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/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*
* Chrome OS EC i8042 interface code.
*/
#include "board.h"
#include "common.h"
#include "i8042.h"
#include "keyboard.h"
/* TODO: Code in common.c should not directly access chip registers */
#include "registers.h"
#include "task.h"
#include "timer.h"
#include "uart.h"
#include "util.h"
#define I8042_DEBUG 1
#define MAX_QUEUED_KEY_PRESS 16
/* Circular buffer to host.
* head: next to dequeqe
* tail: next to enqueue
* head == tail: empty.
* tail + 1 == head: full
*/
static int head_to_buffer = 0;
static int tail_to_buffer = 0;
#define HOST_BUFFER_SIZE (16)
static uint8_t to_host_buffer[HOST_BUFFER_SIZE];
void i8042_init()
{
head_to_buffer = tail_to_buffer = 0;
LM4_LPC_ST(LPC_CH_KEYBOARD) = 0; /* clear the TOH bit */
}
void i8042_receives_data(int data)
{
int ret_len;
uint8_t output[MAX_SCAN_CODE_LEN];
enum ec_error_list ret;
ret_len = handle_keyboard_data(data, output);
ret = i8042_send_to_host(ret_len, output);
ASSERT(ret == EC_SUCCESS);
}
void i8042_receives_command(int cmd)
{
int ret_len;
uint8_t output[MAX_SCAN_CODE_LEN];
enum ec_error_list ret;
ret_len = handle_keyboard_command(cmd, output);
ret = i8042_send_to_host(ret_len, output);
ASSERT(ret == EC_SUCCESS);
}
static void enq_to_host(int len, uint8_t *to_host)
{
int from, to;
/* TODO: need atomic protection */
if ((tail_to_buffer + len) <= (head_to_buffer + HOST_BUFFER_SIZE - 1)) {
for (from = 0, to = tail_to_buffer; from < len;) {
to_host_buffer[to++] = to_host[from++];
to %= HOST_BUFFER_SIZE;
}
tail_to_buffer = (tail_to_buffer + len) % HOST_BUFFER_SIZE;
}
/* end of atomic protection */
}
void i8042_command_task(void)
{
while (1) {
/* Either a new byte to host or host picking up can un-block. */
task_wait_msg(-1);
while (1) {
uint8_t chr;
int empty = 0;
/* TODO: need atomic protection */
if (head_to_buffer == tail_to_buffer) {
empty = 1; /* nothing to host */
}
/* end of atomic protection */
if (empty) break;
/* if the host still didn't read that away,
try next time. */
if (LM4_LPC_ST(LPC_CH_KEYBOARD) & (1 << 0 /* TOH */)) {
#if I8042_DEBUG >= 5
uart_printf("[%d] i8042_command_task() "
"cannot send to host due to TOH\n",
get_time().le.lo);
#endif
break;
}
/* TODO: need atomic protection */
chr = to_host_buffer[head_to_buffer];
head_to_buffer =
(head_to_buffer + 1) % HOST_BUFFER_SIZE;
/* end of atomic protection */
/* Write to host. TOH is set automatically. */
LPC_POOL_KEYBOARD[1] = chr;
#if I8042_DEBUG >= 4
uart_printf("[%d] i8042_command_task() "
"sends to host: 0x%02x\n",
get_time().le.lo, chr);
#endif
}
}
}
enum ec_error_list i8042_send_to_host(int len, uint8_t *to_host)
{
enq_to_host(len, to_host);
/* Wake up the task to handle the command */
task_send_msg(TASK_ID_I8042CMD, TASK_ID_I8042CMD, 0);
return EC_SUCCESS;
}
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