blob: 01699c06377128e2467125e7aaeb6ad5eb078638 [file] [log] [blame]
/*
* 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 goodix_gt911
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/input/input.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(gt911, CONFIG_INPUT_LOG_LEVEL);
/* GT911 used registers */
#define DEVICE_ID BSWAP_16(0x8140U)
#define REG_STATUS BSWAP_16(0x814EU)
#define REG_FIRST_POINT BSWAP_16(0x814FU)
/* REG_TD_STATUS: Touch points. */
#define TOUCH_POINTS_MSK 0x0FU
/* REG_TD_STATUS: Pressed. */
#define TOUCH_STATUS_MSK (1 << 7U)
/* The GT911's config */
#define GT911_CONFIG_REG BSWAP_16(0x8047U)
#define REG_CONFIG_VERSION GT911_CONFIG_REG
#define REG_CONFIG_SIZE (186U)
#define GT911_PRODUCT_ID (0x00313139U)
/** GT911 configuration (DT). */
struct gt911_config {
/** I2C bus. */
struct i2c_dt_spec bus;
struct gpio_dt_spec rst_gpio;
/** Interrupt GPIO information. */
struct gpio_dt_spec int_gpio;
/* Alternate fallback I2C address */
uint8_t alt_addr;
};
/** GT911 data. */
struct gt911_data {
/** Device pointer. */
const struct device *dev;
/** Work queue (for deferred read). */
struct k_work work;
/** Actual device I2C address */
uint8_t actual_address;
#ifdef CONFIG_INPUT_GT911_INTERRUPT
/** Interrupt GPIO callback. */
struct gpio_callback int_gpio_cb;
#else
/** Timer (polling mode). */
struct k_timer timer;
#endif
};
/** gt911 point reg */
struct gt911_point_reg_t {
uint8_t id; /*!< Track ID. */
uint8_t lowX; /*!< Low byte of x coordinate. */
uint8_t highX; /*!< High byte of x coordinate. */
uint8_t lowY; /*!< Low byte of y coordinate. */
uint8_t highY; /*!< High byte of x coordinate. */
uint8_t lowSize; /*!< Low byte of point size. */
uint8_t highSize; /*!< High byte of point size. */
uint8_t reserved; /*!< Reserved. */
};
/*
* Device-specific wrappers around i2c_write_dt and i2c_write_read_dt.
* These wrappers handle the case where the GT911 did not accept the requested
* I2C address, and the alternate I2C address is used.
*/
static int gt911_i2c_write(const struct device *dev,
const uint8_t *buf, uint32_t num_bytes)
{
const struct gt911_config *config = dev->config;
struct gt911_data *data = dev->data;
return i2c_write(config->bus.bus, buf, num_bytes, data->actual_address);
}
static int gt911_i2c_write_read(const struct device *dev,
const void *write_buf, size_t num_write,
void *read_buf, size_t num_read)
{
const struct gt911_config *config = dev->config;
struct gt911_data *data = dev->data;
return i2c_write_read(config->bus.bus, data->actual_address, write_buf,
num_write, read_buf, num_read);
}
static int gt911_process(const struct device *dev)
{
int r;
uint16_t reg_addr;
uint8_t status;
uint8_t points;
struct gt911_point_reg_t pointRegs;
uint16_t row, col;
bool pressed;
/* obtain number of touch points (NOTE: multi-touch ignored) */
reg_addr = REG_STATUS;
r = gt911_i2c_write_read(dev, &reg_addr, sizeof(reg_addr),
&status, sizeof(status));
if (r < 0) {
return r;
}
points = status & TOUCH_POINTS_MSK;
if (points != 0U && points != 1U && (0 != (status & TOUCH_STATUS_MSK))) {
points = 1;
}
if (!(status & TOUCH_STATUS_MSK)) {
/* Status bit not set, ignore this event */
return 0;
}
/* need to clear the status */
uint8_t clear_buffer[3] = {(uint8_t)REG_STATUS, (uint8_t)(REG_STATUS >> 8), 0};
r = gt911_i2c_write(dev, clear_buffer, sizeof(clear_buffer));
if (r < 0) {
return r;
}
/* obtain first point X, Y coordinates and event from:
* REG_P1_XH, REG_P1_XL, REG_P1_YH, REG_P1_YL.
*/
reg_addr = REG_FIRST_POINT;
r = gt911_i2c_write_read(dev, &reg_addr, sizeof(reg_addr),
&pointRegs, sizeof(pointRegs));
if (r < 0) {
return r;
}
pressed = (points == 1);
row = ((pointRegs.highY) << 8U) | pointRegs.lowY;
col = ((pointRegs.highX) << 8U) | pointRegs.lowX;
LOG_DBG("pressed: %d, row: %d, col: %d", pressed, row, col);
if (pressed) {
input_report_abs(dev, INPUT_ABS_X, col, false, K_FOREVER);
input_report_abs(dev, INPUT_ABS_Y, row, false, K_FOREVER);
input_report_key(dev, INPUT_BTN_TOUCH, 1, true, K_FOREVER);
} else {
input_report_key(dev, INPUT_BTN_TOUCH, 0, true, K_FOREVER);
}
return 0;
}
static void gt911_work_handler(struct k_work *work)
{
struct gt911_data *data = CONTAINER_OF(work, struct gt911_data, work);
gt911_process(data->dev);
}
#ifdef CONFIG_INPUT_GT911_INTERRUPT
static void gt911_isr_handler(const struct device *dev,
struct gpio_callback *cb, uint32_t pins)
{
struct gt911_data *data = CONTAINER_OF(cb, struct gt911_data, int_gpio_cb);
k_work_submit(&data->work);
}
#else
static void gt911_timer_handler(struct k_timer *timer)
{
struct gt911_data *data = CONTAINER_OF(timer, struct gt911_data, timer);
k_work_submit(&data->work);
}
#endif
static uint8_t gt911_get_firmware_checksum(const uint8_t *firmware)
{
uint8_t sum = 0;
uint16_t i = 0;
for (i = 0; i < REG_CONFIG_SIZE - 2U; i++) {
sum += (*firmware);
firmware++;
}
return (~sum + 1U);
}
static bool gt911_verify_firmware(const uint8_t *firmware)
{
return ((firmware[REG_CONFIG_VERSION - GT911_CONFIG_REG] != 0U) &&
(gt911_get_firmware_checksum(firmware) == firmware[REG_CONFIG_SIZE - 2U]));
}
static int gt911_init(const struct device *dev)
{
const struct gt911_config *config = dev->config;
struct gt911_data *data = dev->data;
if (!i2c_is_ready_dt(&config->bus)) {
LOG_ERR("I2C controller device not ready");
return -ENODEV;
}
data->dev = dev;
data->actual_address = config->bus.addr;
k_work_init(&data->work, gt911_work_handler);
int r;
if (!gpio_is_ready_dt(&config->int_gpio)) {
LOG_ERR("Interrupt GPIO controller device not ready");
return -ENODEV;
}
if (!gpio_is_ready_dt(&config->rst_gpio)) {
LOG_ERR("Reset GPIO controller device not ready");
return -ENODEV;
}
r = gpio_pin_configure_dt(&config->rst_gpio, GPIO_OUTPUT_ACTIVE);
if (r < 0) {
LOG_ERR("Could not configure reset GPIO pin");
return r;
}
if (config->alt_addr == 0x0) {
/*
* We need to configure the int-pin to 0, in order to enter the
* AddressMode0. Keeping the INT pin low during the reset sequence
* should result in the device selecting an I2C address of 0x5D.
* Note we skip this step if an alternate I2C address is set,
* and fall through to probing for the actual address.
*/
r = gpio_pin_configure_dt(&config->int_gpio, GPIO_OUTPUT_INACTIVE);
if (r < 0) {
LOG_ERR("Could not configure int GPIO pin");
return r;
}
}
/* Delay at least 10 ms after power on before we configure gt911 */
k_sleep(K_MSEC(20));
/* reset the device and confgiure the addr mode0 */
gpio_pin_set_dt(&config->rst_gpio, 1);
/* hold down at least 1us, 1ms here */
k_sleep(K_MSEC(1));
gpio_pin_set_dt(&config->rst_gpio, 0);
/* hold down at least 5ms. This is the point the INT pin must be low. */
k_sleep(K_MSEC(5));
/* hold down 50ms to make sure the address available */
k_sleep(K_MSEC(50));
r = gpio_pin_configure_dt(&config->int_gpio, GPIO_INPUT);
if (r < 0) {
LOG_ERR("Could not configure interrupt GPIO pin");
return r;
}
#ifdef CONFIG_INPUT_GT911_INTERRUPT
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, gt911_isr_handler,
BIT(config->int_gpio.pin));
#else
k_timer_init(&data->timer, gt911_timer_handler, NULL);
#endif
/* check the Device ID first: '911' */
uint32_t reg_id = 0;
uint16_t reg_addr = DEVICE_ID;
if (config->alt_addr != 0x0) {
/*
* The level of the INT pin during reset is used by the GT911
* to select the I2C address mode. If an alternate I2C address
* is set, we should probe the GT911 to determine which address
* it actually selected. This is useful for boards that do not
* route the INT pin, or can only read it as an input (IE when
* using a level shifter).
*/
r = gt911_i2c_write_read(dev, &reg_addr, sizeof(reg_addr),
&reg_id, sizeof(reg_id));
if (r < 0) {
/* Try alternate address */
data->actual_address = config->alt_addr;
r = gt911_i2c_write_read(dev, &reg_addr,
sizeof(reg_addr),
&reg_id, sizeof(reg_id));
LOG_INF("Device did not accept I2C address, "
"updated to 0x%02X", data->actual_address);
}
} else {
r = gt911_i2c_write_read(dev, &reg_addr, sizeof(reg_addr),
&reg_id, sizeof(reg_id));
}
if (r < 0) {
LOG_ERR("Device did not respond to I2C request");
return r;
}
if (reg_id != GT911_PRODUCT_ID) {
LOG_ERR("The Device ID is not correct");
return -ENODEV;
}
/* need to setup the firmware first: read and write */
uint8_t gt911Config[REG_CONFIG_SIZE + 2] = {
(uint8_t)GT911_CONFIG_REG, (uint8_t)(GT911_CONFIG_REG >> 8)
};
reg_addr = GT911_CONFIG_REG;
r = gt911_i2c_write_read(dev, &reg_addr, sizeof(reg_addr),
gt911Config + 2, REG_CONFIG_SIZE);
if (r < 0) {
return r;
}
if (!gt911_verify_firmware(gt911Config + 2)) {
return -ENODEV;
}
gt911Config[REG_CONFIG_SIZE] = gt911_get_firmware_checksum(gt911Config + 2);
gt911Config[REG_CONFIG_SIZE + 1] = 1;
r = gt911_i2c_write(dev, gt911Config, sizeof(gt911Config));
if (r < 0) {
return r;
}
#ifdef CONFIG_INPUT_GT911_INTERRUPT
r = gpio_add_callback(config->int_gpio.port, &data->int_gpio_cb);
if (r < 0) {
LOG_ERR("Could not set gpio callback");
return r;
}
#else
k_timer_start(&data->timer, K_MSEC(CONFIG_INPUT_GT911_PERIOD_MS),
K_MSEC(CONFIG_INPUT_GT911_PERIOD_MS));
#endif
return 0;
}
#define GT911_INIT(index) \
static const struct gt911_config gt911_config_##index = { \
.bus = I2C_DT_SPEC_INST_GET(index), \
.rst_gpio = GPIO_DT_SPEC_INST_GET(index, reset_gpios), \
.int_gpio = GPIO_DT_SPEC_INST_GET(index, irq_gpios), \
.alt_addr = DT_INST_PROP_OR(index, alt_addr, 0), \
}; \
static struct gt911_data gt911_data_##index; \
DEVICE_DT_INST_DEFINE(index, gt911_init, NULL, \
&gt911_data_##index, &gt911_config_##index, \
POST_KERNEL, CONFIG_INPUT_INIT_PRIORITY, \
NULL);
DT_INST_FOREACH_STATUS_OKAY(GT911_INIT)