* (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.
*
*
* @author R. Steve McKown <rsmckown@gmail.com>
*/
-
+
generic module Msp430UartP() {
provides {
interface UartStream;
implementation {
enum {
/* Bit positions in m_pins */
- PINS_RXD = 1,
+ PINS_RXD = 0,
PINS_TXD
};
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();
}
}
call Registers.clrIeTx();
call Registers.clrIfgRx();
+ /* 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;
atomic {
if (m_sobuf || !buf || !len)
return FAIL;
- m_sobuf = buf;
- m_solen = len;
- while (!call Registers.getIfgTx());
+ 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();
- 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);
+ }
}
}
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,