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#include <stdbool.h>
#include <nrvn.h>
#include <acpi.h>
#include <vga.h>
#define data_port 0x60
#define status_reg 0x64
#define cmd_reg 0x64
#define config_rcmd 0x20
#define config_wcmd 0x60
#define ctrl_test_cmd 0xaa
static inline void print_port_status(bool second_port, const char *msg) {
vga_puts("ps/2 port ");
vga_puts(second_port ? "2 " : "1 ");
vga_puts(msg);
}
static inline void send_cmd(uint8_t cmd) {
while (inb(status_reg) & 0x2);
outb(cmd_reg, cmd);
}
static inline bool read_data(uint8_t *data_out) {
size_t counter = 50;
while (!(inb(status_reg) & 0x1) && --counter > 0);
if (counter == 0)
return false;
*data_out = inb(data_port);
return true;
}
static inline void send_data(uint8_t data, bool second_device) {
if (second_device)
send_cmd(0xd4);
while (inb(status_reg) & 0x2);
outb(data_port, data);
}
// TODO: ps/2 mouse interface is weird.
static bool interface_test(bool second_device) {
uint8_t rply;
// Test port
send_cmd(second_device ? 0xa9 : 0xab);
read_data(&rply);
switch (rply) {
case 0x00:
print_port_status(second_device, "port test PASS\n");
break;
case 0x01:
print_port_status(second_device, "FAIL clock line stuck low\n");
return false;
case 0x02:
print_port_status(second_device, "FAIL clock line stuck high\n");
return false;
case 0x03:
print_port_status(second_device, "FAIL data line stuck low\n");
return false;
case 0x04:
print_port_status(second_device, "FAIL data line stuck data\n");
return false;
}
// Re-enable interface
send_cmd(second_device ? 0xa8 : 0xae);
// reset and self test device
send_data(0xff, second_device);
if (!read_data(&rply)) {
print_port_status(second_device, "self-test FAIL: no reply\n");
return false;
}
switch (rply) {
case 0xFA:
if (read_data(&rply), rply == 0xaa) {
print_port_status(second_device, "self-test PASS\n");
} else {
print_port_status(second_device, "self-test FAIL");
vga_putx(rply);
vga_putc('\n');
return false;
}
(void) inb(data_port); // PS/2 mouses send their id, we need to flush
break;
case 0xFC:
print_port_status(second_device, "self-test FAIL: ");
vga_putx(rply);
vga_putc('\n');
return false;
default:
print_port_status(second_device, "self-test unknown reply: ");
vga_putx(rply);
vga_putc('\n');
return false;
}
// Disable device
print_port_status(second_device, "disabling scanning.\n");
send_data(0xf5, second_device);
if (!read_data(&rply)) {
print_port_status( second_device, "failed to disable: ");
return false;
}
if (rply != 0xfa && rply != 0xaa) {
print_port_status( second_device, "failed to disable: ");
vga_putx(rply);
vga_putc('\n');
return false;
}
print_port_status(second_device, "scanning disabled.\n");
print_port_status(second_device, "detecting device type.\n");
send_data(0xf2, second_device);
if (read_data(&rply), rply != 0xfa) {
print_port_status(second_device, "failed to identify: ");
vga_putx(rply);
vga_putc('\n');
return false;
}
print_port_status(second_device, "id ack: ");
vga_putx((read_data(&rply), rply));
vga_putc(' ');
if (read_data(&rply))
vga_putx(rply);
vga_putc('\n');
// Enable device
send_data(0xf4, second_device);
if (read_data(&rply), rply != 0xfa) {
print_port_status(second_device, "failed to enable: ");
vga_putx(rply);
vga_putc('\n');
return false;
}
print_port_status(second_device, "scanning enabled.\n");
return true;
}
bool ps2_init(struct fadt *fadt) {
if (fadt != NULL && !(fadt->boot_arch_flags & 0x2)) {
vga_puts("fadt boot arch bit 1 not set: ");
vga_putx(fadt->boot_arch_flags);
vga_putc(' ');
vga_putx(((char*)fadt)[109]);
vga_putc('\n');
}
uint8_t rply;
// Disable ps/2 devices
vga_puts("disabling first device\n");
send_cmd(0xad);
vga_puts("disabling second device\n");
send_cmd(0xa7);
// flush output buffer
(void) inb(data_port);
// set controller config, clearing bits 0, 1, and 6
send_cmd(config_rcmd);
uint8_t config = (read_data(&rply), rply) & ~0b01000011;
// check if dual channel is already set
bool dual_channel = !(config & 0x5);
send_cmd(config_wcmd);
send_data(config, false);
// perform controller self test
send_cmd(ctrl_test_cmd);
if (read_data(&rply), rply != 0x55) {
vga_puts("ps/2 controller self test failed: ");
vga_putx(rply);
vga_putc('\n');
return false;
}
// re-set config in case the self tests reset the device
send_cmd(config_wcmd);
send_data(config, false);
// determine if there are two ports
if (!dual_channel) {
// attempt to enable second channel
send_cmd(0xa8);
// check if configuration show second port
// and disable it again if it shows.
send_cmd(0x20);
if ((dual_channel = !((read_data(&rply), rply) & 0x5)))
send_cmd(0xa7);
}
// enable and reset devices
if (!interface_test(false))
vga_puts("failed to test port 1 interface\n");
if (dual_channel && !interface_test(true))
vga_puts("failed to test port 2 interface\n");
// re enabled bits 1 and 2 (interrupts)
send_cmd(0x20);
config = (read_data(&rply), rply) | 0x3;
send_cmd(0x60);
send_data(config, false);
return true;
}
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