xref: /btstack/src/hci_transport_h4.c (revision 8334d3d848d4b982e94c50bb19c1186089449d05)
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  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 uint16_t bytes_to_read;
144 static uint16_t 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 // Baudrate change bugs in TI CC256x and CYW20704
151 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
152 #define ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
153 static const uint8_t baud_rate_command_prefix[]   = { 0x01, 0x36, 0xff, 0x04};
154 #endif
155 
156 #ifdef ENABLE_CYPRESS_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
157 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
158 #error "Please enable either ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND or ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND"
159 #endif
160 #define ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
161 static const uint8_t baud_rate_command_prefix[]   = { 0x01, 0x18, 0xfc, 0x06};
162 #endif
163 
164 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
165 static const uint8_t local_version_event_prefix[] = { 0x04, 0x0e, 0x0c, 0x01, 0x01, 0x10};
166 static enum {
167     BAUDRATE_CHANGE_WORKAROUND_IDLE,
168     BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED,
169     BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT,
170     BAUDRATE_CHANGE_WORKAROUND_DONE
171 } baudrate_change_workaround_state;
172 #endif
173 
174 static int hci_transport_h4_set_baudrate(uint32_t baudrate){
175     log_info("hci_transport_h4_set_baudrate %"PRIu32, baudrate);
176     return btstack_uart->set_baudrate(baudrate);
177 }
178 
179 static void hci_transport_h4_reset_statemachine(void){
180     h4_state = H4_W4_PACKET_TYPE;
181     read_pos = 0;
182     bytes_to_read = 1;
183 }
184 
185 static void hci_transport_h4_trigger_next_read(void){
186     // log_info("hci_transport_h4_trigger_next_read: %u bytes", bytes_to_read);
187     btstack_uart->receive_block(&hci_packet[read_pos], bytes_to_read);
188 }
189 
190 static void hci_transport_h4_block_read(void){
191 
192     uint16_t packet_len;
193 
194     read_pos += bytes_to_read;
195 
196     switch (h4_state) {
197         case H4_W4_PACKET_TYPE:
198             switch (hci_packet[0]){
199                 case HCI_EVENT_PACKET:
200                     bytes_to_read = HCI_EVENT_HEADER_SIZE;
201                     h4_state = H4_W4_EVENT_HEADER;
202                     break;
203                 case HCI_ACL_DATA_PACKET:
204                     bytes_to_read = HCI_ACL_HEADER_SIZE;
205                     h4_state = H4_W4_ACL_HEADER;
206                     break;
207                 case HCI_SCO_DATA_PACKET:
208                     bytes_to_read = HCI_SCO_HEADER_SIZE;
209                     h4_state = H4_W4_SCO_HEADER;
210                     break;
211 #ifdef ENABLE_EHCILL
212                 case EHCILL_GO_TO_SLEEP_IND:
213                 case EHCILL_GO_TO_SLEEP_ACK:
214                 case EHCILL_WAKE_UP_IND:
215                 case EHCILL_WAKE_UP_ACK:
216                     hci_transport_h4_ehcill_handle_command(hci_packet[0]);
217                     hci_transport_h4_reset_statemachine();
218                     break;
219 #endif
220                 default:
221                     log_error("hci_transport_h4: invalid packet type 0x%02x", hci_packet[0]);
222                     hci_transport_h4_reset_statemachine();
223                     break;
224             }
225             break;
226 
227         case H4_W4_EVENT_HEADER:
228             bytes_to_read = hci_packet[2];
229             // check Event length
230             if (bytes_to_read > (HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_EVENT_HEADER_SIZE)){
231                 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);
232                 hci_transport_h4_reset_statemachine();
233                 break;
234             }
235             h4_state = H4_W4_PAYLOAD;
236             break;
237 
238         case H4_W4_ACL_HEADER:
239             bytes_to_read = little_endian_read_16( hci_packet, 3);
240             // check ACL length
241             if (bytes_to_read > (HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_ACL_HEADER_SIZE)){
242                 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);
243                 hci_transport_h4_reset_statemachine();
244                 break;
245             }
246             h4_state = H4_W4_PAYLOAD;
247             break;
248 
249         case H4_W4_SCO_HEADER:
250             bytes_to_read = hci_packet[3];
251             // check SCO length
252             if (bytes_to_read > (HCI_INCOMING_PACKET_BUFFER_SIZE - HCI_SCO_HEADER_SIZE)){
253                 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);
254                 hci_transport_h4_reset_statemachine();
255                 break;
256             }
257             h4_state = H4_W4_PAYLOAD;
258             break;
259 
260         case H4_W4_PAYLOAD:
261 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
262             if (baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_IDLE
263             && memcmp(hci_packet, local_version_event_prefix, sizeof(local_version_event_prefix)) == 0){
264 #ifdef ENABLE_CC256X_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
265                 if (little_endian_read_16(hci_packet, 11) == BLUETOOTH_COMPANY_ID_TEXAS_INSTRUMENTS_INC){
266                     // detect TI CC256x controller based on manufacturer
267                     log_info("Detected CC256x controller");
268                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED;
269                 } else {
270                     // work around not needed
271                     log_info("Bluetooth controller not by TI");
272                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_DONE;
273                 }
274 #endif
275 #ifdef ENABLE_CYPRESS_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
276                 if (little_endian_read_16(hci_packet, 11) == BLUETOOTH_COMPANY_ID_CYPRESS_SEMICONDUCTOR){
277                     // detect Cypress controller based on manufacturer
278                     log_info("Detected Cypress controller");
279                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED;
280                 } else {
281                     // work around not needed
282                     log_info("Bluetooth controller not by Cypress");
283                     baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_DONE;
284                 }
285 #endif
286             }
287 #endif
288             packet_len = read_pos-1;
289 
290             // reset state machine before delivering packet to stack as it might close the transport
291             hci_transport_h4_reset_statemachine();
292             packet_handler(hci_packet[0], &hci_packet[1], packet_len);
293             break;
294 
295         case H4_OFF:
296             bytes_to_read = 0;
297             break;
298     }
299 
300 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
301     if (baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT){
302         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_IDLE;
303         // avoid flowcontrol problem by reading expected hci command complete event of 7 bytes in a single block read
304         h4_state = H4_W4_PAYLOAD;
305         bytes_to_read = 7;
306     }
307 #endif
308 
309     if (h4_state != H4_OFF) {
310         hci_transport_h4_trigger_next_read();
311     }
312 }
313 
314 static void hci_transport_h4_block_sent(void){
315 
316     static const uint8_t packet_sent_event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
317 
318     switch (tx_state){
319         case TX_W4_PACKET_SENT:
320             // packet fully sent, reset state
321 #ifdef ENABLE_EHCILL
322             ehcill_tx_len = 0;
323 #endif
324             tx_state = TX_IDLE;
325 
326 #ifdef ENABLE_EHCILL
327             // notify eHCILL engine
328             hci_transport_h4_ehcill_handle_packet_sent();
329 #endif
330             // notify upper stack that it can send again
331             packet_handler(HCI_EVENT_PACKET, &packet_sent_event[0], sizeof(packet_sent_event));
332             break;
333 
334 #ifdef ENABLE_EHCILL
335         case TX_W4_EHCILL_SENT:
336         case TX_W4_WAKEUP:
337             hci_transport_h4_ehcill_handle_ehcill_command_sent();
338             break;
339 #endif
340 
341         default:
342             break;
343     }
344 }
345 
346 static int hci_transport_h4_can_send_now(uint8_t packet_type){
347     UNUSED(packet_type);
348     return tx_state == TX_IDLE;
349 }
350 
351 static int hci_transport_h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
352 
353     // store packet type before actual data and increase size
354     size++;
355     packet--;
356     *packet = packet_type;
357 
358 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
359     if ((baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED)
360     && (memcmp(packet, baud_rate_command_prefix, sizeof(baud_rate_command_prefix)) == 0)) {
361         log_info("Baud rate command detected, expect command complete event next");
362         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT;
363     }
364 #endif
365 
366 #ifdef ENABLE_EHCILL
367     // store request for later
368     ehcill_tx_len   = size;
369     ehcill_tx_data  = packet;
370     switch (ehcill_state){
371         case EHCILL_STATE_SLEEP:
372             hci_transport_h4_ehcill_trigger_wakeup();
373             return 0;
374         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
375             log_info("eHILL: send next packet, state EHCILL_STATE_W2_SEND_SLEEP_ACK");
376             return 0;
377         default:
378             break;
379     }
380 #endif
381 
382     // start sending
383     tx_state = TX_W4_PACKET_SENT;
384     btstack_uart->send_block(packet, size);
385     return 0;
386 }
387 
388 static void hci_transport_h4_init(const void * transport_config){
389     // check for hci_transport_config_uart_t
390     if (!transport_config) {
391         log_error("hci_transport_h4: no config!");
392         return;
393     }
394     if (((hci_transport_config_t*)transport_config)->type != HCI_TRANSPORT_CONFIG_UART) {
395         log_error("hci_transport_h4: config not of type != HCI_TRANSPORT_CONFIG_UART!");
396         return;
397     }
398 
399     // extract UART config from transport config
400     hci_transport_config_uart_t * hci_transport_config_uart = (hci_transport_config_uart_t*) transport_config;
401     uart_config.baudrate    = hci_transport_config_uart->baudrate_init;
402     uart_config.flowcontrol = hci_transport_config_uart->flowcontrol;
403     uart_config.device_name = hci_transport_config_uart->device_name;
404 
405     // set state to off
406     tx_state = TX_OFF;
407     h4_state = H4_OFF;
408 
409     // setup UART driver
410     btstack_uart->init(&uart_config);
411     btstack_uart->set_block_received(&hci_transport_h4_block_read);
412     btstack_uart->set_block_sent(&hci_transport_h4_block_sent);
413 }
414 
415 static int hci_transport_h4_open(void){
416     // open uart driver
417     int res = btstack_uart->open();
418     if (res){
419         return res;
420     }
421 
422     // init rx + tx state machines
423     hci_transport_h4_reset_statemachine();
424     hci_transport_h4_trigger_next_read();
425     tx_state = TX_IDLE;
426 
427 #ifdef ENABLE_EHCILL
428     hci_transport_h4_ehcill_open();
429 #endif
430     return 0;
431 }
432 
433 static int hci_transport_h4_close(void){
434     // set state to off
435     tx_state = TX_OFF;
436     h4_state = H4_OFF;
437 
438     // close uart driver
439     return btstack_uart->close();
440 }
441 
442 static void hci_transport_h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
443     packet_handler = handler;
444 }
445 
446 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
447     UNUSED(packet_type);
448     UNUSED(packet);
449     UNUSED(size);
450 }
451 
452 //
453 // --- main part of eHCILL implementation ---
454 //
455 
456 #ifdef ENABLE_EHCILL
457 
458 static void hci_transport_h4_ehcill_emit_sleep_state(int sleep_active){
459     static int last_state = 0;
460     if (sleep_active == last_state) return;
461     last_state = sleep_active;
462 
463     log_info("hci_transport_h4_ehcill_emit_sleep_state: %u", sleep_active);
464     uint8_t event[3];
465     event[0] = HCI_EVENT_TRANSPORT_SLEEP_MODE;
466     event[1] = sizeof(event) - 2;
467     event[2] = sleep_active;
468     packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));
469 }
470 
471 static void hci_transport_h4_ehcill_wakeup_handler(void){
472 #ifdef ENABLE_LOG_EHCILL
473     log_info("eHCILL: UART wakeup received");
474 #endif
475     hci_transport_h4_ehcill_handle_command(EHCILL_WAKEUP_SIGNAL);
476 }
477 
478 static void hci_transport_h4_ehcill_open(void){
479     hci_transport_h4_ehcill_reset_statemachine();
480 
481     // find best sleep mode to use: wake on CTS, wake on RX, none
482     btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_OFF;
483     int supported_sleep_modes = 0;
484     if (btstack_uart->get_supported_sleep_modes){
485         supported_sleep_modes = btstack_uart->get_supported_sleep_modes();
486     }
487     if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_HIGH_WAKE_ON_CTS_PULSE){
488         log_info("eHCILL: using wake on CTS");
489         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_HIGH_WAKE_ON_CTS_PULSE;
490     } else if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_LOW_WAKE_ON_RX_EDGE){
491         log_info("eHCILL: using wake on RX");
492         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_LOW_WAKE_ON_RX_EDGE;
493     } else {
494         log_info("eHCILL: UART driver does not provide compatible sleep mode");
495     }
496     if (btstack_uart->set_wakeup_handler){
497         btstack_uart->set_wakeup_handler(&hci_transport_h4_ehcill_wakeup_handler);
498     }
499 }
500 
501 static void hci_transport_h4_echill_send_wakeup_ind(void){
502 #ifdef ENABLE_LOG_EHCILL
503     log_info("eHCILL: send WAKEUP_IND");
504 #endif
505     // update state
506     tx_state     = TX_W4_WAKEUP;
507     ehcill_state = EHCILL_STATE_W4_WAKEUP_IND_OR_ACK;
508     ehcill_command_to_send = EHCILL_WAKE_UP_IND;
509     btstack_uart->send_block(&ehcill_command_to_send, 1);
510 }
511 
512 static int hci_transport_h4_ehcill_outgoing_packet_ready(void){
513     return ehcill_tx_len != 0;
514 }
515 
516 static void hci_transport_h4_ehcill_reset_statemachine(void){
517     ehcill_state = EHCILL_STATE_AWAKE;
518 }
519 
520 static void hci_transport_h4_ehcill_send_ehcill_command(void){
521 #ifdef ENABLE_LOG_EHCILL
522     log_info("eHCILL: send command %02x", ehcill_command_to_send);
523 #endif
524     tx_state = TX_W4_EHCILL_SENT;
525     if (ehcill_command_to_send == EHCILL_GO_TO_SLEEP_ACK){
526         ehcill_state = EHCILL_STATE_SLEEP;
527     }
528     btstack_uart->send_block(&ehcill_command_to_send, 1);
529 }
530 
531 static void hci_transport_h4_ehcill_sleep_ack_timer_handler(btstack_timer_source_t * timer){
532 	UNUSED(timer);
533 #ifdef ENABLE_LOG_EHCILL
534     log_info("eHCILL: timer triggered");
535 #endif
536     hci_transport_h4_ehcill_send_ehcill_command();
537 }
538 
539 static void hci_transport_h4_ehcill_sleep_ack_timer_setup(void){
540     // setup timer
541 #ifdef ENABLE_LOG_EHCILL
542     log_info("eHCILL: set timer for sending command %02x", ehcill_command_to_send);
543 #endif
544     btstack_run_loop_set_timer_handler(&ehcill_sleep_ack_timer, &hci_transport_h4_ehcill_sleep_ack_timer_handler);
545     btstack_run_loop_set_timer(&ehcill_sleep_ack_timer, 50);
546     btstack_run_loop_add_timer(&ehcill_sleep_ack_timer);
547 }
548 
549 static void hci_transport_h4_ehcill_trigger_wakeup(void){
550     switch (tx_state){
551         case TX_W2_EHCILL_SEND:
552         case TX_W4_EHCILL_SENT:
553             // wake up / sleep ack in progress, nothing to do now
554             return;
555         case TX_IDLE:
556         default:
557             // all clear, prepare for wakeup
558             break;
559     }
560     // UART needed again
561     hci_transport_h4_ehcill_emit_sleep_state(0);
562     if (btstack_uart_sleep_mode){
563         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
564     }
565     hci_transport_h4_echill_send_wakeup_ind();
566 }
567 
568 static void hci_transport_h4_ehcill_schedule_ehcill_command(uint8_t command){
569 #ifdef ENABLE_LOG_EHCILL
570     log_info("eHCILL: schedule eHCILL command %02x", command);
571 #endif
572     ehcill_command_to_send = command;
573     switch (tx_state){
574         case TX_IDLE:
575             if (ehcill_command_to_send == EHCILL_WAKE_UP_ACK){
576                 // send right away
577                 hci_transport_h4_ehcill_send_ehcill_command();
578             } else {
579                 // change state so BTstack cannot send and setup timer
580                 tx_state = TX_W2_EHCILL_SEND;
581                 hci_transport_h4_ehcill_sleep_ack_timer_setup();
582             }
583             break;
584         default:
585             break;
586     }
587 }
588 
589 static void hci_transport_h4_ehcill_handle_command(uint8_t action){
590     // log_info("hci_transport_h4_ehcill_handle: %x, state %u, defer_rx %u", action, ehcill_state, ehcill_defer_rx_size);
591     switch(ehcill_state){
592         case EHCILL_STATE_AWAKE:
593             switch(action){
594                 case EHCILL_GO_TO_SLEEP_IND:
595                     ehcill_state = EHCILL_STATE_W2_SEND_SLEEP_ACK;
596 #ifdef ENABLE_LOG_EHCILL
597                     log_info("eHCILL: Received GO_TO_SLEEP_IND RX");
598 #endif
599                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_GO_TO_SLEEP_ACK);
600                     break;
601                 default:
602                     break;
603             }
604             break;
605 
606         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
607             switch(action){
608                 case EHCILL_WAKE_UP_IND:
609                     ehcill_state = EHCILL_STATE_AWAKE;
610                     hci_transport_h4_ehcill_emit_sleep_state(0);
611                     if (btstack_uart_sleep_mode){
612                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
613                     }
614 #ifdef ENABLE_LOG_EHCILL
615                     log_info("eHCILL: Received WAKE_UP_IND RX");
616 #endif
617                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
618                     break;
619 
620                 default:
621                     break;
622             }
623             break;
624 
625         case EHCILL_STATE_SLEEP:
626             switch(action){
627                 case EHCILL_WAKEUP_SIGNAL:
628                     hci_transport_h4_ehcill_emit_sleep_state(0);
629                     if (btstack_uart_sleep_mode){
630                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
631                     }
632                     break;
633                 case EHCILL_WAKE_UP_IND:
634                     ehcill_state = EHCILL_STATE_AWAKE;
635                     hci_transport_h4_ehcill_emit_sleep_state(0);
636                     if (btstack_uart_sleep_mode){
637                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
638                     }
639 #ifdef ENABLE_LOG_EHCILL
640                     log_info("eHCILL: Received WAKE_UP_IND RX");
641 #endif
642                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
643                     break;
644 
645                 default:
646                     break;
647             }
648             break;
649 
650         case EHCILL_STATE_W4_WAKEUP_IND_OR_ACK:
651             switch(action){
652                 case EHCILL_WAKE_UP_IND:
653                 case EHCILL_WAKE_UP_ACK:
654 #ifdef ENABLE_LOG_EHCILL
655                     log_info("eHCILL: Received WAKE_UP (%02x)", action);
656 #endif
657                     tx_state = TX_W4_PACKET_SENT;
658                     ehcill_state = EHCILL_STATE_AWAKE;
659                     btstack_uart->send_block(ehcill_tx_data, ehcill_tx_len);
660                     break;
661                 default:
662                     break;
663             }
664             break;
665     }
666 }
667 
668 static void hci_transport_h4_ehcill_handle_packet_sent(void){
669 #ifdef ENABLE_LOG_EHCILL
670         log_info("eHCILL: handle packet sent, command to send %02x", ehcill_command_to_send);
671 #endif
672     // now, send pending ehcill command if neccessary
673     switch (ehcill_command_to_send){
674         case EHCILL_GO_TO_SLEEP_ACK:
675             hci_transport_h4_ehcill_sleep_ack_timer_setup();
676             break;
677         case EHCILL_WAKE_UP_IND:
678             hci_transport_h4_ehcill_send_ehcill_command();
679             break;
680         default:
681             break;
682     }
683 }
684 
685 static void hci_transport_h4_ehcill_handle_ehcill_command_sent(void){
686     tx_state = TX_IDLE;
687     int command = ehcill_command_to_send;
688     ehcill_command_to_send = 0;
689 
690 #ifdef ENABLE_LOG_EHCILL
691         log_info("eHCILL: handle eHCILL sent, command was %02x", command);
692 #endif
693 
694     if (command == EHCILL_GO_TO_SLEEP_ACK) {
695 #ifdef ENABLE_LOG_EHCILL
696         log_info("eHCILL: GO_TO_SLEEP_ACK sent, enter sleep mode");
697 #endif
698         // UART not needed after EHCILL_GO_TO_SLEEP_ACK was sent
699         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
700             btstack_uart->set_sleep(btstack_uart_sleep_mode);
701         }
702         hci_transport_h4_ehcill_emit_sleep_state(1);
703     }
704     // already packet ready? then start wakeup
705     if (hci_transport_h4_ehcill_outgoing_packet_ready()){
706         hci_transport_h4_ehcill_emit_sleep_state(0);
707         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
708             btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
709         }
710         if (command != EHCILL_WAKE_UP_IND){
711             hci_transport_h4_echill_send_wakeup_ind();
712         }
713     }
714 }
715 
716 #endif
717 // --- end of eHCILL implementation ---------
718 
719 
720 // configure and return h4 singleton
721 const hci_transport_t * hci_transport_h4_instance(const btstack_uart_block_t * uart_driver) {
722 
723     static const hci_transport_t hci_transport_h4 = {
724             /* const char * name; */                                        "H4",
725             /* void   (*init) (const void *transport_config); */            &hci_transport_h4_init,
726             /* int    (*open)(void); */                                     &hci_transport_h4_open,
727             /* int    (*close)(void); */                                    &hci_transport_h4_close,
728             /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_h4_register_packet_handler,
729             /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_h4_can_send_now,
730             /* int    (*send_packet)(...); */                               &hci_transport_h4_send_packet,
731             /* int    (*set_baudrate)(uint32_t baudrate); */                &hci_transport_h4_set_baudrate,
732             /* void   (*reset_link)(void); */                               NULL,
733             /* void   (*set_sco_config)(uint16_t voice_setting, int num_connections); */ NULL,
734     };
735 
736     btstack_uart = uart_driver;
737     return &hci_transport_h4;
738 }
739