diff options
Diffstat (limited to 'pit.cpp')
| -rw-r--r-- | pit.cpp | 10 |
1 files changed, 6 insertions, 4 deletions
@@ -3,6 +3,8 @@ #include "portio.hpp" #include "tasking.hpp" +constexpr std::uint32_t Frequency = 1000; + static volatile std::uint32_t ticks = 0; static void timer_callback(const Registers& regs) @@ -12,7 +14,7 @@ static void timer_callback(const Registers& regs) schedule(regs); } -void pit_initialize(std::uint32_t frequency) +void pit_initialize() { // Firstly, register our timer callback. idt_register_callback(32, timer_callback); @@ -20,7 +22,7 @@ void pit_initialize(std::uint32_t frequency) // The value we send to the PIT is the value to divide it's input clock // (1193180 Hz) by, to get our required frequency. Important to note is // that the divisor must be small enough to fit into 16-bits. - auto divisor = 1193180 / frequency; + const auto divisor = 1193180ul / Frequency; // Send the command byte. outb(0x43, 0x36); @@ -30,9 +32,9 @@ void pit_initialize(std::uint32_t frequency) outb(0x40, (divisor >> 8) & 0xFF); } -void pit_busy_wait(std::int32_t tks) +void pit_delay_ms(std::int32_t ms) { - const auto end = ticks + tks; + const auto end = ticks + ms; while (static_cast<std::int32_t>(end - ticks) > 0) asm volatile("nop"); } |