zmk_mf68/app/drivers/kscan/kscan_gpio_matrix.c
Joel Spadin 82cb762698 refactor(kscan): Demacroify GPIO matrix driver
Refactored the GPIO matrix kscan driver so that only the data and config
structures are defined in the foreach macro. Functionality is unchanged
except for the addition of DT properties to adjust polling speed.

This should make it easier to add other enhancements later, like
improved and customizable debounce behavior.
2021-09-08 14:34:28 -04:00

459 lines
17 KiB
C

/*
* 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)