From 2be180cd54e988fa5abf0eabb7ee7138f31469f0 Mon Sep 17 00:00:00 2001
From: Tilman Sauerbeck <tilman@code-monkey.de>
Date: Sat, 4 Jan 2020 19:19:02 +0100
Subject: [PATCH] common: Add the mx25l module.

Provides access to the status register and device ID only for now.
---
 SConscript.libcommon |  1 +
 src/common/lib.rs    |  1 +
 src/common/mx25l.rs  | 76 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 src/common/mx25l.rs

diff --git a/SConscript.libcommon b/SConscript.libcommon
index 0ca199e..061400f 100644
--- a/SConscript.libcommon
+++ b/SConscript.libcommon
@@ -22,6 +22,7 @@ source_files_rs = [
     'src/common/gps.rs',
     'src/common/fmt.rs',
     'src/common/time.rs',
+    'src/common/mx25l.rs',
 ]
 
 source_files_c = [
diff --git a/src/common/lib.rs b/src/common/lib.rs
index c74704c..e06cc33 100644
--- a/src/common/lib.rs
+++ b/src/common/lib.rs
@@ -44,3 +44,4 @@ pub mod display;
 pub mod gps;
 pub mod fmt;
 pub mod time;
+pub mod mx25l;
diff --git a/src/common/mx25l.rs b/src/common/mx25l.rs
new file mode 100644
index 0000000..6e74f4a
--- /dev/null
+++ b/src/common/mx25l.rs
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2020 Tilman Sauerbeck (tilman at code-monkey de)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+use gpio;
+use spi;
+
+pub struct Mx25l {
+    cs_gpio: u32,
+    cs_gpio_pin: u32,
+}
+
+enum Command {
+    RDSR = 0x05,
+    RDID = 0x9f,
+}
+
+impl Mx25l {
+    pub fn new(cs_gpio: u32, cs_gpio_pin: u32) -> Mx25l {
+        Mx25l {
+            cs_gpio: cs_gpio,
+            cs_gpio_pin: cs_gpio_pin,
+        }
+    }
+
+    pub fn read_status(&self) -> u8 {
+        self.with_selected(|| {
+            spi::tx8(spi::SPI0, Command::RDSR as u8);
+
+            spi::tx8(spi::SPI0, 0xff)
+        })
+    }
+
+    pub fn read_id(&self) -> (u8, u16) {
+        self.with_selected(|| {
+            spi::tx8(spi::SPI0, Command::RDID as u8);
+
+            let manufacturer_id = spi::tx8(spi::SPI0, 0xff);
+            let device_id0 = spi::tx8(spi::SPI0, 0xff) as u16;
+            let device_id1 = spi::tx8(spi::SPI0, 0xff) as u16;
+
+            (manufacturer_id, device_id0 | (device_id1 << 8))
+        })
+    }
+
+    fn with_selected<F, T>(&self, func: F) -> T
+        where F: FnOnce() -> T
+    {
+        gpio::clear(self.cs_gpio, self.cs_gpio_pin);
+
+        let r = func();
+
+        gpio::set(self.cs_gpio, self.cs_gpio_pin);
+
+        r
+    }
+}
-- 
2.30.2