xref: /btstack/src/hci_transport_em9304_spi.c (revision e6c9673776c7f85e24c76da7f4b1b83031102d2b)
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_em9304_spi.c"
39 
40 #include "btstack_config.h"
41 #include "btstack_em9304_spi.h"
42 
43 // EM9304 SPI Driver
44 static const btstack_em9304_spi_t * btstack_em9304_spi;
45 
46 /////////////////////////
47 // em9304 engine
48 #include "btstack_ring_buffer.h"
49 #include "btstack_debug.h"
50 #include "btstack_util.h"
51 #include "hci.h"
52 #include "hci_transport.h"
53 
54 static void em9304_spi_engine_run(void);
55 
56 #define STS_SLAVE_READY 0xc0
57 
58 #define EM9304_SPI_HEADER_TX        0x42
59 #define EM9304_SPI_HEADER_RX        0x81
60 
61 #define SPI_EM9304_BUFFER_SIZE        64
62 #define SPI_EM9304_RING_BUFFER_SIZE  128
63 
64 // state
65 static volatile enum {
66     SPI_EM9304_READY_FOR_TX,
67     SPI_EM9304_READY_FOR_TX_AND_RX,
68     SPI_EM9304_RX_W4_READ_COMMAND_SENT,
69     SPI_EM9304_RX_READ_COMMAND_SENT,
70     SPI_EM9304_RX_W4_STS2_RECEIVED,
71     SPI_EM9304_RX_STS2_RECEIVED,
72     SPI_EM9304_RX_W4_DATA_RECEIVED,
73     SPI_EM9304_RX_DATA_RECEIVED,
74     SPI_EM9304_TX_W4_RDY,
75     SPI_EM9304_TX_W4_WRITE_COMMAND_SENT,
76     SPI_EM9304_TX_WRITE_COMMAND_SENT,
77     SPI_EM9304_TX_W4_STS2_RECEIVED,
78     SPI_EM9304_TX_STS2_RECEIVED,
79     SPI_EM9304_TX_W4_DATA_SENT,
80     SPI_EM9304_TX_DATA_SENT,
81     SPI_EM9304_DONE,
82 } em9304_spi_engine_state;
83 
84 static uint16_t em9304_spi_engine_rx_request_len;
85 static uint16_t em9304_spi_engine_tx_request_len;
86 
87 static btstack_ring_buffer_t em9304_spi_engine_rx_ring_buffer;
88 
89 // note: needs to be aligned
90 static uint8_t em9304_spi_engine_rx_ring_buffer_storage[SPI_EM9304_RING_BUFFER_SIZE];
91 
92 static const uint8_t  * em9304_spi_engine_tx_data;
93 static uint16_t         em9304_spi_engine_tx_size;
94 
95 // handlers
96 static void (*em9304_spi_engine_rx_available_handler)(void);
97 static void (*em9304_spi_engine_tx_done_handler)(void);
98 
99 // TODO: get rid of alignment requirement
100 union {
101     uint32_t words[1];
102     uint8_t  bytes[1];
103 } sCommand;
104 
105 union {
106     uint32_t words[1];
107     uint8_t  bytes[1];
108 } sStas;
109 
110 union {
111     uint32_t words[SPI_EM9304_BUFFER_SIZE/4];
112     uint8_t  bytes[SPI_EM9304_BUFFER_SIZE];
113 } em9304_spi_engine_spi_buffer;
114 
115 static void em9304_spi_engine_ready_callback(void){
116     // TODO: collect states
117     em9304_spi_engine_run();
118 }
119 
120 static void em9304_spi_engine_transfer_done(void){
121     switch (em9304_spi_engine_state){
122         case SPI_EM9304_RX_W4_READ_COMMAND_SENT:
123             em9304_spi_engine_state = SPI_EM9304_RX_READ_COMMAND_SENT;
124             break;
125         case SPI_EM9304_RX_W4_STS2_RECEIVED:
126             em9304_spi_engine_state = SPI_EM9304_RX_STS2_RECEIVED;
127             break;
128         case SPI_EM9304_RX_W4_DATA_RECEIVED:
129             em9304_spi_engine_state = SPI_EM9304_RX_DATA_RECEIVED;
130             break;
131         case SPI_EM9304_TX_W4_WRITE_COMMAND_SENT:
132             em9304_spi_engine_state = SPI_EM9304_TX_WRITE_COMMAND_SENT;
133             break;
134         case SPI_EM9304_TX_W4_STS2_RECEIVED:
135             em9304_spi_engine_state = SPI_EM9304_TX_STS2_RECEIVED;
136             break;
137         case SPI_EM9304_TX_W4_DATA_SENT:
138             em9304_spi_engine_state = SPI_EM9304_TX_DATA_SENT;
139             break;
140         default:
141             return;
142     }
143     em9304_spi_engine_run();
144 }
145 
146 static void em9304_spi_engine_start_tx_transaction(void){
147     // state = wait for RDY
148     em9304_spi_engine_state = SPI_EM9304_TX_W4_RDY;
149 
150     // chip select
151     btstack_em9304_spi->set_chip_select(1);
152 
153     // enable IRQ
154     btstack_em9304_spi->set_ready_callback(&em9304_spi_engine_ready_callback);
155 }
156 
157 static inline int em9304_engine_space_in_rx_buffer(void){
158     return btstack_ring_buffer_bytes_free(&em9304_spi_engine_rx_ring_buffer) >= SPI_EM9304_BUFFER_SIZE;
159 }
160 
161 static void em9304_engine_receive_buffer_ready(void){
162     // no data ready for receive or transmit, but space in rx ringbuffer  -> enable READY IRQ
163     em9304_spi_engine_state = SPI_EM9304_READY_FOR_TX_AND_RX;
164     btstack_em9304_spi->set_ready_callback(&em9304_spi_engine_ready_callback);
165 }
166 
167 static void em9304_engine_start_next_transaction(void){
168 
169     if (em9304_spi_engine_state != SPI_EM9304_DONE) return;
170 
171     if (btstack_em9304_spi->get_ready()){
172         // RDY -> data available
173         if (em9304_engine_space_in_rx_buffer()) {
174             // disable interrupt again
175             btstack_em9304_spi->set_ready_callback(NULL);
176 
177             // enable chip select
178             btstack_em9304_spi->set_chip_select(1);
179 
180             // send read command
181             em9304_spi_engine_state = SPI_EM9304_RX_W4_READ_COMMAND_SENT;
182             sCommand.bytes[0] = EM9304_SPI_HEADER_RX;
183             btstack_em9304_spi->transmit(sCommand.bytes, 1);
184         }
185     } else if (em9304_spi_engine_tx_size){
186         em9304_spi_engine_start_tx_transaction();
187     } else if (em9304_engine_space_in_rx_buffer()){
188         em9304_engine_receive_buffer_ready();
189     }
190 }
191 
192 static void em9304_engine_action_done(void){
193     // chip deselect & done
194     btstack_em9304_spi->set_chip_select(0);
195     em9304_spi_engine_state = SPI_EM9304_DONE;
196 }
197 
198 static void em9304_spi_engine_run(void){
199     uint16_t max_bytes_to_send;
200     switch (em9304_spi_engine_state){
201 
202         case SPI_EM9304_RX_READ_COMMAND_SENT:
203             em9304_spi_engine_state = SPI_EM9304_RX_W4_STS2_RECEIVED;
204             btstack_em9304_spi->receive(sStas.bytes, 1);
205             break;
206 
207         case SPI_EM9304_RX_STS2_RECEIVED:
208             // check slave status
209             log_debug("RX: STS2 0x%02X", sStas.bytes[0]);
210 
211             // read data
212             em9304_spi_engine_state = SPI_EM9304_RX_W4_DATA_RECEIVED;
213             em9304_spi_engine_rx_request_len = sStas.bytes[0];
214             btstack_em9304_spi->receive(em9304_spi_engine_spi_buffer.bytes, em9304_spi_engine_rx_request_len);
215             break;
216 
217         case SPI_EM9304_RX_DATA_RECEIVED:
218             // done
219             em9304_engine_action_done();
220 
221             // move data into ring buffer
222             btstack_ring_buffer_write(&em9304_spi_engine_rx_ring_buffer, em9304_spi_engine_spi_buffer.bytes, em9304_spi_engine_rx_request_len);
223             em9304_spi_engine_rx_request_len = 0;
224 
225             // notify about new data available -- assume empty
226             (*em9304_spi_engine_rx_available_handler)();
227 
228             // next
229             em9304_engine_start_next_transaction();
230             break;
231 
232         case SPI_EM9304_TX_W4_RDY:
233             // check if ready
234             if (!btstack_em9304_spi->get_ready()) break;
235 
236             // disable interrupt again
237             btstack_em9304_spi->set_ready_callback(NULL);
238 
239             // send write command
240             em9304_spi_engine_state = SPI_EM9304_TX_W4_WRITE_COMMAND_SENT;
241             sCommand.bytes[0] = EM9304_SPI_HEADER_TX;
242             btstack_em9304_spi->transmit(sCommand.bytes, 1);
243             break;
244 
245         case SPI_EM9304_TX_WRITE_COMMAND_SENT:
246             em9304_spi_engine_state = SPI_EM9304_TX_W4_STS2_RECEIVED;
247             btstack_em9304_spi->receive(sStas.bytes, 1);
248             break;
249 
250         case SPI_EM9304_TX_STS2_RECEIVED:
251             // check slave status and em9304 rx buffer space
252             log_debug("TX: STS2 0x%02X", sStas.bytes[0]);
253             max_bytes_to_send = sStas.bytes[0];
254             if (max_bytes_to_send == 0){
255                 // done
256                 em9304_engine_action_done();
257                 // next
258                 em9304_engine_start_next_transaction();
259                 break;
260             }
261 
262             // number bytes to send
263             em9304_spi_engine_tx_request_len = btstack_min(em9304_spi_engine_tx_size, max_bytes_to_send);
264 
265             // send command
266             em9304_spi_engine_state = SPI_EM9304_TX_W4_DATA_SENT;
267             if ( (((uintptr_t) em9304_spi_engine_tx_data) & 0x03) == 0){
268                 // 4-byte aligned
269                 btstack_em9304_spi->transmit( (uint8_t*) em9304_spi_engine_tx_data, em9304_spi_engine_tx_request_len);
270             } else {
271                 // TODO: get rid of alignment requirement
272                 // enforce alignment by copying to spi buffer first
273                 memcpy(em9304_spi_engine_spi_buffer.bytes, em9304_spi_engine_tx_data, em9304_spi_engine_tx_request_len);
274                 btstack_em9304_spi->transmit( (uint8_t*) em9304_spi_engine_spi_buffer.bytes, em9304_spi_engine_tx_request_len);
275             }
276             break;
277 
278         case SPI_EM9304_TX_DATA_SENT:
279             // done
280             em9304_engine_action_done();
281 
282             // chunk sent
283             em9304_spi_engine_tx_size -= em9304_spi_engine_tx_request_len;
284             em9304_spi_engine_tx_data += em9304_spi_engine_tx_request_len;
285             em9304_spi_engine_tx_request_len = 0;
286 
287             // notify higher layer when complete
288             if (em9304_spi_engine_tx_size == 0){
289                 (*em9304_spi_engine_tx_done_handler)();
290             }
291 
292             // next
293             em9304_engine_start_next_transaction();
294             break;
295 
296         default:
297             break;
298     }
299 }
300 
301 static void em9304_spi_engine_init(void){
302     btstack_em9304_spi->open();
303     btstack_em9304_spi->set_transfer_done_callback(&em9304_spi_engine_transfer_done);
304     btstack_ring_buffer_init(&em9304_spi_engine_rx_ring_buffer, &em9304_spi_engine_rx_ring_buffer_storage[0], SPI_EM9304_RING_BUFFER_SIZE);
305     em9304_spi_engine_state = SPI_EM9304_DONE;
306     em9304_engine_start_next_transaction();
307 }
308 
309 static void em9304_spi_engine_close(void){
310     btstack_em9304_spi->close();
311 }
312 
313 static void em9304_spi_engine_set_data_available( void (*the_block_handler)(void)){
314     em9304_spi_engine_rx_available_handler = the_block_handler;
315 }
316 
317 static void em9304_spi_engine_set_block_sent( void (*the_block_handler)(void)){
318     em9304_spi_engine_tx_done_handler = the_block_handler;
319 }
320 
321 static void em9304_spi_engine_send_block(const uint8_t *buffer, uint16_t length){
322     em9304_spi_engine_tx_data = buffer;
323     em9304_spi_engine_tx_size = length;
324     em9304_engine_start_next_transaction();
325 }
326 
327 static uint16_t em9304_engine_num_bytes_available(void){
328     return btstack_ring_buffer_bytes_available(&em9304_spi_engine_rx_ring_buffer);
329 }
330 
331 static void em9304_engine_get_bytes(uint8_t * buffer, uint16_t num_bytes){
332     uint32_t bytes_read;
333     btstack_ring_buffer_read(&em9304_spi_engine_rx_ring_buffer, buffer, num_bytes, &bytes_read);
334 }
335 
336 //////////////////////////////////////////////////////////////////////////////
337 
338 // assert pre-buffer for packet type is available
339 #if !defined(HCI_OUTGOING_PRE_BUFFER_SIZE) || (HCI_OUTGOING_PRE_BUFFER_SIZE == 0)
340 #error HCI_OUTGOING_PRE_BUFFER_SIZE not defined. Please update hci.h
341 #endif
342 
343 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size);
344 
345 typedef enum {
346     H4_W4_PACKET_TYPE,
347     H4_W4_EVENT_HEADER,
348     H4_W4_ACL_HEADER,
349     H4_W4_PAYLOAD,
350 } H4_STATE;
351 
352 typedef enum {
353     TX_IDLE = 1,
354     TX_W4_PACKET_SENT,
355 } TX_STATE;
356 
357 // write state
358 static TX_STATE tx_state;
359 
360 static uint8_t packet_sent_event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
361 
362 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
363 
364 // packet reader state machine
365 static H4_STATE hci_transport_em9304_h4_state;
366 static uint16_t hci_transport_em9304_spi_bytes_to_read;
367 static uint16_t hci_transport_em9304_spi_read_pos;
368 
369 // incoming packet buffer
370 static uint8_t hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE + 1 + HCI_PACKET_BUFFER_SIZE]; // packet type + max(acl header + acl payload, event header + event data)
371 static uint8_t * hci_packet = &hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE];
372 
373 static void hci_transport_em9304_spi_block_read(void);
374 
375 static void hci_transport_em9304_spi_reset_statemachine(void){
376     hci_transport_em9304_h4_state = H4_W4_PACKET_TYPE;
377     hci_transport_em9304_spi_read_pos = 0;
378     hci_transport_em9304_spi_bytes_to_read = 1;
379 }
380 
381 static void hci_transport_em9304_spi_process_data(void){
382     while (1){
383 
384         uint16_t bytes_available = em9304_engine_num_bytes_available();
385         log_debug("transfer_rx_data: ring buffer has %u -> hci wants %u", bytes_available, hci_transport_em9304_spi_bytes_to_read);
386 
387         if (!bytes_available) break;
388         if (!hci_transport_em9304_spi_bytes_to_read) break;
389 
390         uint16_t bytes_to_copy = btstack_min(bytes_available, hci_transport_em9304_spi_bytes_to_read);
391         em9304_engine_get_bytes(&hci_packet[hci_transport_em9304_spi_read_pos], bytes_to_copy);
392 
393         hci_transport_em9304_spi_read_pos      += bytes_to_copy;
394         hci_transport_em9304_spi_bytes_to_read -= bytes_to_copy;
395 
396         if (hci_transport_em9304_spi_bytes_to_read == 0){
397             hci_transport_em9304_spi_block_read();
398         }
399     }
400 }
401 
402 static void hci_transport_em9304_spi_block_read(void){
403     switch (hci_transport_em9304_h4_state) {
404         case H4_W4_PACKET_TYPE:
405             switch (hci_packet[0]){
406                 case HCI_EVENT_PACKET:
407                     hci_transport_em9304_spi_bytes_to_read = HCI_EVENT_HEADER_SIZE;
408                     hci_transport_em9304_h4_state = H4_W4_EVENT_HEADER;
409                     break;
410                 case HCI_ACL_DATA_PACKET:
411                     hci_transport_em9304_spi_bytes_to_read = HCI_ACL_HEADER_SIZE;
412                     hci_transport_em9304_h4_state = H4_W4_ACL_HEADER;
413                     break;
414                 default:
415                     log_error("invalid packet type 0x%02x", hci_packet[0]);
416                     hci_transport_em9304_spi_reset_statemachine();
417                     break;
418             }
419             break;
420 
421         case H4_W4_EVENT_HEADER:
422             hci_transport_em9304_spi_bytes_to_read = hci_packet[2];
423             hci_transport_em9304_h4_state = H4_W4_PAYLOAD;
424             break;
425 
426         case H4_W4_ACL_HEADER:
427             hci_transport_em9304_spi_bytes_to_read = little_endian_read_16( hci_packet, 3);
428             // check ACL length
429             if (HCI_ACL_HEADER_SIZE + hci_transport_em9304_spi_bytes_to_read >  HCI_PACKET_BUFFER_SIZE){
430                 log_error("invalid ACL payload len %d - only space for %u", hci_transport_em9304_spi_bytes_to_read, HCI_PACKET_BUFFER_SIZE - HCI_ACL_HEADER_SIZE);
431                 hci_transport_em9304_spi_reset_statemachine();
432                 break;
433             }
434             hci_transport_em9304_h4_state = H4_W4_PAYLOAD;
435             break;
436 
437         case H4_W4_PAYLOAD:
438             packet_handler(hci_packet[0], &hci_packet[1], hci_transport_em9304_spi_read_pos-1);
439             hci_transport_em9304_spi_reset_statemachine();
440             break;
441         default:
442             break;
443     }
444 }
445 
446 static void hci_transport_em9304_spi_block_sent(void){
447     switch (tx_state){
448         case TX_W4_PACKET_SENT:
449             // packet fully sent, reset state
450             tx_state = TX_IDLE;
451             // notify upper stack that it can send again
452             packet_handler(HCI_EVENT_PACKET, &packet_sent_event[0], sizeof(packet_sent_event));
453             break;
454         default:
455             break;
456     }
457 }
458 
459 static int hci_transport_em9304_spi_can_send_now(uint8_t packet_type){
460     return tx_state == TX_IDLE;
461 }
462 
463 static int hci_transport_em9304_spi_send_packet(uint8_t packet_type, uint8_t * packet, int size){
464 
465     // store packet type before actual data and increase size
466     size++;
467     packet--;
468     *packet = packet_type;
469 
470     // start sending
471     tx_state = TX_W4_PACKET_SENT;
472     em9304_spi_engine_send_block(packet, size);
473     return 0;
474 }
475 
476 static void hci_transport_em9304_spi_init(const void * transport_config){
477 }
478 
479 static int hci_transport_em9304_spi_open(void){
480 
481     // setup UART driver
482     em9304_spi_engine_init();
483     em9304_spi_engine_set_data_available(&hci_transport_em9304_spi_process_data);
484     em9304_spi_engine_set_block_sent(&hci_transport_em9304_spi_block_sent);
485     // setup H4 RX
486     hci_transport_em9304_spi_reset_statemachine();
487     // setup H4 TX
488     tx_state = TX_IDLE;
489     return 0;
490 }
491 
492 static int hci_transport_em9304_spi_close(void){
493     em9304_spi_engine_close();
494     return 0;
495 }
496 
497 static void hci_transport_em9304_spi_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
498     packet_handler = handler;
499 }
500 
501 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
502 }
503 
504 // --- end of eHCILL implementation ---------
505 
506 static const hci_transport_t hci_transport_em9304_spi = {
507     /* const char * name; */                                        "H4",
508     /* void   (*init) (const void *transport_config); */            &hci_transport_em9304_spi_init,
509     /* int    (*open)(void); */                                     &hci_transport_em9304_spi_open,
510     /* int    (*close)(void); */                                    &hci_transport_em9304_spi_close,
511     /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_em9304_spi_register_packet_handler,
512     /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_em9304_spi_can_send_now,
513     /* int    (*send_packet)(...); */                               &hci_transport_em9304_spi_send_packet,
514     /* int    (*set_baudrate)(uint32_t baudrate); */                NULL,
515     /* void   (*reset_link)(void); */                               NULL,
516     /* void   (*set_sco_config)(uint16_t voice_setting, int num_connections); */ NULL,
517 };
518 
519 // configure and return h4 singleton
520 const hci_transport_t * hci_transport_em9304_spi_instance(const btstack_em9304_spi_t * em9304_spi_driver) {
521     btstack_em9304_spi = em9304_spi_driver;
522     return &hci_transport_em9304_spi;
523 }
524