xref: /btstack/platform/embedded/btstack_run_loop_embedded.c (revision 7907f06931c075b55e3402fa469abbe35eebee25)
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 /*
39  *  btstack_run_loop_embedded.c
40  *
41  *  For this run loop, we assume that there's no global way to wait for a list
42  *  of data sources to get ready. Instead, each data source has to queried
43  *  individually. Calling ds->isReady() before calling ds->process() doesn't
44  *  make sense, so we just poll each data source round robin.
45  *
46  *  To support an idle state, where an MCU could go to sleep, the process function
47  *  has to return if it has to called again as soon as possible
48  *
49  *  After calling process() on every data source and evaluating the pending timers,
50  *  the idle hook gets called if no data source did indicate that it needs to be
51  *  called right away.
52  *
53  */
54 
55 
56 #include "btstack_run_loop.h"
57 #include "btstack_run_loop_embedded.h"
58 #include "btstack_linked_list.h"
59 #include "hal_tick.h"
60 #include "hal_cpu.h"
61 
62 #include "btstack_debug.h"
63 
64 #include <stddef.h> // NULL
65 
66 #ifdef HAVE_TIME_MS
67 #include "hal_time_ms.h"
68 #endif
69 
70 #if defined(HAVE_TICK) && defined(HAVE_TIME_MS)
71 #error "Please specify either HAVE_TICK or HAVE_TIME_MS"
72 #endif
73 
74 #if defined(HAVE_TICK) || defined(HAVE_TIME_MS)
75 #define TIMER_SUPPORT
76 #endif
77 
78 static const btstack_run_loop_t btstack_run_loop_embedded;
79 
80 // the run loop
81 static btstack_linked_list_t data_sources;
82 
83 #ifdef TIMER_SUPPORT
84 static btstack_linked_list_t timers;
85 #endif
86 
87 #ifdef HAVE_TICK
88 static volatile uint32_t system_ticks;
89 #endif
90 
91 static int trigger_event_received = 0;
92 
93 /**
94  * Add data_source to run_loop
95  */
96 static void btstack_run_loop_embedded_add_data_source(btstack_data_source_t *ds){
97     btstack_linked_list_add(&data_sources, (btstack_linked_item_t *) ds);
98 }
99 
100 /**
101  * Remove data_source from run loop
102  */
103 static int btstack_run_loop_embedded_remove_data_source(btstack_data_source_t *ds){
104     return btstack_linked_list_remove(&data_sources, (btstack_linked_item_t *) ds);
105 }
106 
107 // set timer
108 static void btstack_run_loop_embedded_set_timer(btstack_timer_source_t *ts, uint32_t timeout_in_ms){
109 #ifdef HAVE_TICK
110     uint32_t ticks = btstack_run_loop_embedded_ticks_for_ms(timeout_in_ms);
111     if (ticks == 0) ticks++;
112     // time until next tick is < hal_tick_get_tick_period_in_ms() and we don't know, so we add one
113     ts->timeout = system_ticks + 1 + ticks;
114 #endif
115 #ifdef HAVE_TIME_MS
116     ts->timeout = hal_time_ms() + timeout_in_ms + 1;
117 #endif
118 }
119 
120 /**
121  * Add timer to run_loop (keep list sorted)
122  */
123 static void btstack_run_loop_embedded_add_timer(btstack_timer_source_t *ts){
124 #ifdef TIMER_SUPPORT
125     btstack_linked_item_t *it;
126     for (it = (btstack_linked_item_t *) &timers; it->next ; it = it->next){
127         // don't add timer that's already in there
128         if ((btstack_timer_source_t *) it->next == ts){
129             log_error( "btstack_run_loop_timer_add error: timer to add already in list!");
130             return;
131         }
132         if (ts->timeout < ((btstack_timer_source_t *) it->next)->timeout) {
133             break;
134         }
135     }
136     ts->item.next = it->next;
137     it->next = (btstack_linked_item_t *) ts;
138 #endif
139 }
140 
141 /**
142  * Remove timer from run loop
143  */
144 static int btstack_run_loop_embedded_remove_timer(btstack_timer_source_t *ts){
145 #ifdef TIMER_SUPPORT
146     return btstack_linked_list_remove(&timers, (btstack_linked_item_t *) ts);
147 #else
148     return 0;
149 #endif
150 }
151 
152 static void btstack_run_loop_embedded_dump_timer(void){
153 #ifdef TIMER_SUPPORT
154 #ifdef ENABLE_LOG_INFO
155     btstack_linked_item_t *it;
156     int i = 0;
157     for (it = (btstack_linked_item_t *) timers; it ; it = it->next){
158         btstack_timer_source_t *ts = (btstack_timer_source_t*) it;
159         log_info("timer %u, timeout %u\n", i, (unsigned int) ts->timeout);
160     }
161 #endif
162 #endif
163 }
164 
165 /**
166  * Execute run_loop once
167  */
168 void btstack_run_loop_embedded_execute_once(void) {
169     btstack_data_source_t *ds;
170 
171     // process data sources
172     btstack_data_source_t *next;
173     for (ds = (btstack_data_source_t *) data_sources; ds != NULL ; ds = next){
174         next = (btstack_data_source_t *) ds->item.next; // cache pointer to next data_source to allow data source to remove itself
175         ds->process(ds);
176     }
177 
178 #ifdef HAVE_TICK
179     uint32_t now = system_ticks;
180 #endif
181 #ifdef HAVE_TIME_MS
182     uint32_t now = hal_time_ms();
183 #endif
184 #ifdef TIMER_SUPPORT
185     // process timers
186     while (timers) {
187         btstack_timer_source_t *ts = (btstack_timer_source_t *) timers;
188         if (ts->timeout > now) break;
189         btstack_run_loop_remove_timer(ts);
190         ts->process(ts);
191     }
192 #endif
193 
194     // disable IRQs and check if run loop iteration has been requested. if not, go to sleep
195     hal_cpu_disable_irqs();
196     if (trigger_event_received){
197         trigger_event_received = 0;
198         hal_cpu_enable_irqs();
199     } else {
200         hal_cpu_enable_irqs_and_sleep();
201     }
202 }
203 
204 /**
205  * Execute run_loop
206  */
207 static void btstack_run_loop_embedded_execute(void) {
208     while (1) {
209         btstack_run_loop_embedded_execute_once();
210     }
211 }
212 
213 #ifdef HAVE_TICK
214 static void btstack_run_loop_embedded_tick_handler(void){
215     system_ticks++;
216     trigger_event_received = 1;
217 }
218 
219 uint32_t btstack_run_loop_embedded_get_ticks(void){
220     return system_ticks;
221 }
222 
223 uint32_t btstack_run_loop_embedded_ticks_for_ms(uint32_t time_in_ms){
224     return time_in_ms / hal_tick_get_tick_period_in_ms();
225 }
226 #endif
227 
228 static uint32_t btstack_run_loop_embedded_get_time_ms(void){
229 #ifdef HAVE_TIME_MS
230     return hal_time_ms();
231 #endif
232 #ifdef HAVE_TICK
233     return system_ticks * hal_tick_get_tick_period_in_ms();
234 #endif
235     return 0;
236 }
237 
238 
239 /**
240  * trigger run loop iteration
241  */
242 void btstack_run_loop_embedded_trigger(void){
243     trigger_event_received = 1;
244 }
245 
246 static void btstack_run_loop_embedded_init(void){
247     data_sources = NULL;
248 
249 #ifdef TIMER_SUPPORT
250     timers = NULL;
251 #endif
252 
253 #ifdef HAVE_TICK
254     system_ticks = 0;
255     hal_tick_init();
256     hal_tick_set_handler(&btstack_run_loop_embedded_tick_handler);
257 #endif
258 }
259 
260 /**
261  * Provide btstack_run_loop_embedded instance
262  */
263 const btstack_run_loop_t * btstack_run_loop_embedded_get_instance(void){
264     return &btstack_run_loop_embedded;
265 }
266 
267 static const btstack_run_loop_t btstack_run_loop_embedded = {
268     &btstack_run_loop_embedded_init,
269     &btstack_run_loop_embedded_add_data_source,
270     &btstack_run_loop_embedded_remove_data_source,
271     &btstack_run_loop_embedded_set_timer,
272     &btstack_run_loop_embedded_add_timer,
273     &btstack_run_loop_embedded_remove_timer,
274     &btstack_run_loop_embedded_execute,
275     &btstack_run_loop_embedded_dump_timer,
276     &btstack_run_loop_embedded_get_time_ms,
277 };
278