From 2a7e3f00256e20d9abcc059a0d666968c0280611 Mon Sep 17 00:00:00 2001
From: Baptiste Wicht <baptiste.wicht@gmail.com>
Date: Sat, 6 Aug 2016 22:13:26 +0200
Subject: [PATCH] Implement a PS/2 mouse driver

---
 kernel/include/mouse.hpp |  22 +++++++
 kernel/src/kernel.cpp    |   2 +
 kernel/src/mouse.cpp     | 122 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 146 insertions(+)
 create mode 100644 kernel/include/mouse.hpp
 create mode 100644 kernel/src/mouse.cpp

diff --git a/kernel/include/mouse.hpp b/kernel/include/mouse.hpp
new file mode 100644
index 00000000..9599839a
--- /dev/null
+++ b/kernel/include/mouse.hpp
@@ -0,0 +1,22 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2016.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#ifndef MOUSE_HPP
+#define MOUSE_HPP
+
+#include <types.hpp>
+
+namespace mouse {
+
+void install();
+
+uint64_t x();
+uint64_t y();
+
+} //end of namespace mouse
+
+#endif
diff --git a/kernel/src/kernel.cpp b/kernel/src/kernel.cpp
index f31814d9..0a5975da 100644
--- a/kernel/src/kernel.cpp
+++ b/kernel/src/kernel.cpp
@@ -12,6 +12,7 @@
 #include "kalloc.hpp"
 #include "timer.hpp"
 #include "keyboard.hpp"
+#include "mouse.hpp"
 #include "serial.hpp"
 #include "disks.hpp"
 #include "pci.hpp"
@@ -106,6 +107,7 @@ void kernel_main(){
     //Install drivers
     timer::install();
     keyboard::install_driver();
+    mouse::install();
     disks::detect_disks();
     pci::detect_devices();
     network::init();
diff --git a/kernel/src/mouse.cpp b/kernel/src/mouse.cpp
new file mode 100644
index 00000000..f3eb7e05
--- /dev/null
+++ b/kernel/src/mouse.cpp
@@ -0,0 +1,122 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2016.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#include <algorithms.hpp>
+
+#include "mouse.hpp"
+#include "interrupts.hpp"
+#include "kernel_utils.hpp"
+#include "logging.hpp"
+#include "vesa.hpp"
+
+namespace {
+
+constexpr const uint16_t DATA_PORT = 0x60;
+constexpr const uint16_t STATUS_PORT = 0x64;
+
+uint8_t cycle = 0; // The interrupt cycles through different information
+
+uint8_t mouse_packet[3];
+uint16_t position_x = 0;
+uint16_t position_y = 0;
+
+void mouse_handler(interrupt::syscall_regs*, void*){
+    mouse_packet[cycle++] = in_byte(DATA_PORT);
+
+    if(cycle == 3){
+        cycle = 0;
+
+        auto state = mouse_packet[0];
+
+        // Discard overflow packets
+        if(state & ((1 << 6) | (1 << 7))){
+            return;
+        }
+
+        // Compute the 9bit delta values
+        int16_t delta_x = mouse_packet[1] - ((state << 4) & 0x100);
+        int16_t delta_y = mouse_packet[2] - ((state << 3) & 0x100);
+
+        // Reverse the y direction
+        delta_y = -delta_y;
+
+        position_x = std::max(int16_t(position_x) + delta_x, 0);
+        position_y = std::max(int16_t(position_y) + delta_y, 0);
+
+        if(vesa::enabled()){
+            position_x = std::min(position_x, uint16_t(vesa::width()));
+            position_y = std::min(position_y, uint16_t(vesa::height()));
+        }
+
+        logging::logf(logging::log_level::TRACE, "mouse: interrupt %d:%d \n", int64_t(position_x), int64_t(position_y));
+    }
+}
+
+void ps2_data_wait(){
+    auto timeout = 100000;
+    while(timeout-- && (in_byte(STATUS_PORT) & 1) != 1){}
+}
+
+void ps2_signal_wait(){
+    auto timeout = 100000;
+    while(timeout-- && (in_byte(STATUS_PORT) & 2) != 0){}
+}
+
+void ps2_mouse_write(uint8_t value){
+    // Send a command
+    ps2_signal_wait();
+    out_byte(STATUS_PORT, 0xD4);
+
+    // Send the data
+    ps2_signal_wait();
+    out_byte(DATA_PORT, value);
+}
+
+uint8_t ps2_mouse_read(){
+    ps2_data_wait();
+    return in_byte(DATA_PORT);
+}
+
+} //end of anonymous namespace
+
+void mouse::install(){
+    if(!interrupt::register_irq_handler(12, mouse_handler, nullptr)){
+        logging::logf(logging::log_level::ERROR, "mouse: Unable to register IRQ handler 12\n");
+        return;
+    }
+
+    // Enable the mouse auxiliary device
+    ps2_signal_wait();
+    out_byte(STATUS_PORT, 0xA8);
+
+    // Enable interrupts
+    ps2_signal_wait();
+    out_byte(STATUS_PORT, 0x20);
+    auto status = ps2_mouse_read() | 2;
+    ps2_signal_wait();
+    out_byte(STATUS_PORT, 0x60);
+    ps2_signal_wait();
+    out_byte(DATA_PORT, status);
+
+    // Use default settings
+    ps2_mouse_write(0xF6);
+    ps2_mouse_read();
+
+    // Enable the mouse
+    ps2_mouse_write(0xF4);
+    ps2_mouse_read();
+
+    logging::logf(logging::log_level::TRACE, "mouse: PS/2 mouse driver installed\n");
+}
+
+uint64_t mouse::x(){
+    return position_x;
+}
+
+uint64_t mouse::y(){
+    return position_y;
+}