ladybird/Kernel/Devices/I8042Controller.cpp
Tom 91db31880f Kernel: Add I8042Controller to detect and manage PS/2 devices
Rework the PS/2 keyboard and mouse drivers to use a common 8042
controller driver. Also, reset and reconfigure the 8042 controller
as they are not guaranteed to be in the state that we expect.
2020-11-12 18:04:16 +01:00

272 lines
8.5 KiB
C++

/*
* Copyright (c) 2020, The SerenityOS developers.
* All rights reserved.
*
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#include <Kernel/ACPI/Parser.h>
#include <Kernel/Devices/KeyboardDevice.h>
#include <Kernel/Devices/PS2MouseDevice.h>
#include <Kernel/IO.h>
namespace Kernel {
static I8042Controller* s_the;
void I8042Controller::initialize()
{
if (ACPI::Parser::the()->have_8042())
new I8042Controller;
}
I8042Controller& I8042Controller::the()
{
ASSERT(s_the);
return *s_the;
}
I8042Controller::I8042Controller()
{
ASSERT(!s_the);
s_the = this;
u8 configuration;
{
ScopedSpinLock lock(m_lock);
// Disable devices
do_wait_then_write(I8042_STATUS, 0xad);
do_wait_then_write(I8042_STATUS, 0xa7); // ignored if it doesn't exist
// Drain buffers
do_drain();
do_wait_then_write(I8042_STATUS, 0x20);
configuration = do_wait_then_read(I8042_BUFFER);
do_wait_then_write(I8042_STATUS, 0x60);
configuration &= ~3; // Disable IRQs for all
do_wait_then_write(I8042_BUFFER, configuration);
m_is_dual_channel = (configuration & (1 << 5)) != 0;
dbg() << "I8042: " << (m_is_dual_channel ? "Dual" : "Single") << " channel controller";
// Perform controller self-test
do_wait_then_write(I8042_STATUS, 0xaa);
if (do_wait_then_read(I8042_BUFFER) == 0x55) {
// Restore configuration in case the controller reset
do_wait_then_write(I8042_STATUS, 0x60);
do_wait_then_write(I8042_BUFFER, configuration);
} else {
dbg() << "I8042: Controller self test failed";
}
// Test ports and enable them if available
do_wait_then_write(I8042_STATUS, 0xab); // test
m_devices[0].available = (do_wait_then_read(I8042_BUFFER) == 0);
if (m_devices[0].available) {
do_wait_then_write(I8042_STATUS, 0xae); //enable
configuration |= 1;
configuration &= ~(1 << 4);
} else {
dbg() << "I8042: Keyboard port not available";
}
if (m_is_dual_channel) {
do_wait_then_write(I8042_STATUS, 0xa9); // test
m_devices[1].available = (do_wait_then_read(I8042_BUFFER) == 0);
if (m_devices[1].available) {
do_wait_then_write(I8042_STATUS, 0xa8); // enable
configuration |= 2;
configuration &= ~(1 << 5);
} else {
dbg() << "I8042: Mouse port not available";
}
}
// Enable IRQs for the ports that are usable
if (m_devices[0].available || m_devices[1].available) {
configuration &= ~0x30; // renable clocks
do_wait_then_write(I8042_STATUS, 0x60);
do_wait_then_write(I8042_BUFFER, configuration);
}
}
// Try to detect and initialize the devices
if (m_devices[0].available) {
if (KeyboardDevice::the().initialize()) {
m_devices[0].device = &KeyboardDevice::the();
} else {
dbg() << "I8042: Keyboard device failed to initialize, disable";
m_devices[0].available = false;
configuration &= ~1;
configuration |= 1 << 4;
ScopedSpinLock lock(m_lock);
do_wait_then_write(I8042_STATUS, 0x60);
do_wait_then_write(I8042_BUFFER, configuration);
}
}
if (m_devices[1].available) {
if (PS2MouseDevice::the().initialize()) {
m_devices[1].device = &PS2MouseDevice::the();
} else {
dbg() << "I8042: Mouse device failed to initialize, disable";
m_devices[1].available = false;
configuration |= 1 << 5;
ScopedSpinLock lock(m_lock);
do_wait_then_write(I8042_STATUS, 0x60);
do_wait_then_write(I8042_BUFFER, configuration);
}
}
// Enable IRQs after both are detected and initialized
if (m_devices[0].device)
m_devices[0].device->enable_interrupts();
if (m_devices[1].device)
m_devices[1].device->enable_interrupts();
}
void I8042Controller::irq_process_input_buffer(Device)
{
ASSERT(Processor::current().in_irq());
u8 status = IO::in8(I8042_STATUS);
if (!(status & I8042_BUFFER_FULL))
return;
Device data_for_device = ((status & I8042_WHICH_BUFFER) == I8042_MOUSE_BUFFER) ? Device::Mouse : Device::Keyboard;
u8 byte = IO::in8(I8042_BUFFER);
if (auto* device = m_devices[data_for_device == Device::Keyboard ? 0 : 1].device)
device->irq_handle_byte_read(byte);
}
void I8042Controller::do_drain()
{
for (;;) {
u8 status = IO::in8(I8042_STATUS);
if (!(status & I8042_BUFFER_FULL))
return;
IO::in8(I8042_BUFFER);
}
}
bool I8042Controller::do_reset_device(Device device)
{
ASSERT(device != Device::None);
ASSERT(m_lock.is_locked());
ASSERT(!Processor::current().in_irq());
if (do_send_command(device, 0xff) != I8042_ACK)
return false;
// Wait until we get the self-test result
return do_wait_then_read(I8042_BUFFER) == 0xaa;
}
u8 I8042Controller::do_send_command(Device device, u8 command)
{
ASSERT(device != Device::None);
ASSERT(m_lock.is_locked());
ASSERT(!Processor::current().in_irq());
return do_write_to_device(device, command);
}
u8 I8042Controller::do_send_command(Device device, u8 command, u8 data)
{
ASSERT(device != Device::None);
ASSERT(m_lock.is_locked());
ASSERT(!Processor::current().in_irq());
u8 response = do_write_to_device(device, command);
if (response == I8042_ACK)
response = do_write_to_device(device, data);
return response;
}
u8 I8042Controller::do_write_to_device(Device device, u8 data)
{
ASSERT(device != Device::None);
ASSERT(m_lock.is_locked());
ASSERT(!Processor::current().in_irq());
int attempts = 0;
u8 response;
do {
if (device != Device::Keyboard) {
prepare_for_output();
IO::out8(I8042_STATUS, 0xd4);
}
prepare_for_output();
IO::out8(I8042_BUFFER, data);
response = do_wait_then_read(I8042_BUFFER);
} while (response == I8042_RESEND && ++attempts < 3);
if (attempts >= 3)
dbg() << "Failed to write byte to device, gave up";
return response;
}
u8 I8042Controller::do_read_from_device(Device device)
{
ASSERT(device != Device::None);
prepare_for_input(device);
return IO::in8(I8042_BUFFER);
}
void I8042Controller::prepare_for_input(Device device)
{
ASSERT(m_lock.is_locked());
const u8 buffer_type = device == Device::Keyboard ? I8042_KEYBOARD_BUFFER : I8042_MOUSE_BUFFER;
for (;;) {
u8 status = IO::in8(I8042_STATUS);
if ((status & I8042_BUFFER_FULL) && (device == Device::None || ((status & I8042_WHICH_BUFFER) == buffer_type)))
return;
}
}
void I8042Controller::prepare_for_output()
{
ASSERT(m_lock.is_locked());
for (;;) {
if (!(IO::in8(I8042_STATUS) & 2))
return;
}
}
void I8042Controller::do_wait_then_write(u8 port, u8 data)
{
ASSERT(m_lock.is_locked());
prepare_for_output();
IO::out8(port, data);
}
u8 I8042Controller::do_wait_then_read(u8 port)
{
ASSERT(m_lock.is_locked());
prepare_for_input(Device::None);
return IO::in8(port);
}
}