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#include "input.h"
#include "port.h"
#include "i8042.h"
#include "pic8259.h"
#include <libc/stdio.h>
static void i8042_init(void);
static void i8042_enable(void) {}
static void i8042_disable(void) {}
static int i8042_append_callback(input_callback func) {(void)func; return 0;}
static void i8042_delete_callback(input_callback func) {(void)func;}
const struct input_source i8042_input_source =
{
"i8042",
i8042_init,
i8042_enable,
i8042_disable,
i8042_append_callback,
i8042_delete_callback,
};
#define PS2_STATUS 0x64
#define PS2_COMMAND 0x64
#define PS2_DATA 0x60
#define PS2_IRQ 1
static void i8042_disable_ports()
{
outb(PS2_COMMAND, 0xad);
outb(PS2_COMMAND, 0xa7);
}
static uint8_t i8042_command(int c)
{
outb(PS2_COMMAND, c);
return (uint8_t)c;
}
static uint8_t i8042_status()
{
return inb(PS2_STATUS);
}
static bool i8042_read(uint8_t *b)
{
if (i8042_status() & 1)
{
(b != NULL) ? *b = inb(PS2_DATA) : inb(PS2_DATA);
return true;
}
return false;
}
static void i8042_flush()
{
while(i8042_status() & 1)
{
i8042_read(NULL);
}
}
static int i8042_callback(uint8_t irq)
{
(void)irq;
i8042_flush();
return 0;
}
#define I8042_MAX_TRIES 4096
static bool i8042_write(uint8_t b)
{
for (int i = 0; i < I8042_MAX_TRIES; i++)
{
if (i8042_status() & 2)
{
continue;
}
outb(PS2_DATA, b);
return true;
}
return false;
}
static void i8042_set_config(void)
{
bool channel_a_enable = false;
bool channel_b_enable = false;
bool maybe_dual_channel = false;
bool is_dual_channel = false;
i8042_command(0x20);
uint8_t config_byte;
i8042_read(&config_byte);
printf("i8042: current config: %#0.2x\n", config_byte);
config_byte &= 0xfc;
if (config_byte & (0x1 << 5))
{
maybe_dual_channel = true;
}
config_byte |= 0x01;
printf("i8042: new config: %#0.2x\n", config_byte);
i8042_command(0x60);
i8042_write(config_byte);
i8042_command(0xaa);
uint8_t bist_result;
if (i8042_read(&bist_result) && bist_result != 0x55)
{
printf("i8042: warning: error self-testing device. aborting.\n");
return;
}
if (maybe_dual_channel)
{
i8042_command(0xa8);
i8042_command(0x20);
uint8_t config_byte;
if (i8042_read(&config_byte) && config_byte & (0x1 << 5))
{
printf("i8042: single-channel controller detected\n");
}
else
{
printf("i8042: dual-channel controller detected\n");
is_dual_channel = true;
}
}
outb(PS2_COMMAND, 0xab);
if (inb(PS2_DATA) != 0x00)
{
printf("i8042: failed testing port a\n");
}
else
{
channel_a_enable = true;
}
if (is_dual_channel)
{
outb(PS2_COMMAND, 0xa9);
if (inb(PS2_DATA) != 0x00)
{
printf("i8042: failed testing port b\n");
}
else
{
channel_b_enable = true;
}
i8042_disable_ports();
}
if (channel_a_enable)
{
outb(PS2_COMMAND, 0xae);
i8042_write(0xff);
if(inb(PS2_DATA) == 0xfa && inb(PS2_DATA) == 0xaa)
{
printf("i8042: detected device on channel, type %#0.2x\n", inb(PS2_DATA));
}
}
i8042_flush();
(void)channel_b_enable;
}
static void i8042_init(void)
{
i8042_disable_ports();
i8042_flush();
i8042_set_config();
pic8259_irq_install(PS2_IRQ, i8042_callback);
pic8259_irq_unmask(PS2_IRQ);
}
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