/***************************************************************************************
* Pushbutton - Interrupt Service Routine
*
* This routine checks which KEY has been pressed. If it is KEY1 or KEY2, it writes this
* value to the global variable key_pressed. If it is KEY3 then it loads the SW switch
* values and stores in the variable pattern
****************************************************************************************/
void PS2_ISR(struct alt_up_dev *up_dev, unsigned int id)
{
unsigned char PS2_data;
/* check for PS/2 data--display on HEX displays */
if (alt_up_ps2_read_data_byte (up_dev->PS2_dev, &PS2_data) == 0)
{
/* allows save the last three bytes of data */
byte1 = byte2;
byte2 = byte3;
byte3 = PS2_data;
if ( (byte2 == (unsigned char) 0xAA) && (byte3 == (unsigned char) 0x00) )
// mouse inserted; initialize sending of data
(void) alt_up_ps2_write_data_byte (up_dev->PS2_dev, (unsigned char) 0xF4);
}
return;
}
alt_up_ps2_dev *init_mouse() {
alt_up_ps2_dev *mouse = alt_up_ps2_open_dev("/dev/PS2_Port");
alt_up_ps2_init(mouse);
alt_up_ps2_clear_fifo(mouse);
alt_up_ps2_write_data_byte(mouse, 0xFF);
int state = INIT;
int status;
while (state != ERROR && state != MSG1) {
unsigned char data;
do {
status = alt_up_ps2_read_data_byte(mouse, &data);
} while (status < 0);
switch (state) {
case INIT:
if (data == 0xF4) {
state = ACK;
alt_printf("Mouse sent ACK (0xF4).");
} else if (data == 0xAA) {
state = OK;
alt_printf("Mouse skipped ACK (0xF4).");
} else {
if (data == 0xFC) {
state = ERROR;
alt_printf("Mouse replied with an error message (0xFC).\n");
} else {
alt_printf("Mouse replied with an unknown message: 0x%x. Ignoring...\n", data);
}
}
break;
case ACK:
if (data == 0xAA) {
state = OK;
} else {
alt_printf("Mouse replied sent unknown message: %x. Expected 0xAA. Ignoring...\n");
}
break;
case OK:
if (data == 0x00) {
state = ENABLING;
alt_up_ps2_write_data_byte(mouse, 0xF4);;
alt_printf("Mouse ready. Enabling position and button status messages...\n");
} else {
state = ACK; // Back to waiting for 0xAA00.
alt_printf("Mouse replied sent unknown byte: %x. Expected 0x00. Ignoring...\n");
}
break;
case ENABLING:
if (data == 0xFA) {
state = MSG1;
alt_printf("OK ! Waiting for messages.\n");
} else {
alt_printf("Mouse replied sent unknown message: %x. Expected 0xF4. Ignoring...\n");
}
break;
}
}
if (state == ERROR)
return 0;
return mouse;
}
