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/*
* Copyright (c) 2020-2021 The ZMK Contributors
*
* SPDX-License-Identifier: MIT
*/
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>
#include <drivers/kscan.h>
#include <logging/log.h>
#include <sys/__assert.h>
#include <sys/util.h>
LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
#define DT_DRV_COMPAT zmk_kscan_gpio_matrix
#if DT_HAS_COMPAT_STATUS_OKAY(DT_DRV_COMPAT)
#define INST_DIODE_DIR(n) DT_ENUM_IDX(DT_DRV_INST(n), diode_direction)
#define COND_DIODE_DIR(n, row2col_code, col2row_code) \
COND_CODE_0(INST_DIODE_DIR(n), row2col_code, col2row_code)
#define INST_ROWS_LEN(n) DT_INST_PROP_LEN(n, row_gpios)
#define INST_COLS_LEN(n) DT_INST_PROP_LEN(n, col_gpios)
#define INST_MATRIX_LEN(n) (INST_ROWS_LEN(n) * INST_COLS_LEN(n))
#define INST_INPUTS_LEN(n) COND_DIODE_DIR(n, (INST_COLS_LEN(n)), (INST_ROWS_LEN(n)))
#define USE_POLLING IS_ENABLED(CONFIG_ZMK_KSCAN_MATRIX_POLLING)
#define USE_INTERRUPTS (!USE_POLLING)
#define COND_INTERRUPTS(code) COND_CODE_1(CONFIG_ZMK_KSCAN_MATRIX_POLLING, (), code)
#define COND_POLL_OR_INTERRUPTS(pollcode, intcode) \
COND_CODE_1(CONFIG_ZMK_KSCAN_MATRIX_POLLING, pollcode, intcode)
// TODO (Zephr 2.6): replace the following
// kscan_gpio_dt_spec -> gpio_dt_spec
// KSCAN_GPIO_DT_SPEC_GET_BY_IDX -> GPIO_DT_SPEC_GET_BY_IDX
// gpio_pin_get -> gpio_pin_get_dt
// gpio_pin_set -> gpio_pin_set_dt
// gpio_pin_interrupt_configure -> gpio_pin_interrupt_configure_dt
struct kscan_gpio_dt_spec {
const struct device *port;
gpio_pin_t pin;
gpio_dt_flags_t dt_flags;
};
#define KSCAN_GPIO_DT_SPEC_GET_BY_IDX(node_id, prop, idx) \
{ \
.port = DEVICE_DT_GET(DT_GPIO_CTLR_BY_IDX(node_id, prop, idx)), \
.pin = DT_GPIO_PIN_BY_IDX(node_id, prop, idx), \
.dt_flags = DT_GPIO_FLAGS_BY_IDX(node_id, prop, idx), \
}
#define KSCAN_GPIO_ROW_CFG_INIT(idx, inst_idx) \
KSCAN_GPIO_DT_SPEC_GET_BY_IDX(DT_DRV_INST(inst_idx), row_gpios, idx),
#define KSCAN_GPIO_COL_CFG_INIT(idx, inst_idx) \
KSCAN_GPIO_DT_SPEC_GET_BY_IDX(DT_DRV_INST(inst_idx), col_gpios, idx),
enum kscan_diode_direction {
KSCAN_ROW2COL,
KSCAN_COL2ROW,
};
struct kscan_matrix_irq_callback {
const struct device *dev;
struct gpio_callback callback;
struct k_delayed_work *work;
};
struct kscan_matrix_data {
const struct device *dev;
kscan_callback_t callback;
struct k_delayed_work work;
#if USE_POLLING
struct k_timer poll_timer;
#else
/** Array of length config->inputs.len */
struct kscan_matrix_irq_callback *irqs;
#endif
/**
* Current state of the matrix as a flattened 2D array of length
* (config->rows.len * config->cols.len)
*/
bool *current_state;
/** Buffer for reading in the next matrix state. Parallel array to current_state. */
bool *next_state;
};
struct kscan_gpio_list {
const struct kscan_gpio_dt_spec *gpios;
size_t len;
};
/** Define a kscan_gpio_list from a compile-time GPIO array. */
#define KSCAN_GPIO_LIST(gpio_array) \
((struct kscan_gpio_list){.gpios = gpio_array, .len = ARRAY_SIZE(gpio_array)})
struct kscan_matrix_config {
struct kscan_gpio_list rows;
struct kscan_gpio_list cols;
struct kscan_gpio_list inputs;
struct kscan_gpio_list outputs;
int32_t debounce_period_ms;
int32_t poll_period_ms;
enum kscan_diode_direction diode_direction;
};
/**
* Get the index into a matrix state array from a row and column.
*/
static int state_index_rc(const struct kscan_matrix_config *config, const int row, const int col) {
__ASSERT(row < config->rows.len, "Invalid row %i", row);
__ASSERT(col < config->cols.len, "Invalid column %i", col);
return (col * config->rows.len) + row;
}
/**
* Get the index into a matrix state array from input/output pin indices.
*/
static int state_index_io(const struct kscan_matrix_config *config, const int input_idx,
const int output_idx) {
return (config->diode_direction == KSCAN_ROW2COL)
? state_index_rc(config, output_idx, input_idx)
: state_index_rc(config, input_idx, output_idx);
}
static int kscan_matrix_set_all_outputs(const struct device *dev, const int value) {
const struct kscan_matrix_config *config = dev->config;
for (int i = 0; i < config->outputs.len; i++) {
const struct kscan_gpio_dt_spec *gpio = &config->outputs.gpios[i];
int err = gpio_pin_set(gpio->port, gpio->pin, value);
if (err) {
LOG_ERR("Failed to set output %i to %i: %i", i, value, err);
return err;
}
}
return 0;
}
#if USE_INTERRUPTS
static int kscan_matrix_interrupt_configure(const struct device *dev, const gpio_flags_t flags) {
const struct kscan_matrix_config *config = dev->config;
for (int i = 0; i < config->inputs.len; i++) {
const struct kscan_gpio_dt_spec *gpio = &config->inputs.gpios[i];
int err = gpio_pin_interrupt_configure(gpio->port, gpio->pin, flags);
if (err) {
LOG_ERR("Unable to configure interrupt for pin %u on %s", gpio->pin, gpio->port->name);
return err;
}
}
return 0;
}
#endif
#if USE_INTERRUPTS
static int kscan_matrix_interrupt_enable(const struct device *dev) {
int err = kscan_matrix_interrupt_configure(dev, GPIO_INT_LEVEL_ACTIVE);
if (err) {
return err;
}
// While interrupts are enabled, set all outputs active so a pressed key
// will trigger an interrupt.
return kscan_matrix_set_all_outputs(dev, 1);
}
#endif
#if USE_INTERRUPTS
static int kscan_matrix_interrupt_disable(const struct device *dev) {
int err = kscan_matrix_interrupt_configure(dev, GPIO_INT_DISABLE);
if (err) {
return err;
}
// While interrupts are disabled, set all outputs inactive so
// kscan_matrix_read() can scan them one by one.
return kscan_matrix_set_all_outputs(dev, 0);
}
#endif
#if USE_INTERRUPTS
static void kscan_matrix_irq_callback_handler(const struct device *port, struct gpio_callback *cb,
const gpio_port_pins_t pin) {
struct kscan_matrix_irq_callback *data =
CONTAINER_OF(cb, struct kscan_matrix_irq_callback, callback);
const struct kscan_matrix_config *config = data->dev->config;
// Disable our interrupts temporarily to avoid re-entry while we scan.
kscan_matrix_interrupt_disable(data->dev);
// TODO (Zephyr 2.6): use k_work_reschedule()
k_delayed_work_cancel(data->work);
k_delayed_work_submit(data->work, K_MSEC(config->debounce_period_ms));
}
#endif
static int kscan_matrix_read(const struct device *dev) {
struct kscan_matrix_data *data = dev->data;
const struct kscan_matrix_config *config = dev->config;
// Scan the matrix.
for (int o = 0; o < config->outputs.len; o++) {
const struct kscan_gpio_dt_spec *out_gpio = &config->outputs.gpios[o];
int err = gpio_pin_set(out_gpio->port, out_gpio->pin, 1);
if (err) {
LOG_ERR("Failed to set output %i active: %i", o, err);
return err;
}
for (int i = 0; i < config->inputs.len; i++) {
const struct kscan_gpio_dt_spec *in_gpio = &config->inputs.gpios[i];
const int index = state_index_io(config, i, o);
data->next_state[index] = gpio_pin_get(in_gpio->port, in_gpio->pin);
}
err = gpio_pin_set(out_gpio->port, out_gpio->pin, 0);
if (err) {
LOG_ERR("Failed to set output %i inactive: %i", o, err);
return err;
}
}
// Process the new state.
#if USE_INTERRUPTS
bool submit_followup_read = false;
#endif
for (int r = 0; r < config->rows.len; r++) {
for (int c = 0; c < config->cols.len; c++) {
const int index = state_index_rc(config, r, c);
const bool pressed = data->next_state[index];
// Follow up reads are needed if any key is pressed because further
// interrupts won't fire on already tripped GPIO pins.
#if USE_INTERRUPTS
submit_followup_read = submit_followup_read || pressed;
#endif
if (pressed != data->current_state[index]) {
LOG_DBG("Sending event at %i,%i state %s", r, c, pressed ? "on" : "off");
data->current_state[index] = pressed;
data->callback(dev, r, c, pressed);
}
}
}
#if USE_INTERRUPTS
if (submit_followup_read) {
// At least one key is pressed. Poll until everything is released.
// TODO (Zephyr 2.6): use k_work_reschedule()
k_delayed_work_cancel(&data->work);
k_delayed_work_submit(&data->work, K_MSEC(config->debounce_period_ms));
} else {
// All keys are released. Return to waiting for an interrupt.
kscan_matrix_interrupt_enable(dev);
}
#endif
return 0;
}
#if USE_POLLING
static void kscan_matrix_timer_handler(struct k_timer *timer) {
struct kscan_matrix_data *data = CONTAINER_OF(timer, struct kscan_matrix_data, poll_timer);
k_delayed_work_submit(&data->work, K_NO_WAIT);
}
#endif
static void kscan_matrix_work_handler(struct k_work *work) {
struct k_delayed_work *dwork = CONTAINER_OF(work, struct k_delayed_work, work);
struct kscan_matrix_data *data = CONTAINER_OF(dwork, struct kscan_matrix_data, work);
kscan_matrix_read(data->dev);
}
static int kscan_matrix_configure(const struct device *dev, const kscan_callback_t callback) {
struct kscan_matrix_data *data = dev->data;
if (!callback) {
return -EINVAL;
}
data->callback = callback;
return 0;
}
static int kscan_matrix_enable(const struct device *dev) {
#if USE_POLLING
struct kscan_matrix_data *data = dev->data;
const struct kscan_matrix_config *config = dev->config;
k_timer_start(&data->poll_timer, K_MSEC(config->poll_period_ms),
K_MSEC(config->poll_period_ms));
return 0;
#else
// Read will automatically enable interrupts once done.
return kscan_matrix_read(dev);
#endif
}
static int kscan_matrix_disable(const struct device *dev) {
#if USE_POLLING
struct kscan_matrix_data *data = dev->data;
k_timer_stop(&data->poll_timer);
return 0;
#else
return kscan_matrix_interrupt_disable(dev);
#endif
}
static int kscan_matrix_init_input_inst(const struct device *dev,
const struct kscan_gpio_dt_spec *gpio, const int index) {
if (!device_is_ready(gpio->port)) {
LOG_ERR("GPIO is not ready: %s", gpio->port->name);
return -ENODEV;
}
int err = gpio_pin_configure(gpio->port, gpio->pin, GPIO_INPUT | gpio->dt_flags);
if (err) {
LOG_ERR("Unable to configure pin %u on %s for input", gpio->pin, gpio->port->name);
return err;
}
LOG_DBG("Configured pin %u on %s for input", gpio->pin, gpio->port->name);
#if USE_INTERRUPTS
struct kscan_matrix_data *data = dev->data;
struct kscan_matrix_irq_callback *irq = &data->irqs[index];
irq->dev = dev;
irq->work = &data->work;
gpio_init_callback(&irq->callback, kscan_matrix_irq_callback_handler, BIT(gpio->pin));
err = gpio_add_callback(gpio->port, &irq->callback);
if (err) {
LOG_ERR("Error adding the callback to the input device: %i", err);
return err;
}
#endif
return 0;
}
static int kscan_matrix_init_inputs(const struct device *dev) {
const struct kscan_matrix_config *config = dev->config;
for (int i = 0; i < config->inputs.len; i++) {
const struct kscan_gpio_dt_spec *gpio = &config->inputs.gpios[i];
int err = kscan_matrix_init_input_inst(dev, gpio, i);
if (err) {
return err;
}
}
return 0;
}
static int kscan_matrix_init_output_inst(const struct device *dev,
const struct kscan_gpio_dt_spec *gpio) {
if (!device_is_ready(gpio->port)) {
LOG_ERR("GPIO is not ready: %s", gpio->port->name);
return -ENODEV;
}
int err = gpio_pin_configure(gpio->port, gpio->pin, GPIO_OUTPUT | gpio->dt_flags);
if (err) {
LOG_ERR("Unable to configure pin %u on %s for output", gpio->pin, gpio->port->name);
return err;
}
LOG_DBG("Configured pin %u on %s for output", gpio->pin, gpio->port->name);
return 0;
}
static int kscan_matrix_init_outputs(const struct device *dev) {
const struct kscan_matrix_config *config = dev->config;
for (int i = 0; i < config->outputs.len; i++) {
const struct kscan_gpio_dt_spec *gpio = &config->outputs.gpios[i];
int err = kscan_matrix_init_output_inst(dev, gpio);
if (err) {
return err;
}
}
return 0;
}
static int kscan_matrix_init(const struct device *dev) {
struct kscan_matrix_data *data = dev->data;
data->dev = dev;
kscan_matrix_init_inputs(dev);
kscan_matrix_init_outputs(dev);
kscan_matrix_set_all_outputs(dev, 0);
k_delayed_work_init(&data->work, kscan_matrix_work_handler);
#if USE_POLLING
k_timer_init(&data->poll_timer, kscan_matrix_timer_handler, NULL);
#endif
return 0;
}
static const struct kscan_driver_api kscan_matrix_api = {
.config = kscan_matrix_configure,
.enable_callback = kscan_matrix_enable,
.disable_callback = kscan_matrix_disable,
};
#define KSCAN_MATRIX_INIT(index) \
static const struct kscan_gpio_dt_spec kscan_matrix_rows_##index[] = { \
UTIL_LISTIFY(INST_ROWS_LEN(index), KSCAN_GPIO_ROW_CFG_INIT, index)}; \
\
static const struct kscan_gpio_dt_spec kscan_matrix_cols_##index[] = { \
UTIL_LISTIFY(INST_COLS_LEN(index), KSCAN_GPIO_COL_CFG_INIT, index)}; \
\
static bool kscan_current_state_##index[INST_MATRIX_LEN(index)]; \
static bool kscan_next_state_##index[INST_MATRIX_LEN(index)]; \
\
COND_INTERRUPTS((static struct kscan_matrix_irq_callback \
kscan_matrix_irqs_##index[INST_INPUTS_LEN(index)];)) \
\
static struct kscan_matrix_data kscan_matrix_data_##index = { \
.current_state = kscan_current_state_##index, \
.next_state = kscan_next_state_##index, \
COND_INTERRUPTS((.irqs = kscan_matrix_irqs_##index, ))}; \
\
static struct kscan_matrix_config kscan_matrix_config_##index = { \
.rows = KSCAN_GPIO_LIST(kscan_matrix_rows_##index), \
.cols = KSCAN_GPIO_LIST(kscan_matrix_cols_##index), \
.inputs = KSCAN_GPIO_LIST( \
COND_DIODE_DIR(index, (kscan_matrix_cols_##index), (kscan_matrix_rows_##index))), \
.outputs = KSCAN_GPIO_LIST( \
COND_DIODE_DIR(index, (kscan_matrix_rows_##index), (kscan_matrix_cols_##index))), \
.debounce_period_ms = DT_INST_PROP(index, debounce_period), \
.poll_period_ms = DT_INST_PROP(index, poll_period_ms), \
.diode_direction = INST_DIODE_DIR(index), \
}; \
\
DEVICE_DT_INST_DEFINE(index, &kscan_matrix_init, device_pm_control_nop, \
&kscan_matrix_data_##index, &kscan_matrix_config_##index, APPLICATION, \
CONFIG_APPLICATION_INIT_PRIORITY, &kscan_matrix_api);
DT_INST_FOREACH_STATUS_OKAY(KSCAN_MATRIX_INIT);
#endif // DT_HAS_COMPAT_STATUS_OKAY(DT_DRV_COMPAT)