esp-idf/components/mbedtls/port/include/esp_crypto_shared_gdma.h

// Copyright 2021 Espressif Systems (Shanghai) PTE 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.

#pragma once

#include "soc/lldesc.h"
#include "esp_private/gdma.h"
#include "esp_err.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Start a GDMA transfer on the shared crypto DMA channel
 *
 * @note Will allocate a GDMA channel for AES & SHA if no such channel is already allocated
 *
 * @param input Input linked list descriptor
 * @param output Output linked list descriptor
 * @param peripheral Crypto peripheral to connect the DMA to, either GDMA_TRIG_PERIPH_AES or
 *                   GDMA_TRIG_PERIPH_SHA
 * @return esp_err_t ESP_FAIL if no GDMA channel available
 */
esp_err_t esp_crypto_shared_gdma_start(const lldesc_t *input, const lldesc_t *output, gdma_trigger_peripheral_t peripheral);


/**
 * @brief Frees any shared crypto DMA channel, if esp_crypto_shared_gdma_start is called after
 *        this, new GDMA channels will be allocated.
 *
 * @note Function is meant to be called from user code, and thus takes AES/SHA lock.
 *       This means this function should not be called from code which already takes these locks,
 *       i.e. inside our AES/SHA code.
 *
 *       If you are continously using AES/SHA (e.g. because of a wifi connection) then it's not recommended
 *       to use this API. Freeing the channel is mainly for use cases where you are finished with the crypto peripherals
 *       and need the DMA channel for other peripherals. An example would be doing some processing after disconnecting WiFi
 */
void esp_crypto_shared_gdma_free(void);

#ifdef __cplusplus
}
#endif