1 /*
2 * Copyright (C) 2020 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 BLUEKITCHEN
24 * GMBH 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__ "hal_timer_nrf5.c"
39
40 /*
41 * hal_timer.c
42 * HAL for 32.768 kHz low power timer with 16 bit resolution
43 * @note Only uses one of multiple RTCs and only a single Capture-Compare unit
44 */
45
46 #include <stddef.h>
47
48 #include "hal_timer.h"
49 #include "btstack_debug.h"
50
51 #include "nrf.h"
52
53 static void (*hal_timer_callback)(void);
54
RTC0_IRQHandler(void)55 void RTC0_IRQHandler(void){
56 if (NRF_RTC0->EVENTS_COMPARE[0]){
57 NRF_RTC0->EVENTS_COMPARE[0] = 0;
58 btstack_assert(hal_timer_callback != NULL);
59 (*hal_timer_callback)();
60 }
61 }
62
hal_timer_init(void)63 void hal_timer_init(void) {
64 /* Stop the timer first */
65 NRF_RTC0->TASKS_STOP = 1;
66 NRF_RTC0->TASKS_CLEAR = 1;
67
68 /* Always no prescaler */
69 NRF_RTC0->PRESCALER = 0;
70
71 /* Clear overflow events and set overflow interrupt */
72 NRF_RTC0->EVENTS_OVRFLW = 0;
73 NRF_RTC0->INTENSET = RTC_INTENSET_OVRFLW_Msk;
74
75 /* Start the timer */
76 NRF_RTC0->TASKS_START = 1;
77
78 /* Set isr in vector table and enable interrupt */
79 NVIC_EnableIRQ( RTC0_IRQn );
80 }
81
hal_timer_set_callback(void (* callback)(void))82 void hal_timer_set_callback(void (*callback)(void)){
83 hal_timer_callback = callback;
84 }
85
hal_timer_get_ticks(void)86 uint32_t hal_timer_get_ticks(void){
87 return NRF_RTC0->COUNTER;
88 }
89
hal_timer_stop(void)90 void hal_timer_stop(void){
91 NRF_RTC0->INTENCLR =RTC_INTENCLR_COMPARE0_Msk;
92 }
93
hal_timer_start(uint32_t timeout_ticks)94 void hal_timer_start(uint32_t timeout_ticks){
95 NRF_RTC0->CC[0] = timeout_ticks & 0x00ffffff;
96 NRF_RTC0->EVENTS_COMPARE[0] = 0;
97 NRF_RTC0->INTENSET =RTC_INTENSET_COMPARE0_Msk;
98 }
99