xref: /btstack/src/hci_transport_h4.c (revision 7741d2d0723f163597ad5845ffd7c2387d278ea1)
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_W4_PACKET_TYPE,
110     H4_W4_EVENT_HEADER,
111     H4_W4_ACL_HEADER,
112     H4_W4_SCO_HEADER,
113     H4_W4_PAYLOAD,
114 } H4_STATE;
115 
116 typedef enum {
117     TX_IDLE = 1,
118     TX_W4_PACKET_SENT,
119 #ifdef ENABLE_EHCILL
120     TX_W4_WAKEUP,
121     TX_W2_EHCILL_SEND,
122     TX_W4_EHCILL_SENT,
123 #endif
124 } TX_STATE;
125 
126 // UART Driver + Config
127 static const btstack_uart_block_t * btstack_uart;
128 static btstack_uart_config_t uart_config;
129 
130 // write state
131 static TX_STATE tx_state;
132 #ifdef ENABLE_EHCILL
133 static uint8_t * ehcill_tx_data;
134 static uint16_t  ehcill_tx_len;   // 0 == no outgoing packet
135 #endif
136 
137 static uint8_t packet_sent_event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
138 
139 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
140 
141 // packet reader state machine
142 static  H4_STATE h4_state;
143 static int bytes_to_read;
144 static int read_pos;
145 
146 // incoming packet buffer
147 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)
148 static uint8_t * hci_packet = &hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE];
149 
150 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
151 static const uint8_t local_version_event_prefix[] = { 0x04, 0x0e, 0x0c, 0x01, 0x01, 0x10};
152 static const uint8_t baud_rate_command_prefix[]   = { 0x01, 0x36, 0xff, 0x04};
153 static enum {
154     BAUDRATE_CHANGE_WORKAROUND_IDLE,
155     BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED,
156     BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT,
157     BAUDRATE_CHANGE_WORKAROUND_DONE
158 } baudrate_change_workaround_state;
159 #endif
160 
161 static int hci_transport_h4_set_baudrate(uint32_t baudrate){
162     log_info("hci_transport_h4_set_baudrate %"PRIu32, baudrate);
163     return btstack_uart->set_baudrate(baudrate);
164 }
165 
166 static void hci_transport_h4_reset_statemachine(void){
167     h4_state = H4_W4_PACKET_TYPE;
168     read_pos = 0;
169     bytes_to_read = 1;
170 }
171 
172 static void hci_transport_h4_trigger_next_read(void){
173     // log_info("hci_transport_h4_trigger_next_read: %u bytes", bytes_to_read);
174     btstack_uart->receive_block(&hci_packet[read_pos], bytes_to_read);
175 }
176 
177 static void hci_transport_h4_block_read(void){
178 
179     read_pos += bytes_to_read;
180 
181     switch (h4_state) {
182         case H4_W4_PACKET_TYPE:
183             switch (hci_packet[0]){
184                 case HCI_EVENT_PACKET:
185                     bytes_to_read = HCI_EVENT_HEADER_SIZE;
186                     h4_state = H4_W4_EVENT_HEADER;
187                     break;
188                 case HCI_ACL_DATA_PACKET:
189                     bytes_to_read = HCI_ACL_HEADER_SIZE;
190                     h4_state = H4_W4_ACL_HEADER;
191                     break;
192                 case HCI_SCO_DATA_PACKET:
193                     bytes_to_read = HCI_SCO_HEADER_SIZE;
194                     h4_state = H4_W4_SCO_HEADER;
195                     break;
196 #ifdef ENABLE_EHCILL
197                 case EHCILL_GO_TO_SLEEP_IND:
198                 case EHCILL_GO_TO_SLEEP_ACK:
199                 case EHCILL_WAKE_UP_IND:
200                 case EHCILL_WAKE_UP_ACK:
201                     hci_transport_h4_ehcill_handle_command(hci_packet[0]);
202                     hci_transport_h4_reset_statemachine();
203                     break;
204 #endif
205                 default:
206                     log_error("hci_transport_h4: invalid packet type 0x%02x", hci_packet[0]);
207                     hci_transport_h4_reset_statemachine();
208                     break;
209             }
210             break;
211 
212         case H4_W4_EVENT_HEADER:
213             bytes_to_read = hci_packet[2];
214             // check Event length
215             if (HCI_EVENT_HEADER_SIZE + bytes_to_read >  HCI_INCOMING_PACKET_BUFFER_SIZE){
216                 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);
217                 hci_transport_h4_reset_statemachine();
218                 break;
219             }
220             h4_state = H4_W4_PAYLOAD;
221             break;
222 
223         case H4_W4_ACL_HEADER:
224             bytes_to_read = little_endian_read_16( hci_packet, 3);
225             // check ACL length
226             if (HCI_ACL_HEADER_SIZE + bytes_to_read >  HCI_INCOMING_PACKET_BUFFER_SIZE){
227                 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);
228                 hci_transport_h4_reset_statemachine();
229                 break;
230             }
231             h4_state = H4_W4_PAYLOAD;
232             break;
233 
234         case H4_W4_SCO_HEADER:
235             bytes_to_read = hci_packet[3];
236             // check SCO length
237             if (HCI_SCO_HEADER_SIZE + bytes_to_read >  HCI_INCOMING_PACKET_BUFFER_SIZE){
238                 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);
239                 hci_transport_h4_reset_statemachine();
240                 break;
241             }
242             h4_state = H4_W4_PAYLOAD;
243             break;
244 
245         case H4_W4_PAYLOAD:
246 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
247             if (baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_IDLE
248             && memcmp(hci_packet, local_version_event_prefix, sizeof(local_version_event_prefix)) == 0){
249                 if (little_endian_read_16(hci_packet, 11) == BLUETOOTH_COMPANY_ID_TEXAS_INSTRUMENTS_INC){
250                     // detect TI CC256x controller based on manufacturer
251                     log_info("Detected CC256x controller");
252                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED;
253                 } else {
254                     // work around not needed
255                     log_info("Bluetooth controller not by TI");
256                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_DONE;
257                 }
258             }
259 #endif
260             packet_handler(hci_packet[0], &hci_packet[1], read_pos-1);
261             hci_transport_h4_reset_statemachine();
262             break;
263         default:
264             break;
265     }
266 
267 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
268     if (baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT){
269         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_IDLE;
270         // avoid flowcontrol problem by reading expected hci command complete event of 7 bytes in a single block read
271         h4_state = H4_W4_PAYLOAD;
272         bytes_to_read = 7;
273     }
274 #endif
275 
276     hci_transport_h4_trigger_next_read();
277 }
278 
279 static void hci_transport_h4_block_sent(void){
280     switch (tx_state){
281         case TX_W4_PACKET_SENT:
282             // packet fully sent, reset state
283 #ifdef ENABLE_EHCILL
284             ehcill_tx_len = 0;
285 #endif
286             tx_state = TX_IDLE;
287 
288 #ifdef ENABLE_EHCILL
289             // notify eHCILL engine
290             hci_transport_h4_ehcill_handle_packet_sent();
291 #endif
292             // notify upper stack that it can send again
293             packet_handler(HCI_EVENT_PACKET, &packet_sent_event[0], sizeof(packet_sent_event));
294             break;
295 
296 #ifdef ENABLE_EHCILL
297         case TX_W4_EHCILL_SENT:
298         case TX_W4_WAKEUP:
299             hci_transport_h4_ehcill_handle_ehcill_command_sent();
300             break;
301 #endif
302 
303         default:
304             break;
305     }
306 }
307 
308 static int hci_transport_h4_can_send_now(uint8_t packet_type){
309     return tx_state == TX_IDLE;
310 }
311 
312 static int hci_transport_h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
313 
314     // store packet type before actual data and increase size
315     size++;
316     packet--;
317     *packet = packet_type;
318 
319 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
320     if ((baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED)
321     && (memcmp(packet, baud_rate_command_prefix, sizeof(baud_rate_command_prefix)) == 0)) {
322         log_info("Baud rate command detected, expect command complete event next");
323         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT;
324     }
325 #endif
326 
327 #ifdef ENABLE_EHCILL
328     // store request for later
329     ehcill_tx_len   = size;
330     ehcill_tx_data  = packet;
331     switch (ehcill_state){
332         case EHCILL_STATE_SLEEP:
333             hci_transport_h4_ehcill_trigger_wakeup();
334             return 0;
335         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
336             log_info("eHILL: send next packet, state EHCILL_STATE_W2_SEND_SLEEP_ACK");
337             return 0;
338         default:
339             break;
340     }
341 #endif
342 
343     // start sending
344     tx_state = TX_W4_PACKET_SENT;
345     btstack_uart->send_block(packet, size);
346     return 0;
347 }
348 
349 static void hci_transport_h4_init(const void * transport_config){
350     // check for hci_transport_config_uart_t
351     if (!transport_config) {
352         log_error("hci_transport_h4: no config!");
353         return;
354     }
355     if (((hci_transport_config_t*)transport_config)->type != HCI_TRANSPORT_CONFIG_UART) {
356         log_error("hci_transport_h4: config not of type != HCI_TRANSPORT_CONFIG_UART!");
357         return;
358     }
359 
360     // extract UART config from transport config
361     hci_transport_config_uart_t * hci_transport_config_uart = (hci_transport_config_uart_t*) transport_config;
362     uart_config.baudrate    = hci_transport_config_uart->baudrate_init;
363     uart_config.flowcontrol = hci_transport_config_uart->flowcontrol;
364     uart_config.device_name = hci_transport_config_uart->device_name;
365 
366     // setup UART driver
367     btstack_uart->init(&uart_config);
368     btstack_uart->set_block_received(&hci_transport_h4_block_read);
369     btstack_uart->set_block_sent(&hci_transport_h4_block_sent);
370 }
371 
372 static int hci_transport_h4_open(void){
373     int res = btstack_uart->open();
374     if (res){
375         return res;
376     }
377     hci_transport_h4_reset_statemachine();
378     hci_transport_h4_trigger_next_read();
379 
380     tx_state = TX_IDLE;
381 
382 #ifdef ENABLE_EHCILL
383     hci_transport_h4_ehcill_open();
384 #endif
385     return 0;
386 }
387 
388 static int hci_transport_h4_close(void){
389     return btstack_uart->close();
390 }
391 
392 static void hci_transport_h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
393     packet_handler = handler;
394 }
395 
396 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
397 }
398 
399 //
400 // --- main part of eHCILL implementation ---
401 //
402 
403 #ifdef ENABLE_EHCILL
404 
405 static void hci_transport_h4_ehcill_emit_sleep_state(int sleep_active){
406     static int last_state = 0;
407     if (sleep_active == last_state) return;
408     last_state = sleep_active;
409 
410     log_info("hci_transport_h4_ehcill_emit_sleep_state: %u", sleep_active);
411     uint8_t event[3];
412     event[0] = HCI_EVENT_TRANSPORT_SLEEP_MODE;
413     event[1] = sizeof(event) - 2;
414     event[2] = sleep_active;
415     packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));
416 }
417 
418 static void hci_transport_h4_ehcill_wakeup_handler(void){
419 #ifdef ENABLE_LOG_EHCILL
420     log_info("eHCILL: UART wakeup received");
421 #endif
422     hci_transport_h4_ehcill_handle_command(EHCILL_WAKEUP_SIGNAL);
423 }
424 
425 static void hci_transport_h4_ehcill_open(void){
426     hci_transport_h4_ehcill_reset_statemachine();
427 
428     // find best sleep mode to use: wake on CTS, wake on RX, none
429     btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_OFF;
430     int supported_sleep_modes = 0;
431     if (btstack_uart->get_supported_sleep_modes){
432         supported_sleep_modes = btstack_uart->get_supported_sleep_modes();
433     }
434     if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_HIGH_WAKE_ON_CTS_PULSE){
435         log_info("eHCILL: using wake on CTS");
436         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_HIGH_WAKE_ON_CTS_PULSE;
437     } else if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_LOW_WAKE_ON_RX_EDGE){
438         log_info("eHCILL: using wake on RX");
439         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_LOW_WAKE_ON_RX_EDGE;
440     } else {
441         log_info("eHCILL: UART driver does not provide compatible sleep mode");
442     }
443     if (btstack_uart->set_wakeup_handler){
444         btstack_uart->set_wakeup_handler(&hci_transport_h4_ehcill_wakeup_handler);
445     }
446 }
447 
448 static void hci_transport_h4_echill_send_wakeup_ind(void){
449 #ifdef ENABLE_LOG_EHCILL
450     log_info("eHCILL: send WAKEUP_IND");
451 #endif
452     // update state
453     tx_state     = TX_W4_WAKEUP;
454     ehcill_state = EHCILL_STATE_W4_WAKEUP_IND_OR_ACK;
455     ehcill_command_to_send = EHCILL_WAKE_UP_IND;
456     btstack_uart->send_block(&ehcill_command_to_send, 1);
457 }
458 
459 static int hci_transport_h4_ehcill_outgoing_packet_ready(void){
460     return ehcill_tx_len != 0;
461 }
462 
463 static void hci_transport_h4_ehcill_reset_statemachine(void){
464     ehcill_state = EHCILL_STATE_AWAKE;
465 }
466 
467 static void hci_transport_h4_ehcill_send_ehcill_command(void){
468 #ifdef ENABLE_LOG_EHCILL
469     log_info("eHCILL: send command %02x", ehcill_command_to_send);
470 #endif
471     tx_state = TX_W4_EHCILL_SENT;
472     if (ehcill_command_to_send == EHCILL_GO_TO_SLEEP_ACK){
473         ehcill_state = EHCILL_STATE_SLEEP;
474     }
475     btstack_uart->send_block(&ehcill_command_to_send, 1);
476 }
477 
478 static void hci_transport_h4_ehcill_sleep_ack_timer_handler(btstack_timer_source_t * timer){
479 	UNUSED(timer);
480 #ifdef ENABLE_LOG_EHCILL
481     log_info("eHCILL: timer triggered");
482 #endif
483     hci_transport_h4_ehcill_send_ehcill_command();
484 }
485 
486 static void hci_transport_h4_ehcill_sleep_ack_timer_setup(void){
487     // setup timer
488 #ifdef ENABLE_LOG_EHCILL
489     log_info("eHCILL: set timer for sending command %02x", ehcill_command_to_send);
490 #endif
491     btstack_run_loop_set_timer_handler(&ehcill_sleep_ack_timer, &hci_transport_h4_ehcill_sleep_ack_timer_handler);
492     btstack_run_loop_set_timer(&ehcill_sleep_ack_timer, 50);
493     btstack_run_loop_add_timer(&ehcill_sleep_ack_timer);
494 }
495 
496 static void hci_transport_h4_ehcill_trigger_wakeup(void){
497     switch (tx_state){
498         case TX_W2_EHCILL_SEND:
499         case TX_W4_EHCILL_SENT:
500             // wake up / sleep ack in progress, nothing to do now
501             return;
502         case TX_IDLE:
503         default:
504             // all clear, prepare for wakeup
505             break;
506     }
507     // UART needed again
508     hci_transport_h4_ehcill_emit_sleep_state(0);
509     if (btstack_uart_sleep_mode){
510         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
511     }
512     hci_transport_h4_echill_send_wakeup_ind();
513 }
514 
515 static void hci_transport_h4_ehcill_schedule_ehcill_command(uint8_t command){
516 #ifdef ENABLE_LOG_EHCILL
517     log_info("eHCILL: schedule eHCILL command %02x", command);
518 #endif
519     ehcill_command_to_send = command;
520     switch (tx_state){
521         case TX_IDLE:
522             if (ehcill_command_to_send == EHCILL_WAKE_UP_ACK){
523                 // send right away
524                 hci_transport_h4_ehcill_send_ehcill_command();
525             } else {
526                 // change state so BTstack cannot send and setup timer
527                 tx_state = TX_W2_EHCILL_SEND;
528                 hci_transport_h4_ehcill_sleep_ack_timer_setup();
529             }
530             break;
531         default:
532             break;
533     }
534 }
535 
536 static void hci_transport_h4_ehcill_handle_command(uint8_t action){
537     // log_info("hci_transport_h4_ehcill_handle: %x, state %u, defer_rx %u", action, ehcill_state, ehcill_defer_rx_size);
538     switch(ehcill_state){
539         case EHCILL_STATE_AWAKE:
540             switch(action){
541                 case EHCILL_GO_TO_SLEEP_IND:
542                     ehcill_state = EHCILL_STATE_W2_SEND_SLEEP_ACK;
543 #ifdef ENABLE_LOG_EHCILL
544                     log_info("eHCILL: Received GO_TO_SLEEP_IND RX");
545 #endif
546                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_GO_TO_SLEEP_ACK);
547                     break;
548                 default:
549                     break;
550             }
551             break;
552 
553         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
554             switch(action){
555                 case EHCILL_WAKE_UP_IND:
556                     ehcill_state = EHCILL_STATE_AWAKE;
557                     hci_transport_h4_ehcill_emit_sleep_state(0);
558                     if (btstack_uart_sleep_mode){
559                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
560                     }
561 #ifdef ENABLE_LOG_EHCILL
562                     log_info("eHCILL: Received WAKE_UP_IND RX");
563 #endif
564                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
565                     break;
566 
567                 default:
568                     break;
569             }
570             break;
571 
572         case EHCILL_STATE_SLEEP:
573             switch(action){
574                 case EHCILL_WAKEUP_SIGNAL:
575                     hci_transport_h4_ehcill_emit_sleep_state(0);
576                     if (btstack_uart_sleep_mode){
577                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
578                     }
579                     break;
580                 case EHCILL_WAKE_UP_IND:
581                     ehcill_state = EHCILL_STATE_AWAKE;
582                     hci_transport_h4_ehcill_emit_sleep_state(0);
583                     if (btstack_uart_sleep_mode){
584                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
585                     }
586 #ifdef ENABLE_LOG_EHCILL
587                     log_info("eHCILL: Received WAKE_UP_IND RX");
588 #endif
589                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
590                     break;
591 
592                 default:
593                     break;
594             }
595             break;
596 
597         case EHCILL_STATE_W4_WAKEUP_IND_OR_ACK:
598             switch(action){
599                 case EHCILL_WAKE_UP_IND:
600                 case EHCILL_WAKE_UP_ACK:
601 #ifdef ENABLE_LOG_EHCILL
602                     log_info("eHCILL: Received WAKE_UP (%02x)", action);
603 #endif
604                     tx_state = TX_W4_PACKET_SENT;
605                     ehcill_state = EHCILL_STATE_AWAKE;
606                     btstack_uart->send_block(ehcill_tx_data, ehcill_tx_len);
607                     break;
608                 default:
609                     break;
610             }
611             break;
612     }
613 }
614 
615 static void hci_transport_h4_ehcill_handle_packet_sent(void){
616 #ifdef ENABLE_LOG_EHCILL
617         log_info("eHCILL: handle packet sent, command to send %02x", ehcill_command_to_send);
618 #endif
619     // now, send pending ehcill command if neccessary
620     switch (ehcill_command_to_send){
621         case EHCILL_GO_TO_SLEEP_ACK:
622             hci_transport_h4_ehcill_sleep_ack_timer_setup();
623             break;
624         case EHCILL_WAKE_UP_IND:
625             hci_transport_h4_ehcill_send_ehcill_command();
626             break;
627         default:
628             break;
629     }
630 }
631 
632 static void hci_transport_h4_ehcill_handle_ehcill_command_sent(void){
633     tx_state = TX_IDLE;
634     int command = ehcill_command_to_send;
635     ehcill_command_to_send = 0;
636 
637 #ifdef ENABLE_LOG_EHCILL
638         log_info("eHCILL: handle eHCILL sent, command was %02x", command);
639 #endif
640 
641     if (command == EHCILL_GO_TO_SLEEP_ACK) {
642 #ifdef ENABLE_LOG_EHCILL
643         log_info("eHCILL: GO_TO_SLEEP_ACK sent, enter sleep mode");
644 #endif
645         // UART not needed after EHCILL_GO_TO_SLEEP_ACK was sent
646         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
647             btstack_uart->set_sleep(btstack_uart_sleep_mode);
648         }
649         hci_transport_h4_ehcill_emit_sleep_state(1);
650     }
651     // already packet ready? then start wakeup
652     if (hci_transport_h4_ehcill_outgoing_packet_ready()){
653         hci_transport_h4_ehcill_emit_sleep_state(0);
654         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
655             btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
656         }
657         if (command != EHCILL_WAKE_UP_IND){
658             hci_transport_h4_echill_send_wakeup_ind();
659         }
660     }
661 }
662 
663 #endif
664 // --- end of eHCILL implementation ---------
665 
666 static const hci_transport_t hci_transport_h4 = {
667     /* const char * name; */                                        "H4",
668     /* void   (*init) (const void *transport_config); */            &hci_transport_h4_init,
669     /* int    (*open)(void); */                                     &hci_transport_h4_open,
670     /* int    (*close)(void); */                                    &hci_transport_h4_close,
671     /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_h4_register_packet_handler,
672     /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_h4_can_send_now,
673     /* int    (*send_packet)(...); */                               &hci_transport_h4_send_packet,
674     /* int    (*set_baudrate)(uint32_t baudrate); */                &hci_transport_h4_set_baudrate,
675     /* void   (*reset_link)(void); */                               NULL,
676     /* void   (*set_sco_config)(uint16_t voice_setting, int num_connections); */ NULL,
677 };
678 
679 // configure and return h4 singleton
680 const hci_transport_t * hci_transport_h4_instance(const btstack_uart_block_t * uart_driver) {
681     btstack_uart = uart_driver;
682     return &hci_transport_h4;
683 }
684