common: Implement Mx25l::erase_all().

[gps-watch.git] / src / common / mx25l.rs

diff --git a/src/common/mx25l.rs b/src/common/mx25l.rs
index 2c498cefa6950d5459f5a9764fc964bb536971f5..388d31172497b858c86c2ac36731156d1d16e2ed 100644 (file)
--- a/src/common/mx25l.rs
+++ b/src/common/mx25l.rs
@@ -23,9 +23,10 @@
 
 use gpio;
 use spi;
-use storage::Storage;
+use storage::{Storage, Error};
 
 const SECTOR_SIZE: usize = 4096;
+const PAGE_SIZE:   usize = 256;
 
 pub struct Mx25l {
     cs_gpio: u32,
@@ -33,17 +34,15 @@ pub struct Mx25l {
 }
 
 enum Command {
+    PP   = 0x02,
     READ = 0x03,
     RDSR = 0x05,
     WREN = 0x06,
     SE   = 0x20,
+    CE   = 0x60,
     RDID = 0x9f,
 }
 
-pub enum Error {
-    UnalignedAddress = 1,
-}
-
 const SR_WIP: u8 = 1 << 0;
 
 impl Mx25l {
@@ -74,6 +73,17 @@ impl Mx25l {
         })
     }
 
+    pub fn erase_all(&self) {
+        self.write_enable();
+
+        self.with_selected(|| {
+            spi::tx8(spi::SPI0, Command::CE as u8);
+        });
+
+        while self.write_in_progress() {
+        }
+    }
+
     pub fn erase_sector(&self, address: usize) -> Result<(), Error> {
         if (address & (SECTOR_SIZE - 1)) != 0 {
             return Err(Error::UnalignedAddress);
@@ -95,6 +105,34 @@ impl Mx25l {
         Ok(())
     }
 
+    pub fn program_page(&self, address: usize, buffer: &[u8; PAGE_SIZE])
+                        -> Result<(), Error> {
+        if (address & (PAGE_SIZE - 1)) != 0 {
+            return Err(Error::UnalignedAddress);
+        }
+
+        if buffer.iter().all(|&b| b == 0xff) {
+            return Ok(());
+        }
+
+        self.with_selected(|| {
+            spi::tx8(spi::SPI0, Command::PP as u8);
+
+            spi::tx8(spi::SPI0, (address >> 16) as u8);
+            spi::tx8(spi::SPI0, (address >>  8) as u8);
+            spi::tx8(spi::SPI0, (address >>  0) as u8);
+
+            for &b in buffer.iter() {
+                spi::tx8(spi::SPI0, b);
+            }
+        });
+
+        while self.write_in_progress() {
+        }
+
+        Ok(())
+    }
+
     fn write_enable(&self) {
         self.with_selected(|| {
             spi::tx8(spi::SPI0, Command::WREN as u8);
@@ -132,4 +170,25 @@ impl Storage for Mx25l {
             }
         })
     }
+
+    fn write(&mut self, address: usize, buffer: &[u8; SECTOR_SIZE])
+             -> Result<(), Error> {
+        if let Err(e) = self.erase_sector(address) {
+            return Err(e);
+        }
+
+        for (i, page_bytes) in buffer.chunks(PAGE_SIZE).enumerate() {
+            let page_address = address + (i * PAGE_SIZE);
+
+            // XXX: Inefficient.
+            let mut ba = [0xff; PAGE_SIZE];
+            ba.copy_from_slice(&page_bytes);
+
+            if let Err(e) = self.program_page(page_address, &ba) {
+                return Err(e);
+            }
+        }
+
+        Ok(())
+    }
 }