xref: /btstack/src/hci_transport_em9304_spi.c (revision fc46bba0b04f44e8257f3c8a274906c777f927c3)
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_RX_BUFFER_SIZE     64
62 #define SPI_EM9304_TX_BUFFER_SIZE     64
63 #define SPI_EM9304_RING_BUFFER_SIZE  128
64 
65 // state
66 static volatile enum {
67     SPI_EM9304_READY_FOR_TX,
68     SPI_EM9304_READY_FOR_TX_AND_RX,
69     SPI_EM9304_RX_W4_READ_COMMAND_SENT,
70     SPI_EM9304_RX_READ_COMMAND_SENT,
71     SPI_EM9304_RX_W4_STS2_RECEIVED,
72     SPI_EM9304_RX_STS2_RECEIVED,
73     SPI_EM9304_RX_W4_DATA_RECEIVED,
74     SPI_EM9304_RX_DATA_RECEIVED,
75     SPI_EM9304_TX_W4_RDY,
76     SPI_EM9304_TX_W4_WRITE_COMMAND_SENT,
77     SPI_EM9304_TX_WRITE_COMMAND_SENT,
78     SPI_EM9304_TX_W4_STS2_RECEIVED,
79     SPI_EM9304_TX_STS2_RECEIVED,
80     SPI_EM9304_TX_W4_DATA_SENT,
81     SPI_EM9304_TX_DATA_SENT,
82     SPI_EM9304_DONE,
83 } em9304_spi_engine_state;
84 
85 static uint16_t em9304_spi_engine_rx_request_len;
86 static uint16_t em9304_spi_engine_tx_request_len;
87 
88 static btstack_ring_buffer_t em9304_spi_engine_rx_ring_buffer;
89 static uint8_t em9304_spi_engine_rx_ring_buffer_storage[SPI_EM9304_RING_BUFFER_SIZE];
90 
91 static const uint8_t  * em9304_spi_engine_tx_data;
92 static uint16_t         em9304_spi_engine_tx_size;
93 
94 // handlers
95 static void (*em9304_spi_engine_rx_available_handler)(void);
96 static void (*em9304_spi_engine_tx_done_handler)(void);
97 
98 // TODO: get rid of alignment requirement
99 union {
100     uint32_t words[1];
101     uint8_t  bytes[1];
102 } sCommand;
103 
104 union {
105     uint32_t words[1];
106     uint8_t  bytes[1];
107 } sStas;
108 
109 union {
110     uint32_t words[SPI_EM9304_RX_BUFFER_SIZE/4];
111     uint8_t  bytes[SPI_EM9304_RX_BUFFER_SIZE];
112 } em9304_spi_engine_spi_rx_buffer;
113 
114 static void em9304_spi_engine_ready_callback(void){
115     // TODO: collect states
116     em9304_spi_engine_run();
117 }
118 
119 static void em9304_spi_engine_transfer_done(void){
120     switch (em9304_spi_engine_state){
121         case SPI_EM9304_RX_W4_READ_COMMAND_SENT:
122             em9304_spi_engine_state = SPI_EM9304_RX_READ_COMMAND_SENT;
123             break;
124         case SPI_EM9304_RX_W4_STS2_RECEIVED:
125             em9304_spi_engine_state = SPI_EM9304_RX_STS2_RECEIVED;
126             break;
127         case SPI_EM9304_RX_W4_DATA_RECEIVED:
128             em9304_spi_engine_state = SPI_EM9304_RX_DATA_RECEIVED;
129             break;
130         case SPI_EM9304_TX_W4_WRITE_COMMAND_SENT:
131             em9304_spi_engine_state = SPI_EM9304_TX_WRITE_COMMAND_SENT;
132             break;
133         case SPI_EM9304_TX_W4_STS2_RECEIVED:
134             em9304_spi_engine_state = SPI_EM9304_TX_STS2_RECEIVED;
135             break;
136         case SPI_EM9304_TX_W4_DATA_SENT:
137             em9304_spi_engine_state = SPI_EM9304_TX_DATA_SENT;
138             break;
139         default:
140             return;
141     }
142     em9304_spi_engine_run();
143 }
144 
145 static void em9304_spi_engine_start_tx_transaction(void){
146     // state = wait for RDY
147     em9304_spi_engine_state = SPI_EM9304_TX_W4_RDY;
148 
149     // chip select
150     btstack_em9304_spi->set_chip_select(1);
151 
152     // enable IRQ
153     btstack_em9304_spi->set_ready_callback(&em9304_spi_engine_ready_callback);
154 }
155 
156 static inline int em9304_engine_space_in_rx_buffer(void){
157     return btstack_ring_buffer_bytes_free(&em9304_spi_engine_rx_ring_buffer) >= SPI_EM9304_RX_BUFFER_SIZE;
158 }
159 
160 static void em9304_engine_receive_buffer_ready(void){
161     // no data ready for receive or transmit, but space in rx ringbuffer  -> enable READY IRQ
162     em9304_spi_engine_state = SPI_EM9304_READY_FOR_TX_AND_RX;
163     btstack_em9304_spi->set_ready_callback(&em9304_spi_engine_ready_callback);
164 }
165 
166 static void em9304_engine_start_next_transaction(void){
167 
168     if (em9304_spi_engine_state != SPI_EM9304_DONE) return;
169 
170     if (btstack_em9304_spi->get_ready()){
171         // RDY -> data available
172         if (em9304_engine_space_in_rx_buffer()) {
173             // disable interrupt again
174             btstack_em9304_spi->set_ready_callback(NULL);
175 
176             // enable chip select
177             btstack_em9304_spi->set_chip_select(1);
178 
179             // send read command
180             em9304_spi_engine_state = SPI_EM9304_RX_W4_READ_COMMAND_SENT;
181             sCommand.bytes[0] = EM9304_SPI_HEADER_RX;
182             btstack_em9304_spi->transmit(sCommand.bytes, 1);
183         }
184     } else if (em9304_spi_engine_tx_size){
185         em9304_spi_engine_start_tx_transaction();
186     } else if (em9304_engine_space_in_rx_buffer()){
187         em9304_engine_receive_buffer_ready();
188     }
189 }
190 
191 static void em9304_engine_action_done(void){
192     // chip deselect & done
193     btstack_em9304_spi->set_chip_select(0);
194     em9304_spi_engine_state = SPI_EM9304_DONE;
195 }
196 
197 static void em9304_spi_engine_run(void){
198     uint16_t max_bytes_to_send;
199     switch (em9304_spi_engine_state){
200 
201         case SPI_EM9304_RX_READ_COMMAND_SENT:
202             em9304_spi_engine_state = SPI_EM9304_RX_W4_STS2_RECEIVED;
203             btstack_em9304_spi->receive(sStas.bytes, 1);
204             break;
205 
206         case SPI_EM9304_RX_STS2_RECEIVED:
207             // check slave status
208             log_debug("RX: STS2 0x%02X", sStas.bytes[0]);
209 
210             // read data
211             em9304_spi_engine_state = SPI_EM9304_RX_W4_DATA_RECEIVED;
212             em9304_spi_engine_rx_request_len = sStas.bytes[0];
213             btstack_em9304_spi->receive(em9304_spi_engine_spi_rx_buffer.bytes, em9304_spi_engine_rx_request_len);
214             break;
215 
216         case SPI_EM9304_RX_DATA_RECEIVED:
217             // done
218             em9304_engine_action_done();
219 
220             // move data into ring buffer
221             btstack_ring_buffer_write(&em9304_spi_engine_rx_ring_buffer, em9304_spi_engine_spi_rx_buffer.bytes, em9304_spi_engine_rx_request_len);
222             em9304_spi_engine_rx_request_len = 0;
223 
224             // notify about new data available -- assume empty
225             (*em9304_spi_engine_rx_available_handler)();
226 
227             // next
228             em9304_engine_start_next_transaction();
229             break;
230 
231         case SPI_EM9304_TX_W4_RDY:
232             // check if ready
233             if (!btstack_em9304_spi->get_ready()) break;
234 
235             // disable interrupt again
236             btstack_em9304_spi->set_ready_callback(NULL);
237 
238             // send write command
239             em9304_spi_engine_state = SPI_EM9304_TX_W4_WRITE_COMMAND_SENT;
240             sCommand.bytes[0] = EM9304_SPI_HEADER_TX;
241             btstack_em9304_spi->transmit(sCommand.bytes, 1);
242             break;
243 
244         case SPI_EM9304_TX_WRITE_COMMAND_SENT:
245             em9304_spi_engine_state = SPI_EM9304_TX_W4_STS2_RECEIVED;
246             btstack_em9304_spi->receive(sStas.bytes, 1);
247             break;
248 
249         case SPI_EM9304_TX_STS2_RECEIVED:
250             // check slave status and em9304 rx buffer space
251             log_debug("TX: STS2 0x%02X", sStas.bytes[0]);
252             max_bytes_to_send = sStas.bytes[0];
253             if (max_bytes_to_send == 0){
254                 // done
255                 em9304_engine_action_done();
256                 // next
257                 em9304_engine_start_next_transaction();
258                 break;
259             }
260 
261             // number bytes to send
262             em9304_spi_engine_tx_request_len = btstack_min(em9304_spi_engine_tx_size, max_bytes_to_send);
263 
264             // send command
265             em9304_spi_engine_state = SPI_EM9304_TX_W4_DATA_SENT;
266             btstack_em9304_spi->transmit( (uint8_t*) em9304_spi_engine_tx_data, em9304_spi_engine_tx_request_len);
267             break;
268 
269         case SPI_EM9304_TX_DATA_SENT:
270             // done
271             em9304_engine_action_done();
272 
273             // chunk sent
274             em9304_spi_engine_tx_size -= em9304_spi_engine_tx_request_len;
275             em9304_spi_engine_tx_data += em9304_spi_engine_tx_request_len;
276             em9304_spi_engine_tx_request_len = 0;
277 
278             // notify higher layer when complete
279             if (em9304_spi_engine_tx_size == 0){
280                 (*em9304_spi_engine_tx_done_handler)();
281             }
282 
283             // next
284             em9304_engine_start_next_transaction();
285             break;
286 
287         default:
288             break;
289     }
290 }
291 
292 static void em9304_spi_engine_init(void){
293     btstack_em9304_spi->open();
294     btstack_em9304_spi->set_transfer_done_callback(&em9304_spi_engine_transfer_done);
295     btstack_ring_buffer_init(&em9304_spi_engine_rx_ring_buffer, &em9304_spi_engine_rx_ring_buffer_storage[0], SPI_EM9304_RING_BUFFER_SIZE);
296     em9304_spi_engine_state = SPI_EM9304_DONE;
297     em9304_engine_start_next_transaction();
298 }
299 
300 static void em9304_spi_engine_close(void){
301     btstack_em9304_spi->close();
302 }
303 
304 static void em9304_spi_engine_set_data_available( void (*the_block_handler)(void)){
305     em9304_spi_engine_rx_available_handler = the_block_handler;
306 }
307 
308 static void em9304_spi_engine_set_block_sent( void (*the_block_handler)(void)){
309     em9304_spi_engine_tx_done_handler = the_block_handler;
310 }
311 
312 static void em9304_spi_engine_send_block(const uint8_t *buffer, uint16_t length){
313     em9304_spi_engine_tx_data = buffer;
314     em9304_spi_engine_tx_size = length;
315     em9304_engine_start_next_transaction();
316 }
317 
318 static uint16_t em9304_engine_num_bytes_available(void){
319     return btstack_ring_buffer_bytes_available(&em9304_spi_engine_rx_ring_buffer);
320 }
321 
322 static void em9304_engine_get_bytes(uint8_t * buffer, uint16_t num_bytes){
323     uint32_t bytes_read;
324     btstack_ring_buffer_read(&em9304_spi_engine_rx_ring_buffer, buffer, num_bytes, &bytes_read);
325 }
326 
327 //////////////////////////////////////////////////////////////////////////////
328 
329 // assert pre-buffer for packet type is available
330 #if !defined(HCI_OUTGOING_PRE_BUFFER_SIZE) || (HCI_OUTGOING_PRE_BUFFER_SIZE == 0)
331 #error HCI_OUTGOING_PRE_BUFFER_SIZE not defined. Please update hci.h
332 #endif
333 
334 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size);
335 
336 typedef enum {
337     H4_W4_PACKET_TYPE,
338     H4_W4_EVENT_HEADER,
339     H4_W4_ACL_HEADER,
340     H4_W4_PAYLOAD,
341 } H4_STATE;
342 
343 typedef enum {
344     TX_IDLE = 1,
345     TX_W4_PACKET_SENT,
346 } TX_STATE;
347 
348 // write state
349 static TX_STATE tx_state;
350 
351 static uint8_t packet_sent_event[] = { HCI_EVENT_TRANSPORT_PACKET_SENT, 0};
352 
353 static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;
354 
355 // packet reader state machine
356 static H4_STATE hci_transport_em9304_h4_state;
357 static uint16_t hci_transport_em9304_spi_bytes_to_read;
358 static uint16_t hci_transport_em9304_spi_read_pos;
359 
360 // incoming packet buffer
361 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)
362 static uint8_t * hci_packet = &hci_packet_with_pre_buffer[HCI_INCOMING_PRE_BUFFER_SIZE];
363 
364 static void hci_transport_em9304_spi_block_read(void);
365 
366 static void hci_transport_em9304_spi_reset_statemachine(void){
367     hci_transport_em9304_h4_state = H4_W4_PACKET_TYPE;
368     hci_transport_em9304_spi_read_pos = 0;
369     hci_transport_em9304_spi_bytes_to_read = 1;
370 }
371 
372 static void hci_transport_em9304_spi_process_data(void){
373     while (1){
374 
375         uint16_t bytes_available = em9304_engine_num_bytes_available();
376         log_debug("transfer_rx_data: ring buffer has %u -> hci wants %u", bytes_available, hci_transport_em9304_spi_bytes_to_read);
377 
378         if (!bytes_available) break;
379         if (!hci_transport_em9304_spi_bytes_to_read) break;
380 
381         uint16_t bytes_to_copy = btstack_min(bytes_available, hci_transport_em9304_spi_bytes_to_read);
382         em9304_engine_get_bytes(&hci_packet[hci_transport_em9304_spi_read_pos], bytes_to_copy);
383 
384         hci_transport_em9304_spi_read_pos      += bytes_to_copy;
385         hci_transport_em9304_spi_bytes_to_read -= bytes_to_copy;
386 
387         if (hci_transport_em9304_spi_bytes_to_read == 0){
388             hci_transport_em9304_spi_block_read();
389         }
390     }
391 }
392 
393 static void hci_transport_em9304_spi_block_read(void){
394     switch (hci_transport_em9304_h4_state) {
395         case H4_W4_PACKET_TYPE:
396             switch (hci_packet[0]){
397                 case HCI_EVENT_PACKET:
398                     hci_transport_em9304_spi_bytes_to_read = HCI_EVENT_HEADER_SIZE;
399                     hci_transport_em9304_h4_state = H4_W4_EVENT_HEADER;
400                     break;
401                 case HCI_ACL_DATA_PACKET:
402                     hci_transport_em9304_spi_bytes_to_read = HCI_ACL_HEADER_SIZE;
403                     hci_transport_em9304_h4_state = H4_W4_ACL_HEADER;
404                     break;
405                 default:
406                     log_error("invalid packet type 0x%02x", hci_packet[0]);
407                     hci_transport_em9304_spi_reset_statemachine();
408                     break;
409             }
410             break;
411 
412         case H4_W4_EVENT_HEADER:
413             hci_transport_em9304_spi_bytes_to_read = hci_packet[2];
414             hci_transport_em9304_h4_state = H4_W4_PAYLOAD;
415             break;
416 
417         case H4_W4_ACL_HEADER:
418             hci_transport_em9304_spi_bytes_to_read = little_endian_read_16( hci_packet, 3);
419             // check ACL length
420             if (HCI_ACL_HEADER_SIZE + hci_transport_em9304_spi_bytes_to_read >  HCI_PACKET_BUFFER_SIZE){
421                 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);
422                 hci_transport_em9304_spi_reset_statemachine();
423                 break;
424             }
425             hci_transport_em9304_h4_state = H4_W4_PAYLOAD;
426             break;
427 
428         case H4_W4_PAYLOAD:
429             packet_handler(hci_packet[0], &hci_packet[1], hci_transport_em9304_spi_read_pos-1);
430             hci_transport_em9304_spi_reset_statemachine();
431             break;
432         default:
433             break;
434     }
435 }
436 
437 static void hci_transport_em9304_spi_block_sent(void){
438     switch (tx_state){
439         case TX_W4_PACKET_SENT:
440             // packet fully sent, reset state
441             tx_state = TX_IDLE;
442             // notify upper stack that it can send again
443             packet_handler(HCI_EVENT_PACKET, &packet_sent_event[0], sizeof(packet_sent_event));
444             break;
445         default:
446             break;
447     }
448 }
449 
450 static int hci_transport_em9304_spi_can_send_now(uint8_t packet_type){
451     return tx_state == TX_IDLE;
452 }
453 
454 static int hci_transport_em9304_spi_send_packet(uint8_t packet_type, uint8_t * packet, int size){
455 
456     // store packet type before actual data and increase size
457     size++;
458     packet--;
459     *packet = packet_type;
460 
461     // start sending
462     tx_state = TX_W4_PACKET_SENT;
463     em9304_spi_engine_send_block(packet, size);
464     return 0;
465 }
466 
467 static void hci_transport_em9304_spi_init(const void * transport_config){
468 }
469 
470 static int hci_transport_em9304_spi_open(void){
471 
472     // setup UART driver
473     em9304_spi_engine_init();
474     em9304_spi_engine_set_data_available(&hci_transport_em9304_spi_process_data);
475     em9304_spi_engine_set_block_sent(&hci_transport_em9304_spi_block_sent);
476     // setup H4 RX
477     hci_transport_em9304_spi_reset_statemachine();
478     // setup H4 TX
479     tx_state = TX_IDLE;
480     return 0;
481 }
482 
483 static int hci_transport_em9304_spi_close(void){
484     em9304_spi_engine_close();
485     return 0;
486 }
487 
488 static void hci_transport_em9304_spi_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
489     packet_handler = handler;
490 }
491 
492 static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
493 }
494 
495 // --- end of eHCILL implementation ---------
496 
497 static const hci_transport_t hci_transport_em9304_spi = {
498     /* const char * name; */                                        "H4",
499     /* void   (*init) (const void *transport_config); */            &hci_transport_em9304_spi_init,
500     /* int    (*open)(void); */                                     &hci_transport_em9304_spi_open,
501     /* int    (*close)(void); */                                    &hci_transport_em9304_spi_close,
502     /* void   (*register_packet_handler)(void (*handler)(...); */   &hci_transport_em9304_spi_register_packet_handler,
503     /* int    (*can_send_packet_now)(uint8_t packet_type); */       &hci_transport_em9304_spi_can_send_now,
504     /* int    (*send_packet)(...); */                               &hci_transport_em9304_spi_send_packet,
505     /* int    (*set_baudrate)(uint32_t baudrate); */                NULL,
506     /* void   (*reset_link)(void); */                               NULL,
507     /* void   (*set_sco_config)(uint16_t voice_setting, int num_connections); */ NULL,
508 };
509 
510 // configure and return h4 singleton
511 const hci_transport_t * hci_transport_em9304_spi_instance(const btstack_em9304_spi_t * em9304_spi_driver) {
512     btstack_em9304_spi = em9304_spi_driver;
513     return &hci_transport_em9304_spi;
514 }
515