Tactility/Platforms/platform-esp32/source/drivers/esp32_spi.cpp

// SPDX-License-Identifier: Apache-2.0
#include <tactility/device.h>
#include <tactility/drivers/esp32_spi.h>
#include <tactility/concurrent/recursive_mutex.h>

#include "tactility/drivers/gpio_descriptor.h"
#include <tactility/drivers/esp32_gpio_helpers.h>
#include <cstring>
#include <esp_log.h>
#include <new>
#include <soc/gpio_num.h>

#define TAG "esp32_spi"

#define GET_CONFIG(device) ((const struct Esp32SpiConfig*)device->config)
#define GET_DATA(device) ((struct Esp32SpiInternal*)device_get_driver_data(device))

extern "C" {

struct Esp32SpiInternal {
    RecursiveMutex mutex = {};
    bool initialized = false;

    // Pin descriptors
    GpioDescriptor* sclk_descriptor = nullptr;
    GpioDescriptor* mosi_descriptor = nullptr;
    GpioDescriptor* miso_descriptor = nullptr;
    GpioDescriptor* wp_descriptor = nullptr;
    GpioDescriptor* hd_descriptor = nullptr;

    explicit Esp32SpiInternal() {
        recursive_mutex_construct(&mutex);
    }

    ~Esp32SpiInternal() {
        cleanup_pins();
        recursive_mutex_destruct(&mutex);
    }

    void cleanup_pins() {
        release_pin(&sclk_descriptor);
        release_pin(&mosi_descriptor);
        release_pin(&miso_descriptor);
        release_pin(&wp_descriptor);
        release_pin(&hd_descriptor);
    }
};

static error_t lock(Device* device) {
    auto* driver_data = GET_DATA(device);
    recursive_mutex_lock(&driver_data->mutex);
    return ERROR_NONE;
}

static error_t try_lock(Device* device, TickType_t timeout) {
    auto* driver_data = GET_DATA(device);
    if (recursive_mutex_try_lock(&driver_data->mutex, timeout)) {
        return ERROR_NONE;
    }
    return ERROR_TIMEOUT;
}

static error_t unlock(Device* device) {
    auto* driver_data = GET_DATA(device);
    recursive_mutex_unlock(&driver_data->mutex);
    return ERROR_NONE;
}

static error_t start(Device* device) {
    ESP_LOGI(TAG, "start %s", device->name);
    auto* data = new (std::nothrow) Esp32SpiInternal();
    if (!data) return ERROR_OUT_OF_MEMORY;

    device_set_driver_data(device, data);

    auto* dts_config = GET_CONFIG(device);

    // Acquire pins from the specified GPIO pin specs. Optional pins are allowed.
    bool pins_ok =
        acquire_pin_or_set_null(dts_config->pin_sclk, &data->sclk_descriptor) &&
        acquire_pin_or_set_null(dts_config->pin_mosi, &data->mosi_descriptor) &&
        acquire_pin_or_set_null(dts_config->pin_miso, &data->miso_descriptor) &&
        acquire_pin_or_set_null(dts_config->pin_wp, &data->wp_descriptor) &&
        acquire_pin_or_set_null(dts_config->pin_hd, &data->hd_descriptor);

    if (!pins_ok) {
        ESP_LOGE(TAG, "Failed to acquire required SPI pins");
        data->cleanup_pins();
        device_set_driver_data(device, nullptr);
        delete data;
        return ERROR_RESOURCE;
    }

    spi_bus_config_t buscfg = {
        .mosi_io_num = get_native_pin(data->mosi_descriptor),
        .miso_io_num = get_native_pin(data->miso_descriptor),
        .sclk_io_num = get_native_pin(data->sclk_descriptor),
        .data2_io_num = get_native_pin(data->wp_descriptor),
        .data3_io_num = get_native_pin(data->hd_descriptor),
        .data4_io_num = GPIO_NUM_NC,
        .data5_io_num = GPIO_NUM_NC,
        .data6_io_num = GPIO_NUM_NC,
        .data7_io_num = GPIO_NUM_NC,
        .data_io_default_level = false,
        .max_transfer_sz = dts_config->max_transfer_size,
        .flags = 0,
        .isr_cpu_id = ESP_INTR_CPU_AFFINITY_AUTO,
        .intr_flags = 0
    };

    esp_err_t ret = spi_bus_initialize(dts_config->host, &buscfg, SPI_DMA_CH_AUTO);
    if (ret != ESP_OK) {
        data->cleanup_pins();
        device_set_driver_data(device, nullptr);
        delete data;
        ESP_LOGE(TAG, "Failed to initialize SPI bus: %s", esp_err_to_name(ret));
        return ERROR_RESOURCE;
    }

    data->initialized = true;
    return ERROR_NONE;
}

static error_t stop(Device* device) {
    ESP_LOGI(TAG, "stop %s", device->name);
    auto* driver_data = GET_DATA(device);
    auto* dts_config = GET_CONFIG(device);

    if (driver_data->initialized) {
        spi_bus_free(dts_config->host);
    }

    driver_data->cleanup_pins();
    device_set_driver_data(device, nullptr);
    delete driver_data;
    return ERROR_NONE;
}

const static struct SpiControllerApi esp32_spi_api = {
    .lock = lock,
    .try_lock = try_lock,
    .unlock = unlock
};

extern struct Module platform_module;

Driver esp32_spi_driver = {
    .name = "esp32_spi",
    .compatible = (const char*[]) { "espressif,esp32-spi", nullptr },
    .start_device = start,
    .stop_device = stop,
    .api = (void*)&esp32_spi_api,
    .device_type = &SPI_CONTROLLER_TYPE,
    .owner = &platform_module,
    .internal = nullptr
};

} // extern "C"