1 /*
2 * Copyright (c) 2017-2019 Oticon A/S
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 /**
8 * Driver for the timer model of the POSIX native_sim/posix board
9 * It provides the interfaces required by the kernel and the sanity testcases
10 * It also provides a custom k_busy_wait() which can be used with the
11 * POSIX arch and InfClock SOC
12 */
13 #include <zephyr/types.h>
14 #include <zephyr/irq.h>
15 #include <zephyr/init.h>
16 #include <zephyr/drivers/timer/system_timer.h>
17 #include <zephyr/sys_clock.h>
18 #include "timer_model.h"
19 #include "soc.h"
20 #include <zephyr/arch/posix/posix_trace.h>
21
22 static uint64_t tick_period; /* System tick period in microseconds */
23 /* Time (microseconds since boot) of the last timer tick interrupt */
24 static uint64_t last_tick_time;
25
26 /**
27 * Return the current HW cycle counter
28 * (number of microseconds since boot in 32bits)
29 */
sys_clock_cycle_get_32(void)30 uint32_t sys_clock_cycle_get_32(void)
31 {
32 return hwm_get_time();
33 }
34
sys_clock_cycle_get_64(void)35 uint64_t sys_clock_cycle_get_64(void)
36 {
37 return hwm_get_time();
38 }
39
40 /**
41 * Interrupt handler for the timer interrupt
42 * Announce to the kernel that a number of ticks have passed
43 */
np_timer_isr(const void * arg)44 static void np_timer_isr(const void *arg)
45 {
46 ARG_UNUSED(arg);
47
48 uint64_t now = hwm_get_time();
49 int32_t elapsed_ticks = (now - last_tick_time)/tick_period;
50
51 last_tick_time += elapsed_ticks*tick_period;
52 sys_clock_announce(elapsed_ticks);
53 }
54
55 /**
56 * This function exists only to enable tests to call into the timer ISR
57 */
np_timer_isr_test_hook(const void * arg)58 void np_timer_isr_test_hook(const void *arg)
59 {
60 np_timer_isr(NULL);
61 }
62
63 /**
64 * @brief Set system clock timeout
65 *
66 * Informs the system clock driver that the next needed call to
67 * sys_clock_announce() will not be until the specified number of ticks
68 * from the the current time have elapsed.
69 *
70 * See system_timer.h for more information
71 *
72 * @param ticks Timeout in tick units
73 * @param idle Hint to the driver that the system is about to enter
74 * the idle state immediately after setting the timeout
75 */
sys_clock_set_timeout(int32_t ticks,bool idle)76 void sys_clock_set_timeout(int32_t ticks, bool idle)
77 {
78 ARG_UNUSED(idle);
79
80 #if defined(CONFIG_TICKLESS_KERNEL)
81 uint64_t silent_ticks;
82
83 /* Note that we treat INT_MAX literally as anyhow the maximum amount of
84 * ticks we can report with sys_clock_announce() is INT_MAX
85 */
86 if (ticks == K_TICKS_FOREVER) {
87 silent_ticks = INT64_MAX;
88 } else if (ticks > 0) {
89 silent_ticks = ticks - 1;
90 } else {
91 silent_ticks = 0;
92 }
93 hwtimer_set_silent_ticks(silent_ticks);
94 #endif
95 }
96
97 /**
98 * @brief Ticks elapsed since last sys_clock_announce() call
99 *
100 * Queries the clock driver for the current time elapsed since the
101 * last call to sys_clock_announce() was made. The kernel will call
102 * this with appropriate locking, the driver needs only provide an
103 * instantaneous answer.
104 */
sys_clock_elapsed(void)105 uint32_t sys_clock_elapsed(void)
106 {
107 return (hwm_get_time() - last_tick_time)/tick_period;
108 }
109
110 /**
111 * @brief Stop announcing sys ticks into the kernel
112 *
113 * Disable the system ticks generation
114 */
sys_clock_disable(void)115 void sys_clock_disable(void)
116 {
117 irq_disable(TIMER_TICK_IRQ);
118 hwtimer_set_silent_ticks(INT64_MAX);
119 }
120
121 /**
122 * @brief Initialize system timer driver
123 *
124 * Enable the hw timer, setting its tick period, and setup its interrupt
125 */
sys_clock_driver_init(void)126 static int sys_clock_driver_init(void)
127 {
128
129 tick_period = 1000000ul / CONFIG_SYS_CLOCK_TICKS_PER_SEC;
130
131 last_tick_time = hwm_get_time();
132 hwtimer_enable(tick_period);
133
134 IRQ_CONNECT(TIMER_TICK_IRQ, 1, np_timer_isr, 0, 0);
135 irq_enable(TIMER_TICK_IRQ);
136
137 return 0;
138 }
139
140 SYS_INIT(sys_clock_driver_init, PRE_KERNEL_2,
141 CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);
142
