xref: /btstack/src/hci_transport_h4.c (revision 642d7e9741339d2b73cce9b61da24f31ddf49d19)
1 /*
2  * Copyright (C) 2009 by Matthias Ringwald
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
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 copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
20  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
21  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
24  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
27  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  */
31 
32 /*
33  *  hci_h4_transport.c
34  *
35  *  HCI Transport API implementation for basic H4 protocol
36  *
37  *  Created by Matthias Ringwald on 4/29/09.
38  */
39 #include <termios.h>  /* POSIX terminal control definitions */
40 #include <fcntl.h>    /* File control definitions */
41 #include <unistd.h>   /* UNIX standard function definitions */
42 #include <stdio.h>
43 #include <string.h>
44 #include <pthread.h>
45 
46 #include "debug.h"
47 #include "hci.h"
48 #include "hci_transport.h"
49 #include "hci_dump.h"
50 
51 // #define USE_HCI_READER_THREAD
52 
53 typedef enum {
54     H4_W4_PACKET_TYPE,
55     H4_W4_EVENT_HEADER,
56     H4_W4_ACL_HEADER,
57     H4_W4_PAYLOAD,
58     H4_W4_PICKUP
59 } H4_STATE;
60 
61 typedef struct hci_transport_h4 {
62     hci_transport_t transport;
63     data_source_t *ds;
64     int uart_fd;    // different from ds->fd for HCI reader thread
65 
66 #ifdef USE_HCI_READER_THREAD
67     // synchronization facilities for dedicated reader thread
68     int pipe_fds[2];
69     pthread_mutex_t mutex;
70     pthread_cond_t cond;
71 #endif
72 } hci_transport_h4_t;
73 
74 // single instance
75 static hci_transport_h4_t * hci_transport_h4 = NULL;
76 
77 static int  h4_process(struct data_source *ds);
78 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size);
79 static      hci_uart_config_t *hci_uart_config;
80 
81 #ifdef USE_HCI_READER_THREAD
82 static void *h4_reader(void *context);
83 static int  h4_reader_process(struct data_source *ds);
84 #endif
85 
86 
87 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
88 
89 // packet reader state machine
90 static  H4_STATE h4_state;
91 static int bytes_to_read;
92 static int read_pos;
93 
94 static uint8_t hci_packet[1+HCI_PACKET_BUFFER_SIZE]; // packet type + max(acl header + acl payload, event header + event data)
95 
96 // prototypes
97 static int    h4_open(void *transport_config){
98     hci_uart_config = (hci_uart_config_t*) transport_config;
99     struct termios toptions;
100     int flags = O_RDWR | O_NOCTTY;
101 #ifndef USE_HCI_READER_THREAD
102     flags |= O_NONBLOCK;
103 #endif
104     int fd = open(hci_uart_config->device_name, flags);
105     if (fd == -1)  {
106         perror("init_serialport: Unable to open port ");
107         perror(hci_uart_config->device_name);
108         return -1;
109     }
110 
111     if (tcgetattr(fd, &toptions) < 0) {
112         perror("init_serialport: Couldn't get term attributes");
113         return -1;
114     }
115     speed_t brate = hci_uart_config->baudrate_init; // let you override switch below if needed
116     switch(hci_uart_config->baudrate_init) {
117         case 57600:  brate=B57600;  break;
118         case 115200: brate=B115200; break;
119 #ifdef B230400
120         case 230400: brate=B230400; break;
121 #endif
122 #ifdef B460800
123         case 460800: brate=B460800; break;
124 #endif
125 #ifdef B921600
126         case 921600: brate=B921600; break;
127 #endif
128     }
129     cfsetispeed(&toptions, brate);
130     cfsetospeed(&toptions, brate);
131 
132     // 8N1
133     toptions.c_cflag &= ~PARENB;
134     toptions.c_cflag &= ~CSTOPB;
135     toptions.c_cflag &= ~CSIZE;
136     toptions.c_cflag |= CS8;
137 
138     if (hci_uart_config->flowcontrol) {
139         // with flow control
140         toptions.c_cflag |= CRTSCTS;
141     } else {
142         // no flow control
143         toptions.c_cflag &= ~CRTSCTS;
144     }
145 
146     toptions.c_cflag |= CREAD | CLOCAL;  // turn on READ & ignore ctrl lines
147     toptions.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl
148 
149     toptions.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
150     toptions.c_oflag &= ~OPOST; // make raw
151 
152     // see: http://unixwiz.net/techtips/termios-vmin-vtime.html
153     toptions.c_cc[VMIN]  = 1;
154     toptions.c_cc[VTIME] = 0;
155 
156     if( tcsetattr(fd, TCSANOW, &toptions) < 0) {
157         perror("init_serialport: Couldn't set term attributes");
158         return -1;
159     }
160 
161     // set up data_source
162     hci_transport_h4->ds = malloc(sizeof(data_source_t));
163     if (!hci_transport_h4->ds) return -1;
164     hci_transport_h4->uart_fd = fd;
165 
166 #ifdef USE_HCI_READER_THREAD
167     // init synchronization tools
168     pthread_mutex_init(&hci_transport_h4->mutex, NULL);
169     pthread_cond_init(&hci_transport_h4->cond, NULL);
170 
171 	// create pipe
172 	pipe(hci_transport_h4->pipe_fds);
173 
174 	// create reader thread
175 	pthread_t hci_reader_thread;
176 	pthread_create(&hci_reader_thread, NULL, &h4_reader, NULL);
177 
178     hci_transport_h4->ds->fd = hci_transport_h4->pipe_fds[0];
179     hci_transport_h4->ds->process = h4_reader_process;
180 #else
181     hci_transport_h4->ds->fd = fd;
182     hci_transport_h4->ds->process = h4_process;
183 #endif
184     run_loop_add_data_source(hci_transport_h4->ds);
185 
186     // init state machine
187     bytes_to_read = 1;
188     h4_state = H4_W4_PACKET_TYPE;
189     read_pos = 0;
190 
191     return 0;
192 }
193 
194 static int    h4_close(void *transport_config){
195     // first remove run loop handler
196 	run_loop_remove_data_source(hci_transport_h4->ds);
197 
198     // close device
199     close(hci_transport_h4->ds->fd);
200 
201     // free struct
202     free(hci_transport_h4->ds);
203     hci_transport_h4->ds = NULL;
204     return 0;
205 }
206 
207 static int h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
208     if (hci_transport_h4->ds == NULL) return -1;
209     if (hci_transport_h4->uart_fd == 0) return -1;
210     hci_dump_packet( (uint8_t) packet_type, 0, packet, size);
211     char *data = (char*) packet;
212     int bytes_written = write(hci_transport_h4->uart_fd, &packet_type, 1);
213     while (bytes_written < 1) {
214         usleep(5000);
215         bytes_written = write(hci_transport_h4->uart_fd, &packet_type, 1);
216     };
217     while (size > 0) {
218         int bytes_written = write(hci_transport_h4->uart_fd, data, size);
219         if (bytes_written < 0) {
220             usleep(5000);
221             continue;
222         }
223         data += bytes_written;
224         size -= bytes_written;
225     }
226     return 0;
227 }
228 
229 static void   h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
230     packet_handler = handler;
231 }
232 
233 static void   h4_deliver_packet(void){
234     if (read_pos < 3) return; // sanity check
235     hci_dump_packet( hci_packet[0], 1, &hci_packet[1], read_pos-1);
236     packet_handler(hci_packet[0], &hci_packet[1], read_pos-1);
237 
238     h4_state = H4_W4_PACKET_TYPE;
239     read_pos = 0;
240     bytes_to_read = 1;
241 }
242 
243 static void h4_statemachine(void){
244     switch (h4_state) {
245 
246         case H4_W4_PACKET_TYPE:
247             if (hci_packet[0] == HCI_EVENT_PACKET){
248                 bytes_to_read = HCI_EVENT_HEADER_SIZE;
249                 h4_state = H4_W4_EVENT_HEADER;
250             } else if (hci_packet[0] == HCI_ACL_DATA_PACKET){
251                 bytes_to_read = HCI_ACL_HEADER_SIZE;
252                 h4_state = H4_W4_ACL_HEADER;
253             } else {
254                 log_error("h4_process: invalid packet type 0x%02x\n", hci_packet[0]);
255                 read_pos = 0;
256                 bytes_to_read = 1;
257             }
258             break;
259 
260         case H4_W4_EVENT_HEADER:
261             bytes_to_read = hci_packet[2];
262             h4_state = H4_W4_PAYLOAD;
263             break;
264 
265         case H4_W4_ACL_HEADER:
266             bytes_to_read = READ_BT_16( hci_packet, 3);
267             h4_state = H4_W4_PAYLOAD;
268             break;
269 
270         case H4_W4_PAYLOAD:
271 #ifdef USE_HCI_READER_THREAD
272             h4_state = H4_W4_PICKUP;
273 #else
274             h4_deliver_packet();
275 #endif
276             break;
277         default:
278             break;
279     }
280 }
281 
282 static int    h4_process(struct data_source *ds) {
283     if (hci_transport_h4->uart_fd == 0) return -1;
284 
285     int read_now = bytes_to_read;
286     //    if (read_now > 100) {
287     //        read_now = 100;
288     //    }
289 
290     // read up to bytes_to_read data in
291     ssize_t bytes_read = read(hci_transport_h4->uart_fd, &hci_packet[read_pos], read_now);
292     // printf("h4_process: bytes read %u\n", bytes_read);
293     if (bytes_read < 0) {
294         return bytes_read;
295     }
296 
297     // hexdump(&hci_packet[read_pos], bytes_read);
298 
299     bytes_to_read -= bytes_read;
300     read_pos      += bytes_read;
301     if (bytes_to_read > 0) {
302         return 0;
303     }
304 
305     h4_statemachine();
306     return 0;
307 }
308 
309 #ifdef USE_HCI_READER_THREAD
310 static int h4_reader_process(struct data_source *ds) {
311     // get token
312     char token;
313     int tokens_read = read(hci_transport_h4->pipe_fds[0], &token, 1);
314     if (tokens_read < 1) {
315         return 0;
316     }
317 
318     // hci_reader received complete packet, just pick it up
319     h4_deliver_packet();
320 
321     // un-block reader
322     pthread_mutex_lock(&hci_transport_h4->mutex);
323     pthread_cond_signal(&hci_transport_h4->cond);
324     pthread_mutex_unlock(&hci_transport_h4->mutex);
325     return 0;
326 }
327 
328 static void *h4_reader(void *context){
329 	while(1){
330         // read up to bytes_to_read data in
331         int bytes_read = read(hci_transport_h4->uart_fd, &hci_packet[read_pos], bytes_to_read);
332         // error
333         if (bytes_read < 0) {
334             h4_state = H4_W4_PACKET_TYPE;
335             read_pos = 0;
336             bytes_to_read = 1;
337             continue;
338         }
339 
340         bytes_to_read -= bytes_read;
341         read_pos      += bytes_read;
342 
343         if (bytes_to_read > 0) continue;
344 
345         h4_statemachine();
346 
347         if (h4_state != H4_W4_PICKUP) continue;
348 
349 		// notify main thread
350         char data = 'h';
351 		write(hci_transport_h4->pipe_fds[1], &data, 1);
352 
353 		// wait for response
354 		pthread_mutex_lock(&hci_transport_h4->mutex);
355 		pthread_cond_wait(&hci_transport_h4->cond,&hci_transport_h4->mutex);
356 		pthread_mutex_unlock(&hci_transport_h4->mutex);
357 	}
358 }
359 #endif
360 
361 static const char * h4_get_transport_name(void){
362     return "H4";
363 }
364 
365 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
366 }
367 
368 // get h4 singleton
369 hci_transport_t * hci_transport_h4_instance() {
370     if (hci_transport_h4 == NULL) {
371         hci_transport_h4 = malloc( sizeof(hci_transport_h4_t));
372         hci_transport_h4->ds                                      = NULL;
373         hci_transport_h4->transport.open                          = h4_open;
374         hci_transport_h4->transport.close                         = h4_close;
375         hci_transport_h4->transport.send_packet                   = h4_send_packet;
376         hci_transport_h4->transport.register_packet_handler       = h4_register_packet_handler;
377         hci_transport_h4->transport.get_transport_name            = h4_get_transport_name;
378         hci_transport_h4->transport.set_baudrate                  = NULL;
379         hci_transport_h4->transport.can_send_packet_now           = NULL;
380     }
381     return (hci_transport_t *) hci_transport_h4;
382 }
383