1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/**
* @file
*
* @ingroup bsp_clock
*
* @brief riscv clock support.
*/
/*
* riscv_generic Clock driver
*
* COPYRIGHT (c) 2015 Hesham Alatary <hesham@alumni.york.ac.uk>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <rtems.h>
#include <bsp.h>
#include <bsp/irq.h>
#include <rtems/score/riscv-utility.h>
#include <rtems/score/cpu.h>
#include <rtems/timecounter.h>
/* The number of clock cycles before generating a tick timer interrupt. */
#define TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT 1000
#define RISCV_CLOCK_CYCLE_TIME_NANOSECONDS 1
static struct timecounter riscv_generic_tc;
/* CPU counter */
static CPU_Counter_ticks cpu_counter_ticks;
/* This prototype is added here to Avoid warnings */
void Clock_isr(void *arg);
static void riscv_generic_clock_at_tick(void)
{
REG(MTIME_MM) = 0;
REG(MTIMECMP_MM) = TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT;
cpu_counter_ticks += TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT * 10000;
}
static void riscv_generic_clock_handler_install(proc_ptr new_isr)
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
_CPU_ISR_install_vector(RISCV_MACHINE_TIMER_INTERRUPT,
new_isr,
NULL);
if (sc != RTEMS_SUCCESSFUL) {
rtems_fatal_error_occurred(0xdeadbeef);
}
}
static uint32_t riscv_generic_get_timecount(struct timecounter *tc)
{
uint32_t ticks_since_last_timer_interrupt = REG(MTIME_MM);
return cpu_counter_ticks + ticks_since_last_timer_interrupt;
}
CPU_Counter_ticks _CPU_Counter_read(void)
{
return riscv_generic_get_timecount(NULL);
}
static void riscv_generic_clock_initialize(void)
{
uint32_t mtimecmp = TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT;
uint64_t frequency = (1000000000 / RISCV_CLOCK_CYCLE_TIME_NANOSECONDS);
REG(MTIME_MM) = 0;
REG(MTIMECMP_MM) = TTMR_NUM_OF_CLOCK_TICKS_INTERRUPT;
/* Enable mtimer interrupts */
set_csr(mie, MIP_MTIP);
set_csr(mip, MIP_MTIP);
/* Initialize timecounter */
riscv_generic_tc.tc_get_timecount = riscv_generic_get_timecount;
riscv_generic_tc.tc_counter_mask = 0xffffffff;
riscv_generic_tc.tc_frequency = frequency;
riscv_generic_tc.tc_quality = RTEMS_TIMECOUNTER_QUALITY_CLOCK_DRIVER;
rtems_timecounter_install(&riscv_generic_tc);
}
static void riscv_generic_clock_cleanup(void)
{
/* Disable mtimer interrupts */
clear_csr(mie, MIP_MTIP);
clear_csr(mip, MIP_MTIP);
}
CPU_Counter_ticks _CPU_Counter_difference(
CPU_Counter_ticks second,
CPU_Counter_ticks first
)
{
return second - first;
}
#define Clock_driver_support_at_tick() riscv_generic_clock_at_tick()
#define Clock_driver_support_initialize_hardware() riscv_generic_clock_initialize()
#define Clock_driver_support_install_isr(isr) \
riscv_generic_clock_handler_install(isr)
#define Clock_driver_support_shutdown_hardware() riscv_generic_clock_cleanup()
#include "../../../shared/dev/clock/clockimpl.h"
|
