xref: /btstack/src/hci_transport_h4.c (revision 6f3fd12d2666a6213f4b3282f2093a091e66963a)
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     return tx_state == TX_IDLE;
347 }
348 
349 static int hci_transport_h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
350 
351     // store packet type before actual data and increase size
352     size++;
353     packet--;
354     *packet = packet_type;
355 
356 #ifdef ENABLE_BAUDRATE_CHANGE_FLOWCONTROL_BUG_WORKAROUND
357     if ((baudrate_change_workaround_state == BAUDRATE_CHANGE_WORKAROUND_CHIPSET_DETECTED)
358     && (memcmp(packet, baud_rate_command_prefix, sizeof(baud_rate_command_prefix)) == 0)) {
359         log_info("Baud rate command detected, expect command complete event next");
360         baudrate_change_workaround_state = BAUDRATE_CHANGE_WORKAROUND_BAUDRATE_COMMAND_SENT;
361     }
362 #endif
363 
364 #ifdef ENABLE_EHCILL
365     // store request for later
366     ehcill_tx_len   = size;
367     ehcill_tx_data  = packet;
368     switch (ehcill_state){
369         case EHCILL_STATE_SLEEP:
370             hci_transport_h4_ehcill_trigger_wakeup();
371             return 0;
372         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
373             log_info("eHILL: send next packet, state EHCILL_STATE_W2_SEND_SLEEP_ACK");
374             return 0;
375         default:
376             break;
377     }
378 #endif
379 
380     // start sending
381     tx_state = TX_W4_PACKET_SENT;
382     btstack_uart->send_block(packet, size);
383     return 0;
384 }
385 
386 static void hci_transport_h4_init(const void * transport_config){
387     // check for hci_transport_config_uart_t
388     if (!transport_config) {
389         log_error("hci_transport_h4: no config!");
390         return;
391     }
392     if (((hci_transport_config_t*)transport_config)->type != HCI_TRANSPORT_CONFIG_UART) {
393         log_error("hci_transport_h4: config not of type != HCI_TRANSPORT_CONFIG_UART!");
394         return;
395     }
396 
397     // extract UART config from transport config
398     hci_transport_config_uart_t * hci_transport_config_uart = (hci_transport_config_uart_t*) transport_config;
399     uart_config.baudrate    = hci_transport_config_uart->baudrate_init;
400     uart_config.flowcontrol = hci_transport_config_uart->flowcontrol;
401     uart_config.device_name = hci_transport_config_uart->device_name;
402 
403     // set state to off
404     tx_state = TX_OFF;
405     h4_state = H4_OFF;
406 
407     // setup UART driver
408     btstack_uart->init(&uart_config);
409     btstack_uart->set_block_received(&hci_transport_h4_block_read);
410     btstack_uart->set_block_sent(&hci_transport_h4_block_sent);
411 }
412 
413 static int hci_transport_h4_open(void){
414     // open uart driver
415     int res = btstack_uart->open();
416     if (res){
417         return res;
418     }
419 
420     // init rx + tx state machines
421     hci_transport_h4_reset_statemachine();
422     hci_transport_h4_trigger_next_read();
423     tx_state = TX_IDLE;
424 
425 #ifdef ENABLE_EHCILL
426     hci_transport_h4_ehcill_open();
427 #endif
428     return 0;
429 }
430 
431 static int hci_transport_h4_close(void){
432     // set state to off
433     tx_state = TX_OFF;
434     h4_state = H4_OFF;
435 
436     // close uart driver
437     return btstack_uart->close();
438 }
439 
440 static void hci_transport_h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
441     packet_handler = handler;
442 }
443 
444 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
445 }
446 
447 //
448 // --- main part of eHCILL implementation ---
449 //
450 
451 #ifdef ENABLE_EHCILL
452 
453 static void hci_transport_h4_ehcill_emit_sleep_state(int sleep_active){
454     static int last_state = 0;
455     if (sleep_active == last_state) return;
456     last_state = sleep_active;
457 
458     log_info("hci_transport_h4_ehcill_emit_sleep_state: %u", sleep_active);
459     uint8_t event[3];
460     event[0] = HCI_EVENT_TRANSPORT_SLEEP_MODE;
461     event[1] = sizeof(event) - 2;
462     event[2] = sleep_active;
463     packet_handler(HCI_EVENT_PACKET, &event[0], sizeof(event));
464 }
465 
466 static void hci_transport_h4_ehcill_wakeup_handler(void){
467 #ifdef ENABLE_LOG_EHCILL
468     log_info("eHCILL: UART wakeup received");
469 #endif
470     hci_transport_h4_ehcill_handle_command(EHCILL_WAKEUP_SIGNAL);
471 }
472 
473 static void hci_transport_h4_ehcill_open(void){
474     hci_transport_h4_ehcill_reset_statemachine();
475 
476     // find best sleep mode to use: wake on CTS, wake on RX, none
477     btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_OFF;
478     int supported_sleep_modes = 0;
479     if (btstack_uart->get_supported_sleep_modes){
480         supported_sleep_modes = btstack_uart->get_supported_sleep_modes();
481     }
482     if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_HIGH_WAKE_ON_CTS_PULSE){
483         log_info("eHCILL: using wake on CTS");
484         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_HIGH_WAKE_ON_CTS_PULSE;
485     } else if (supported_sleep_modes & BTSTACK_UART_SLEEP_MASK_RTS_LOW_WAKE_ON_RX_EDGE){
486         log_info("eHCILL: using wake on RX");
487         btstack_uart_sleep_mode = BTSTACK_UART_SLEEP_RTS_LOW_WAKE_ON_RX_EDGE;
488     } else {
489         log_info("eHCILL: UART driver does not provide compatible sleep mode");
490     }
491     if (btstack_uart->set_wakeup_handler){
492         btstack_uart->set_wakeup_handler(&hci_transport_h4_ehcill_wakeup_handler);
493     }
494 }
495 
496 static void hci_transport_h4_echill_send_wakeup_ind(void){
497 #ifdef ENABLE_LOG_EHCILL
498     log_info("eHCILL: send WAKEUP_IND");
499 #endif
500     // update state
501     tx_state     = TX_W4_WAKEUP;
502     ehcill_state = EHCILL_STATE_W4_WAKEUP_IND_OR_ACK;
503     ehcill_command_to_send = EHCILL_WAKE_UP_IND;
504     btstack_uart->send_block(&ehcill_command_to_send, 1);
505 }
506 
507 static int hci_transport_h4_ehcill_outgoing_packet_ready(void){
508     return ehcill_tx_len != 0;
509 }
510 
511 static void hci_transport_h4_ehcill_reset_statemachine(void){
512     ehcill_state = EHCILL_STATE_AWAKE;
513 }
514 
515 static void hci_transport_h4_ehcill_send_ehcill_command(void){
516 #ifdef ENABLE_LOG_EHCILL
517     log_info("eHCILL: send command %02x", ehcill_command_to_send);
518 #endif
519     tx_state = TX_W4_EHCILL_SENT;
520     if (ehcill_command_to_send == EHCILL_GO_TO_SLEEP_ACK){
521         ehcill_state = EHCILL_STATE_SLEEP;
522     }
523     btstack_uart->send_block(&ehcill_command_to_send, 1);
524 }
525 
526 static void hci_transport_h4_ehcill_sleep_ack_timer_handler(btstack_timer_source_t * timer){
527 	UNUSED(timer);
528 #ifdef ENABLE_LOG_EHCILL
529     log_info("eHCILL: timer triggered");
530 #endif
531     hci_transport_h4_ehcill_send_ehcill_command();
532 }
533 
534 static void hci_transport_h4_ehcill_sleep_ack_timer_setup(void){
535     // setup timer
536 #ifdef ENABLE_LOG_EHCILL
537     log_info("eHCILL: set timer for sending command %02x", ehcill_command_to_send);
538 #endif
539     btstack_run_loop_set_timer_handler(&ehcill_sleep_ack_timer, &hci_transport_h4_ehcill_sleep_ack_timer_handler);
540     btstack_run_loop_set_timer(&ehcill_sleep_ack_timer, 50);
541     btstack_run_loop_add_timer(&ehcill_sleep_ack_timer);
542 }
543 
544 static void hci_transport_h4_ehcill_trigger_wakeup(void){
545     switch (tx_state){
546         case TX_W2_EHCILL_SEND:
547         case TX_W4_EHCILL_SENT:
548             // wake up / sleep ack in progress, nothing to do now
549             return;
550         case TX_IDLE:
551         default:
552             // all clear, prepare for wakeup
553             break;
554     }
555     // UART needed again
556     hci_transport_h4_ehcill_emit_sleep_state(0);
557     if (btstack_uart_sleep_mode){
558         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
559     }
560     hci_transport_h4_echill_send_wakeup_ind();
561 }
562 
563 static void hci_transport_h4_ehcill_schedule_ehcill_command(uint8_t command){
564 #ifdef ENABLE_LOG_EHCILL
565     log_info("eHCILL: schedule eHCILL command %02x", command);
566 #endif
567     ehcill_command_to_send = command;
568     switch (tx_state){
569         case TX_IDLE:
570             if (ehcill_command_to_send == EHCILL_WAKE_UP_ACK){
571                 // send right away
572                 hci_transport_h4_ehcill_send_ehcill_command();
573             } else {
574                 // change state so BTstack cannot send and setup timer
575                 tx_state = TX_W2_EHCILL_SEND;
576                 hci_transport_h4_ehcill_sleep_ack_timer_setup();
577             }
578             break;
579         default:
580             break;
581     }
582 }
583 
584 static void hci_transport_h4_ehcill_handle_command(uint8_t action){
585     // log_info("hci_transport_h4_ehcill_handle: %x, state %u, defer_rx %u", action, ehcill_state, ehcill_defer_rx_size);
586     switch(ehcill_state){
587         case EHCILL_STATE_AWAKE:
588             switch(action){
589                 case EHCILL_GO_TO_SLEEP_IND:
590                     ehcill_state = EHCILL_STATE_W2_SEND_SLEEP_ACK;
591 #ifdef ENABLE_LOG_EHCILL
592                     log_info("eHCILL: Received GO_TO_SLEEP_IND RX");
593 #endif
594                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_GO_TO_SLEEP_ACK);
595                     break;
596                 default:
597                     break;
598             }
599             break;
600 
601         case EHCILL_STATE_W2_SEND_SLEEP_ACK:
602             switch(action){
603                 case EHCILL_WAKE_UP_IND:
604                     ehcill_state = EHCILL_STATE_AWAKE;
605                     hci_transport_h4_ehcill_emit_sleep_state(0);
606                     if (btstack_uart_sleep_mode){
607                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
608                     }
609 #ifdef ENABLE_LOG_EHCILL
610                     log_info("eHCILL: Received WAKE_UP_IND RX");
611 #endif
612                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
613                     break;
614 
615                 default:
616                     break;
617             }
618             break;
619 
620         case EHCILL_STATE_SLEEP:
621             switch(action){
622                 case EHCILL_WAKEUP_SIGNAL:
623                     hci_transport_h4_ehcill_emit_sleep_state(0);
624                     if (btstack_uart_sleep_mode){
625                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
626                     }
627                     break;
628                 case EHCILL_WAKE_UP_IND:
629                     ehcill_state = EHCILL_STATE_AWAKE;
630                     hci_transport_h4_ehcill_emit_sleep_state(0);
631                     if (btstack_uart_sleep_mode){
632                         btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
633                     }
634 #ifdef ENABLE_LOG_EHCILL
635                     log_info("eHCILL: Received WAKE_UP_IND RX");
636 #endif
637                     hci_transport_h4_ehcill_schedule_ehcill_command(EHCILL_WAKE_UP_ACK);
638                     break;
639 
640                 default:
641                     break;
642             }
643             break;
644 
645         case EHCILL_STATE_W4_WAKEUP_IND_OR_ACK:
646             switch(action){
647                 case EHCILL_WAKE_UP_IND:
648                 case EHCILL_WAKE_UP_ACK:
649 #ifdef ENABLE_LOG_EHCILL
650                     log_info("eHCILL: Received WAKE_UP (%02x)", action);
651 #endif
652                     tx_state = TX_W4_PACKET_SENT;
653                     ehcill_state = EHCILL_STATE_AWAKE;
654                     btstack_uart->send_block(ehcill_tx_data, ehcill_tx_len);
655                     break;
656                 default:
657                     break;
658             }
659             break;
660     }
661 }
662 
663 static void hci_transport_h4_ehcill_handle_packet_sent(void){
664 #ifdef ENABLE_LOG_EHCILL
665         log_info("eHCILL: handle packet sent, command to send %02x", ehcill_command_to_send);
666 #endif
667     // now, send pending ehcill command if neccessary
668     switch (ehcill_command_to_send){
669         case EHCILL_GO_TO_SLEEP_ACK:
670             hci_transport_h4_ehcill_sleep_ack_timer_setup();
671             break;
672         case EHCILL_WAKE_UP_IND:
673             hci_transport_h4_ehcill_send_ehcill_command();
674             break;
675         default:
676             break;
677     }
678 }
679 
680 static void hci_transport_h4_ehcill_handle_ehcill_command_sent(void){
681     tx_state = TX_IDLE;
682     int command = ehcill_command_to_send;
683     ehcill_command_to_send = 0;
684 
685 #ifdef ENABLE_LOG_EHCILL
686         log_info("eHCILL: handle eHCILL sent, command was %02x", command);
687 #endif
688 
689     if (command == EHCILL_GO_TO_SLEEP_ACK) {
690 #ifdef ENABLE_LOG_EHCILL
691         log_info("eHCILL: GO_TO_SLEEP_ACK sent, enter sleep mode");
692 #endif
693         // UART not needed after EHCILL_GO_TO_SLEEP_ACK was sent
694         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
695             btstack_uart->set_sleep(btstack_uart_sleep_mode);
696         }
697         hci_transport_h4_ehcill_emit_sleep_state(1);
698     }
699     // already packet ready? then start wakeup
700     if (hci_transport_h4_ehcill_outgoing_packet_ready()){
701         hci_transport_h4_ehcill_emit_sleep_state(0);
702         if (btstack_uart_sleep_mode != BTSTACK_UART_SLEEP_OFF){
703             btstack_uart->set_sleep(BTSTACK_UART_SLEEP_OFF);
704         }
705         if (command != EHCILL_WAKE_UP_IND){
706             hci_transport_h4_echill_send_wakeup_ind();
707         }
708     }
709 }
710 
711 #endif
712 // --- end of eHCILL implementation ---------
713 
714 static const hci_transport_t hci_transport_h4 = {
715     /* const char * name; */                                        "H4",
716     /* void   (*init) (const void *transport_config); */            &hci_transport_h4_init,
717     /* int    (*open)(void); */                                     &hci_transport_h4_open,
718     /* int    (*close)(void); */                                    &hci_transport_h4_close,
719     /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_h4_register_packet_handler,
720     /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_h4_can_send_now,
721     /* int    (*send_packet)(...); */                               &hci_transport_h4_send_packet,
722     /* int    (*set_baudrate)(uint32_t baudrate); */                &hci_transport_h4_set_baudrate,
723     /* void   (*reset_link)(void); */                               NULL,
724     /* void   (*set_sco_config)(uint16_t voice_setting, int num_connections); */ NULL,
725 };
726 
727 // configure and return h4 singleton
728 const hci_transport_t * hci_transport_h4_instance(const btstack_uart_block_t * uart_driver) {
729     btstack_uart = uart_driver;
730     return &hci_transport_h4;
731 }
732