nrf: add NVMC driver.

embassy-nrf/src/nvmc.rs

@@ -0,0 +1,123 @@
+//! Nvmcerature sensor interface.
+
+use crate::pac;
+use crate::peripherals::NVMC;
+
+use core::marker::PhantomData;
+use core::ptr;
+use core::slice;
+use embassy::util::Unborrow;
+use embassy_hal_common::unborrow;
+use embedded_storage::nor_flash::{MultiwriteNorFlash, NorFlash, ReadNorFlash};
+
+const PAGE_SIZE: usize = 4096;
+const FLASH_SIZE: usize = crate::chip::FLASH_SIZE;
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum Error {
+    OutOfBounds,
+    Unaligned,
+}
+
+pub struct Nvmc<'d> {
+    _p: PhantomData<&'d NVMC>,
+}
+
+impl<'d> Nvmc<'d> {
+    pub fn new(_p: impl Unborrow<Target = NVMC> + 'd) -> Self {
+        unborrow!(_p);
+
+        Self { _p: PhantomData }
+    }
+
+    fn regs() -> &'static pac::nvmc::RegisterBlock {
+        unsafe { &*pac::NVMC::ptr() }
+    }
+
+    fn wait_ready(&mut self) {
+        let p = Self::regs();
+        while p.ready.read().ready().is_busy() {}
+    }
+}
+
+impl<'d> MultiwriteNorFlash for Nvmc<'d> {}
+
+impl<'d> ReadNorFlash for Nvmc<'d> {
+    type Error = Error;
+
+    const READ_SIZE: usize = 1;
+
+    fn read(&mut self, offset: u32, bytes: &mut [u8]) -> Result<(), Self::Error> {
+        if offset as usize >= FLASH_SIZE || offset as usize + bytes.len() > FLASH_SIZE {
+            return Err(Error::OutOfBounds);
+        }
+
+        let flash_data = unsafe { slice::from_raw_parts(offset as *const u8, bytes.len()) };
+        bytes.copy_from_slice(flash_data);
+        Ok(())
+    }
+
+    fn capacity(&self) -> usize {
+        FLASH_SIZE
+    }
+}
+
+impl<'d> NorFlash for Nvmc<'d> {
+    const WRITE_SIZE: usize = 4;
+    const ERASE_SIZE: usize = PAGE_SIZE;
+
+    fn erase(&mut self, from: u32, to: u32) -> Result<(), Self::Error> {
+        if to < from || to as usize > FLASH_SIZE {
+            return Err(Error::OutOfBounds);
+        }
+        if from as usize % PAGE_SIZE != 0 || to as usize % PAGE_SIZE != 0 {
+            return Err(Error::Unaligned);
+        }
+
+        let p = Self::regs();
+
+        p.config.write(|w| w.wen().een());
+        self.wait_ready();
+
+        for page in (from..to).step_by(PAGE_SIZE) {
+            p.erasepage().write(|w| unsafe { w.bits(page) });
+            self.wait_ready();
+        }
+
+        p.config.reset();
+        self.wait_ready();
+
+        Ok(())
+    }
+
+    fn write(&mut self, offset: u32, bytes: &[u8]) -> Result<(), Self::Error> {
+        if offset as usize + bytes.len() > FLASH_SIZE {
+            return Err(Error::OutOfBounds);
+        }
+        if offset as usize % 4 != 0 || bytes.len() as usize % 4 != 0 {
+            return Err(Error::Unaligned);
+        }
+
+        let p = Self::regs();
+
+        p.config.write(|w| w.wen().wen());
+        self.wait_ready();
+
+        unsafe {
+            let p_src = bytes.as_ptr() as *const u32;
+            let p_dst = offset as *mut u32;
+            let words = bytes.len() / 4;
+            for i in 0..words {
+                let w = ptr::read_unaligned(p_src.add(i));
+                ptr::write_volatile(p_dst.add(i), w);
+                self.wait_ready();
+            }
+        }
+
+        p.config.reset();
+        self.wait_ready();
+
+        Ok(())
+    }
+}