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#include "PS2MouseDevice.h"
#include "IO.h"
#define IRQ_MOUSE 1
#define I8042_BUFFER 0x60
#define I8042_STATUS 0x64
#define I8042_ACK 0xFA
#define I8042_BUFFER_FULL 0x01
#define I8042_WHICH_BUFFER 0x20
#define I8042_MOUSE_BUFFER 0x20
#define I8042_KEYBOARD_BUFFER 0x00
//#define PS2MOUSE_DEBUG
static PS2MouseDevice* s_the;
PS2MouseDevice::PS2MouseDevice()
: IRQHandler(12)
, CharacterDevice(10, 1)
{
s_the = this;
initialize();
}
PS2MouseDevice::~PS2MouseDevice()
{
}
PS2MouseDevice& PS2MouseDevice::the()
{
return *s_the;
}
void PS2MouseDevice::handle_irq()
{
for (;;) {
byte status = IO::in8(I8042_STATUS);
if (!(((status & I8042_WHICH_BUFFER) == I8042_MOUSE_BUFFER) && (status & I8042_BUFFER_FULL)))
return;
byte data = IO::in8(I8042_BUFFER);
m_data[m_data_state] = data;
switch (m_data_state) {
case 0:
if (!(data & 0x08)) {
dbgprintf("PS2Mouse: Stream out of sync.\n");
break;
}
++m_data_state;
break;
case 1:
++m_data_state;
break;
case 2:
m_data_state = 0;
#ifdef PS2MOUSE_DEBUG
dbgprintf("PS2Mouse: %d, %d %s %s (buffered: %u)\n",
m_data[1],
m_data[2],
(m_data[0] & 1) ? "Left" : "",
(m_data[0] & 2) ? "Right" : "",
m_queue.size()
);
#endif
parse_data_packet();
break;
}
}
}
void PS2MouseDevice::parse_data_packet()
{
int x = m_data[1];
int y = m_data[2];
bool x_overflow = m_data[0] & 0x40;
bool y_overflow = m_data[0] & 0x80;
bool x_sign = m_data[0] & 0x10;
bool y_sign = m_data[0] & 0x20;
if (x && x_sign)
x -= 0x100;
if (y && y_sign)
y -= 0x100;
if (x_overflow || y_overflow) {
x = 0;
y = 0;
}
MousePacket packet;
packet.dx = x;
packet.dy = y;
packet.buttons = m_data[0] & 0x07;
m_queue.enqueue(packet);
}
void PS2MouseDevice::wait_then_write(byte port, byte data)
{
prepare_for_output();
IO::out8(port, data);
}
byte PS2MouseDevice::wait_then_read(byte port)
{
prepare_for_input();
return IO::in8(port);
}
void PS2MouseDevice::initialize()
{
// Enable PS aux port
wait_then_write(0x64, 0xa8);
// Enable interrupts
wait_then_write(0x64, 0x20);
// Enable the PS/2 mouse IRQ (12).
// NOTE: The keyboard uses IRQ 1 (and is enabled by bit 0 in this register).
byte status = wait_then_read(0x60) | 2;
wait_then_write(0x64, 0x60);
wait_then_write(0x60, status);
// Set default settings.
mouse_write(0xf6);
byte ack1 = mouse_read();
ASSERT(ack1 == 0xfa);
// Enable.
mouse_write(0xf4);
byte ack2 = mouse_read();
ASSERT(ack2 == 0xfa);
enable_irq();
}
void PS2MouseDevice::prepare_for_input()
{
for (;;) {
if (IO::in8(0x64) & 1)
return;
}
}
void PS2MouseDevice::prepare_for_output()
{
for (;;) {
if (!(IO::in8(0x64) & 2))
return;
}
}
void PS2MouseDevice::mouse_write(byte data)
{
prepare_for_output();
IO::out8(0x64, 0xd4);
prepare_for_output();
IO::out8(0x60, data);
}
byte PS2MouseDevice::mouse_read()
{
prepare_for_input();
return IO::in8(0x60);
}
bool PS2MouseDevice::can_read(Process&) const
{
return !m_queue.is_empty();
}
ssize_t PS2MouseDevice::read(Process&, byte* buffer, ssize_t size)
{
ssize_t nread = 0;
while (nread < size) {
if (m_queue.is_empty())
break;
// Don't return partial data frames.
if ((size - nread) < (ssize_t)sizeof(MousePacket))
break;
auto packet = m_queue.dequeue();
memcpy(buffer, &packet, sizeof(MousePacket));
nread += sizeof(MousePacket);
}
return nread;
}
ssize_t PS2MouseDevice::write(Process&, const byte*, ssize_t)
{
return 0;
}
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