esp-idf/components/tinyusb/additions/src/tusb_cdc_acm.c

// Copyright 2020 Espressif Systems (Shanghai) Co. Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <stdint.h>
#include "esp_err.h"
#include "esp_log.h"
#include "tusb.h"
#include "tusb_cdc_acm.h"
#include "cdc.h"
#include "sdkconfig.h"

#define ESP_RETURN_ON_ERROR(x) do{esp_err_t r = (x); if (r != ESP_OK) return r;} while(0)

#define RX_UNREADBUF_SZ_DEFAULT 64 // buffer storing all unread RX data


typedef struct {
    bool initialized;
    size_t rx_unread_buf_sz;
    RingbufHandle_t rx_unread_buf;
    uint8_t *rx_tfbuf;
    tusb_cdcacm_callback_t callback_rx;
    tusb_cdcacm_callback_t callback_rx_wanted_char;
    tusb_cdcacm_callback_t callback_line_state_changed;
    tusb_cdcacm_callback_t callback_line_coding_changed;
    xTimerHandle flush_timer;
} esp_tusb_cdcacm_t; /*!< CDC_AMC object */

static const char *TAG = "tusb_cdc_acm";

static inline esp_tusb_cdcacm_t *get_acm(tinyusb_cdcacm_itf_t itf)
{
    esp_tusb_cdc_t *cdc_inst = tinyusb_cdc_get_intf(itf);
    if (cdc_inst == NULL) {
        return (esp_tusb_cdcacm_t *)NULL;
    }
    return (esp_tusb_cdcacm_t *)(cdc_inst->subclass_obj);
}


/* TinyUSB callbacks
   ********************************************************************* */

/* Invoked when cdc when line state changed e.g connected/disconnected */
void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (dtr && rts) { // connected
        if (acm != NULL) {
            ESP_LOGV(TAG, "Host connected to CDC no.%d.", itf);
        } else {
            ESP_LOGW(TAG, "Host is connected to CDC no.%d, but it is not initialized. Initialize it using `tinyusb_cdc_init`.", itf);
            return;
        }
    } else { // disconnected
        if (acm != NULL) {
            ESP_LOGV(TAG, "Serial device is ready to connect to CDC no.%d", itf);
        } else {
            return;
        }
    }
    if (acm) {
        tusb_cdcacm_callback_t cb = acm->callback_line_state_changed;
        if (cb) {
            cdcacm_event_t event = {
                .type = CDC_EVENT_LINE_STATE_CHANGED,
                .line_state_changed_data = {
                    .dtr = dtr,
                    .rts = rts
                }
            };
            cb(itf, &event);
        }
    }
}


/* Invoked when CDC interface received data from host */
void tud_cdc_rx_cb(uint8_t itf)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (acm) {
        if (!acm->rx_unread_buf) {
            ESP_LOGE(TAG, "There is no RX buffer created");
            abort();
        }
    } else {
        tud_cdc_n_read_flush(itf); // we have no place to store data, so just drop it
        return;
    }
    while (tud_cdc_n_available(itf)) {
        int read_res = tud_cdc_n_read(  itf,
                                        acm->rx_tfbuf,
                                        CONFIG_USB_CDC_RX_BUFSIZE );
        int res = xRingbufferSend(acm->rx_unread_buf,
                                  acm->rx_tfbuf,
                                  read_res, 0);
        if (res != pdTRUE) {
            ESP_LOGW(TAG, "The unread buffer is too small, the data has been lost");
        } else {
            ESP_LOGV(TAG, "Sent %d bytes to the buffer", read_res);
        }
    }
    if (acm) {
        tusb_cdcacm_callback_t cb = acm->callback_rx;
        if (cb) {
            cdcacm_event_t event = {
                .type = CDC_EVENT_RX
            };
            cb(itf, &event);
        }
    }
}

// Invoked when line coding is change via SET_LINE_CODING
void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const *p_line_coding)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (acm) {
        tusb_cdcacm_callback_t cb = acm->callback_line_coding_changed;
        if (cb) {
            cdcacm_event_t event = {
                .type = CDC_EVENT_LINE_CODING_CHANGED,
                .line_coding_changed_data = {
                    .p_line_coding = p_line_coding,
                }
            };
            cb(itf, &event);
        }
    } else {
        return;
    }
}

// Invoked when received `wanted_char`
void tud_cdc_rx_wanted_cb(uint8_t itf, char wanted_char)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (acm) {
        tusb_cdcacm_callback_t cb = acm->callback_rx_wanted_char;
        if (cb) {
            cdcacm_event_t event = {
                .type = CDC_EVENT_RX_WANTED_CHAR,
                .rx_wanted_char_data = {
                    .wanted_char = wanted_char,
                }
            };
            cb(itf, &event);
        }
    } else {
        return;
    }
}



esp_err_t tinyusb_cdcacm_register_callback(tinyusb_cdcacm_itf_t itf,
        cdcacm_event_type_t event_type,
        tusb_cdcacm_callback_t callback)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (acm) {
        switch (event_type) {
        case CDC_EVENT_RX:
            acm->callback_rx = callback;
            return ESP_OK;
        case CDC_EVENT_RX_WANTED_CHAR:
            acm->callback_rx_wanted_char = callback;
            return ESP_OK;
        case CDC_EVENT_LINE_STATE_CHANGED:
            acm->callback_line_state_changed = callback;
            return ESP_OK;
        case CDC_EVENT_LINE_CODING_CHANGED:
            acm->callback_line_coding_changed = callback;
            return ESP_OK;
        default:
            ESP_LOGE(TAG, "Wrong event type");
            return ESP_ERR_INVALID_ARG;
        }
    } else {
        ESP_LOGE(TAG, "CDC-ACM is not initialized");
        return ESP_ERR_INVALID_STATE;
    }
}


esp_err_t tinyusb_cdcacm_unregister_callback(tinyusb_cdcacm_itf_t itf,
        cdcacm_event_type_t event_type)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (!acm) {
        ESP_LOGE(TAG, "Interface is not initialized. Use `tinyusb_cdc_init` for initialization");
        return ESP_ERR_INVALID_STATE;
    }
    switch (event_type) {
    case CDC_EVENT_RX:
        acm->callback_rx = NULL;
        return ESP_OK;
    case CDC_EVENT_RX_WANTED_CHAR:
        acm->callback_rx_wanted_char = NULL;
        return ESP_OK;
    case CDC_EVENT_LINE_STATE_CHANGED:
        acm->callback_line_state_changed = NULL;
        return ESP_OK;
    case CDC_EVENT_LINE_CODING_CHANGED:
        acm->callback_line_coding_changed = NULL;
        return ESP_OK;
    default:
        ESP_LOGE(TAG, "Wrong event type");
        return ESP_ERR_INVALID_ARG;
    }
}

/*********************************************************************** TinyUSB callbacks*/
/* CDC-ACM
   ********************************************************************* */
esp_err_t tinyusb_cdcacm_read(tinyusb_cdcacm_itf_t itf, uint8_t *out_buf, size_t out_buf_sz, size_t *rx_data_size)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (!acm) {
        ESP_LOGE(TAG, "Interface is not initialized. Use `tinyusb_cdc_init` for initialization");
        return ESP_ERR_INVALID_STATE;
    }
    uint8_t *buf = xRingbufferReceiveUpTo(acm->rx_unread_buf, rx_data_size, 0, out_buf_sz);
    if (buf) {
        memcpy(out_buf, buf, *rx_data_size);
        vRingbufferReturnItem(acm->rx_unread_buf, (void *)buf);
        return ESP_OK;
    } else {
        ESP_LOGE(TAG, "Failed to receive item");
        return ESP_ERR_NO_MEM;
    }
}


size_t tinyusb_cdcacm_write_queue_char(tinyusb_cdcacm_itf_t itf, char ch)
{
    if (!get_acm(itf)) { // non-initialized
        return 0;
    }
    return tud_cdc_n_write_char(itf, ch);
}


size_t tinyusb_cdcacm_write_queue(tinyusb_cdcacm_itf_t itf, uint8_t *in_buf, size_t in_size)
{
    if (!get_acm(itf)) { // non-initialized
        return 0;
    }
    return tud_cdc_n_write(itf, in_buf, in_size);
}


static inline bool timer_isactive(tinyusb_cdcacm_itf_t itf)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    return xTimerIsTimerActive(acm->flush_timer);
}

static inline esp_err_t timer_start(tinyusb_cdcacm_itf_t itf, uint32_t timeout_ticks)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    xTimerChangePeriod(acm->flush_timer, timeout_ticks, 0); // set the timer
    if (!xTimerIsTimerActive(acm->flush_timer)) {
        if (xTimerStart(acm->flush_timer, 0) != pdPASS) { // start
            ESP_LOGE(TAG, "Can't start the timer");
            return ESP_FAIL;
        }
    }
    return ESP_OK;
}

static inline void timer_stop(tinyusb_cdcacm_itf_t itf)
{
    if (timer_isactive(itf)) {
        xTimerStop(get_acm(itf)->flush_timer, 0);
    }
}


esp_err_t tinyusb_cdcacm_write_flush(tinyusb_cdcacm_itf_t itf, uint32_t timeout_ticks)
{
    if (!get_acm(itf)) { // non-initialized
        return ESP_FAIL;
    }

    if (!timeout_ticks) { // if no timeout - nonblocking mode
        int res = tud_cdc_n_write_flush(itf);
        if (!res) {
            return ESP_FAIL;
        } else {
            if (tud_cdc_n_write_available(itf)) {
                return ESP_FAIL;
            }
        }
        return ESP_ERR_TIMEOUT;
    } else { // if timeout use timer
        ESP_RETURN_ON_ERROR(timer_start(itf, timeout_ticks));
        while (1) { // loop until success or until the time runs out
            if (!tud_cdc_n_write_available(itf)) { // if nothing to write - nothing to flush
                break;
            }
            if (tud_cdc_n_write_flush(itf)) { // Success
                break;
            }
            if (!timer_isactive(itf)) { // Time is up
                ESP_LOGW(TAG, "Flush failed");
                return ESP_ERR_TIMEOUT;
            }
            vTaskDelay(1);
        }
        timer_stop(itf);
        return ESP_OK;
    }
}


static void flush_timer_cb(xTimerHandle pxTimer)
{
    ESP_LOGV(TAG, "flush_timer stopped");
    xTimerStop(pxTimer, 0);
}

static esp_err_t alloc_obj(tinyusb_cdcacm_itf_t itf)
{
    esp_tusb_cdc_t *cdc_inst = tinyusb_cdc_get_intf(itf);
    cdc_inst->subclass_obj = calloc(1, sizeof(esp_tusb_cdcacm_t));
    if (!cdc_inst->subclass_obj) {
        return ESP_FAIL;
    } else {
        return ESP_OK;
    }
}

static void free_obj(tinyusb_cdcacm_itf_t itf)
{
    esp_tusb_cdc_t *cdc_inst = tinyusb_cdc_get_intf(itf);
    free(cdc_inst->subclass_obj);
    cdc_inst->subclass_obj = NULL;
}

esp_err_t tusb_cdc_acm_init(const tinyusb_config_cdcacm_t *cfg)
{
    int itf = (int)cfg->cdc_port;
    /* Creating a CDC object */
    const tinyusb_config_cdc_t cdc_cfg = {
        .usb_dev = cfg->usb_dev,
        .cdc_class = TUSB_CLASS_CDC,
        .cdc_subclass.comm_subclass = CDC_COMM_SUBCLASS_ABSTRACT_CONTROL_MODEL
    };
    ESP_RETURN_ON_ERROR(tinyusb_cdc_init(itf, &cdc_cfg));
    ESP_RETURN_ON_ERROR(alloc_obj(itf));

    esp_tusb_cdcacm_t *acm = get_acm(itf);
    /* Callbacks setting up*/
    if (cfg->callback_rx) {
        tinyusb_cdcacm_register_callback(itf, CDC_EVENT_RX, cfg->callback_rx);
    }
    if (cfg->callback_rx_wanted_char) {
        tinyusb_cdcacm_register_callback(itf, CDC_EVENT_RX_WANTED_CHAR, cfg->callback_rx_wanted_char);
    }
    if (cfg->callback_line_state_changed) {
        tinyusb_cdcacm_register_callback(itf, CDC_EVENT_LINE_STATE_CHANGED, cfg->callback_line_state_changed);
    }
    if (cfg->callback_line_coding_changed) {
        tinyusb_cdcacm_register_callback( itf, CDC_EVENT_LINE_CODING_CHANGED, cfg->callback_line_coding_changed);
    }

    /* SW timer*/
    acm->flush_timer = xTimerCreate(
                           "flush_timer", 10 / portTICK_PERIOD_MS, pdTRUE, (void *)itf, flush_timer_cb);

    /* Buffers */
    acm->rx_tfbuf = malloc(CONFIG_USB_CDC_RX_BUFSIZE);
    if (!acm->rx_tfbuf) {
        ESP_LOGE(TAG, "Creation buffer error");
        free_obj(itf);
        return ESP_ERR_NO_MEM;
    }
    acm->rx_unread_buf_sz = cfg->rx_unread_buf_sz == 0 ? RX_UNREADBUF_SZ_DEFAULT : cfg->rx_unread_buf_sz;
    acm->rx_unread_buf = xRingbufferCreate(acm->rx_unread_buf_sz, RINGBUF_TYPE_BYTEBUF);
    if (acm->rx_unread_buf == NULL) {
        ESP_LOGE(TAG, "Creation buffer error");
        free_obj(itf);
        return ESP_ERR_NO_MEM;
    } else {
        ESP_LOGD(TAG, "Comm Initialized buff:%d bytes", cfg->rx_unread_buf_sz);
        return ESP_OK;
    }
}

bool tusb_cdc_acm_initialized(tinyusb_cdcacm_itf_t itf)
{
    esp_tusb_cdcacm_t *acm = get_acm(itf);
    if (acm) {
        return true;
    } else {
        return false;
    }
}
/*********************************************************************** CDC-ACM*/