u-boot/drivers/input/cros_ec_keyb.c

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/*
* Chromium OS Matrix Keyboard
*
* Copyright (c) 2012 The Chromium OS Authors.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <cros_ec.h>
#include <errno.h>
#include <fdtdec.h>
#include <input.h>
#include <key_matrix.h>
#include <stdio_dev.h>
DECLARE_GLOBAL_DATA_PTR;
enum {
KBC_MAX_KEYS = 8, /* Maximum keys held down at once */
KBC_REPEAT_RATE_MS = 30,
KBC_REPEAT_DELAY_MS = 240,
};
static struct keyb {
struct cros_ec_dev *dev; /* The CROS_EC device */
struct input_config input; /* The input layer */
struct key_matrix matrix; /* The key matrix layer */
int key_rows; /* Number of keyboard rows */
int key_cols; /* Number of keyboard columns */
int ghost_filter; /* 1 to enable ghost filter, else 0 */
int inited; /* 1 if keyboard is ready */
} config;
/**
* Check the keyboard controller and return a list of key matrix positions
* for which a key is pressed
*
* @param config Keyboard config
* @param keys List of keys that we have detected
* @param max_count Maximum number of keys to return
* @param samep Set to true if this scan repeats the last, else false
* @return number of pressed keys, 0 for none, -EIO on error
*/
static int check_for_keys(struct keyb *config,
struct key_matrix_key *keys, int max_count,
bool *samep)
{
struct key_matrix_key *key;
static struct mbkp_keyscan last_scan;
static bool last_scan_valid;
struct mbkp_keyscan scan;
unsigned int row, col, bit, data;
int num_keys;
if (cros_ec_scan_keyboard(config->dev, &scan)) {
debug("%s: keyboard scan failed\n", __func__);
return -EIO;
}
*samep = last_scan_valid && !memcmp(&last_scan, &scan, sizeof(scan));
/*
* This is a bit odd. The EC has no way to tell us that it has run
* out of key scans. It just returns the same scan over and over
* again. So the only way to detect that we have run out is to detect
* that this scan is the same as the last.
*/
last_scan_valid = true;
memcpy(&last_scan, &scan, sizeof(last_scan));
for (col = num_keys = bit = 0; col < config->matrix.num_cols;
col++) {
for (row = 0; row < config->matrix.num_rows; row++) {
unsigned int mask = 1 << (bit & 7);
data = scan.data[bit / 8];
if ((data & mask) && num_keys < max_count) {
key = keys + num_keys++;
key->row = row;
key->col = col;
key->valid = 1;
}
bit++;
}
}
return num_keys;
}
/**
* Test if keys are available to be read
*
* @return 0 if no keys available, 1 if keys are available
*/
static int kbd_tstc(struct stdio_dev *dev)
{
/* Just get input to do this for us */
return config.inited ? input_tstc(&config.input) : 0;
}
/**
* Read a key
*
* @return ASCII key code, or 0 if no key, or -1 if error
*/
static int kbd_getc(struct stdio_dev *dev)
{
/* Just get input to do this for us */
return config.inited ? input_getc(&config.input) : 0;
}
/**
* Check the keyboard, and send any keys that are pressed.
*
* This is called by input_tstc() and input_getc() when they need more
* characters
*
* @param input Input configuration
* @return 1, to indicate that we have something to look at
*/
int cros_ec_kbc_check(struct input_config *input)
{
static struct key_matrix_key last_keys[KBC_MAX_KEYS];
static int last_num_keys;
struct key_matrix_key keys[KBC_MAX_KEYS];
int keycodes[KBC_MAX_KEYS];
int num_keys, num_keycodes;
int irq_pending, sent;
bool same = false;
/*
* Loop until the EC has no more keyscan records, or we have
* received at least one character. This means we know that tstc()
* will always return non-zero if keys have been pressed.
*
* Without this loop, a key release (which generates no new ascii
* characters) will cause us to exit this function, and just tstc()
* may return 0 before all keys have been read from the EC.
*/
do {
irq_pending = cros_ec_interrupt_pending(config.dev);
if (irq_pending) {
num_keys = check_for_keys(&config, keys, KBC_MAX_KEYS,
&same);
if (num_keys < 0)
return 0;
last_num_keys = num_keys;
memcpy(last_keys, keys, sizeof(keys));
} else {
/*
* EC doesn't want to be asked, so use keys from last
* time.
*/
num_keys = last_num_keys;
memcpy(keys, last_keys, sizeof(keys));
}
if (num_keys < 0)
return -1;
num_keycodes = key_matrix_decode(&config.matrix, keys,
num_keys, keycodes, KBC_MAX_KEYS);
sent = input_send_keycodes(input, keycodes, num_keycodes);
/*
* For those ECs without an interrupt, stop scanning when we
* see that the scan is the same as last time.
*/
if ((irq_pending < 0) && same)
break;
} while (irq_pending && !sent);
return 1;
}
/**
* Decode MBKP keyboard details from the device tree
*
* @param blob Device tree blob
* @param node Node to decode from
* @param config Configuration data read from fdt
* @return 0 if ok, -1 on error
*/
static int cros_ec_keyb_decode_fdt(const void *blob, int node,
struct keyb *config)
{
/*
* Get keyboard rows and columns - at present we are limited to
* 8 columns by the protocol (one byte per row scan)
*/
config->key_rows = fdtdec_get_int(blob, node, "keypad,num-rows", 0);
config->key_cols = fdtdec_get_int(blob, node, "keypad,num-columns", 0);
if (!config->key_rows || !config->key_cols ||
config->key_rows * config->key_cols / 8
> CROS_EC_KEYSCAN_COLS) {
debug("%s: Invalid key matrix size %d x %d\n", __func__,
config->key_rows, config->key_cols);
return -1;
}
config->ghost_filter = fdtdec_get_bool(blob, node,
"google,needs-ghost-filter");
return 0;
}
/**
* Set up the keyboard. This is called by the stdio device handler.
*
* We want to do this init when the keyboard is actually used rather than
* at start-up, since keyboard input may not currently be selected.
*
* @return 0 if ok, -1 on error
*/
static int cros_ec_init_keyboard(struct stdio_dev *dev)
{
const void *blob = gd->fdt_blob;
int node;
config.dev = board_get_cros_ec_dev();
if (!config.dev) {
debug("%s: no cros_ec device: cannot init keyboard\n",
__func__);
return -1;
}
node = fdtdec_next_compatible(blob, 0, COMPAT_GOOGLE_CROS_EC_KEYB);
if (node < 0) {
debug("%s: Node not found\n", __func__);
return -1;
}
if (cros_ec_keyb_decode_fdt(blob, node, &config))
return -1;
input_set_delays(&config.input, KBC_REPEAT_DELAY_MS,
KBC_REPEAT_RATE_MS);
if (key_matrix_init(&config.matrix, config.key_rows,
config.key_cols, config.ghost_filter)) {
debug("%s: cannot init key matrix\n", __func__);
return -1;
}
if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) {
debug("%s: Could not decode key matrix from fdt\n", __func__);
return -1;
}
config.inited = 1;
debug("%s: Matrix keyboard %dx%d ready\n", __func__, config.key_rows,
config.key_cols);
return 0;
}
int drv_keyboard_init(void)
{
struct stdio_dev dev;
if (input_init(&config.input, 0)) {
debug("%s: Cannot set up input\n", __func__);
return -1;
}
config.input.read_keys = cros_ec_kbc_check;
memset(&dev, '\0', sizeof(dev));
strcpy(dev.name, "cros-ec-keyb");
dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM;
dev.getc = kbd_getc;
dev.tstc = kbd_tstc;
dev.start = cros_ec_init_keyboard;
/* Register the device. cros_ec_init_keyboard() will be called soon */
return input_stdio_register(&dev);
}