ladybird/Kernel/Devices/PS2MouseDevice.cpp
Andreas Kling 1b2ef8582c Kernel: Make File's can_read/can_write take a const FileDescription&
Asking a File if we could possibly read or write it will never mutate
the asking FileDescription&, so it should be const.
2019-11-04 14:03:14 +01:00

282 lines
6.4 KiB
C++

#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_SET_RESOLUTION 0xE8
#define PS2MOUSE_STATUS_REQUEST 0xE9
#define PS2MOUSE_REQUEST_SINGLE_PACKET 0xEB
#define PS2MOUSE_GET_DEVICE_ID 0xF2
#define PS2MOUSE_SET_SAMPLE_RATE 0xF3
#define PS2MOUSE_ENABLE_PACKET_STREAMING 0xF4
#define PS2MOUSE_DISABLE_PACKET_STREAMING 0xF5
#define PS2MOUSE_SET_DEFAULTS 0xF6
#define PS2MOUSE_RESEND 0xFE
#define PS2MOUSE_RESET 0xFF
#define PS2MOUSE_INTELLIMOUSE_ID 0x03
//#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 (;;) {
u8 status = IO::in8(I8042_STATUS);
if (!(((status & I8042_WHICH_BUFFER) == I8042_MOUSE_BUFFER) && (status & I8042_BUFFER_FULL)))
return;
u8 data = IO::in8(I8042_BUFFER);
m_data[m_data_state] = data;
auto commit_packet = [&] {
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();
};
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:
if (m_has_wheel) {
++m_data_state;
break;
}
commit_packet();
break;
case 3:
ASSERT(m_has_wheel);
commit_packet();
break;
}
}
}
void PS2MouseDevice::parse_data_packet()
{
int x = m_data[1];
int y = m_data[2];
int z = 0;
if (m_has_wheel)
z = (char)m_data[3];
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.dz = z;
packet.buttons = m_data[0] & 0x07;
m_queue.enqueue(packet);
}
void PS2MouseDevice::wait_then_write(u8 port, u8 data)
{
prepare_for_output();
IO::out8(port, data);
}
u8 PS2MouseDevice::wait_then_read(u8 port)
{
prepare_for_input();
return IO::in8(port);
}
void PS2MouseDevice::initialize()
{
// Enable PS aux port
wait_then_write(I8042_STATUS, 0xa8);
check_device_presence();
if (m_device_present)
initialize_device();
}
void PS2MouseDevice::check_device_presence()
{
mouse_write(PS2MOUSE_REQUEST_SINGLE_PACKET);
u8 maybe_ack = mouse_read();
if (maybe_ack == I8042_ACK) {
m_device_present = true;
kprintf("PS2MouseDevice: Device detected\n");
// the mouse will send a packet of data, since that's what we asked
// for. we don't care about the content.
mouse_read();
mouse_read();
mouse_read();
} else {
m_device_present = false;
kprintf("PS2MouseDevice: Device not detected\n");
}
}
void PS2MouseDevice::initialize_device()
{
if (!m_device_present)
return;
// Enable interrupts
wait_then_write(I8042_STATUS, 0x20);
// Enable the PS/2 mouse IRQ (12).
// NOTE: The keyboard uses IRQ 1 (and is enabled by bit 0 in this register).
u8 status = wait_then_read(I8042_BUFFER) | 2;
wait_then_write(I8042_STATUS, 0x60);
wait_then_write(I8042_BUFFER, status);
// Set default settings.
mouse_write(PS2MOUSE_SET_DEFAULTS);
expect_ack();
// Enable.
mouse_write(PS2MOUSE_ENABLE_PACKET_STREAMING);
expect_ack();
mouse_write(PS2MOUSE_GET_DEVICE_ID);
expect_ack();
u8 device_id = mouse_read();
if (device_id != PS2MOUSE_INTELLIMOUSE_ID) {
// Send magical wheel initiation sequence.
mouse_write(PS2MOUSE_SET_SAMPLE_RATE);
expect_ack();
mouse_write(200);
expect_ack();
mouse_write(PS2MOUSE_SET_SAMPLE_RATE);
expect_ack();
mouse_write(100);
expect_ack();
mouse_write(PS2MOUSE_SET_SAMPLE_RATE);
expect_ack();
mouse_write(80);
expect_ack();
mouse_write(PS2MOUSE_GET_DEVICE_ID);
expect_ack();
device_id = mouse_read();
}
if (device_id == PS2MOUSE_INTELLIMOUSE_ID) {
m_has_wheel = true;
kprintf("PS2MouseDevice: Mouse wheel enabled!\n");
} else {
kprintf("PS2MouseDevice: No mouse wheel detected!\n");
}
enable_irq();
}
void PS2MouseDevice::expect_ack()
{
u8 data = mouse_read();
ASSERT(data == I8042_ACK);
}
void PS2MouseDevice::prepare_for_input()
{
for (;;) {
if (IO::in8(I8042_STATUS) & 1)
return;
}
}
void PS2MouseDevice::prepare_for_output()
{
for (;;) {
if (!(IO::in8(I8042_STATUS) & 2))
return;
}
}
void PS2MouseDevice::mouse_write(u8 data)
{
prepare_for_output();
IO::out8(I8042_STATUS, 0xd4);
prepare_for_output();
IO::out8(I8042_BUFFER, data);
}
u8 PS2MouseDevice::mouse_read()
{
prepare_for_input();
return IO::in8(I8042_BUFFER);
}
bool PS2MouseDevice::can_read(const FileDescription&) const
{
return !m_queue.is_empty();
}
ssize_t PS2MouseDevice::read(FileDescription&, u8* 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(FileDescription&, const u8*, ssize_t)
{
return 0;
}