Diff: targets/TARGET_Cypress/TARGET_PSOC6/crc_api.c

Revision:

189:f392fc9709a3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Cypress/TARGET_PSOC6/crc_api.c	Wed Feb 20 22:31:08 2019 +0000
@@ -0,0 +1,100 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2019 Cypress Semiconductor Corporation
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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 "device.h"
+
+#if DEVICE_CRC
+
+#include "mbed_assert.h"
+#include "crc_api.h"
+
+#include "psoc6_utils.h"
+
+#include "cy_crypto_core_crc.h"
+
+static uint32_t crcWidth = 0;
+static uint32_t crcShift = 0;
+static uint32_t crcXorMask;
+
+/* Cypress CRYPTO HW supports ANY CRC algorithms from CRC-3 to CRC-32 */
+bool hal_crc_is_supported(const crc_mbed_config_t *config)
+{
+    return (config != NULL);
+}
+
+void hal_crc_compute_partial_start(const crc_mbed_config_t *config)
+{
+    uint32_t myMask = 0;
+
+    if (!hal_crc_is_supported(config) || (cy_reserve_crypto(CY_CRYPTO_CRC_HW) != 0))
+    {
+        return;
+    }
+
+    crcWidth = config->width;
+
+    crcShift = (uint32_t)(!config->reflect_out) * (crcWidth & 7u);
+    if (crcShift) {
+        crcShift = 8u - crcShift;
+        for (uint32_t i = 0; i < crcShift; i++) {
+            myMask |= 1 << i;
+        }
+        crcXorMask = config->final_xor & myMask;
+    }
+
+    Cy_Crypto_Core_Crc_CalcInit(CRYPTO, config->width,
+                                config->polynomial,
+                                config->reflect_in,
+                                0,
+                                config->reflect_out,
+                                config->final_xor >> crcShift,
+                                config->initial_xor);
+}
+
+void hal_crc_compute_partial(const uint8_t *data, const size_t size)
+{
+    if ((data == NULL) || (size <= 0) || (crcWidth == 0)) {
+        return;
+    }
+
+    Cy_Crypto_Core_Crc_CalcPartial(CRYPTO, data, size);
+}
+
+uint32_t hal_crc_get_result(void)
+{
+    uint32_t result = 0;
+
+    if (crcWidth == 0) {
+        return 0xffffffffu;
+    }
+
+    Cy_Crypto_Core_Crc_CalcFinish(CRYPTO, crcWidth, &result);
+
+    if (crcShift) {
+        result = result << crcShift;
+        result = result ^  crcXorMask;
+    }
+
+    crcWidth = 0;
+
+    cy_free_crypto(CY_CRYPTO_CRC_HW);
+
+    return result;
+}
+
+#endif //DEVICE_CRC
+