// SPDX-License-Identifier: GPL-2.0-only
/*
* GPIO driven matrix keyboard driver
*
* Copyright (c) 2008 Marek Vasut <[email protected]>
*
* Based on corgikbd.c
*/
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/input/matrix_keypad.h>
#include <linux/slab.h>
#include <linux/of.h>
struct matrix_keypad {
struct input_dev *input_dev;
unsigned int row_shift;
unsigned int col_scan_delay_us;
/* key debounce interval in milli-second */
unsigned int debounce_ms;
bool drive_inactive_cols;
struct gpio_desc *row_gpios[MATRIX_MAX_ROWS];
unsigned int num_row_gpios;
struct gpio_desc *col_gpios[MATRIX_MAX_ROWS];
unsigned int num_col_gpios;
unsigned int row_irqs[MATRIX_MAX_ROWS];
DECLARE_BITMAP(wakeup_enabled_irqs, MATRIX_MAX_ROWS);
uint32_t last_key_state[MATRIX_MAX_COLS];
struct delayed_work work;
spinlock_t lock;
bool scan_pending;
bool stopped;
};
/*
* NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
* HiZ when de-activated to cause minmal side effect when scanning other
* columns. In that case it is configured here to be input, otherwise it is
* driven with the inactive value.
*/
static void __activate_col(struct matrix_keypad *keypad, int col, bool on)
{
if (on) {
gpiod_direction_output(keypad->col_gpios[col], 1);
} else {
gpiod_set_value_cansleep(keypad->col_gpios[col], 0);
if (!keypad->drive_inactive_cols)
gpiod_direction_input(keypad->col_gpios[col]);
}
}
static void activate_col(struct matrix_keypad *keypad, int col, bool on)
{
__activate_col(keypad, col, on);
if (on && keypad->col_scan_delay_us)
udelay(keypad->col_scan_delay_us);
}
static void activate_all_cols(struct matrix_keypad *keypad, bool on)
{
int col;
for (col = 0; col < keypad->num_col_gpios; col++)
__activate_col(keypad, col, on);
}
static bool row_asserted(struct matrix_keypad *keypad, int row)
{
return gpiod_get_value_cansleep(keypad->row_gpios[row]);
}
static void enable_row_irqs(struct matrix_keypad *keypad)
{
int i;
for (i = 0; i < keypad->num_row_gpios; i++)
enable_irq(keypad->row_irqs[i]);
}
static void disable_row_irqs(struct matrix_keypad *keypad)
{
int i;
for (i = 0; i < keypad->num_row_gpios; i++)
disable_irq_nosync(keypad->row_irqs[i]);
}
/*
* This gets the keys from keyboard and reports it to input subsystem
*/
static void matrix_keypad_scan(struct work_struct *work)
{
struct matrix_keypad *keypad =
container_of(work, struct matrix_keypad, work.work);
struct input_dev *input_dev = keypad->input_dev;
const unsigned short *keycodes = input_dev->keycode;
uint32_t new_state[MATRIX_MAX_COLS];
int row, col, code;
/* de-activate all columns for scanning */
activate_all_cols(keypad, false);
memset(new_state, 0, sizeof(new_state));
for (row = 0; row < keypad->num_row_gpios; row++)
gpiod_direction_input(keypad->row_gpios[row]);
/* assert each column and read the row status out */
for (col = 0; col < keypad->num_col_gpios; col++) {
activate_col(keypad, col, true);
for (row = 0; row < keypad->num_row_gpios; row++)
new_state[col] |=
row_asserted(keypad, row) ? BIT(row) : 0;
activate_col(keypad, col, false);
}
for (col = 0; col < keypad->num_col_gpios; col++) {
uint32_t bits_changed;
bits_changed = keypad->last_key_state[col] ^ new_state[col];
if (bits_changed == 0)
continue;
for (row = 0; row < keypad->num_row_gpios; row++) {
if (!(bits_changed & BIT(row)))
continue;
code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
input_event(input_dev, EV_MSC, MSC_SCAN, code);
input_report_key(input_dev,
keycodes[code],
new_state[col] & (1 << row));
}
}
input_sync(input_dev);
memcpy(keypad->last_key_state, new_state, sizeof(new_state));
activate_all_cols(keypad, true);
/* Enable IRQs again */
spin_lock_irq(&keypad->lock);
keypad->scan_pending = false;
enable_row_irqs(keypad);
spin_unlock_irq(&keypad->lock);
}
static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
{
struct matrix_keypad *keypad = id;
unsigned long flags;
spin_lock_irqsave(&keypad->lock, flags);
/*
* See if another IRQ beaten us to it and scheduled the
* scan already. In that case we should not try to
* disable IRQs again.
*/
if (unlikely(keypad->scan_pending || keypad->stopped))
goto out;
disable_row_irqs(keypad);
keypad->scan_pending = true;
schedule_delayed_work(&keypad->work,
msecs_to_jiffies(keypad->debounce_ms));
out:
spin_unlock_irqrestore(&keypad->lock, flags);
return IRQ_HANDLED;
}
static int matrix_keypad_start(struct input_dev *dev)
{
struct matrix_keypad *keypad = input_get_drvdata(dev);
keypad->stopped = false;
mb();
/*
* Schedule an immediate key scan to capture current key state;
* columns will be activated and IRQs be enabled after the scan.
*/
schedule_delayed_work(&keypad->work, 0);
return 0;
}
static void matrix_keypad_stop(struct input_dev *dev)
{
struct matrix_keypad *keypad = input_get_drvdata(dev);
spin_lock_irq(&keypad->lock);
keypad->stopped = true;
spin_unlock_irq(&keypad->lock);
flush_delayed_work(&keypad->work);
/*
* matrix_keypad_scan() will leave IRQs enabled;
* we should disable them now.
*/
disable_row_irqs(keypad);
}
static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
{
int i;
for_each_clear_bit(i, keypad->wakeup_enabled_irqs,
keypad->num_row_gpios)
if (enable_irq_wake(keypad->row_irqs[i]) == 0)
__set_bit(i, keypad->wakeup_enabled_irqs);
}
static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
{
int i;
for_each_set_bit(i, keypad->wakeup_enabled_irqs,
keypad->num_row_gpios) {
disable_irq_wake(keypad->row_irqs[i]);
__clear_bit(i, keypad->wakeup_enabled_irqs);
}
}
static int matrix_keypad_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct matrix_keypad *keypad = platform_get_drvdata(pdev);
matrix_keypad_stop(keypad->input_dev);
if (device_may_wakeup(&pdev->dev))
matrix_keypad_enable_wakeup(keypad);
return 0;
}
static int matrix_keypad_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct matrix_keypad *keypad = platform_get_drvdata(pdev);
if (device_may_wakeup(&pdev->dev))
matrix_keypad_disable_wakeup(keypad);
matrix_keypad_start(keypad->input_dev);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
matrix_keypad_suspend, matrix_keypad_resume);
static int matrix_keypad_init_gpio(struct platform_device *pdev,
struct matrix_keypad *keypad)
{
bool active_low;
int nrow, ncol;
int err;
int i;
nrow = gpiod_count(&pdev->dev, "row");
ncol = gpiod_count(&pdev->dev, "col");
if (nrow < 0 || ncol < 0) {
dev_err(&pdev->dev, "missing row or column GPIOs\n");
return -EINVAL;
}
keypad->num_row_gpios = nrow;
keypad->num_col_gpios = ncol;
active_low = device_property_read_bool(&pdev->dev, "gpio-activelow");
/* initialize strobe lines as outputs, activated */
for (i = 0; i < keypad->num_col_gpios; i++) {
keypad->col_gpios[i] = devm_gpiod_get_index(&pdev->dev, "col",
i, GPIOD_ASIS);
err = PTR_ERR_OR_ZERO(keypad->col_gpios[i]);
if (err) {
dev_err(&pdev->dev,
"failed to request GPIO for COL%d: %d\n",
i, err);
return err;
}
gpiod_set_consumer_name(keypad->col_gpios[i], "matrix_kbd_col");
if (active_low ^ gpiod_is_active_low(keypad->col_gpios[i]))
gpiod_toggle_active_low(keypad->col_gpios[i]);
gpiod_direction_output(keypad->col_gpios[i], 1);
}
for (i = 0; i < keypad->num_row_gpios; i++) {
keypad->row_gpios[i] = devm_gpiod_get_index(&pdev->dev, "row",
i, GPIOD_IN);
err = PTR_ERR_OR_ZERO(keypad->row_gpios[i]);
if (err) {
dev_err(&pdev->dev,
"failed to request GPIO for ROW%d: %d\n",
i, err);
return err;
}
gpiod_set_consumer_name(keypad->row_gpios[i], "matrix_kbd_row");
if (active_low ^ gpiod_is_active_low(keypad->row_gpios[i]))
gpiod_toggle_active_low(keypad->row_gpios[i]);
}
return 0;
}
static int matrix_keypad_setup_interrupts(struct platform_device *pdev,
struct matrix_keypad *keypad)
{
int err;
int irq;
int i;
for (i = 0; i < keypad->num_row_gpios; i++) {
irq = gpiod_to_irq(keypad->row_gpios[i]);
if (irq < 0) {
err = irq;
dev_err(&pdev->dev,
"Unable to convert GPIO line %i to irq: %d\n",
i, err);
return err;
}
err = devm_request_any_context_irq(&pdev->dev, irq,
matrix_keypad_interrupt,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING,
"matrix-keypad", keypad);
if (err < 0) {
dev_err(&pdev->dev,
"Unable to acquire interrupt for row %i: %d\n",
i, err);
return err;
}
keypad->row_irqs[i] = irq;
}
/* initialized as disabled - enabled by input->open */
disable_row_irqs(keypad);
return 0;
}
static int matrix_keypad_probe(struct platform_device *pdev)
{
struct matrix_keypad *keypad;
struct input_dev *input_dev;
bool wakeup;
int err;
keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
if (!keypad)
return -ENOMEM;
input_dev = devm_input_allocate_device(&pdev->dev);
if (!input_dev)
return -ENOMEM;
keypad->input_dev = input_dev;
keypad->stopped = true;
INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
spin_lock_init(&keypad->lock);
keypad->drive_inactive_cols =
device_property_read_bool(&pdev->dev, "drive-inactive-cols");
device_property_read_u32(&pdev->dev, "debounce-delay-ms",
&keypad->debounce_ms);
device_property_read_u32(&pdev->dev, "col-scan-delay-us",
&keypad->col_scan_delay_us);
err = matrix_keypad_init_gpio(pdev, keypad);
if (err)
return err;
keypad->row_shift = get_count_order(keypad->num_col_gpios);
err = matrix_keypad_setup_interrupts(pdev, keypad);
if (err)
return err;
input_dev->name = pdev->name;
input_dev->id.bustype = BUS_HOST;
input_dev->open = matrix_keypad_start;
input_dev->close = matrix_keypad_stop;
err = matrix_keypad_build_keymap(NULL, NULL,
keypad->num_row_gpios,
keypad->num_col_gpios,
NULL, input_dev);
if (err) {
dev_err(&pdev->dev, "failed to build keymap\n");
return -ENOMEM;
}
if (!device_property_read_bool(&pdev->dev, "linux,no-autorepeat"))
__set_bit(EV_REP, input_dev->evbit);
input_set_capability(input_dev, EV_MSC, MSC_SCAN);
input_set_drvdata(input_dev, keypad);
err = input_register_device(keypad->input_dev);
if (err)
return err;
wakeup = device_property_read_bool(&pdev->dev, "wakeup-source") ||
/* legacy */
device_property_read_bool(&pdev->dev, "linux,wakeup");
device_init_wakeup(&pdev->dev, wakeup);
platform_set_drvdata(pdev, keypad);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id matrix_keypad_dt_match[] = {
{ .compatible = "gpio-matrix-keypad" },
{ }
};
MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
#endif
static struct platform_driver matrix_keypad_driver = {
.probe = matrix_keypad_probe,
.driver = {
.name = "matrix-keypad",
.pm = pm_sleep_ptr(&matrix_keypad_pm_ops),
.of_match_table = of_match_ptr(matrix_keypad_dt_match),
},
};
module_platform_driver(matrix_keypad_driver);
MODULE_AUTHOR("Marek Vasut <[email protected]>");
MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:matrix-keypad");
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