X-Git-Url: https://oss.titaniummirror.com/gitweb/?a=blobdiff_plain;f=tos%2Fchips%2Fmsp430%2Fusci%2FMsp430UartP.nc;h=605c426960f5d926d10670ec8582a70dc76383f6;hb=2d252cfb688eee6ff8aa13bef1efb1627cb866f8;hp=f998e3cef3a39cc52f137cb631d0e67d400b8b79;hpb=86e1f38f71efaa4ef35d676dde514fb9884f124e;p=tinyos-2.x.git

diff --git a/tos/chips/msp430/usci/Msp430UartP.nc b/tos/chips/msp430/usci/Msp430UartP.nc
index f998e3ce..605c4269 100644
--- a/tos/chips/msp430/usci/Msp430UartP.nc
+++ b/tos/chips/msp430/usci/Msp430UartP.nc
@@ -26,7 +26,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
- 
+
 /**
  * Uart implementation using a USCI device.
  *
@@ -35,7 +35,7 @@
  *
  * @author R. Steve McKown <rsmckown@gmail.com>
  */
- 
+
 generic module Msp430UartP() {
   provides {
     interface UartStream;
@@ -55,20 +55,20 @@ generic module Msp430UartP() {
 implementation {
   enum {
     /* Bit positions in m_pins */
-    PINS_RXD = 1,
+    PINS_RXD = 0,
     PINS_TXD
   };
 
   uint8_t m_pins;
   uint8_t* m_sobuf; 	/* Original buffer ptr from UartStream.send() */
-  uint8_t m_solen;	/* Original buffer len from UartStream.send() */
+  uint16_t m_solen;	/* Original buffer len from UartStream.send() */
   uint8_t* m_sbuf;	/* Position of next char to send */
-  uint8_t m_slen;	/* Len of chars in m_sbuf to send */
+  uint16_t m_slen;	/* Len of chars in m_sbuf to send */
   bool m_rxie;		/* Set if rxie has been enabled to UartStream.receive() */
   uint8_t* m_robuf;	/* Original receive buffer */
-  uint8_t m_rolen;	/* Original (maximum) receive len */
+  uint16_t m_rolen;	/* Original (maximum) receive len */
   uint8_t* m_rbuf;	/* Position of next byte in which to receive a char */
-  uint8_t m_rlen;	/* Remaining length in receive buffer */
+  uint16_t m_rlen;	/* Remaining length in receive buffer */
 
   sfrb(MYBRX, 219U);
 
@@ -104,12 +104,20 @@ implementation {
 	call TXD.selectModuleFunc();
       }
 
+      /* Reset important state variables */
+      m_robuf = 0;
+      m_sobuf = 0;
+
       /* Clear interrupts; we'll add them as needed */
       call Registers.clrIeRx();
       call Registers.clrIeTx();
 
       /* Enable the device */
       call Registers.clrCtl1(UCSWRST);
+
+      /* TOS convention is for receive interrupts on by default. */
+      call Registers.clrIfgRx();
+      call Registers.setIeRx();
     }
   }
 
@@ -117,28 +125,28 @@ implementation {
   {
     atomic {
       /* Disable the device */
-      call Registers.setCtl1(UCSYNC);
+      call Registers.setCtl1(UCSWRST);
 
       /* Clear interrupts and interrupt flags */
       call Registers.clrIeRx();
       call Registers.clrIeTx();
       call Registers.clrIfgRx();
-      call Registers.clrIfgTx();
+
+      /* Reset important state variables */
+      m_robuf = 0;
+      m_sobuf = 0;
 
       /* Restore pins to their pre-configure state */
-      if (m_pins & PINS_RXD)
+      if (m_pins & (1 << PINS_RXD))
 	call RXD.selectIOFunc();
-      if (m_pins & PINS_TXD)
+      if (m_pins & (1 << PINS_TXD))
 	call TXD.selectIOFunc();
     }
   }
 
   async command error_t UartByte.send(uint8_t byte)
   {
-    /* FIXME: race with UartStream.send() */
     atomic {
-      if (m_sobuf)
-	return FAIL;
       while (!call Registers.getIfgTx());
       call Registers.setTxbuf(byte);
       return SUCCESS;
@@ -150,29 +158,30 @@ implementation {
     atomic {
       if (m_sobuf || !buf || !len)
 	return FAIL;
-      m_sobuf = buf;
-      m_solen = len;
+      m_sbuf = m_sobuf = buf;
+      m_slen = m_solen = len;
       call Registers.setIeTx();
-      call Registers.setTxbuf(*m_sobuf);
-      m_slen = m_solen - 1;
-      if (m_slen)
-	m_sbuf = m_sobuf + 1;
       return SUCCESS;
     }
   }
 
   async event void Interrupts.tx()
   {
-    while (m_slen && call Registers.getIfgTx()) {
-      call Registers.setTxbuf(*m_sbuf);
-      if (--m_slen)
-	m_sbuf++;
-    }
-    if (m_slen == 0 && m_sobuf) {
-      call Registers.clrIeTx();
-      call Registers.clrIfgTx();
-      m_sobuf = 0;
-      signal UartStream.sendDone(m_sobuf, m_solen, SUCCESS);
+    /* FIXME: this can cause an arbitrarily long ISR, if m_slen is large.
+     * But depending on timing, we may always only write 1 byte.
+     */
+    if (m_sobuf) {
+      while (!call Registers.getIfgTx()); /* in case interleaved UB.send */
+      while (m_slen && call Registers.getIfgTx()) {
+	call Registers.setTxbuf(*m_sbuf);
+	if (--m_slen)
+	  m_sbuf++;
+      }
+      if (m_slen == 0) {
+	call Registers.clrIeTx();
+	m_sobuf = 0;
+	signal UartStream.sendDone(m_sobuf, m_solen, SUCCESS);
+      }
     }
   }
 
@@ -237,30 +246,31 @@ implementation {
 
   async event void Interrupts.rx(uint8_t byte)
   {
-    atomic {
-      if (m_robuf) {
-	/* receive() takes precedence if active */
-	while (m_rlen && call Registers.getIfgRx()) {
-	  *m_rbuf = byte;
-	  if (--m_rlen)
-	    m_rbuf++;
-	}
-	if (m_rlen == 0 && m_robuf) {
-	  if (m_rxie) {
-	    call Registers.clrIeRx();
-	    call Registers.clrIfgRx();
-	  }
-	  m_robuf = 0;
-	  signal UartStream.receiveDone(m_robuf, m_rolen, SUCCESS);
+    if (m_robuf) {
+      /* receive() takes precedence if active */
+      /* FIXME: an arbitrarily long ISR may occur if m_rlen is large.
+       * But depending on timing, we may always only read 1 byte.
+       */
+      while (m_rlen && call Registers.getIfgRx()) {
+	*m_rbuf = byte;
+	if (--m_rlen)
+	  m_rbuf++;
+      }
+      if (m_rlen == 0 && m_robuf) {
+	if (m_rxie) {
+	  call Registers.clrIeRx();
+	  call Registers.clrIfgRx();
 	}
-      } else
-	signal UartStream.receivedByte(byte);
-    }
+	m_robuf = 0;
+	signal UartStream.receiveDone(m_robuf, m_rolen, SUCCESS);
+      }
+    } else
+      signal UartStream.receivedByte(byte);
   }
 
   default async command const msp430_usci_uart_t* Configure.get()
   {
-    const static msp430_usci_uart_t def = { 
+    const static msp430_usci_uart_t def = {
       ctl0: UCMODE_0,		/* async, lsb first, 8N1 */
       ctl1: UCSWRST | UCSSEL_3,	/* clock uart from SMCLK */
       brx: UBRX_1MHZ_115200,