spi_slave: add a private API to reset transaction queue

components/driver/include/esp_private/spi_slave_internal.h

@@ -0,0 +1,39 @@
+/*
+ * SPDX-FileCopyrightText: 2020-2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @brief
+ * This file contains SPI Slave private/internal APIs. Private/Internal APIs are:
+ * - Visible to other IDF components
+ * - Suggest NOT to use these APIs in your applications
+ * - We don't provide backward compatibility on these APIs either
+ */
+
+#pragma once
+#include "sdkconfig.h"
+#include "esp_err.h"
+#include "hal/spi_types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/**
+ * @note
+ * This API is used to reset SPI Slave transaction queue. After calling this function:
+ * - The SPI Slave transaction queue will be reset.
+ *
+ * @note This API shouldn't be called when the corresponding SPI Master is doing an SPI transaction.
+ * If this gets called when its corresponding SPI Master is doing an SPI transaction, the SPI Slave behaviour is undefined
+ *
+ * @param host SPI peripheral that is acting as a slave
+ *
+ * @return
+ *         - ESP_ERR_INVALID_ARG   if parameter is invalid
+ *         - ESP_OK                on success
+ */
+esp_err_t spi_slave_queue_reset(spi_host_device_t host);

components/driver/spi_slave.c

@@ -283,6 +283,33 @@ esp_err_t spi_slave_free(spi_host_device_t host)
     return ESP_OK;
 }
 
+/**
+ * @note
+ * This API is used to reset SPI Slave transaction queue. After calling this function:
+ * - The SPI Slave transaction queue will be reset.
+ *
+ * Therefore, this API shouldn't be called when the corresponding SPI Master is doing an SPI transaction.
+ *
+ * @note
+ * We don't actually need to enter a critical section here.
+ * SPI Slave ISR will only get triggered when its corresponding SPI Master's transaction is done.
+ * As we don't expect this function to be called when its corresponding SPI Master is doing an SPI transaction,
+ * so concurrent call to these registers won't happen
+ *
+ */
+esp_err_t SPI_SLAVE_ATTR spi_slave_queue_reset(spi_host_device_t host)
+{
+    SPI_CHECK(is_valid_host(host), "invalid host", ESP_ERR_INVALID_ARG);
+    SPI_CHECK(spihost[host], "host not slave", ESP_ERR_INVALID_ARG);
+
+    esp_intr_disable(spihost[host]->intr);
+    spi_ll_set_int_stat(spihost[host]->hal.hw);
+
+    spihost[host]->cur_trans = NULL;
+    xQueueReset(spihost[host]->trans_queue);
+
+    return ESP_OK;
+}
 
 esp_err_t SPI_SLAVE_ATTR spi_slave_queue_trans(spi_host_device_t host, const spi_slave_transaction_t *trans_desc, TickType_t ticks_to_wait)
 {

components/hal/include/hal/spi_slave_hal.h

@@ -1,16 +1,8 @@
-// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
+/*
-//
+ * SPDX-FileCopyrightText: 2015-2022 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.
+ * SPDX-License-Identifier: Apache-2.0
-// 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.
 
 /*******************************************************************************
  * NOTICE

tools/ci/check_copyright_ignore.txt

@@ -699,7 +699,6 @@ components/hal/include/hal/rtc_io_types.h
 components/hal/include/hal/sdio_slave_ll.h
 components/hal/include/hal/sha_hal.h
 components/hal/include/hal/spi_flash_encrypt_hal.h
-components/hal/include/hal/spi_slave_hal.h
 components/hal/include/hal/spi_slave_hd_hal.h
 components/hal/include/hal/uhci_types.h
 components/hal/include/hal/usb_hal.h