xref: /btstack/src/hci_transport_h4.c (revision df25739fc3ea5a0a90f0f5925e6461d653697d2e)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
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  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 /*
39  *  hci_h4_transport.c
40  *
41  *  HCI Transport API implementation for basic H4 protocol over POSIX
42  *
43  *  Created by Matthias Ringwald on 4/29/09.
44  */
45 
46 #include "btstack_config.h"
47 
48 #include "btstack_debug.h"
49 #include "hci.h"
50 #include "hci_transport.h"
51 #include "btstack_uart_block.h"
52 
53 #ifdef HAVE_EHCILL
54 #error "HCI Transport H4 POSIX does not support eHCILL yet. Please remove HAVE_EHCILL from your btstack-config.h"
55 #endif
56 
57 // assert pre-buffer for packet type is available
58 #if !defined(HCI_OUTGOING_PRE_BUFFER_SIZE) || (HCI_OUTGOING_PRE_BUFFER_SIZE == 0)
59 #error HCI_OUTGOING_PRE_BUFFER_SIZE not defined. Please update hci.h
60 #endif
61 
62 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size);
63 
64 typedef enum {
65     H4_W4_PACKET_TYPE,
66     H4_W4_EVENT_HEADER,
67     H4_W4_ACL_HEADER,
68     H4_W4_SCO_HEADER,
69     H4_W4_PAYLOAD,
70 } H4_STATE;
71 
72 // UART Driver + Config
73 static const btstack_uart_block_t * btstack_uart;
74 static btstack_uart_config_t uart_config;
75 
76 // write mutex
77 static int uart_write_active;
78 
79 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
80 
81 // packet reader state machine
82 static  H4_STATE h4_state;
83 static int bytes_to_read;
84 static int read_pos;
85 
86 // incoming packet buffer
87 static uint8_t hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + 1 + HCI_PACKET_BUFFER_SIZE]; // packet type + max(acl header + acl payload, event header + event data)
88 static uint8_t * hci_packet = &hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE];
89 
90 static int hci_transport_h4_set_baudrate(uint32_t baudrate){
91     log_info("hci_transport_h4_set_baudrate %u", baudrate);
92     return btstack_uart->set_baudrate(baudrate);
93 }
94 
95 static void hci_transport_h4_reset_statemachine(void){
96     h4_state = H4_W4_PACKET_TYPE;
97     read_pos = 0;
98     bytes_to_read = 1;
99 }
100 
101 static void hci_transport_h4_trigger_next_read(void){
102     // trigger next read
103     btstack_uart->receive_block(&hci_packet[read_pos], bytes_to_read);
104 }
105 
106 static void hci_transport_h4_block_sent(void){
107     // free mutex
108     uart_write_active = 0;
109 
110     // notify upper stack that it can send again
111     uint8_t event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
112     packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));
113 }
114 
115 static void hci_transport_h4_block_read(void){
116 
117     read_pos += bytes_to_read;
118 
119     switch (h4_state) {
120         case H4_W4_PACKET_TYPE:
121             switch (hci_packet[0]){
122                 case HCI_EVENT_PACKET:
123                     bytes_to_read = HCI_EVENT_HEADER_SIZE;
124                     h4_state = H4_W4_EVENT_HEADER;
125                     break;
126                 case HCI_ACL_DATA_PACKET:
127                     bytes_to_read = HCI_ACL_HEADER_SIZE;
128                     h4_state = H4_W4_ACL_HEADER;
129                     break;
130                 case HCI_SCO_DATA_PACKET:
131                     bytes_to_read = HCI_SCO_HEADER_SIZE;
132                     h4_state = H4_W4_SCO_HEADER;
133                     break;
134                 default:
135                     log_error("h4_process: invalid packet type 0x%02x", hci_packet[0]);
136                     hci_transport_h4_reset_statemachine();
137                     break;
138             }
139             break;
140 
141         case H4_W4_EVENT_HEADER:
142             bytes_to_read = hci_packet[2];
143             h4_state = H4_W4_PAYLOAD;
144             break;
145 
146         case H4_W4_ACL_HEADER:
147             bytes_to_read = little_endian_read_16( hci_packet, 3);
148             // check ACL length
149             if (HCI_ACL_HEADER_SIZE + bytes_to_read >  HCI_PACKET_BUFFER_SIZE){
150                 log_error("h4_process: invalid ACL payload len %u - only space for %u", bytes_to_read, HCI_PACKET_BUFFER_SIZE - HCI_ACL_HEADER_SIZE);
151                 hci_transport_h4_reset_statemachine();
152                 break;
153             }
154             h4_state = H4_W4_PAYLOAD;
155             break;
156 
157         case H4_W4_SCO_HEADER:
158             bytes_to_read = hci_packet[3];
159             h4_state = H4_W4_PAYLOAD;
160             break;
161 
162         case H4_W4_PAYLOAD:
163             packet_handler(hci_packet[0], &hci_packet[1], read_pos-1);
164             hci_transport_h4_reset_statemachine();
165             break;
166         default:
167             break;
168     }
169     hci_transport_h4_trigger_next_read();
170 }
171 
172 static void hci_transport_h4_init(const void * transport_config){
173     // check for hci_transport_config_uart_t
174     if (!transport_config) {
175         log_error("hci_transport_h4: no config!");
176         return;
177     }
178     if (((hci_transport_config_t*)transport_config)->type != HCI_TRANSPORT_CONFIG_UART) {
179         log_error("hci_transport_h4: config not of type != HCI_TRANSPORT_CONFIG_UART!");
180         return;
181     }
182 
183     // extract UART config from transport config
184     hci_transport_config_uart_t * hci_transport_config_uart = (hci_transport_config_uart_t*) transport_config;
185     uart_config.baudrate    = hci_transport_config_uart->baudrate_init;
186     uart_config.flowcontrol = hci_transport_config_uart->flowcontrol;
187     uart_config.device_name = hci_transport_config_uart->device_name;
188 
189     // setup UART driver
190     btstack_uart->init(&uart_config);
191     btstack_uart->set_block_received(&hci_transport_h4_block_read);
192     btstack_uart->set_block_sent(&hci_transport_h4_block_sent);
193 }
194 
195 static int hci_transport_h4_open(void){
196     int res = btstack_uart->open();
197     if (res){
198         return res;
199     }
200     hci_transport_h4_reset_statemachine();
201     hci_transport_h4_trigger_next_read();
202     return 0;
203 }
204 
205 static int hci_transport_h4_close(void){
206     return btstack_uart->close();
207 }
208 
209 static void hci_transport_h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
210     packet_handler = handler;
211 }
212 
213 static int hci_transport_h4_can_send_now(uint8_t packet_type){
214     return uart_write_active == 0;
215 }
216 
217 static int hci_transport_h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
218     // store packet type before actual data and increase size
219     size++;
220     packet--;
221     *packet = packet_type;
222 
223     // lock mutex
224     uart_write_active = 1;
225 
226     //
227     btstack_uart->send_block(packet, size);
228     return 0;
229 }
230 
231 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
232 }
233 
234 static const hci_transport_t hci_transport_h4 = {
235     /* const char * name; */                                        "H4",
236     /* void   (*init) (const void *transport_config); */            &hci_transport_h4_init,
237     /* int    (*open)(void); */                                     &hci_transport_h4_open,
238     /* int    (*close)(void); */                                    &hci_transport_h4_close,
239     /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_h4_register_packet_handler,
240     /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_h4_can_send_now,
241     /* int    (*send_packet)(...); */                               &hci_transport_h4_send_packet,
242     /* int    (*set_baudrate)(uint32_t baudrate); */                &hci_transport_h4_set_baudrate,
243     /* void   (*reset_link)(void); */                               NULL,
244 };
245 
246 // configure and return h4 singleton
247 const hci_transport_t * hci_transport_h4_instance(const btstack_uart_block_t * uart_driver) {
248     btstack_uart = uart_driver;
249     return &hci_transport_h4;
250 }
251