb_pre: AHBPrescaler,
+    pub apb_pre: APBPrescaler,
+    pub low_power_run: bool,
+}
+
+impl Default for Config {
+    #[inline]
+    fn default() -> Config {
+        Config {
+            mux: ClockSrc::HSI16(HSI16Prescaler::NotDivided),
+            ahb_pre: AHBPrescaler::NotDivided,
+            apb_pre: APBPrescaler::NotDivided,
+            low_power_run: false,
+        }
+    }
+}
+
+/// RCC peripheral
+pub struct Rcc<'d> {
+    _rb: peripherals::RCC,
+    phantom: PhantomData<&'d mut peripherals::RCC>,
+}
+
+impl<'d> Rcc<'d> {
+    pub fn new(rcc: impl Unborrow<Target = peripherals::RCC> + 'd) -> Self {
+        unborrow!(rcc);
+        Self {
+            _rb: rcc,
+            phantom: PhantomData,
+        }
+    }
+
+    // Safety: RCC init must have been called
+    pub fn clocks(&self) -> &'static Clocks {
+        unsafe { get_freqs() }
+    }
+}
+
+/// Extension trait that freezes the `RCC` peripheral with provided clocks configuration
+pub trait RccExt {
+    fn freeze(self, config: Config) -> Clocks;
+}
+
+impl RccExt for RCC {
+    #[inline]
+    fn freeze(self, cfgr: Config) -> Clocks {
+        let rcc = pac::RCC;
+        let (sys_clk, sw) = match cfgr.mux {
+            ClockSrc::HSI16(div) => {
+                // Enable HSI16
+                let div: u8 = div.into();
+                unsafe {
+                    rcc.cr().write(|w| {
+                        w.set_hsidiv(div);
+                        w.set_hsion(true)
+                    });
+                    while !rcc.cr().read().hsirdy() {}
+                }
+
+                (HSI_FREQ >> div, 0x00)
+            }
+            ClockSrc::HSE(freq) => {
+                // Enable HSE
+                unsafe {
+                    rcc.cr().write(|w| w.set_hseon(true));
+                    while !rcc.cr().read().hserdy() {}
+                }
+
+                (freq.0, 0x01)
+            }
+            ClockSrc::LSI => {
+                // Enable LSI
+                unsafe {
+                    rcc.csr().write(|w| w.set_lsion(true));
+                    while !rcc.csr().read().lsirdy() {}
+                }
+                (LSI_FREQ, 0x03)
+            }
+        };
+
+        unsafe {
+            rcc.cfgr().modify(|w| {
+                w.set_sw(sw.into());
+                w.set_hpre(cfgr.ahb_pre.into());
+                w.set_ppre(cfgr.apb_pre.into());
+            });
+        }
+
+        let ahb_freq: u32 = match cfgr.ahb_pre {
+            AHBPrescaler::NotDivided => sys_clk,
+            pre => {
+                let pre: u8 = pre.into();
+                let pre = 1 << (pre as u32 - 7);
+                sys_clk / pre
+            }
+        };
+
+        let (apb_freq, apb_tim_freq) = match cfgr.apb_pre {
+            APBPrescaler::NotDivided => (ahb_freq, ahb_freq),
+            pre => {
+                let pre: u8 = pre.into();
+                let pre: u8 = 1 << (pre - 3);
+                let freq = ahb_freq / pre as u32;
+                (freq, freq * 2)
+            }
+        };
+
+        let pwr = pac::PWR;
+        if cfgr.low_power_run {
+            assert!(sys_clk.hz() <= 2_000_000.hz());
+            unsafe {
+                pwr.cr1().modify(|w| w.set_lpr(true));
+            }
+        }
+
+        Clocks {
+            sys: sys_clk.hz(),
+            ahb: ahb_freq.hz(),
+            apb: apb_freq.hz(),
+            apb_tim: apb_tim_freq.hz(),
+        }
+    }
+}
+
+pub(crate) unsafe fn init(config: Config) {
+    let r = <peripherals::RCC as embassy::util::Steal>::steal();
+    let clocks = r.freeze(config);
+    set_freqs(clocks);
+}