xref: /btstack/src/hci_transport_h4.c (revision a8271db87877a7d929c76c2ef6122d0c09850d76)
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 
52 // determine size of receive buffer
53 // use one extra byte to guarantee zero terminated device name in remote name event
54 #if (HCI_ACL_DATA_PKT_HDR + HCI_ACL_BUFFER_SIZE) > (HCI_EVENT_PKT_HDR + HCI_EVENT_PKT_SIZE + 1)
55 #define HCI_PACKET_BUFFER_SIZE (HCI_ACL_DATA_PKT_HDR + HCI_ACL_BUFFER_SIZE)
56 #else
57 #define HCI_PACKET_BUFFER_SIZE (HCI_EVENT_PKT_HDR + HCI_EVENT_PKT_SIZE + 1)
58 #endif
59 
60 // #define USE_HCI_READER_THREAD
61 
62 typedef enum {
63     H4_W4_PACKET_TYPE,
64     H4_W4_EVENT_HEADER,
65     H4_W4_ACL_HEADER,
66     H4_W4_PAYLOAD,
67     H4_W4_PICKUP
68 } H4_STATE;
69 
70 typedef struct hci_transport_h4 {
71     hci_transport_t transport;
72     data_source_t *ds;
73     int uart_fd;    // different from ds->fd for HCI reader thread
74 
75 #ifdef USE_HCI_READER_THREAD
76     // synchronization facilities for dedicated reader thread
77     int pipe_fds[2];
78     pthread_mutex_t mutex;
79     pthread_cond_t cond;
80 #endif
81 } hci_transport_h4_t;
82 
83 // single instance
84 static hci_transport_h4_t * hci_transport_h4 = NULL;
85 
86 static int  h4_process(struct data_source *ds);
87 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size);
88 static      hci_uart_config_t *hci_uart_config;
89 
90 #ifdef USE_HCI_READER_THREAD
91 static void *h4_reader(void *context);
92 static int  h4_reader_process(struct data_source *ds);
93 #endif
94 
95 
96 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
97 
98 // packet reader state machine
99 static  H4_STATE h4_state;
100 static int bytes_to_read;
101 static int read_pos;
102 
103 static uint8_t hci_packet[1+HCI_PACKET_BUFFER_SIZE]; // packet type + max(acl header + acl payload, event header + event data)
104 
105 // prototypes
106 static int    h4_open(void *transport_config){
107     hci_uart_config = (hci_uart_config_t*) transport_config;
108     struct termios toptions;
109     int flags = O_RDWR | O_NOCTTY;
110 #ifndef USE_HCI_READER_THREAD
111     flags |= O_NONBLOCK;
112 #endif
113     int fd = open(hci_uart_config->device_name, flags);
114     if (fd == -1)  {
115         perror("init_serialport: Unable to open port ");
116         perror(hci_uart_config->device_name);
117         return -1;
118     }
119 
120     if (tcgetattr(fd, &toptions) < 0) {
121         perror("init_serialport: Couldn't get term attributes");
122         return -1;
123     }
124     speed_t brate = hci_uart_config->baudrate_init; // let you override switch below if needed
125     switch(hci_uart_config->baudrate_init) {
126         case 57600:  brate=B57600;  break;
127         case 115200: brate=B115200; break;
128 #ifdef B230400
129         case 230400: brate=B230400; break;
130 #endif
131 #ifdef B460800
132         case 460800: brate=B460800; break;
133 #endif
134 #ifdef B921600
135         case 921600: brate=B921600; break;
136 #endif
137     }
138     cfsetispeed(&toptions, brate);
139     cfsetospeed(&toptions, brate);
140 
141     // 8N1
142     toptions.c_cflag &= ~PARENB;
143     toptions.c_cflag &= ~CSTOPB;
144     toptions.c_cflag &= ~CSIZE;
145     toptions.c_cflag |= CS8;
146 
147     if (hci_uart_config->flowcontrol) {
148         // with flow control
149         toptions.c_cflag |= CRTSCTS;
150     } else {
151         // no flow control
152         toptions.c_cflag &= ~CRTSCTS;
153     }
154 
155     toptions.c_cflag |= CREAD | CLOCAL;  // turn on READ & ignore ctrl lines
156     toptions.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl
157 
158     toptions.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
159     toptions.c_oflag &= ~OPOST; // make raw
160 
161     // see: http://unixwiz.net/techtips/termios-vmin-vtime.html
162     toptions.c_cc[VMIN]  = 1;
163     toptions.c_cc[VTIME] = 0;
164 
165     if( tcsetattr(fd, TCSANOW, &toptions) < 0) {
166         perror("init_serialport: Couldn't set term attributes");
167         return -1;
168     }
169 
170     // set up data_source
171     hci_transport_h4->ds = malloc(sizeof(data_source_t));
172     if (!hci_transport_h4->ds) return -1;
173     hci_transport_h4->uart_fd = fd;
174 
175 #ifdef USE_HCI_READER_THREAD
176     // init synchronization tools
177     pthread_mutex_init(&hci_transport_h4->mutex, NULL);
178     pthread_cond_init(&hci_transport_h4->cond, NULL);
179 
180 	// create pipe
181 	pipe(hci_transport_h4->pipe_fds);
182 
183 	// create reader thread
184 	pthread_t hci_reader_thread;
185 	pthread_create(&hci_reader_thread, NULL, &h4_reader, NULL);
186 
187     hci_transport_h4->ds->fd = hci_transport_h4->pipe_fds[0];
188     hci_transport_h4->ds->process = h4_reader_process;
189 #else
190     hci_transport_h4->ds->fd = fd;
191     hci_transport_h4->ds->process = h4_process;
192 #endif
193     run_loop_add_data_source(hci_transport_h4->ds);
194 
195     // init state machine
196     bytes_to_read = 1;
197     h4_state = H4_W4_PACKET_TYPE;
198     read_pos = 0;
199 
200     return 0;
201 }
202 
203 static int    h4_close(void *transport_config){
204     // first remove run loop handler
205 	run_loop_remove_data_source(hci_transport_h4->ds);
206 
207     // close device
208     close(hci_transport_h4->ds->fd);
209 
210     // free struct
211     free(hci_transport_h4->ds);
212     hci_transport_h4->ds = NULL;
213     return 0;
214 }
215 
216 static int h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
217     if (hci_transport_h4->ds == NULL) return -1;
218     if (hci_transport_h4->uart_fd == 0) return -1;
219     hci_dump_packet( (uint8_t) packet_type, 0, packet, size);
220     char *data = (char*) packet;
221     int bytes_written = write(hci_transport_h4->uart_fd, &packet_type, 1);
222     while (bytes_written < 1) {
223         usleep(5000);
224         bytes_written = write(hci_transport_h4->uart_fd, &packet_type, 1);
225     };
226     while (size > 0) {
227         int bytes_written = write(hci_transport_h4->uart_fd, data, size);
228         if (bytes_written < 0) {
229             usleep(5000);
230             continue;
231         }
232         data += bytes_written;
233         size -= bytes_written;
234     }
235     return 0;
236 }
237 
238 static void   h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
239     packet_handler = handler;
240 }
241 
242 static void   h4_deliver_packet(void){
243     if (read_pos < 3) return; // sanity check
244     hci_dump_packet( hci_packet[0], 1, &hci_packet[1], read_pos-1);
245     packet_handler(hci_packet[0], &hci_packet[1], read_pos-1);
246 
247     h4_state = H4_W4_PACKET_TYPE;
248     read_pos = 0;
249     bytes_to_read = 1;
250 }
251 
252 static void h4_statemachine(void){
253     switch (h4_state) {
254 
255         case H4_W4_PACKET_TYPE:
256             if (hci_packet[0] == HCI_EVENT_PACKET){
257                 bytes_to_read = HCI_EVENT_PKT_HDR;
258                 h4_state = H4_W4_EVENT_HEADER;
259             } else if (hci_packet[0] == HCI_ACL_DATA_PACKET){
260                 bytes_to_read = HCI_ACL_DATA_PKT_HDR;
261                 h4_state = H4_W4_ACL_HEADER;
262             } else {
263                 log_error("h4_process: invalid packet type 0x%02x\n", hci_packet[0]);
264                 read_pos = 0;
265                 bytes_to_read = 1;
266             }
267             break;
268 
269         case H4_W4_EVENT_HEADER:
270             bytes_to_read = hci_packet[2];
271             h4_state = H4_W4_PAYLOAD;
272             break;
273 
274         case H4_W4_ACL_HEADER:
275             bytes_to_read = READ_BT_16( hci_packet, 3);
276             h4_state = H4_W4_PAYLOAD;
277             break;
278 
279         case H4_W4_PAYLOAD:
280 #ifdef USE_HCI_READER_THREAD
281             h4_state = H4_W4_PICKUP;
282 #else
283             h4_deliver_packet();
284 #endif
285             break;
286         default:
287             break;
288     }
289 }
290 
291 static int    h4_process(struct data_source *ds) {
292     if (hci_transport_h4->uart_fd == 0) return -1;
293 
294     int read_now = bytes_to_read;
295     //    if (read_now > 100) {
296     //        read_now = 100;
297     //    }
298 
299     // read up to bytes_to_read data in
300     ssize_t bytes_read = read(hci_transport_h4->uart_fd, &hci_packet[read_pos], read_now);
301     // printf("h4_process: bytes read %u\n", bytes_read);
302     if (bytes_read < 0) {
303         return bytes_read;
304     }
305 
306     // hexdump(&hci_packet[read_pos], bytes_read);
307 
308     bytes_to_read -= bytes_read;
309     read_pos      += bytes_read;
310     if (bytes_to_read > 0) {
311         return 0;
312     }
313 
314     h4_statemachine();
315     return 0;
316 }
317 
318 #ifdef USE_HCI_READER_THREAD
319 static int h4_reader_process(struct data_source *ds) {
320     // get token
321     char token;
322     int tokens_read = read(hci_transport_h4->pipe_fds[0], &token, 1);
323     if (tokens_read < 1) {
324         return 0;
325     }
326 
327     // hci_reader received complete packet, just pick it up
328     h4_deliver_packet();
329 
330     // un-block reader
331     pthread_mutex_lock(&hci_transport_h4->mutex);
332     pthread_cond_signal(&hci_transport_h4->cond);
333     pthread_mutex_unlock(&hci_transport_h4->mutex);
334     return 0;
335 }
336 
337 static void *h4_reader(void *context){
338 	while(1){
339         // read up to bytes_to_read data in
340         int bytes_read = read(hci_transport_h4->uart_fd, &hci_packet[read_pos], bytes_to_read);
341         // error
342         if (bytes_read < 0) {
343             h4_state = H4_W4_PACKET_TYPE;
344             read_pos = 0;
345             bytes_to_read = 1;
346             continue;
347         }
348 
349         bytes_to_read -= bytes_read;
350         read_pos      += bytes_read;
351 
352         if (bytes_to_read > 0) continue;
353 
354         h4_statemachine();
355 
356         if (h4_state != H4_W4_PICKUP) continue;
357 
358 		// notify main thread
359         char data = 'h';
360 		write(hci_transport_h4->pipe_fds[1], &data, 1);
361 
362 		// wait for response
363 		pthread_mutex_lock(&hci_transport_h4->mutex);
364 		pthread_cond_wait(&hci_transport_h4->cond,&hci_transport_h4->mutex);
365 		pthread_mutex_unlock(&hci_transport_h4->mutex);
366 	}
367 }
368 #endif
369 
370 static const char * h4_get_transport_name(void){
371     return "H4";
372 }
373 
374 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
375 }
376 
377 // get h4 singleton
378 hci_transport_t * hci_transport_h4_instance() {
379     if (hci_transport_h4 == NULL) {
380         hci_transport_h4 = malloc( sizeof(hci_transport_h4_t));
381         hci_transport_h4->ds                                      = NULL;
382         hci_transport_h4->transport.open                          = h4_open;
383         hci_transport_h4->transport.close                         = h4_close;
384         hci_transport_h4->transport.send_packet                   = h4_send_packet;
385         hci_transport_h4->transport.register_packet_handler       = h4_register_packet_handler;
386         hci_transport_h4->transport.get_transport_name            = h4_get_transport_name;
387         hci_transport_h4->transport.set_baudrate                  = NULL;
388         hci_transport_h4->transport.can_send_packet_now           = NULL;
389     }
390     return (hci_transport_t *) hci_transport_h4;
391 }
392