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 <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <input.h>
#include <keyboard.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,
};
struct cros_ec_keyb_priv {
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 */
};
/**
* Check the keyboard controller and return a list of key matrix positions
* for which a key is pressed
*
* @param dev Keyboard device
* @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 udevice *dev, struct key_matrix_key *keys,
int max_count, bool *samep)
{
struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
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(dev->parent, &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 < priv->matrix.num_cols;
col++) {
for (row = 0; row < priv->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;
}
/**
* 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)
{
struct udevice *dev = input->dev;
struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
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(dev->parent);
if (irq_pending) {
num_keys = check_for_keys(dev, 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(&priv->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 cros_ec_keyb_priv *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;
}
static int cros_ec_kbd_probe(struct udevice *dev)
{
struct cros_ec_keyb_priv *priv = dev_get_priv(dev);
struct keyboard_priv *uc_priv = dev_get_uclass_priv(dev);
struct stdio_dev *sdev = &uc_priv->sdev;
struct input_config *input = &uc_priv->input;
const void *blob = gd->fdt_blob;
int node = dev->of_offset;
int ret;
if (cros_ec_keyb_decode_fdt(blob, node, priv))
return -1;
input_set_delays(input, KBC_REPEAT_DELAY_MS, KBC_REPEAT_RATE_MS);
ret = key_matrix_init(&priv->matrix, priv->key_rows, priv->key_cols,
priv->ghost_filter);
if (ret) {
debug("%s: cannot init key matrix\n", __func__);
return ret;
}
ret = key_matrix_decode_fdt(&priv->matrix, gd->fdt_blob, node);
if (ret) {
debug("%s: Could not decode key matrix from fdt\n", __func__);
return ret;
}
debug("%s: Matrix keyboard %dx%d ready\n", __func__, priv->key_rows,
priv->key_cols);
priv->input = input;
input->dev = dev;
input_add_tables(input, false);
input->read_keys = cros_ec_kbc_check;
strcpy(sdev->name, "cros-ec-keyb");
/* Register the device. cros_ec_init_keyboard() will be called soon */
return input_stdio_register(sdev);
}
static const struct keyboard_ops cros_ec_kbd_ops = {
};
static const struct udevice_id cros_ec_kbd_ids[] = {
{ .compatible = "google,cros-ec-keyb" },
{ }
};
U_BOOT_DRIVER(cros_ec_kbd) = {
.name = "cros_ec_kbd",
.id = UCLASS_KEYBOARD,
.of_match = cros_ec_kbd_ids,
.probe = cros_ec_kbd_probe,
.ops = &cros_ec_kbd_ops,
.priv_auto_alloc_size = sizeof(struct cros_ec_keyb_priv),
};