blob: 6ea4ce03bd3ceef5a83f95724d3f8564465dbda7 (
plain)
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
|
/*
* Copyright (c) 2021, Nico Weber <thakis@chromium.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Format.h>
#include <Kernel/Arch/aarch64/RPi/MMIO.h>
#include <Kernel/Arch/aarch64/RPi/Mailbox.h>
#include <Kernel/Arch/aarch64/RPi/Timer.h>
namespace Prekernel {
// "12.1 System Timer Registers" / "10.2 System Timer Registers"
struct TimerRegisters {
u32 control_and_status;
u32 counter_low;
u32 counter_high;
u32 compare[4];
};
// Bits of the `control_and_status` register.
// See "CS register" in Broadcom doc for details.
enum FlagBits {
SystemTimerMatch0 = 1 << 0,
SystemTimerMatch1 = 1 << 1,
SystemTimerMatch2 = 1 << 2,
SystemTimerMatch3 = 1 << 3,
};
Timer::Timer()
: m_registers(MMIO::the().peripheral<TimerRegisters>(0x3000))
{
}
Timer& Timer::the()
{
static Timer instance;
return instance;
}
u64 Timer::microseconds_since_boot()
{
u32 high = m_registers->counter_high;
u32 low = m_registers->counter_low;
if (high != m_registers->counter_high) {
high = m_registers->counter_high;
low = m_registers->counter_low;
}
return (static_cast<u64>(high) << 32) | low;
}
class SetClockRateMboxMessage : Prekernel::Mailbox::Message {
public:
u32 clock_id;
u32 rate_hz;
u32 skip_setting_turbo;
SetClockRateMboxMessage()
: Prekernel::Mailbox::Message(0x0003'8002, 12)
{
clock_id = 0;
rate_hz = 0;
skip_setting_turbo = 0;
}
};
u32 Timer::set_clock_rate(ClockID clock_id, u32 rate_hz, bool skip_setting_turbo)
{
struct __attribute__((aligned(16))) {
Prekernel::Mailbox::MessageHeader header;
SetClockRateMboxMessage set_clock_rate;
Prekernel::Mailbox::MessageTail tail;
} message_queue;
message_queue.set_clock_rate.clock_id = static_cast<u32>(clock_id);
message_queue.set_clock_rate.rate_hz = rate_hz;
message_queue.set_clock_rate.skip_setting_turbo = skip_setting_turbo ? 1 : 0;
if (!Prekernel::Mailbox::the().send_queue(&message_queue, sizeof(message_queue))) {
dbgln("Timer::set_clock_rate() failed!");
return 0;
}
return message_queue.set_clock_rate.rate_hz;
}
}
|
