Use inline functions to make others readable

mdclyburn · Aug 5, 2020 · 08d7686 · 08d7686
1 parent a79f0e5
commit 08d7686
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Showing 2 changed files with 41 additions and 24 deletions.
diff --git a/src/usci-i2c.cpp b/src/usci-i2c.cpp
@@ -6,47 +6,43 @@ namespace mardev::msp430::usci::i2c
 
     bool read_begin()
     {
-        // Set receive mode and generate the start condition.
-        *usci::registers::UCB0CTL1 ^= registers::masks::UCTR;
+        __rx_mode();
         __start();
+        while(__generating_start());
 
-        // Wait to be ACKed or NACKed.
-        while(*usci::registers::UCB0CTL1 & registers::masks::UCTXSTT);
-
-        // Read starts without any other intervention.
+        // Reception starts without any other intervention.
         // Checking UCTXNACK will discern an issue with communication.
-        if(*usci::registers::UCB0STAT ^ registers::masks::UCNACKIFG)
+        if(__nack_received())
         {
-            return true;
+            __stop();
+            return false;
         }
         else
         {
-            __stop();
-            return false;
+            return true;
         }
     }
 
     uint8_t read()
     {
-        while(!(*interrupt::registers::IFG2
-                & usci::registers::masks::UCB0RXIFG));
+        while(!__rx_buffer_full());
         return *usci::registers::UCB0RXBUF;
     }
 
     uint8_t read_end()
     {
         __stop();
-        return *usci::registers::UCB0RXBUF;
+        return read();
     }
 
     bool write_begin()
     {
         // Set transmit mode and generate the start condition.
-        *usci::registers::UCB0CTL1 |= registers::masks::UCTR;
+        __tx_mode();
         __start();
 
         // Wait to be ACKed or NACKed.
-        while(*usci::registers::UCB0CTL1 & registers::masks::UCTXSTT);
+        while(__generating_start());
 
         if(*interrupt::registers::IFG2 & usci::registers::masks::UCB0TXIFG)
         {
@@ -62,8 +58,7 @@ namespace mardev::msp430::usci::i2c
     void write(const uint8_t data)
     {
         *usci::registers::UCB0TXBUF = data;
-        while(!(*interrupt::registers::IFG2
-                & usci::registers::masks::UCB0TXIFG));
+        while(!__tx_buffer_empty());
 
         return;
     }

diff --git a/src/usci-i2c.h b/src/usci-i2c.h
@@ -131,35 +131,57 @@ namespace mardev::msp430::usci::i2c
      */
     inline void __stop() { __send_signal(registers::masks::UCTXSTP); }
 
+    /** Issue a start condition.
+     */
     inline void __start() { __send_signal(registers::masks::UCTXSTT); }
 
+    /** Change to transmitter mode.
+     */
+    inline void __tx_mode() { *usci::registers::UCB0CTL1 |= registers::masks::UCTR; }
+
+    /** Change to receiver mode.
+     */
+    inline void __rx_mode() { *usci::registers::UCB0CTL1 ^= registers::masks::UCTR; }
+
     /** Returns true if the I2C clock signal is held low.
      */
-    inline bool clock_is_low() { return *usci::registers::UCB0STAT & registers::masks::UCSCLLOW; }
+    inline bool __clock_is_low() { return *usci::registers::UCB0STAT & registers::masks::UCSCLLOW; }
 
     /** Returns true if the general call address is received.
      */
-    inline bool general_addr_called() { return *usci::registers::UCB0STAT & registers::masks::UCGC; }
+    inline bool __general_addr_called() { return *usci::registers::UCB0STAT & registers::masks::UCGC; }
 
     /** Returns true if the I2C bus is busy.
      */
-    inline bool is_busy() { return *usci::registers::UCB0STAT & registers::masks::UCBBUSY; }
+    inline bool __is_busy() { return *usci::registers::UCB0STAT & registers::masks::UCBBUSY; }
 
     /** Returns true if a NACK was received.
      */
-    inline bool nack_received() { return *usci::registers::UCB0STAT & registers::masks::UCNACKIFG; }
+    inline bool __nack_received() { return *usci::registers::UCB0STAT & registers::masks::UCNACKIFG; }
 
     /** Returns true if a stop condition was received.
      */
-    inline bool stop_received() { return *usci::registers::UCB0STAT & registers::masks::UCSTPIFG; }
+    inline bool __stop_received() { return *usci::registers::UCB0STAT & registers::masks::UCSTPIFG; }
 
     /** Returns true if a start condition was received.
      */
-    inline bool start_received() { return *usci::registers::UCB0STAT & registers::masks::UCSTTIFG; }
+    inline bool __start_received() { return *usci::registers::UCB0STAT & registers::masks::UCSTTIFG; }
 
     /** Returns true if arbitration process was lost.
      */
-    inline bool arbitration_lost() { return *usci::registers::UCB0STAT & registers::masks::UCALIFG; }
+    inline bool __arbitration_lost() { return *usci::registers::UCB0STAT & registers::masks::UCALIFG; }
+
+    /** Returns true if the start condition is being generated.
+     */
+    inline bool __generating_start() { return *usci::registers::UCB0CTL1 & registers::masks::UCTXSTT; }
+
+    /** Returns true if the transmission buffer is empty.
+     */
+    inline bool __tx_buffer_empty() { return *interrupt::registers::IFG2 & usci::registers::masks::UCB0TXIFG; }
+
+    /** Returns true if the reception buffer is holding a byte.
+     */
+    inline bool __rx_buffer_full() { return *interrupt::registers::IFG2 & usci::registers::masks::UCB0RXIFG; }
 
     /** Start a read from a peripheral.
      *