Contiki-NG
uart1.c
1 /*
2  * Copyright (c) 2010, Swedish Institute of Computer Science
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the Institute nor the names of its contributors
14  * may be used to endorse or promote products derived from this software
15  * without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 /*
32  * Machine dependent MSP430X UART1 code.
33  */
34 #include "contiki.h"
35 #include <stdlib.h>
36 #include "dev/uart1.h"
37 #include "dev/watchdog.h"
38 #include "lib/ringbuf.h"
39 #include "isr_compat.h"
40 
41 static int (*uart1_input_handler)(unsigned char c);
42 
43 static volatile uint8_t transmitting;
44 
45 #ifdef UART1_CONF_TX_WITH_INTERRUPT
46 #define TX_WITH_INTERRUPT UART1_CONF_TX_WITH_INTERRUPT
47 #else /* UART1_CONF_TX_WITH_INTERRUPT */
48 #define TX_WITH_INTERRUPT 1
49 #endif /* UART1_CONF_TX_WITH_INTERRUPT */
50 
51 #if TX_WITH_INTERRUPT
52 #define TXBUFSIZE 64
53 
54 static struct ringbuf txbuf;
55 static uint8_t txbuf_data[TXBUFSIZE];
56 #endif /* TX_WITH_INTERRUPT */
57 
58 /*---------------------------------------------------------------------------*/
59 uint8_t
60 uart1_active(void)
61 {
62  return (UCA0STAT & UCBUSY) | transmitting;
63 }
64 /*---------------------------------------------------------------------------*/
65 void
66 uart1_set_input(int (*input)(unsigned char c))
67 {
68  uart1_input_handler = input;
69 }
70 /*---------------------------------------------------------------------------*/
71 void
72 uart1_writeb(unsigned char c)
73 {
74  /* watchdog_periodic(); */
75 #if TX_WITH_INTERRUPT
76 
77  /* Put the outgoing byte on the transmission buffer. If the buffer
78  is full, we just keep on trying to put the byte into the buffer
79  until it is possible to put it there. */
80  while(ringbuf_put(&txbuf, c) == 0);
81 
82  /* If there is no transmission going, we need to start it by putting
83  the first byte into the UART. */
84  if(transmitting == 0) {
85  transmitting = 1;
86  UCA0TXBUF = ringbuf_get(&txbuf);
87  }
88 
89 #else /* TX_WITH_INTERRUPT */
90 
91  /* Loop until the transmission buffer is available. */
92  while(!(IFG2 & UCA0TXIFG));
93 
94  /* Transmit the data. */
95  UCA0TXBUF = c;
96 #endif /* TX_WITH_INTERRUPT */
97 }
98 /*---------------------------------------------------------------------------*/
99 /**
100  * Initalize the RS232 port.
101  *
102  */
103 void
104 uart1_init(unsigned long ubr)
105 {
106  /* RS232 */
107  P3SEL |= 0x30; /* P3.4,5 = USCI_A0 TXD/RXD */
108  UCA0CTL1 |= UCSSEL_2; /* CLK = SMCLK */
109  UCA0BR0 = 0x45; /* 8MHz/115200 = 69 = 0x45 */
110  UCA0BR1 = 0x00;
111  UCA0MCTL = UCBRS2; /* Modulation UCBRSx = 4 */
112  UCA0CTL1 &= ~UCSWRST; /* Initialize USCI state machine */
113 
114  transmitting = 0;
115 
116 }
117 /*---------------------------------------------------------------------------*/
118 ISR(USCIAB1RX, uart1_rx_interrupt)
119 {
120  uint8_t c;
121 
122  /* Check status register for receive errors. */
123  if(UCA0STAT & UCRXERR) {
124  c = UCA0RXBUF; /* Clear error flags by forcing a dummy read. */
125  } else {
126  c = UCA0RXBUF;
127  if(uart1_input_handler != NULL) {
128  if(uart1_input_handler(c)) {
129  LPM4_EXIT;
130  }
131  }
132  }
133 }
134 /*---------------------------------------------------------------------------*/
135 #if TX_WITH_INTERRUPT
136 ISR(USCIAB1TX, uart1_tx_interrupt)
137 {
138  if(IFG2 & UCA0TXIFG) {
139  if(ringbuf_elements(&txbuf) == 0) {
140  transmitting = 0;
141  } else {
142  UCA0TXBUF = ringbuf_get(&txbuf);
143  }
144  }
145 }
146 #endif /* TX_WITH_INTERRUPT */
147 /*---------------------------------------------------------------------------*/
static uint8_t transmitting(void)
Check the RF&#39;s TX status.
Definition: ieee-mode.c:285
int ringbuf_elements(struct ringbuf *r)
Get the number of elements currently in the ring buffer.
Definition: ringbuf.c:119
int ringbuf_get(struct ringbuf *r)
Get a byte from the ring buffer.
Definition: ringbuf.c:80
void uart1_init(unsigned long ubr)
Initalize the RS232 port.
Definition: uart1.c:142
Header file for the ring buffer library
Structure that holds the state of a ring buffer.
Definition: ringbuf.h:68
int ringbuf_put(struct ringbuf *r, uint8_t c)
Insert a byte into the ring buffer.
Definition: ringbuf.c:53
static void input(void)
Process a received 6lowpan packet.
Definition: sicslowpan.c:1847