First pass at CRC_V1

4 files changed, 43 insertions, 8 deletions

diff --git a/embassy-stm32/src/crc/mod.rs b/embassy-stm32/src/crc/mod.rs
index 79e00be73..02fa1278b 100644
--- a/embassy-stm32/src/crc/mod.rs
+++ b/embassy-stm32/src/crc/mod.rs
@@ -1,4 +1,4 @@
 #[cfg_attr(crc_v1, path = "v1.rs")]
 #[cfg_attr(crc_v2, path = "v2.rs")]
 #[cfg_attr(crc_v3, path = "v3.rs")]
-mod _version;
\ No newline at end of file
+mod _version;
diff --git a/embassy-stm32/src/crc/v1.rs b/embassy-stm32/src/crc/v1.rs
index 4fc23fe39..52ccca660 100644
--- a/embassy-stm32/src/crc/v1.rs
+++ b/embassy-stm32/src/crc/v1.rs
@@ -1,21 +1,54 @@
-use crate::pac::{CRC as PAC_CRC, RCC};
+use crate::pac::CRC as PAC_CRC;
 use crate::peripherals::CRC;
 use crate::rcc::sealed::RccPeripheral;
 
 pub struct Crc {
-    _peripheral: CRC
+    _peripheral: CRC,
 }
 
-impl Crc{
-    pub fn new(peripheral: CRC) -> Self{
+impl Crc {
+    /// Instantiates the CRC32 peripheral and initializes it to default values.
+    pub fn new(peripheral: CRC) -> Self {
+        // Note: enable and reset come from RccPeripheral.
         // enable CRC clock in RCC.
         CRC::enable();
         // Reset CRC to default values.
         CRC::reset();
-        Self { _peripheral: peripheral}
+        let mut instance = Self {
+            _peripheral: peripheral,
+        };
+        instance.init();
+        instance
     }
 
-    pub fn reset() {
+    /// Resets the CRC unit to default value (0xFFFF_FFFF)
+    pub fn init(&mut self) {
         unsafe { PAC_CRC.cr().modify(|w| w.set_reset(true)) };
     }
-}
\ No newline at end of file
+
+    /// Feeds a word to the peripheral and returns the current CRC value
+    pub fn feed_word(&mut self, word: u32) -> u32 {
+        // write a single byte to the device, and return the result
+        unsafe {
+            PAC_CRC.dr().write_value(word);
+            PAC_CRC.dr().read()
+        }
+    }
+    /// Feed a slice of words to the peripheral and return the result.
+    pub fn feed_words(&mut self, words: &[u32]) -> u32 {
+        for word in words {
+            unsafe {
+                PAC_CRC.dr().write_value(*word);
+            }
+        }
+
+        unsafe { PAC_CRC.dr().read() }
+    }
+
+    /// Reclaims the CRC peripheral.
+    pub fn release(self) -> CRC {
+        CRC::disable();
+
+        self._peripheral
+    }
+}
diff --git a/embassy-stm32/src/crc/v2.rs b/embassy-stm32/src/crc/v2.rs
index e69de29bb..8b1378917 100644
--- a/embassy-stm32/src/crc/v2.rs
+++ b/embassy-stm32/src/crc/v2.rs
@@ -0,0 +1 @@
+
diff --git a/embassy-stm32/src/crc/v3.rs b/embassy-stm32/src/crc/v3.rs
index e69de29bb..8b1378917 100644
--- a/embassy-stm32/src/crc/v3.rs
+++ b/embassy-stm32/src/crc/v3.rs
@@ -0,0 +1 @@
+