1 /*
2 * SPDX-License-Identifier: Apache-2.0
3 * Copyright (c) 2019 Intel Corp.
4 */
5
6 #include <zephyr/kernel.h>
7 #include <zephyr/device.h>
8 #include <zephyr/drivers/counter.h>
9
10 #define NR_SAMPLES 10 /* sample timer 10 times */
11
12 #if defined(CONFIG_COUNTER_CMOS)
sync(const struct device * cmos)13 static uint32_t sync(const struct device *cmos)
14 {
15 uint32_t this, last;
16 int err;
17
18 err = counter_get_value(cmos, &this);
19 if (err) {
20 printk("\tCan't read CMOS clock device.\n");
21 return 0;
22 }
23
24 do {
25 last = this;
26 err = counter_get_value(cmos, &this);
27 if (err) {
28 printk("\tCan't read CMOS clock device.\n");
29 return 0;
30 }
31 } while (last == this);
32
33 return sys_clock_cycle_get_32();
34 }
35 #endif
36
timer(void)37 void timer(void)
38 {
39 #if defined(CONFIG_APIC_TIMER)
40 printk("TIMER: new local APIC");
41 #elif defined(CONFIG_HPET_TIMER)
42 printk("TIMER: HPET");
43 #else
44 printk("TIMER: unknown");
45 #endif
46
47 printk(", configured frequency = %dHz\n",
48 sys_clock_hw_cycles_per_sec());
49
50 #if defined(CONFIG_COUNTER_CMOS)
51 const struct device *const cmos = DEVICE_DT_GET_ONE(motorola_mc146818);
52
53 if (!device_is_ready(cmos)) {
54 printk("\tCMOS clock device is not ready.\n");
55 } else {
56 uint64_t sum = 0;
57
58 printk("\tUsing CMOS RTC as reference clock:\n");
59
60 for (int i = 0; i < NR_SAMPLES; ++i) {
61 uint32_t start, end;
62
63 start = sync(cmos);
64 end = sync(cmos);
65 sum += end - start;
66
67 printk("\tstart = %u, end = %u, %u cycles\n",
68 start, end, end - start);
69 }
70
71 printk("\taverage = %uHz\n", (unsigned) (sum / NR_SAMPLES));
72 }
73 #endif
74
75 printk("\n");
76 }
77
