coreboot-kgpe-d16/payloads/libpayload/drivers/i8042/i8042.c

405 lines
8.2 KiB
C

/*
* This file is part of the libpayload project.
*
* Patrick Rudolph 2017 <siro@das-labor.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <libpayload-config.h>
#include <libpayload.h>
#include <stddef.h>
#include "i8042.h"
/* Overflowing FIFO implementation */
struct fifo {
u8 *buf;
size_t tx;
size_t rx;
size_t len;
};
/** Initialize a new fifo queue.
* Initialize a new fifo with length @len.
* @len: Length of new fifo
* Returns NULL on error.
*/
static struct fifo *fifo_init(size_t len)
{
struct fifo *ret;
ret = malloc(sizeof(*ret));
if (!ret)
return NULL;
memset(ret, 0, sizeof(*ret));
ret->buf = malloc(len);
if (!ret->buf) {
free(ret);
return NULL;
}
ret->len = len;
return ret;
}
/** Push object onto fifo queue.
* Pushes a new object onto the fifo. In case the fifo
* is full the oldest object is overwritten.
* @fifo: Fifo to use
* @c: Element to push
*/
static void fifo_push(struct fifo *fifo, u8 c)
{
fifo->buf[fifo->tx++] = c;
fifo->tx = fifo->tx % fifo->len;
if (fifo->tx == fifo->rx)
fifo->rx++;
fifo->rx = fifo->rx % fifo->len;
}
/** Test fifo queue element count.
* Returns 1 if fifo is empty.
* @fifo: Fifo to use
*/
static int fifo_is_empty(struct fifo *fifo)
{
if (!fifo)
return 1;
return fifo->tx == fifo->rx;
}
/** Pop element from fifo queue.
* Returns the oldest object from queue if any.
* In case the queue is empty 0 is returned.
* @fifo: Fifo to use
*/
static u8 fifo_pop(struct fifo *fifo)
{
u8 ret;
if (fifo_is_empty(fifo))
return 0;
ret = fifo->buf[fifo->rx++];
fifo->rx = fifo->rx % fifo->len;
return ret;
}
/** Destroys a fifo queue.
* @fifo: Fifo to use
*/
static void fifo_destroy(struct fifo *fifo)
{
if (fifo && fifo->buf)
free(fifo->buf);
if (fifo)
free(fifo);
}
/* i8042 keyboard controller implementation */
static inline u8 read_status(void) { return inb(0x64); }
static inline u8 read_data(void) { return inb(0x60); }
static inline void write_cmd(u8 cmd) { outb(cmd, 0x64); }
static inline void write_data(u8 data) { outb(data, 0x60); }
#define OBF 1
#define IBF 2
/* Keyboard controller methods */
static int initialized = 0;
static int kbc_init = 0;
static struct fifo *aux_fifo = NULL;
static struct fifo *ps2_fifo = NULL;
static int i8042_cmd_with_response(u8 cmd);
/** Wait for command ready.
* Wait for the keyboard controller to accept a new command.
* Returns: 0 on timeout
*/
static u8 i8042_wait_cmd_rdy(void)
{
int retries = 10000;
while (retries-- && (read_status() & IBF))
udelay(50);
return retries > 0;
}
/** Wait for data ready.
* Wait for the keyboard controller to accept new data.
* Returns: 0 on timeout
*/
static u8 i8042_wait_data_rdy(void)
{
int retries = 10000;
while (retries-- && !(read_status() & OBF))
udelay(50);
return retries > 0;
}
/** Keyboard controller has a ps2 port.
* Returns if ps2 port is available.
*/
size_t i8042_has_ps2(void)
{
return !!ps2_fifo;
}
/** Keyboard controller has an aux port.
* Returns if aux port is available.
*/
size_t i8042_has_aux(void)
{
return !!aux_fifo;
}
/**
* Probe for keyboard controller
* Returns: 1 for success, 0 for failure
*/
u8 i8042_probe(void)
{
if (initialized)
return 1;
aux_fifo = NULL;
ps2_fifo = NULL;
/* If 0x64 returns 0xff, then we have no keyboard
* controller */
if (read_status() == 0xFF)
return 0;
if (!i8042_wait_cmd_rdy())
return 0;
kbc_init = 1;
/* Disable first device */
if (i8042_cmd(I8042_CMD_DIS_KB) != 0) {
kbc_init = 0;
return 0;
}
/* Disable second device */
if (i8042_cmd(I8042_CMD_DIS_AUX) != 0) {
kbc_init = 0;
return 0;
}
/* Flush buffer */
while (read_status() & OBF)
read_data();
/* Self test. */
if (i8042_cmd_with_response(I8042_CMD_SELF_TEST)
!= I8042_SELF_TEST_RSP) {
kbc_init = 0;
return 0;
}
/* Test secondary port */
if (CONFIG(LP_PC_MOUSE)) {
if (i8042_cmd_with_response(I8042_CMD_AUX_TEST) == 0)
aux_fifo = fifo_init(4 * 32);
}
/* Test first PS/2 port */
if (i8042_cmd_with_response(I8042_CMD_KB_TEST) == 0)
ps2_fifo = fifo_init(2 * 16);
kbc_init = 0;
initialized = aux_fifo || ps2_fifo;
return initialized;
}
/* Close the keyboard controller */
void i8042_close(void)
{
if (!initialized)
return;
fifo_destroy(aux_fifo);
fifo_destroy(ps2_fifo);
initialized = 0;
aux_fifo = NULL;
ps2_fifo = NULL;
}
/** Send command to keyboard controller.
* @param cmd: The command to be send.
* returns: 0 on success, -1 on failure.
*/
int i8042_cmd(u8 cmd)
{
if (!initialized && !kbc_init)
return -1;
if (!i8042_wait_cmd_rdy())
return -1;
write_cmd(cmd);
if (!i8042_wait_cmd_rdy())
return -1;
return 0;
}
/** Send command to keyboard controller.
* @param cmd: The command to be send.
* returns: Response on success, -1 on failure.
*/
static int i8042_cmd_with_response(u8 cmd)
{
const int ret = i8042_cmd(cmd);
if (ret != 0)
return ret;
if (!i8042_wait_data_rdy())
return -1;
return read_data();
}
/** Send additional data to keyboard controller.
* @param data The data to be send.
*/
void i8042_write_data(u8 data)
{
if (!initialized)
return;
if (!i8042_wait_cmd_rdy())
return;
write_data(data);
if (!i8042_wait_cmd_rdy())
return;
}
/**
* Probe for keyboard controller data and queue it.
*/
static void i8042_data_poll(void)
{
u8 c;
if (!initialized)
return;
c = read_status();
while ((c != 0xFF) && (c & OBF)) {
const u8 in = read_data();
/* Assume "second PS/2 port output buffer full" flag works */
struct fifo *const fifo = (c & 0x20) ? aux_fifo : ps2_fifo;
if (fifo)
fifo_push(fifo, in);
c = read_status();
}
}
/** Keyboard controller data ready status.
* Signals that keyboard data is ready for reading.
*/
u8 i8042_data_ready_ps2(void)
{
if (!initialized)
return 0;
i8042_data_poll();
return !fifo_is_empty(ps2_fifo);
}
/** Keyboard controller data ready status.
* Signals that mouse data is ready for reading.
*/
u8 i8042_data_ready_aux(void)
{
if (!initialized)
return 0;
i8042_data_poll();
return !fifo_is_empty(aux_fifo);
}
/**
* Returns available keyboard data, if any.
*/
u8 i8042_read_data_ps2(void)
{
i8042_data_poll();
return fifo_pop(ps2_fifo);
}
/**
* Returns available mouse data, if any.
*/
u8 i8042_read_data_aux(void)
{
i8042_data_poll();
return fifo_pop(aux_fifo);
}
/**
* Waits for keyboard data.
* Waits for up to 500msec to receive data.
* Returns: -1 on timeout, data received otherwise
*/
int i8042_wait_read_ps2(void)
{
int retries = 10000;
while (retries-- && !i8042_data_ready_ps2())
udelay(50);
return (retries <= 0) ? -1 : i8042_read_data_ps2();
}
/** Waits for mouse data.
* Waits for up to 500msec to receive data.
* Returns: -1 on timeout, data received otherwise
*/
int i8042_wait_read_aux(void)
{
int retries = 10000;
while (retries-- && !i8042_data_ready_aux())
udelay(50);
return (retries <= 0) ? -1 : i8042_read_data_aux();
}