1 /*
2 * Copyright (c) 2017-2019 Oticon A/S
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 /**
8 * Driver for the native_sim board timer
9 * It provides the same API required by the kernel as any other timer driver
10 */
11 #include <zephyr/types.h>
12 #include <zephyr/irq.h>
13 #include <zephyr/init.h>
14 #include <zephyr/drivers/timer/system_timer.h>
15 #include <zephyr/sys_clock.h>
16 #include "nsi_hw_scheduler.h"
17 #include "nsi_timer_model.h"
18 #include "soc.h"
19
20 static uint64_t tick_period; /* System tick period in microseconds */
21 /* Time (microseconds since boot) of the last timer tick interrupt */
22 static uint64_t last_tick_time;
23
24 /**
25 * Return the current HW cycle counter
26 * (number of microseconds since boot in 32bits)
27 */
sys_clock_cycle_get_32(void)28 uint32_t sys_clock_cycle_get_32(void)
29 {
30 return nsi_hws_get_time();
31 }
32
sys_clock_cycle_get_64(void)33 uint64_t sys_clock_cycle_get_64(void)
34 {
35 return nsi_hws_get_time();
36 }
37
38 /**
39 * Interrupt handler for the timer interrupt
40 * Announce to the kernel that a number of ticks have passed
41 */
np_timer_isr(const void * arg)42 static void np_timer_isr(const void *arg)
43 {
44 ARG_UNUSED(arg);
45
46 uint64_t now = nsi_hws_get_time();
47 int32_t elapsed_ticks = (now - last_tick_time)/tick_period;
48
49 last_tick_time += elapsed_ticks*tick_period;
50 sys_clock_announce(elapsed_ticks);
51 }
52
53 /**
54 * This function exists only to enable tests to call into the timer ISR
55 */
np_timer_isr_test_hook(const void * arg)56 void np_timer_isr_test_hook(const void *arg)
57 {
58 np_timer_isr(NULL);
59 }
60
61 /**
62 * @brief Set system clock timeout
63 *
64 * Informs the system clock driver that the next needed call to
65 * sys_clock_announce() will not be until the specified number of ticks
66 * from the current time have elapsed.
67 *
68 * See system_timer.h for more information
69 *
70 * @param ticks Timeout in tick units
71 * @param idle Hint to the driver that the system is about to enter
72 * the idle state immediately after setting the timeout
73 */
sys_clock_set_timeout(int32_t ticks,bool idle)74 void sys_clock_set_timeout(int32_t ticks, bool idle)
75 {
76 ARG_UNUSED(idle);
77
78 #if defined(CONFIG_TICKLESS_KERNEL)
79 uint64_t silent_ticks;
80
81 /* Note that we treat INT_MAX literally as anyhow the maximum amount of
82 * ticks we can report with sys_clock_announce() is INT_MAX
83 */
84 if (ticks == K_TICKS_FOREVER) {
85 silent_ticks = INT64_MAX;
86 } else if (ticks > 0) {
87 silent_ticks = ticks - 1;
88 } else {
89 silent_ticks = 0;
90 }
91 hwtimer_set_silent_ticks(silent_ticks);
92 #endif
93 }
94
95 /**
96 * @brief Ticks elapsed since last sys_clock_announce() call
97 *
98 * Queries the clock driver for the current time elapsed since the
99 * last call to sys_clock_announce() was made. The kernel will call
100 * this with appropriate locking, the driver needs only provide an
101 * instantaneous answer.
102 */
sys_clock_elapsed(void)103 uint32_t sys_clock_elapsed(void)
104 {
105 return (nsi_hws_get_time() - last_tick_time)/tick_period;
106 }
107
108 /**
109 * @brief Stop announcing sys ticks into the kernel
110 *
111 * Disable the system ticks generation
112 */
sys_clock_disable(void)113 void sys_clock_disable(void)
114 {
115 irq_disable(TIMER_TICK_IRQ);
116 hwtimer_set_silent_ticks(INT64_MAX);
117 }
118
119 /**
120 * @brief Initialize system timer driver
121 *
122 * Enable the hw timer, setting its tick period, and setup its interrupt
123 */
sys_clock_driver_init(void)124 static int sys_clock_driver_init(void)
125 {
126
127 tick_period = 1000000ul / CONFIG_SYS_CLOCK_TICKS_PER_SEC;
128
129 last_tick_time = nsi_hws_get_time();
130 hwtimer_enable(tick_period);
131
132 IRQ_CONNECT(TIMER_TICK_IRQ, 1, np_timer_isr, 0, 0);
133 irq_enable(TIMER_TICK_IRQ);
134
135 return 0;
136 }
137
138 SYS_INIT(sys_clock_driver_init, PRE_KERNEL_2,
139 CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);
140
