mouse_ps2.cpp

#include "mouse_ps2.h"


namespace MOSS { namespace Input { namespace Devices {


DevicePS2Mouse::DevicePS2Mouse(ControllerPS2* controller) : DevicePS2Base(controller) {
    //Note: DevicePS2Base maintains a pointer to the PS/2
    //controller in the protected variable "controller".

    ASSERT(sizeof(received_data)==4,"Mouse data packet is the wrong size!");

    mouse_cycle = 0;
    x = last_x = 0;
    y = last_y = 0;
}
DevicePS2Mouse::~DevicePS2Mouse(void) {}

void DevicePS2Mouse::reset(void) {
    //The mouse probably sends ACK (0xFA) plus several more bytes, then resets itself, and always sends 0xAA.
    send_command_device(0xFF);

    uint8_t response;
    do {
        bool result = controller->recv_data(&response,10000);
        ASSERT(result,"PS/2 mouse does not exist or reset failed!");
    } while (response!=0xAA);

    //Tell the mouse to use default settings
    //    Disables streaming, sets the packet rate to 100 per second, and resolution to 4 pixels per mm.
    send_command_device(0xF6);
    wait_response();
}

void DevicePS2Mouse:: enable(void) {
    //Enable packet streaming
    send_command_device(0xF4);
    wait_response();
}
void DevicePS2Mouse::disable(void) {
    //Disable packet streaming
    send_command_device(0xF5);
    wait_response();
}

//List of commands: http://wiki.osdev.org/Mouse_Input#Useful_Mouse_Command_Set
void DevicePS2Mouse::send_command_device(uint8_t command) {
    Kernel::terminal->write("Sending mouse command %d\n",command);

    //Tell the PS/2 controller that the next byte should be redirected to the second port (mouse)
    controller->send_command(0xD4); //No response expected

    //Write command to PS/2 controller, which will now redirect it to the mouse
    controller->send_data(command); //Caller should check for a response, iff applicable!
}
void DevicePS2Mouse::wait_response(uint8_t wait_byte/*=0xFA*/) {
    //Called after most commands, which return 0xFA (ACK).  The only one that (might) not is the reset command.
    uint8_t response;
    controller->recv_data(&response);
    ASSERT(response==wait_byte,"Command to mouse failed (expected %d, got %d)!",wait_byte,response);
}

void DevicePS2Mouse::_handle_current_packet(void) {
    //http://wiki.osdev.org/PS/2_Mouse

    if (received_data.dx_overflowed || received_data.dy_overflowed) return; //Just give up.

    int dx = (int)(received_data.dx) - (int)((received_data.byte1<<4)&0x100);
    int dy = (int)(received_data.dy) - (int)((received_data.byte1<<3)&0x100);

    set_position(x+dx,y+dy);
}
void DevicePS2Mouse::handle_irq(void) /*override*/ {
    //http://forum.osdev.org/viewtopic.php?t=10247
    //http://www.computer-engineering.org/ps2mouse/

    uint8_t byte;
    controller->recv_data(&byte);

    switch (mouse_cycle) {
        case 0:
            received_data.byte1 = byte;
            ++mouse_cycle;
            //if ((received_data.byte1&0x08)!=0) {
            //    ++mouse_cycle; //Only accept this as the first byte if the "must be 1" bit is set
            //}
            break;
        case 1:
            received_data.byte2 = byte;
            ++mouse_cycle;
            break;
        case 2:
            received_data.byte3 = byte;
            _handle_current_packet();
            mouse_cycle = 0;
            break;
    }
}

void DevicePS2Mouse::set_position(int x, int y) {
    int dx = x - this->x;
    int dy = y - this->y;
    if (dx!=0 || dy!=0) {
        last_x = this->x;
        last_y = this->y;
        this->x += dx;
        this->y += dy;
        Kernel::handle_mouse_move(Mouse::EventMove(this->x,this->y,dx,dy));
    }
}


}}}