xref: /btstack/src/hci_transport_h4.c (revision d58a1b5f11ada8ddf896c41fff5a35e7f140c37e)
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 #define BTSTACK_FILE__ "hci_transport_h4.c"
39 
40 /*
41  *  hci_h4_transport.c
42  *
43  *  HCI Transport API implementation for H4 protocol over POSIX with optional support for eHCILL
44  *
45  *  Created by Matthias Ringwald on 4/29/09.
46  */
47 
48 #include <inttypes.h>
49 
50 #include "btstack_config.h"
51 
52 #include "btstack_debug.h"
53 #include "hci.h"
54 #include "hci_transport.h"
55 #include "bluetooth_company_id.h"
56 #include "btstack_uart_block.h"
57 
58 #define ENABLE_LOG_EHCILL
59 
60 #ifdef ENABLE_EHCILL
61 
62 // eHCILL commands
63 enum EHCILL_MESSAGES {
64 	EHCILL_GO_TO_SLEEP_IND = 0x030,
65 	EHCILL_GO_TO_SLEEP_ACK = 0x031,
66 	EHCILL_WAKE_UP_IND     = 0x032,
67 	EHCILL_WAKE_UP_ACK     = 0x033,
68 	EHCILL_WAKEUP_SIGNAL   = 0x034,
69 };
70 
71 static int  hci_transport_h4_ehcill_outgoing_packet_ready(void);
72 static void hci_transport_h4_echill_send_wakeup_ind(void);
73 static void hci_transport_h4_ehcill_handle_command(uint8_t action);
74 static void hci_transport_h4_ehcill_handle_ehcill_command_sent(void);
75 static void hci_transport_h4_ehcill_handle_packet_sent(void);
76 static void hci_transport_h4_ehcill_open(void);
77 static void hci_transport_h4_ehcill_reset_statemachine(void);
78 static void hci_transport_h4_ehcill_send_ehcill_command(void);
79 static void hci_transport_h4_ehcill_sleep_ack_timer_setup(void);
80 static void hci_transport_h4_ehcill_trigger_wakeup(void);
81 
82 typedef enum {
83     EHCILL_STATE_W2_SEND_SLEEP_ACK,
84     EHCILL_STATE_SLEEP,
85     EHCILL_STATE_W4_WAKEUP_IND_OR_ACK,
86     EHCILL_STATE_AWAKE
87 } EHCILL_STATE;
88 
89 // eHCILL state machine
90 static EHCILL_STATE ehcill_state;
91 static uint8_t      ehcill_command_to_send;
92 
93 static btstack_uart_sleep_mode_t btstack_uart_sleep_mode;
94 
95 // work around for eHCILL problem
96 static btstack_timer_source_t ehcill_sleep_ack_timer;
97 
98 #endif
99 
100 
101 // assert pre-buffer for packet type is available
102 #if !defined(HCI_OUTGOING_PRE_BUFFER_SIZE) || (HCI_OUTGOING_PRE_BUFFER_SIZE == 0)
103 #error HCI_OUTGOING_PRE_BUFFER_SIZE not defined. Please update hci.h
104 #endif
105 
106 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size);
107 
108 typedef enum {
109     H4_OFF,
110     H4_W4_PACKET_TYPE,
111     H4_W4_EVENT_HEADER,
112     H4_W4_ACL_HEADER,
113     H4_W4_SCO_HEADER,
114     H4_W4_PAYLOAD,
115 } H4_STATE;
116 
117 typedef enum {
118     TX_OFF,
119     TX_IDLE,
120     TX_W4_PACKET_SENT,
121 #ifdef ENABLE_EHCILL
122     TX_W4_WAKEUP,
123     TX_W2_EHCILL_SEND,
124     TX_W4_EHCILL_SENT,
125 #endif
126 } TX_STATE;
127 
128 // UART Driver + Config
129 static const btstack_uart_block_t * btstack_uart;
130 static btstack_uart_config_t uart_config;
131 
132 // write state
133 static TX_STATE tx_state;
134 #ifdef ENABLE_EHCILL
135 static uint8_t * ehcill_tx_data;
136 static uint16_t  ehcill_tx_len;   // 0 == no outgoing packet
137 #endif
138 
139 static uint8_t packet_sent_event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
140 
141 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
142 
143 // packet reader state machine
144 static  H4_STATE h4_state;
145 static uint16_t bytes_to_read;
146 static uint16_t read_pos;
147 
148 // incoming packet buffer
149 static uint8_t hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + HCI_INCOMING_PACKET_BUFFER_SIZE + 1]; // packet type + max(acl header + acl payload, event header + event data)
150 static uint8_t * hci_packet = &hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE];
151 
152 // Baudrate change bugs in TI CC256x and CYW20704
153 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
154 #define ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
155 static const uint8_t baud_rate_command_prefix[]   = { 0x01, 0x36, 0xff, 0x04};
156 #endif
157 
158 #ifdef ENABLE_CYPRESS_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
159 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
160 #error "Please enable either ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND or ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND"
161 #endif
162 #define ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
163 static const uint8_t baud_rate_command_prefix[]   = { 0x01, 0x18, 0xfc, 0x06};
164 #endif
165 
166 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
167 static const uint8_t local_version_event_prefix[] = { 0x04, 0x0e, 0x0c, 0x01, 0x01, 0x10};
168 static enum {
169     BAUDRATE_CHANGE_WORKAROUND_IDLE,
170     BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED,
171     BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT,
172     BAUDRATE_CHANGE_WORKAROUND_DONE
173 } baudrate_change_workaround_state;
174 #endif
175 
176 static int hci_transport_h4_set_baudrate(uint32_t baudrate){
177     log_info("hci_transport_h4_set_baudrate %"PRIu32, baudrate);
178     return btstack_uart->set_baudrate(baudrate);
179 }
180 
181 static void hci_transport_h4_reset_statemachine(void){
182     h4_state = H4_W4_PACKET_TYPE;
183     read_pos = 0;
184     bytes_to_read = 1;
185 }
186 
187 static void hci_transport_h4_trigger_next_read(void){
188     // log_info("hci_transport_h4_trigger_next_read: %u bytes", bytes_to_read);
189     btstack_uart->receive_block(&hci_packet[read_pos], bytes_to_read);
190 }
191 
192 static void hci_transport_h4_block_read(void){
193 
194     uint16_t packet_len;
195 
196     read_pos += bytes_to_read;
197 
198     switch (h4_state) {
199         case H4_W4_PACKET_TYPE:
200             switch (hci_packet[0]){
201                 case HCI_EVENT_PACKET:
202                     bytes_to_read = HCI_EVENT_HEADER_SIZE;
203                     h4_state = H4_W4_EVENT_HEADER;
204                     break;
205                 case HCI_ACL_DATA_PACKET:
206                     bytes_to_read = HCI_ACL_HEADER_SIZE;
207                     h4_state = H4_W4_ACL_HEADER;
208                     break;
209                 case HCI_SCO_DATA_PACKET:
210                     bytes_to_read = HCI_SCO_HEADER_SIZE;
211                     h4_state = H4_W4_SCO_HEADER;
212                     break;
213 #ifdef ENABLE_EHCILL
214                 case EHCILL_GO_TO_SLEEP_IND:
215                 case EHCILL_GO_TO_SLEEP_ACK:
216                 case EHCILL_WAKE_UP_IND:
217                 case EHCILL_WAKE_UP_ACK:
218                     hci_transport_h4_ehcill_handle_command(hci_packet[0]);
219                     hci_transport_h4_reset_statemachine();
220                     break;
221 #endif
222                 default:
223                     log_error("hci_transport_h4: invalid packet type 0x%02x", hci_packet[0]);
224                     hci_transport_h4_reset_statemachine();
225                     break;
226             }
227             break;
228 
229         case H4_W4_EVENT_HEADER:
230             bytes_to_read = hci_packet[2];
231             // check Event length
232             if (bytes_to_read > (HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_EVENT_HEADER_SIZE)){
233                 log_error("hci_transport_h4: invalid Event len %d - only space for %u", bytes_to_read, HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_EVENT_HEADER_SIZE);
234                 hci_transport_h4_reset_statemachine();
235                 break;
236             }
237             h4_state = H4_W4_PAYLOAD;
238             break;
239 
240         case H4_W4_ACL_HEADER:
241             bytes_to_read = little_endian_read_16( hci_packet, 3);
242             // check ACL length
243             if (bytes_to_read > (HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_ACL_HEADER_SIZE)){
244                 log_error("hci_transport_h4: invalid ACL payload len %d - only space for %u", bytes_to_read, HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_ACL_HEADER_SIZE);
245                 hci_transport_h4_reset_statemachine();
246                 break;
247             }
248             h4_state = H4_W4_PAYLOAD;
249             break;
250 
251         case H4_W4_SCO_HEADER:
252             bytes_to_read = hci_packet[3];
253             // check SCO length
254             if (bytes_to_read > (HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_SCO_HEADER_SIZE)){
255                 log_error("hci_transport_h4: invalid SCO payload len %d - only space for %u", bytes_to_read, HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_SCO_HEADER_SIZE);
256                 hci_transport_h4_reset_statemachine();
257                 break;
258             }
259             h4_state = H4_W4_PAYLOAD;
260             break;
261 
262         case H4_W4_PAYLOAD:
263 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
264             if (baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_IDLE
265             && memcmp(hci_packet, local_version_event_prefix, sizeof(local_version_event_prefix)) == 0){
266 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
267                 if (little_endian_read_16(hci_packet, 11) == BLUETOOTH_COMPANY_ID_TEXAS_INSTRUMENTS_INC){
268                     // detect TI CC256x controller based on manufacturer
269                     log_info("Detected CC256x controller");
270                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED;
271                 } else {
272                     // work around not needed
273                     log_info("Bluetooth controller not by TI");
274                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_DONE;
275                 }
276 #endif
277 #ifdef ENABLE_CYPRESS_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
278                 if (little_endian_read_16(hci_packet, 11) == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
279                     // detect Cypress controller based on manufacturer
280                     log_info("Detected Cypress controller");
281                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED;
282                 } else {
283                     // work around not needed
284                     log_info("Bluetooth controller not by Cypress");
285                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_DONE;
286                 }
287 #endif
288             }
289 #endif
290             packet_len = read_pos-1;
291 
292             // reset state machine before delivering packet to stack as it might close the transport
293             hci_transport_h4_reset_statemachine();
294             packet_handler(hci_packet[0], &hci_packet[1], packet_len);
295             break;
296 
297         case H4_OFF:
298             bytes_to_read = 0;
299             break;
300     }
301 
302 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
303     if (baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT){
304         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_IDLE;
305         // avoid flowcontrol problem by reading expected hci command complete event of 7 bytes in a single block read
306         h4_state = H4_W4_PAYLOAD;
307         bytes_to_read = 7;
308     }
309 #endif
310 
311     if (h4_state != H4_OFF) {
312         hci_transport_h4_trigger_next_read();
313     }
314 }
315 
316 static void hci_transport_h4_block_sent(void){
317     switch (tx_state){
318         case TX_W4_PACKET_SENT:
319             // packet fully sent, reset state
320 #ifdef ENABLE_EHCILL
321             ehcill_tx_len = 0;
322 #endif
323             tx_state = TX_IDLE;
324 
325 #ifdef ENABLE_EHCILL
326             // notify eHCILL engine
327             hci_transport_h4_ehcill_handle_packet_sent();
328 #endif
329             // notify upper stack that it can send again
330             packet_handler(HCI_EVENT_PACKET, &packet_sent_event[0], sizeof(packet_sent_event));
331             break;
332 
333 #ifdef ENABLE_EHCILL
334         case TX_W4_EHCILL_SENT:
335         case TX_W4_WAKEUP:
336             hci_transport_h4_ehcill_handle_ehcill_command_sent();
337             break;
338 #endif
339 
340         default:
341             break;
342     }
343 }
344 
345 static int hci_transport_h4_can_send_now(uint8_t packet_type){
346     UNUSED(packet_type);
347     return tx_state == TX_IDLE;
348 }
349 
350 static int hci_transport_h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
351 
352     // store packet type before actual data and increase size
353     size++;
354     packet--;
355     *packet = packet_type;
356 
357 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
358     if ((baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED)
359     && (memcmp(packet, baud_rate_command_prefix, sizeof(baud_rate_command_prefix)) == 0)) {
360         log_info("Baud rate command detected, expect command complete event next");
361         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT;
362     }
363 #endif
364 
365 #ifdef ENABLE_EHCILL
366     // store request for later
367     ehcill_tx_len   = size;
368     ehcill_tx_data  = packet;
369     switch (ehcill_state){
370         case EHCILL_STATE_SLEEP:
371             hci_transport_h4_ehcill_trigger_wakeup();
372             return 0;
373         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
374             log_info("eHILL: send next packet, state EHCILL_STATE_W2_SEND_SLEEP_ACK");
375             return 0;
376         default:
377             break;
378     }
379 #endif
380 
381     // start sending
382     tx_state = TX_W4_PACKET_SENT;
383     btstack_uart->send_block(packet, size);
384     return 0;
385 }
386 
387 static void hci_transport_h4_init(const void * transport_config){
388     // check for hci_transport_config_uart_t
389     if (!transport_config) {
390         log_error("hci_transport_h4: no config!");
391         return;
392     }
393     if (((hci_transport_config_t*)transport_config)->type != HCI_TRANSPORT_CONFIG_UART) {
394         log_error("hci_transport_h4: config not of type != HCI_TRANSPORT_CONFIG_UART!");
395         return;
396     }
397 
398     // extract UART config from transport config
399     hci_transport_config_uart_t * hci_transport_config_uart = (hci_transport_config_uart_t*) transport_config;
400     uart_config.baudrate    = hci_transport_config_uart->baudrate_init;
401     uart_config.flowcontrol = hci_transport_config_uart->flowcontrol;
402     uart_config.device_name = hci_transport_config_uart->device_name;
403 
404     // set state to off
405     tx_state = TX_OFF;
406     h4_state = H4_OFF;
407 
408     // setup UART driver
409     btstack_uart->init(&uart_config);
410     btstack_uart->set_block_received(&hci_transport_h4_block_read);
411     btstack_uart->set_block_sent(&hci_transport_h4_block_sent);
412 }
413 
414 static int hci_transport_h4_open(void){
415     // open uart driver
416     int res = btstack_uart->open();
417     if (res){
418         return res;
419     }
420 
421     // init rx + tx state machines
422     hci_transport_h4_reset_statemachine();
423     hci_transport_h4_trigger_next_read();
424     tx_state = TX_IDLE;
425 
426 #ifdef ENABLE_EHCILL
427     hci_transport_h4_ehcill_open();
428 #endif
429     return 0;
430 }
431 
432 static int hci_transport_h4_close(void){
433     // set state to off
434     tx_state = TX_OFF;
435     h4_state = H4_OFF;
436 
437     // close uart driver
438     return btstack_uart->close();
439 }
440 
441 static void hci_transport_h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
442     packet_handler = handler;
443 }
444 
445 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
446     UNUSED(packet_type);
447     UNUSED(packet);
448     UNUSED(size);
449 }
450 
451 //
452 // --- main part of eHCILL implementation ---
453 //
454 
455 #ifdef ENABLE_EHCILL
456 
457 static void hci_transport_h4_ehcill_emit_sleep_state(int sleep_active){
458     static int last_state = 0;
459     if (sleep_active == last_state) return;
460     last_state = sleep_active;
461 
462     log_info("hci_transport_h4_ehcill_emit_sleep_state: %u", sleep_active);
463     uint8_t event[3];
464     event[0] = HCI_EVENT_TRANSPORT_SLEEP_MODE;
465     event[1] = sizeof(event) - 2;
466     event[2] = sleep_active;
467     packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));
468 }
469 
470 static void hci_transport_h4_ehcill_wakeup_handler(void){
471 #ifdef ENABLE_LOG_EHCILL
472     log_info("eHCILL: UART wakeup received");
473 #endif
474     hci_transport_h4_ehcill_handle_command(EHCILL_WAKEUP_SIGNAL);
475 }
476 
477 static void hci_transport_h4_ehcill_open(void){
478     hci_transport_h4_ehcill_reset_statemachine();
479 
480     // find best sleep mode to use: wake on CTS, wake on RX, none
481     btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_OFF;
482     int supported_sleep_modes = 0;
483     if (btstack_uart->get_supported_sleep_modes){
484         supported_sleep_modes = btstack_uart->get_supported_sleep_modes();
485     }
486     if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_HIGH_WAKE_ON_CTS_PULSE){
487         log_info("eHCILL: using wake on CTS");
488         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_HIGH_WAKE_ON_CTS_PULSE;
489     } else if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_LOW_WAKE_ON_RX_EDGE){
490         log_info("eHCILL: using wake on RX");
491         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_LOW_WAKE_ON_RX_EDGE;
492     } else {
493         log_info("eHCILL: UART driver does not provide compatible sleep mode");
494     }
495     if (btstack_uart->set_wakeup_handler){
496         btstack_uart->set_wakeup_handler(&hci_transport_h4_ehcill_wakeup_handler);
497     }
498 }
499 
500 static void hci_transport_h4_echill_send_wakeup_ind(void){
501 #ifdef ENABLE_LOG_EHCILL
502     log_info("eHCILL: send WAKEUP_IND");
503 #endif
504     // update state
505     tx_state     = TX_W4_WAKEUP;
506     ehcill_state = EHCILL_STATE_W4_WAKEUP_IND_OR_ACK;
507     ehcill_command_to_send = EHCILL_WAKE_UP_IND;
508     btstack_uart->send_block(&ehcill_command_to_send, 1);
509 }
510 
511 static int hci_transport_h4_ehcill_outgoing_packet_ready(void){
512     return ehcill_tx_len != 0;
513 }
514 
515 static void hci_transport_h4_ehcill_reset_statemachine(void){
516     ehcill_state = EHCILL_STATE_AWAKE;
517 }
518 
519 static void hci_transport_h4_ehcill_send_ehcill_command(void){
520 #ifdef ENABLE_LOG_EHCILL
521     log_info("eHCILL: send command %02x", ehcill_command_to_send);
522 #endif
523     tx_state = TX_W4_EHCILL_SENT;
524     if (ehcill_command_to_send == EHCILL_GO_TO_SLEEP_ACK){
525         ehcill_state = EHCILL_STATE_SLEEP;
526     }
527     btstack_uart->send_block(&ehcill_command_to_send, 1);
528 }
529 
530 static void hci_transport_h4_ehcill_sleep_ack_timer_handler(btstack_timer_source_t * timer){
531 	UNUSED(timer);
532 #ifdef ENABLE_LOG_EHCILL
533     log_info("eHCILL: timer triggered");
534 #endif
535     hci_transport_h4_ehcill_send_ehcill_command();
536 }
537 
538 static void hci_transport_h4_ehcill_sleep_ack_timer_setup(void){
539     // setup timer
540 #ifdef ENABLE_LOG_EHCILL
541     log_info("eHCILL: set timer for sending command %02x", ehcill_command_to_send);
542 #endif
543     btstack_run_loop_set_timer_handler(&ehcill_sleep_ack_timer, &hci_transport_h4_ehcill_sleep_ack_timer_handler);
544     btstack_run_loop_set_timer(&ehcill_sleep_ack_timer, 50);
545     btstack_run_loop_add_timer(&ehcill_sleep_ack_timer);
546 }
547 
548 static void hci_transport_h4_ehcill_trigger_wakeup(void){
549     switch (tx_state){
550         case TX_W2_EHCILL_SEND:
551         case TX_W4_EHCILL_SENT:
552             // wake up / sleep ack in progress, nothing to do now
553             return;
554         case TX_IDLE:
555         default:
556             // all clear, prepare for wakeup
557             break;
558     }
559     // UART needed again
560     hci_transport_h4_ehcill_emit_sleep_state(0);
561     if (btstack_uart_sleep_mode){
562         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
563     }
564     hci_transport_h4_echill_send_wakeup_ind();
565 }
566 
567 static void hci_transport_h4_ehcill_schedule_ehcill_command(uint8_t command){
568 #ifdef ENABLE_LOG_EHCILL
569     log_info("eHCILL: schedule eHCILL command %02x", command);
570 #endif
571     ehcill_command_to_send = command;
572     switch (tx_state){
573         case TX_IDLE:
574             if (ehcill_command_to_send == EHCILL_WAKE_UP_ACK){
575                 // send right away
576                 hci_transport_h4_ehcill_send_ehcill_command();
577             } else {
578                 // change state so BTstack cannot send and setup timer
579                 tx_state = TX_W2_EHCILL_SEND;
580                 hci_transport_h4_ehcill_sleep_ack_timer_setup();
581             }
582             break;
583         default:
584             break;
585     }
586 }
587 
588 static void hci_transport_h4_ehcill_handle_command(uint8_t action){
589     // log_info("hci_transport_h4_ehcill_handle: %x, state %u, defer_rx %u", action, ehcill_state, ehcill_defer_rx_size);
590     switch(ehcill_state){
591         case EHCILL_STATE_AWAKE:
592             switch(action){
593                 case EHCILL_GO_TO_SLEEP_IND:
594                     ehcill_state = EHCILL_STATE_W2_SEND_SLEEP_ACK;
595 #ifdef ENABLE_LOG_EHCILL
596                     log_info("eHCILL: Received GO_TO_SLEEP_IND RX");
597 #endif
598                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_GO_TO_SLEEP_ACK);
599                     break;
600                 default:
601                     break;
602             }
603             break;
604 
605         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
606             switch(action){
607                 case EHCILL_WAKE_UP_IND:
608                     ehcill_state = EHCILL_STATE_AWAKE;
609                     hci_transport_h4_ehcill_emit_sleep_state(0);
610                     if (btstack_uart_sleep_mode){
611                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
612                     }
613 #ifdef ENABLE_LOG_EHCILL
614                     log_info("eHCILL: Received WAKE_UP_IND RX");
615 #endif
616                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
617                     break;
618 
619                 default:
620                     break;
621             }
622             break;
623 
624         case EHCILL_STATE_SLEEP:
625             switch(action){
626                 case EHCILL_WAKEUP_SIGNAL:
627                     hci_transport_h4_ehcill_emit_sleep_state(0);
628                     if (btstack_uart_sleep_mode){
629                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
630                     }
631                     break;
632                 case EHCILL_WAKE_UP_IND:
633                     ehcill_state = EHCILL_STATE_AWAKE;
634                     hci_transport_h4_ehcill_emit_sleep_state(0);
635                     if (btstack_uart_sleep_mode){
636                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
637                     }
638 #ifdef ENABLE_LOG_EHCILL
639                     log_info("eHCILL: Received WAKE_UP_IND RX");
640 #endif
641                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
642                     break;
643 
644                 default:
645                     break;
646             }
647             break;
648 
649         case EHCILL_STATE_W4_WAKEUP_IND_OR_ACK:
650             switch(action){
651                 case EHCILL_WAKE_UP_IND:
652                 case EHCILL_WAKE_UP_ACK:
653 #ifdef ENABLE_LOG_EHCILL
654                     log_info("eHCILL: Received WAKE_UP (%02x)", action);
655 #endif
656                     tx_state = TX_W4_PACKET_SENT;
657                     ehcill_state = EHCILL_STATE_AWAKE;
658                     btstack_uart->send_block(ehcill_tx_data, ehcill_tx_len);
659                     break;
660                 default:
661                     break;
662             }
663             break;
664     }
665 }
666 
667 static void hci_transport_h4_ehcill_handle_packet_sent(void){
668 #ifdef ENABLE_LOG_EHCILL
669         log_info("eHCILL: handle packet sent, command to send %02x", ehcill_command_to_send);
670 #endif
671     // now, send pending ehcill command if neccessary
672     switch (ehcill_command_to_send){
673         case EHCILL_GO_TO_SLEEP_ACK:
674             hci_transport_h4_ehcill_sleep_ack_timer_setup();
675             break;
676         case EHCILL_WAKE_UP_IND:
677             hci_transport_h4_ehcill_send_ehcill_command();
678             break;
679         default:
680             break;
681     }
682 }
683 
684 static void hci_transport_h4_ehcill_handle_ehcill_command_sent(void){
685     tx_state = TX_IDLE;
686     int command = ehcill_command_to_send;
687     ehcill_command_to_send = 0;
688 
689 #ifdef ENABLE_LOG_EHCILL
690         log_info("eHCILL: handle eHCILL sent, command was %02x", command);
691 #endif
692 
693     if (command == EHCILL_GO_TO_SLEEP_ACK) {
694 #ifdef ENABLE_LOG_EHCILL
695         log_info("eHCILL: GO_TO_SLEEP_ACK sent, enter sleep mode");
696 #endif
697         // UART not needed after EHCILL_GO_TO_SLEEP_ACK was sent
698         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
699             btstack_uart->set_sleep(btstack_uart_sleep_mode);
700         }
701         hci_transport_h4_ehcill_emit_sleep_state(1);
702     }
703     // already packet ready? then start wakeup
704     if (hci_transport_h4_ehcill_outgoing_packet_ready()){
705         hci_transport_h4_ehcill_emit_sleep_state(0);
706         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
707             btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
708         }
709         if (command != EHCILL_WAKE_UP_IND){
710             hci_transport_h4_echill_send_wakeup_ind();
711         }
712     }
713 }
714 
715 #endif
716 // --- end of eHCILL implementation ---------
717 
718 static const hci_transport_t hci_transport_h4 = {
719     /* const char * name; */                                        "H4",
720     /* void   (*init) (const void *transport_config); */            &hci_transport_h4_init,
721     /* int    (*open)(void); */                                     &hci_transport_h4_open,
722     /* int    (*close)(void); */                                    &hci_transport_h4_close,
723     /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_h4_register_packet_handler,
724     /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_h4_can_send_now,
725     /* int    (*send_packet)(...); */                               &hci_transport_h4_send_packet,
726     /* int    (*set_baudrate)(uint32_t baudrate); */                &hci_transport_h4_set_baudrate,
727     /* void   (*reset_link)(void); */                               NULL,
728     /* void   (*set_sco_config)(uint16_t voice_setting, int num_connections); */ NULL,
729 };
730 
731 // configure and return h4 singleton
732 const hci_transport_t * hci_transport_h4_instance(const btstack_uart_block_t * uart_driver) {
733     btstack_uart = uart_driver;
734     return &hci_transport_h4;
735 }
736