Contiki-NG
uart1.c
1 /*
2  * Copyright (c) 2011, 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  * Yet another machine dependent MSP430X UART0 code.
32  * IF2, etc. can not be used here... need to abstract to some macros
33  * later.
34  */
35 
36 #include "contiki.h"
37 #include <stdlib.h>
38 #include "dev/uart1.h"
39 #include "dev/watchdog.h"
40 #include "isr_compat.h"
41 
42 static int (*uart1_input_handler)(unsigned char c);
43 
44 static volatile uint8_t transmitting;
45 
46 #ifdef UART1_CONF_RX_WITH_DMA
47 #define RX_WITH_DMA UART1_CONF_RX_WITH_DMA
48 #else /* UART1_CONF_RX_WITH_DMA */
49 #define RX_WITH_DMA 1
50 #endif /* UART1_CONF_RX_WITH_DMA */
51 
52 #if RX_WITH_DMA
53 #define RXBUFSIZE 128
54 
55 static uint8_t rxbuf[RXBUFSIZE];
56 static uint16_t last_size;
57 static struct ctimer rxdma_timer;
58 
59 static void
60 handle_rxdma_timer(void *ptr)
61 {
62  uint16_t size;
63  size = DMA0SZ; /* Note: loop requires that size is less or eq to RXBUFSIZE */
64  while(last_size != size) {
65  uart1_input_handler((unsigned char)rxbuf[RXBUFSIZE - last_size]);
66  last_size--;
67  if(last_size == 0) {
68  last_size = RXBUFSIZE;
69  }
70  }
71 
72  ctimer_reset(&rxdma_timer);
73 }
74 #endif /* RX_WITH_DMA */
75 
76 /*---------------------------------------------------------------------------*/
77 uint8_t
78 uart1_active(void)
79 {
80  return (UCA1STAT & UCBUSY) | transmitting;
81 }
82 /*---------------------------------------------------------------------------*/
83 void
84 uart1_set_input(int (*input)(unsigned char c))
85 {
86 #if RX_WITH_DMA /* This needs to be called after ctimer process is started */
87  ctimer_set(&rxdma_timer, CLOCK_SECOND / 64, handle_rxdma_timer, NULL);
88 #endif
89  uart1_input_handler = input;
90 }
91 /*---------------------------------------------------------------------------*/
92 void
93 uart1_writeb(unsigned char c)
94 {
96  /* Loop until the transmission buffer is available. */
97  while((UCA1STAT & UCBUSY));
98 
99  /* Transmit the data. */
100  UCA1TXBUF = c;
101 }
102 /*---------------------------------------------------------------------------*/
103 /**
104  * Initalize the RS232 port.
105  *
106  */
107 void
108 uart1_init(unsigned long ubr)
109 {
110  /* RS232 */
111  UCA1CTL1 |= UCSWRST; /* Hold peripheral in reset state */
112  UCA1CTL1 |= UCSSEL_2; /* CLK = SMCLK */
113 
114  ubr = (MSP430_CPU_SPEED / ubr);
115  UCA1BR0 = ubr & 0xff;
116  UCA1BR1 = (ubr >> 8) & 0xff;
117  /* UCA1MCTL |= UCBRS_2 + UCBRF_0; // Modulation UCBRFx=0 */
118  UCA1MCTL = UCBRS_3; /* Modulation UCBRSx = 3 */
119 
120  P4DIR |= BIT5;
121  P4OUT |= BIT5;
122  P5SEL |= BIT6 | BIT7; /* P5.6,7 = USCI_A1 TXD/RXD */
123 
124  P4SEL |= BIT7;
125  P4DIR |= BIT7;
126 
127  /*UCA1CTL1 &= ~UCSWRST;*/ /* Initialize USCI state machine */
128 
129  transmitting = 0;
130 
131  /* XXX Clear pending interrupts before enable */
132  UCA1IE &= ~UCRXIFG;
133  UCA1IE &= ~UCTXIFG;
134 
135  UCA1CTL1 &= ~UCSWRST; /* Initialize USCI state machine **before** enabling interrupts */
136  UCA1IE |= UCRXIE; /* Enable UCA1 RX interrupt */
137 
138 #if RX_WITH_DMA
139  UCA1IE &= ~UCRXIE; /* disable USART1 RX interrupt */
140  /* UART1_RX trigger */
141  DMACTL0 = DMA0TSEL_20;
142 
143  /* source address = RXBUF1 */
144  DMA0SA = (unsigned int)&UCA1RXBUF;
145  DMA0DA = (unsigned int)&rxbuf;
146  DMA0SZ = RXBUFSIZE;
147  last_size = RXBUFSIZE;
148  DMA0CTL = DMADT_4 + DMASBDB + DMADSTINCR_3 + DMAEN + DMAREQ;
149 
150  msp430_add_lpm_req(MSP430_REQUIRE_LPM1);
151 #endif /* RX_WITH_DMA */
152 }
153 /*---------------------------------------------------------------------------*/
154 #if !RX_WITH_DMA
155 ISR(USCI_A1, uart1_rx_interrupt)
156 {
157  uint8_t c;
158 
159  if(UCA1IV == 2) {
160  if(UCA1STAT & UCRXERR) {
161  c = UCA1RXBUF; /* Clear error flags by forcing a dummy read. */
162  } else {
163  c = UCA1RXBUF;
164  if(uart1_input_handler != NULL) {
165  if(uart1_input_handler(c)) {
166  LPM4_EXIT;
167  }
168  }
169  }
170  }
171 }
172 #endif /* !RX_WITH_DMA */
173 /*---------------------------------------------------------------------------*/
static uint8_t transmitting(void)
Check the RF&#39;s TX status.
Definition: ieee-mode.c:285
void uart1_init(unsigned long ubr)
Initalize the RS232 port.
Definition: uart1.c:142
void ctimer_reset(struct ctimer *c)
Reset a callback timer with the same interval as was previously set.
Definition: ctimer.c:125
#define CLOCK_SECOND
A second, measured in system clock time.
Definition: clock.h:82
void ctimer_set(struct ctimer *c, clock_time_t t, void(*f)(void *), void *ptr)
Set a callback timer.
Definition: ctimer.c:99
void watchdog_periodic(void)
Writes the WDT clear sequence.
Definition: watchdog.c:85
static void input(void)
Process a received 6lowpan packet.
Definition: sicslowpan.c:1802