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/* Copyright (c) 2012 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.
*/
/*
* Keyboard scanner module for Chrome EC
*
* TODO: Finish cleaning up nomenclature (cols/rows/inputs/outputs),
*/
#include "atomic.h"
#include "board.h"
#include "console.h"
#include "gpio.h"
#include "host_command.h"
#include "keyboard.h"
#include "keyboard_scan.h"
#include "registers.h"
#include "system.h"
#include "task.h"
#include "timer.h"
#include "util.h"
/* Console output macros */
#define CPUTS(outstr) cputs(CC_KEYSCAN, outstr)
#define CPRINTF(format, args...) cprintf(CC_KEYSCAN, format, ## args)
/* used for select_column() */
enum COL_INDEX {
COL_ASSERT_ALL = -2,
COL_TRI_STATE_ALL = -1,
/* 0 ~ 12 for the corresponding column */
};
#define POLLING_MODE_TIMEOUT 100000 /* 100 ms */
#define SCAN_LOOP_DELAY 10000 /* 10 ms */
/* 15:14, 12:8, 2 */
#define IRQ_MASK 0xdf04
/* The keyboard state from the last read */
static uint8_t raw_state[KB_OUTPUTS];
/* status of keyboard related switches */
static uint8_t switches;
/* Mask with 1 bits only for keys that actually exist */
static const uint8_t *actual_key_mask;
/* All actual key masks (todo: move to keyboard matrix definition) */
/* TODO: (crosbug.com/p/7485) fill in real key mask with 0-bits for coords that
aren't keys */
static const uint8_t actual_key_masks[4][KB_OUTPUTS] = {
{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
{0},
{0},
{0},
};
/* Key masks for special boot keys */
#define MASK_INDEX_ESC 1
#define MASK_VALUE_ESC 0x02
#define MASK_INDEX_REFRESH 2
#define MASK_VALUE_REFRESH 0x04
struct kbc_gpio {
int num; /* logical row or column number */
uint32_t port;
int pin;
};
#if defined(BOARD_daisy) || defined(BOARD_snow)
static const uint32_t ports[] = { GPIO_B, GPIO_C, GPIO_D };
#else
#error "Need to specify GPIO ports used by keyboard"
#endif
/* Provide a default function in case the board doesn't have one */
void __board_keyboard_suppress_noise(void)
{
}
void board_keyboard_suppress_noise(void)
__attribute__((weak, alias("__board_keyboard_suppress_noise")));
#define KB_FIFO_DEPTH 16 /* FIXME: this is pretty huge */
static uint32_t kb_fifo_start; /* first entry */
static uint32_t kb_fifo_end; /* last entry */
static uint32_t kb_fifo_entries; /* number of existing entries */
static uint8_t kb_fifo[KB_FIFO_DEPTH][KB_OUTPUTS];
/* clear keyboard state variables */
void keyboard_clear_state(void)
{
int i;
CPRINTF("clearing keyboard fifo\n");
kb_fifo_start = 0;
kb_fifo_end = 0;
kb_fifo_entries = 0;
for (i = 0; i < KB_FIFO_DEPTH; i++)
memset(kb_fifo[i], 0, KB_OUTPUTS);
}
/**
* Add keyboard state into FIFO
*
* @return EC_SUCCESS if entry added, EC_ERROR_OVERFLOW if FIFO is full
*/
static int kb_fifo_add(uint8_t *buffp)
{
int ret = EC_SUCCESS;
if (kb_fifo_entries == KB_FIFO_DEPTH) {
CPRINTF("%s: FIFO depth reached\n", __func__);
ret = EC_ERROR_OVERFLOW;
goto kb_fifo_push_done;
}
memcpy(kb_fifo[kb_fifo_end], buffp, KB_OUTPUTS);
kb_fifo_end = (kb_fifo_end + 1) % KB_FIFO_DEPTH;
atomic_add(&kb_fifo_entries, 1);
kb_fifo_push_done:
return ret;
}
/**
* Pop keyboard state from FIFO
*
* @return EC_SUCCESS if entry popped, EC_ERROR_UNKNOWN if FIFO is empty
*/
static int kb_fifo_remove(uint8_t *buffp)
{
if (!kb_fifo_entries) {
/* no entry remaining in FIFO : return last known state */
memcpy(buffp, kb_fifo[(kb_fifo_start - 1) % KB_FIFO_DEPTH],
KB_OUTPUTS);
/*
* Bail out without changing any FIFO indices and let the
* caller know something strange happened. The buffer will
* will contain the last known state of the keyboard.
*/
return EC_ERROR_UNKNOWN;
}
memcpy(buffp, kb_fifo[kb_fifo_start], KB_OUTPUTS);
kb_fifo_start = (kb_fifo_start + 1) % KB_FIFO_DEPTH;
atomic_sub(&kb_fifo_entries, 1);
return EC_SUCCESS;
}
static void select_column(int col)
{
int i, done = 0;
for (i = 0; i < ARRAY_SIZE(ports); i++) {
uint32_t bsrr = 0;
int j;
for (j = GPIO_KB_OUT00; j <= GPIO_KB_OUT12; j++) {
if (gpio_list[j].port != ports[i])
continue;
if (col == COL_ASSERT_ALL) {
/* drive low (clear output data) */
bsrr |= gpio_list[j].mask << 16;
} else if (col == COL_TRI_STATE_ALL) {
/* put column in hi-Z state (set output data) */
bsrr |= gpio_list[j].mask;
} else {
/* drive specified column low, others => hi-Z */
if (j - GPIO_KB_OUT00 == col) {
/* to avoid conflict, tri-state all
* columns first, then assert column */
select_column(COL_TRI_STATE_ALL);
bsrr |= gpio_list[j].mask << 16;
done = 1;
break;
}
}
}
if (bsrr)
STM32_GPIO_BSRR_OFF(ports[i]) = bsrr;
if (done)
break;
}
}
void wait_for_interrupt(void)
{
uint32_t pr_before, pr_after;
/* Assert all outputs would trigger un-wanted interrupts.
* Clear them before enable interrupt. */
pr_before = STM32_EXTI_PR;
select_column(COL_ASSERT_ALL);
pr_after = STM32_EXTI_PR;
STM32_EXTI_PR |= ((pr_after & ~pr_before) & IRQ_MASK);
STM32_EXTI_IMR |= IRQ_MASK; /* 1: unmask interrupt */
}
void enter_polling_mode(void)
{
STM32_EXTI_IMR &= ~IRQ_MASK; /* 0: mask interrupts */
select_column(COL_TRI_STATE_ALL);
}
/* Returns 1 if any key is still pressed. 0 if no key is pressed. */
static int check_keys_changed(void)
{
int c;
uint8_t r;
int change = 0;
int num_press = 0;
for (c = 0; c < KB_OUTPUTS; c++) {
uint16_t tmp;
/* Select column, then wait a bit for it to settle */
select_column(c);
udelay(50);
r = 0;
tmp = STM32_GPIO_IDR(C);
/* KB_COL00:04 = PC8:12 */
if (tmp & (1 << 8))
r |= 1 << 0;
if (tmp & (1 << 9))
r |= 1 << 1;
if (tmp & (1 << 10))
r |= 1 << 2;
if (tmp & (1 << 11))
r |= 1 << 3;
if (tmp & (1 << 12))
r |= 1 << 4;
/* KB_COL05:06 = PC14:15 */
if (tmp & (1 << 14))
r |= 1 << 5;
if (tmp & (1 << 15))
r |= 1 << 6;
tmp = STM32_GPIO_IDR(D);
/* KB_COL07 = PD2 */
if (tmp & (1 << 2))
r |= 1 << 7;
/* Invert it so 0=not pressed, 1=pressed */
r ^= 0xff;
/* Mask off keys that don't exist so they never show
* as pressed */
r &= actual_key_mask[c];
#ifdef OR_WITH_CURRENT_STATE_FOR_TESTING
/* KLUDGE - or current state in, so we can make sure
* all the lines are hooked up */
r |= raw_state[c];
#endif
/* Check for changes */
if (r != raw_state[c]) {
raw_state[c] = r;
change = 1;
}
}
select_column(COL_TRI_STATE_ALL);
/* Count number of key pressed */
for (c = 0; c < KB_OUTPUTS; c++) {
if (raw_state[c])
++num_press;
}
if (change) {
board_keyboard_suppress_noise();
CPRINTF("[%d keys pressed: ", num_press);
for (c = 0; c < KB_OUTPUTS; c++) {
if (raw_state[c])
CPRINTF(" %02x", raw_state[c]);
else
CPUTS(" --");
}
CPUTS("]\n");
if (kb_fifo_add(raw_state) == EC_SUCCESS)
board_interrupt_host(1);
else
CPRINTF("dropped keystroke\n");
}
return num_press ? 1 : 0;
}
/* Returns non-zero if the user has triggered a recovery reset by pushing
* Power + Refresh + ESC. */
static int check_recovery_key(void)
{
int c;
/* check the recovery key only if we're booting due to a
* reset-pin-caused reset. */
if (system_get_reset_cause() != SYSTEM_RESET_RESET_PIN)
return 0;
/* cold boot : Power + Refresh were pressed,
* check if ESC is also pressed for recovery. */
if (!(raw_state[MASK_INDEX_ESC] & MASK_VALUE_ESC))
return 0;
/* Make sure only other allowed keys are pressed. This protects
* against accidentally triggering the special key when a cat sits on
* your keyboard. Currently, only the requested key and ESC are
* allowed. */
for (c = 0; c < KB_OUTPUTS; c++) {
if (raw_state[c] &&
(c != MASK_INDEX_ESC || raw_state[c] != MASK_VALUE_ESC) &&
(c != MASK_INDEX_REFRESH || raw_state[c] != MASK_VALUE_REFRESH))
return 0; /* Additional disallowed key pressed */
}
CPRINTF("Keyboard RECOVERY detected !\n");
return 1;
}
int keyboard_scan_init(void)
{
/* Tri-state (put into Hi-Z) the outputs */
select_column(COL_TRI_STATE_ALL);
/* TODO: method to set which keyboard we have, so we set the actual
* key mask properly */
actual_key_mask = actual_key_masks[0];
/* Initialize raw state */
check_keys_changed();
/* is recovery key pressed on cold startup ? */
switches |= check_recovery_key() ?
EC_SWITCH_KEYBOARD_RECOVERY : 0;
return EC_SUCCESS;
}
void keyboard_scan_task(void)
{
int key_press_timer = 0;
/* Enable interrupts for keyboard matrix inputs */
gpio_enable_interrupt(GPIO_KB_IN00);
gpio_enable_interrupt(GPIO_KB_IN01);
gpio_enable_interrupt(GPIO_KB_IN02);
gpio_enable_interrupt(GPIO_KB_IN03);
gpio_enable_interrupt(GPIO_KB_IN04);
gpio_enable_interrupt(GPIO_KB_IN05);
gpio_enable_interrupt(GPIO_KB_IN06);
gpio_enable_interrupt(GPIO_KB_IN07);
while (1) {
wait_for_interrupt();
task_wait_event(-1);
enter_polling_mode();
/* Busy polling keyboard state. */
while (1) {
/* sleep for debounce. */
usleep(SCAN_LOOP_DELAY);
/* Check for keys down */
if (check_keys_changed()) {
key_press_timer = 0;
} else {
if (++key_press_timer >=
(POLLING_MODE_TIMEOUT / SCAN_LOOP_DELAY)) {
key_press_timer = 0;
break; /* exit the while loop */
}
}
}
/* TODO: (crosbug.com/p/7484) A race condition here.
* If a key state is changed here (before interrupt is
* enabled), it will be lost.
*/
}
}
void matrix_interrupt(enum gpio_signal signal)
{
task_wake(TASK_ID_KEYSCAN);
}
int keyboard_has_char(void)
{
/* TODO: needs to be implemented */
return 0;
}
void keyboard_put_char(uint8_t chr, int send_irq)
{
/* TODO: needs to be implemented */
}
int keyboard_scan_recovery_pressed(void)
{
return switches & EC_SWITCH_KEYBOARD_RECOVERY;
}
static int keyboard_get_scan(uint8_t *data, int *resp_size)
{
kb_fifo_remove(data);
if (!kb_fifo_entries)
board_interrupt_host(0);
*resp_size = KB_OUTPUTS;
return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_MKBP_STATE, keyboard_get_scan);
static int keyboard_get_info(uint8_t *data, int *resp_size)
{
struct ec_response_mkbp_info *r = (struct ec_response_mkbp_info *)data;
r->rows = 8;
r->cols = KB_OUTPUTS;
r->switches = switches;
*resp_size = sizeof(struct ec_response_mkbp_info);
return EC_RES_SUCCESS;
}
DECLARE_HOST_COMMAND(EC_CMD_MKBP_INFO, keyboard_get_info);
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