From 2cf78552939db0f640f669dc398a06e948fa4a12 Mon Sep 17 00:00:00 2001
From: Diego Barrios Romero <eldruin@gmail.com>
Date: Sun, 28 Oct 2018 15:44:17 +0100
Subject: [PATCH] Add function to get/set the month

---
 README.md              |  1 +
 src/ds323x/datetime.rs | 27 +++++++++++++++++++++------
 src/lib.rs             |  3 +++
 tests/common/mod.rs    |  1 +
 tests/ds323x.rs        | 27 +++++++++++++++++++++++++++
 5 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 5dc8e13..08b4433 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ This driver allows you to:
 - Read/write the hours in 24h or AM/PM format.
 - Read/write the weekday.
 - Read/write the day.
+- Read/write the month.
 
 ## The devices
 
diff --git a/src/ds323x/datetime.rs b/src/ds323x/datetime.rs
index 4f22e75..9d1fbd7 100644
--- a/src/ds323x/datetime.rs
+++ b/src/ds323x/datetime.rs
@@ -17,7 +17,7 @@ pub enum Hours {
 
 impl<DI, IC, E> Ds323x<DI, IC>
 where
-    DI: ReadRegister<Error = E>
+    DI: ReadRegister<Error = E> + WriteRegister<Error = E>
 {
     /// Read the seconds.
     pub fn get_seconds(&mut self) -> Result<u8, Error<E>> {
@@ -57,16 +57,18 @@ where
         self.read_register_decimal(Register::DOM)
     }
 
+    /// Read the month [1-12].
+    pub fn get_month(&mut self) -> Result<u8, Error<E>> {
+        let data = self.iface.read_register(Register::MONTH)?;
+        let value = data & !BitFlags::CENTURY;
+        Ok(packed_bcd_to_decimal(value))
+    }
+
     fn read_register_decimal(&mut self, register: u8) -> Result<u8, Error<E>> {
         let data = self.iface.read_register(register)?;
         Ok(packed_bcd_to_decimal(data))
     }
-}
 
-impl<DI, IC, E> Ds323x<DI, IC>
-where
-    DI: WriteRegister<Error = E>
-{
     /// Set the seconds [0-59].
     ///
     /// Will return an `Error::InvalidInputData` if the seconds are out of range.
@@ -128,6 +130,19 @@ where
         self.iface.write_register(Register::DOM, day)
     }
 
+    /// Set the month [1-12].
+    ///
+    /// Will return an `Error::InvalidInputData` if the month is out of range.
+    pub fn set_month(&mut self, month: u8) -> Result<(), Error<E>> {
+        if month < 1 || month > 12 {
+            return Err(Error::InvalidInputData);
+        }
+        // keep the century bit
+        let data = self.iface.read_register(Register::MONTH)?;
+        let value = (data & BitFlags::CENTURY) | decimal_to_packed_bcd(month);
+        self.iface.write_register(Register::MONTH, value)
+    }
+
     fn write_register_decimal(&mut self, register: u8, decimal_number: u8) -> Result<(), Error<E>> {
         self.iface.write_register(register, decimal_to_packed_bcd(decimal_number))
     }
diff --git a/src/lib.rs b/src/lib.rs
index c691cb9..768a3d5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,6 +9,7 @@
 //! - Read/write the hours in 24h or AM/PM format.
 //! - Read/write the weekday.
 //! - Read/write the day.
+//! - Read/write the month.
 //!
 //! ## The devices
 //!
@@ -185,6 +186,7 @@ impl Register {
     const HOURS     : u8 = 0x02;
     const DOW       : u8 = 0x03;
     const DOM       : u8 = 0x04;
+    const MONTH     : u8 = 0x05;
 }
 
 struct BitFlags;
@@ -192,6 +194,7 @@ struct BitFlags;
 impl BitFlags {
     const H24_H12    : u8 = 0b0100_0000;
     const AM_PM      : u8 = 0b0010_0000;
+    const CENTURY    : u8 = 0b1000_0000;
 }
 
 const DEVICE_ADDRESS: u8 = 0b110_1000;
diff --git a/tests/common/mod.rs b/tests/common/mod.rs
index a0614cc..e9d8be4 100644
--- a/tests/common/mod.rs
+++ b/tests/common/mod.rs
@@ -14,6 +14,7 @@ impl Register {
     pub const HOURS     : u8 = 0x02;
     pub const DOW       : u8 = 0x03;
     pub const DOM       : u8 = 0x04;
+    pub const MONTH     : u8 = 0x05;
 }
 
 pub struct DummyOutputPin;
diff --git a/tests/ds323x.rs b/tests/ds323x.rs
index 01866f4..7a67c33 100644
--- a/tests/ds323x.rs
+++ b/tests/ds323x.rs
@@ -34,6 +34,20 @@ macro_rules! set_param_test {
                   [ SpiTrans::write(vec![Register::$register + 0x80, $binary_value]) ]);
     };
 }
+
+macro_rules! read_set_param_test {
+    ($method:ident, $register:ident, $value:expr, $binary_value_read:expr, $binary_value_write:expr) => {
+        set_test!(can_read_set_ds3231, $method, new_ds3231, $value,
+                  [ I2cTrans::write_read(DEV_ADDR, vec![Register::$register], vec![$binary_value_read]),
+                    I2cTrans::write(DEV_ADDR, vec![Register::$register, $binary_value_write]) ]);
+
+        set_test!(can_read_set_ds3232, $method, new_ds3232, $value,
+                  [ I2cTrans::write_read(DEV_ADDR, vec![Register::$register], vec![$binary_value_read]),
+                    I2cTrans::write(DEV_ADDR, vec![Register::$register, $binary_value_write]) ]);
+
+        set_test!(can_read_set_ds3234, $method, new_ds3234, $value,
+                  [ SpiTrans::transfer(vec![Register::$register, 0], vec![Register::$register, $binary_value_read]),
+                    SpiTrans::write(vec![Register::$register + 0x80, $binary_value_write]) ]);
     };
 }
 
@@ -107,3 +121,16 @@ mod day {
     set_param_test!(set_day, DOM, 1, 1);
     set_invalid_param_range_test!(set_day, 0, 8);
 }
+
+mod month {
+    use super::*;
+    get_param_test!(get_month, MONTH, 1, 1);
+    read_set_param_test!(set_month, MONTH, 12, 0b0000_0010, 0b0001_0010);
+    set_invalid_param_range_test!(set_month, 0, 13);
+
+    mod keeps_century {
+        use super::*;
+        get_param_test!(get_month, MONTH, 12, 0b1001_0010);
+        read_set_param_test!(set_month, MONTH, 12, 0b1000_0010, 0b1001_0010);
+    }
+}