Start work towards CRC_V2

embassy-stm32/src/crc/mod.rs

@@ -1,5 +1,8 @@
-#[cfg_attr(crc_v1, path = "v1.rs")]
-#[cfg_attr(crc_v2, path = "v2.rs")]
+use crate::peripherals::CRC;
+
+
+#[cfg_attr(crc_v2, path = "v1.rs")]
+#[cfg_attr(crc_v1, path = "v2.rs")]
 #[cfg_attr(crc_v3, path = "v3.rs")]
 mod _version;
 

embassy-stm32/src/crc/v2.rs

@@ -1 +1,87 @@
+use crate::pac::CRC as PAC_CRC;
+use crate::pac::crc::vals;
+use crate::peripherals::CRC;
+use crate::rcc::sealed::RccPeripheral;
 
+pub struct Crc {
+    _peripheral: CRC,
+    _config: CrcConfig,
+}
+
+pub enum CrcConfigError {
+    InvalidPolynomial
+}
+
+pub struct CrcConfig {
+    reverse_in: CrcInputReverseConfig,
+    reverse_out: bool,
+    poly_size: PolySize,
+    crc_init_value: u32,
+    crc_poly: u32,
+}
+
+pub enum CrcInputReverseConfig {
+    None,
+    Byte,
+    Halfword,
+    Word,
+}
+
+impl CrcConfig {
+    pub fn new(reverse_in: CrcInputReverseConfig, reverse_out: bool, poly_size: PolySize, crc_init_value: u32, crc_poly: u32) -> Result<Self, CrcConfigError> {
+        // As Per RM0091 (DocID018940 Rev 9), Even polynomials are not supported.
+        if crc_poly % 2 == 0 {
+            Err(CrcConfigError::InvalidPolynomial)
+        } else {
+            Ok(CrcConfig { reverse_in, reverse_out, poly_size, crc_init_value, crc_poly })
+        }
+    }
+}
+
+pub enum PolySize {
+    Width7,
+    Width8,
+    Width16,
+    Width32,
+}
+
+impl Crc {
+    /// Instantiates the CRC32 peripheral and initializes it to default values.
+    pub fn new(peripheral: CRC, init_value: u32, config: CrcConfig) -> Self {
+        // Note: enable and reset come from RccPeripheral.
+        // enable CRC clock in RCC.
+        CRC::enable();
+        // Reset CRC to default values.
+        CRC::reset();
+        let mut instance = Self {
+            _peripheral: peripheral,
+        };
+        instance.init();
+        instance
+    }
+
+    // Configure device settings
+    fn configure_revout(&mut self) {
+        unsafe {
+            PAC_CRC.cr().modify(|w| {w.set_rev_out(
+                match self._config.reverse_out {
+                    true => {vals::RevOut::REVERSED}
+                    false => {vals::RevOut::NORMAL}
+                }
+            )})
+        }
+    }
+
+    fn configure_revin(&mut self) {
+        unsafe {
+            PAC_CRC.cr().modify(|w| {w.set_rev_in(
+                match self._config.reverse_in {
+                    CrcInputReverseConfig::None => {vals::RevIn::NORMAL}
+                    CrcInputReverseConfig::Byte => {vals::RevIn::BYTE}
+                    CrcInputReverseConfig::Halfword => {vals::RevIn::HALFWORD}
+                    CrcInputReverseConfig::Word => {vals::RevIn::WORD}
+                }
+            )})
+        }
+    }
+}