tactility/Drivers/cst816s-module/source/cst816s.cpp

// SPDX-License-Identifier: Apache-2.0
#include <drivers/cst816s.h>
#include <cst816s_module.h>

#include <tactility/check.h>
#include <tactility/device.h>
#include <tactility/driver.h>
#include <tactility/drivers/esp32_i2c.h>
#include <tactility/drivers/esp32_i2c_master.h>
#include <tactility/drivers/i2c_controller.h>
#include <tactility/drivers/pointer.h>
#include <tactility/log.h>

#include <esp_err.h>
#include <esp_lcd_io_i2c.h>
#include <esp_lcd_panel_io.h>
#include <esp_lcd_touch.h>
#include <esp_lcd_touch_cst816s.h>

#include <cstdlib>

#define TAG "CST816S"
#define GET_CONFIG(device) (static_cast<const Cst816sConfig*>((device)->config))

struct Cst816sInternal {
    esp_lcd_panel_io_handle_t io_handle;
    esp_lcd_touch_handle_t touch_handle;
};

static inline gpio_num_t pin_or_nc(const struct GpioPinSpec& pin) {
    return pin.gpio_controller == nullptr ? GPIO_NUM_NC : static_cast<gpio_num_t>(pin.pin);
}

// region Driver lifecycle

// CST816S always sits at a fixed I2C address, unlike GT911's strapping-dependent address,
// so no bus probing is needed here.
static esp_err_t create_io_handle(Device* parent, esp_lcd_panel_io_handle_t* out_handle) {
    esp_lcd_panel_io_i2c_config_t io_config = ESP_LCD_TOUCH_IO_I2C_CST816S_CONFIG();

    auto* parent_driver = device_get_driver(parent);
    if (driver_is_compatible(parent_driver, "espressif,esp32-i2c")) {
        auto port = static_cast<const Esp32I2cConfig*>(parent->config)->port;
        return esp_lcd_new_panel_io_i2c_v1(port, &io_config, out_handle);
    }
    if (driver_is_compatible(parent_driver, "espressif,esp32-i2c-master")) {
        auto bus = esp32_i2c_master_get_bus_handle(parent);
        io_config.scl_speed_hz = esp32_i2c_master_get_clock_frequency(parent);
        return esp_lcd_new_panel_io_i2c_v2(bus, &io_config, out_handle);
    }

    LOG_E(TAG, "Unsupported I2C driver");
    return ESP_ERR_NOT_SUPPORTED;
}

static error_t start(Device* device) {
    auto* parent = device_get_parent(device);
    check(device_get_type(parent) == &I2C_CONTROLLER_TYPE);

    const auto* config = GET_CONFIG(device);

    auto* internal = static_cast<Cst816sInternal*>(malloc(sizeof(Cst816sInternal)));
    if (internal == nullptr) {
        return ERROR_OUT_OF_MEMORY;
    }

    esp_err_t ret = create_io_handle(parent, &internal->io_handle);
    if (ret != ESP_OK) {
        free(internal);
        return ERROR_RESOURCE;
    }

    esp_lcd_touch_config_t touch_config = {
        .x_max = config->x_max,
        .y_max = config->y_max,
        .rst_gpio_num = pin_or_nc(config->pin_reset),
        .int_gpio_num = pin_or_nc(config->pin_interrupt),
        .levels = {
            .reset = config->reset_active_high ? 1u : 0u,
            .interrupt = config->interrupt_active_high ? 1u : 0u,
        },
        .flags = {
            .swap_xy = config->swap_xy ? 1u : 0u,
            .mirror_x = config->mirror_x ? 1u : 0u,
            .mirror_y = config->mirror_y ? 1u : 0u,
        },
        .process_coordinates = nullptr,
        .interrupt_callback = nullptr,
        .user_data = nullptr,
        .driver_data = nullptr,
    };

    ret = esp_lcd_touch_new_i2c_cst816s(internal->io_handle, &touch_config, &internal->touch_handle);
    if (ret != ESP_OK) {
        LOG_E(TAG, "Failed to create touch handle: %s", esp_err_to_name(ret));
        esp_lcd_panel_io_del(internal->io_handle);
        free(internal);
        return ERROR_RESOURCE;
    }

    device_set_driver_data(device, internal);
    return ERROR_NONE;
}

static error_t stop(Device* device) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));

    // esp_lcd_touch_del() only releases the touch-side resources; the panel IO handle is owned
    // separately and needs its own deletion.
    if (internal->touch_handle != nullptr) {
        if (esp_lcd_touch_del(internal->touch_handle) != ESP_OK) {
            LOG_E(TAG, "Failed to delete touch handle");
            return ERROR_RESOURCE;
        }
        internal->touch_handle = nullptr;
    }

    if (internal->io_handle != nullptr) {
        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
            LOG_E(TAG, "Failed to delete panel IO handle");
            return ERROR_RESOURCE;
        }
        internal->io_handle = nullptr;
    }

    free(internal);
    device_set_driver_data(device, nullptr);
    return ERROR_NONE;
}

// endregion

// region PointerApi

static error_t cst816s_enter_sleep(Device* device) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_enter_sleep(internal->touch_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_exit_sleep(Device* device) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_exit_sleep(internal->touch_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_read_data(Device* device, TickType_t timeout) {
    (void)timeout; // esp_lcd_touch_read_data() has no timeout parameter
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_read_data(internal->touch_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static bool cst816s_get_touched_points(Device* device, uint16_t* x, uint16_t* y, uint16_t* strength, uint8_t* point_count, uint8_t max_point_count) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_get_coordinates(internal->touch_handle, x, y, strength, point_count, max_point_count);
}

static error_t cst816s_set_swap_xy(Device* device, bool swap) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_set_swap_xy(internal->touch_handle, swap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_get_swap_xy(Device* device, bool* swap) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_get_swap_xy(internal->touch_handle, swap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_set_mirror_x(Device* device, bool mirror) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_set_mirror_x(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_get_mirror_x(Device* device, bool* mirror) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_get_mirror_x(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_set_mirror_y(Device* device, bool mirror) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_set_mirror_y(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

static error_t cst816s_get_mirror_y(Device* device, bool* mirror) {
    auto* internal = static_cast<Cst816sInternal*>(device_get_driver_data(device));
    return esp_lcd_touch_get_mirror_y(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
}

// endregion

static const PointerApi cst816s_pointer_api = {
    .enter_sleep = cst816s_enter_sleep,
    .exit_sleep = cst816s_exit_sleep,
    .read_data = cst816s_read_data,
    .get_touched_points = cst816s_get_touched_points,
    .set_swap_xy = cst816s_set_swap_xy,
    .get_swap_xy = cst816s_get_swap_xy,
    .set_mirror_x = cst816s_set_mirror_x,
    .get_mirror_x = cst816s_get_mirror_x,
    .set_mirror_y = cst816s_set_mirror_y,
    .get_mirror_y = cst816s_get_mirror_y,
};

Driver cst816s_driver = {
    .name = "cst816s",
    .compatible = (const char*[]) { "hynitron,cst816s", nullptr },
    .start_device = start,
    .stop_device = stop,
    .api = &cst816s_pointer_api,
    .device_type = &POINTER_TYPE,
    .owner = &cst816s_module,
    .internal = nullptr
};