drivers/kscan/kscan_ft5336.c

/*
 * Copyright (c) 2020 NXP
 * Copyright (c) 2020 Mark Olsson <mark@markolsson.se>
 * Copyright (c) 2020 Teslabs Engineering S.L.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT focaltech_ft5336

#include <zephyr/drivers/kscan.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/gpio.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(ft5336, CONFIG_KSCAN_LOG_LEVEL);

/* FT5336 used registers */
#define REG_TD_STATUS		0x02U
#define REG_P1_XH		0x03U

/* REG_TD_STATUS: Touch points. */
#define TOUCH_POINTS_POS	0U
#define TOUCH_POINTS_MSK	0x0FU

/* REG_Pn_XH: Events. */
#define EVENT_POS		6U
#define EVENT_MSK		0x03U

#define EVENT_PRESS_DOWN	0x00U
#define EVENT_LIFT_UP		0x01U
#define EVENT_CONTACT		0x02U
#define EVENT_NONE		0x03U

/* REG_Pn_XH: Position */
#define POSITION_H_MSK		0x0FU

/** FT5336 configuration (DT). */
struct ft5336_config {
	/** I2C bus. */
	struct i2c_dt_spec bus;
#ifdef CONFIG_KSCAN_FT5336_INTERRUPT
	/** Interrupt GPIO information. */
	struct gpio_dt_spec int_gpio;
#endif
};

/** FT5336 data. */
struct ft5336_data {
	/** Device pointer. */
	const struct device *dev;
	/** KSCAN Callback. */
	kscan_callback_t callback;
	/** Work queue (for deferred read). */
	struct k_work work;
#ifdef CONFIG_KSCAN_FT5336_INTERRUPT
	/** Interrupt GPIO callback. */
	struct gpio_callback int_gpio_cb;
#else
	/** Timer (polling mode). */
	struct k_timer timer;
#endif
};

static int ft5336_process(const struct device *dev)
{
	const struct ft5336_config *config = dev->config;
	struct ft5336_data *data = dev->data;

	int r;
	uint8_t points;
	uint8_t coords[4U];
	uint8_t event;
	uint16_t row, col;
	bool pressed;

	/* obtain number of touch points (NOTE: multi-touch ignored) */
	r = i2c_reg_read_byte_dt(&config->bus, REG_TD_STATUS, &points);
	if (r < 0) {
		return r;
	}

	points = (points >> TOUCH_POINTS_POS) & TOUCH_POINTS_MSK;
	if (points != 0U && points != 1U) {
		return 0;
	}

	/* obtain first point X, Y coordinates and event from:
	 * REG_P1_XH, REG_P1_XL, REG_P1_YH, REG_P1_YL.
	 */
	r = i2c_burst_read_dt(&config->bus, REG_P1_XH, coords, sizeof(coords));
	if (r < 0) {
		return r;
	}

	event = (coords[0] >> EVENT_POS) & EVENT_MSK;
	row = ((coords[0] & POSITION_H_MSK) << 8U) | coords[1];
	col = ((coords[2] & POSITION_H_MSK) << 8U) | coords[3];
	pressed = (event == EVENT_PRESS_DOWN) || (event == EVENT_CONTACT);

	LOG_DBG("event: %d, row: %d, col: %d", event, row, col);

	data->callback(dev, row, col, pressed);

	return 0;
}

static void ft5336_work_handler(struct k_work *work)
{
	struct ft5336_data *data = CONTAINER_OF(work, struct ft5336_data, work);

	ft5336_process(data->dev);
}

#ifdef CONFIG_KSCAN_FT5336_INTERRUPT
static void ft5336_isr_handler(const struct device *dev,
			       struct gpio_callback *cb, uint32_t pins)
{
	struct ft5336_data *data = CONTAINER_OF(cb, struct ft5336_data, int_gpio_cb);

	k_work_submit(&data->work);
}
#else
static void ft5336_timer_handler(struct k_timer *timer)
{
	struct ft5336_data *data = CONTAINER_OF(timer, struct ft5336_data, timer);

	k_work_submit(&data->work);
}
#endif

static int ft5336_configure(const struct device *dev,
			    kscan_callback_t callback)
{
	struct ft5336_data *data = dev->data;

	if (!callback) {
		LOG_ERR("Invalid callback (NULL)");
		return -EINVAL;
	}

	data->callback = callback;

	return 0;
}

static int ft5336_enable_callback(const struct device *dev)
{
	struct ft5336_data *data = dev->data;

#ifdef CONFIG_KSCAN_FT5336_INTERRUPT
	const struct ft5336_config *config = dev->config;

	gpio_add_callback(config->int_gpio.port, &data->int_gpio_cb);
#else
	k_timer_start(&data->timer, K_MSEC(CONFIG_KSCAN_FT5336_PERIOD),
		      K_MSEC(CONFIG_KSCAN_FT5336_PERIOD));
#endif

	return 0;
}

static int ft5336_disable_callback(const struct device *dev)
{
	struct ft5336_data *data = dev->data;

#ifdef CONFIG_KSCAN_FT5336_INTERRUPT
	const struct ft5336_config *config = dev->config;

	gpio_remove_callback(config->int_gpio.port, &data->int_gpio_cb);
#else
	k_timer_stop(&data->timer);
#endif

	return 0;
}

static int ft5336_init(const struct device *dev)
{
	const struct ft5336_config *config = dev->config;
	struct ft5336_data *data = dev->data;

	if (!device_is_ready(config->bus.bus)) {
		LOG_ERR("I2C controller device not ready");
		return -ENODEV;
	}

	data->dev = dev;

	k_work_init(&data->work, ft5336_work_handler);

#ifdef CONFIG_KSCAN_FT5336_INTERRUPT
	int r;

	if (!device_is_ready(config->int_gpio.port)) {
		LOG_ERR("Interrupt GPIO controller device not ready");
		return -ENODEV;
	}

	r = gpio_pin_configure_dt(&config->int_gpio, GPIO_INPUT);
	if (r < 0) {
		LOG_ERR("Could not configure interrupt GPIO pin");
		return r;
	}

	r = gpio_pin_interrupt_configure_dt(&config->int_gpio,
					    GPIO_INT_EDGE_TO_ACTIVE);
	if (r < 0) {
		LOG_ERR("Could not configure interrupt GPIO interrupt.");
		return r;
	}

	gpio_init_callback(&data->int_gpio_cb, ft5336_isr_handler,
			   BIT(config->int_gpio.pin));
#else
	k_timer_init(&data->timer, ft5336_timer_handler, NULL);
#endif

	return 0;
}

static const struct kscan_driver_api ft5336_driver_api = {
	.config = ft5336_configure,
	.enable_callback = ft5336_enable_callback,
	.disable_callback = ft5336_disable_callback,
};

#define FT5336_INIT(index)                                                     \
	static const struct ft5336_config ft5336_config_##index = {	       \
		.bus = I2C_DT_SPEC_INST_GET(index),			       \
		IF_ENABLED(CONFIG_KSCAN_FT5336_INTERRUPT,		       \
		(.int_gpio = GPIO_DT_SPEC_INST_GET(index, int_gpios),))	       \
	};								       \
	static struct ft5336_data ft5336_data_##index;			       \
	DEVICE_DT_INST_DEFINE(index, ft5336_init, NULL,			       \
			    &ft5336_data_##index, &ft5336_config_##index,      \
			    POST_KERNEL, CONFIG_KSCAN_INIT_PRIORITY,	       \
			    &ft5336_driver_api);

DT_INST_FOREACH_STATUS_OKAY(FT5336_INIT)