Import Mbed OS hard-float snapshot

targets/TARGET_STM/trng_api.c

@@ -0,0 +1,185 @@
+/*
+ *  Hardware entropy collector for the STM32 families
+ *
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
+ *  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.
+ *
+ */
+
+#if DEVICE_TRNG
+
+#include <stdlib.h>
+#include "cmsis.h"
+#include "trng_api.h"
+#include "mbed_error.h"
+#include "mbed_atomic.h"
+
+#if defined (TARGET_STM32WB)
+/*  Family specific include for WB with HW semaphores */
+#include "hw.h"
+#include "hw_conf.h"
+#endif
+
+
+void trng_init(trng_t *obj)
+{
+    uint32_t dummy;
+
+#if defined(RCC_PERIPHCLK_RNG) /* STM32L4 / STM32H7 / STM32WB */
+
+#if defined(TARGET_STM32WB)
+    /*  No need to configure RngClockSelection as already done in SetSysClock */
+
+#elif defined(TARGET_STM32H7)
+    RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
+
+    /*Select PLLQ output as RNG clock source */
+    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RNG;
+    PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_PLL;
+#if defined(DUAL_CORE)
+    while (LL_HSEM_1StepLock(HSEM, CFG_HW_RCC_SEMID)) {
+    }
+#endif /* DUAL_CORE */
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK) {
+        error("RNG clock configuration error\n");
+    }
+#if defined(DUAL_CORE)
+    LL_HSEM_ReleaseLock(HSEM, CFG_HW_RCC_SEMID, HSEM_CR_COREID_CURRENT);
+#endif /* DUAL_CORE */
+
+#elif defined(TARGET_STM32L4)
+    /* RNG and USB clocks have the same source, so the common source selection could be already done by USB */
+    RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
+
+    PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RNG;
+
+    if (__HAL_RCC_GET_FLAG(RCC_FLAG_MSIRDY)) {
+        /* MSI clock is enabled, MSI selected as RNG clock source if not alredy done */
+        if (__HAL_RCC_GET_RNG_SOURCE() != RCC_RNGCLKSOURCE_MSI) {
+            PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_MSI;
+            if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK) {
+                error("RNG clock configuration error\n");
+            }
+        }
+    } else {
+        /* MSI clock is not enabled, PLL selected as RNG clock source */
+        PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_PLL;
+        if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK) {
+            error("RNG clock configuration error\n");
+        }
+    }
+
+#elif defined(TARGET_STM32L5)
+    /*  No need to reconfigure RngClockSelection as alreday done in SetSysClock */
+
+#else
+#error("RNG clock not configured");
+#endif
+
+#endif /* defined(RCC_PERIPHCLK_RNG) */
+
+    /* RNG Peripheral clock enable */
+    __HAL_RCC_RNG_CLK_ENABLE();
+
+    /* Initialize RNG instance */
+    obj->handle.Instance = RNG;
+    obj->handle.State = HAL_RNG_STATE_RESET;
+    obj->handle.Lock = HAL_UNLOCKED;
+#if defined(RNG_CR_CED)
+    obj->handle.Init.ClockErrorDetection = RNG_CED_ENABLE;
+#endif
+
+#if defined(CFG_HW_RNG_SEMID)
+    /*  In case RNG is a shared ressource, get the HW semaphore first */
+    while (LL_HSEM_1StepLock(HSEM, CFG_HW_RNG_SEMID));
+#endif
+
+    if (HAL_RNG_Init(&obj->handle) != HAL_OK) {
+        error("trng_init: HAL_RNG_Init\n");
+    }
+
+    /* first random number generated after setting the RNGEN bit should not be used */
+    if (HAL_RNG_GenerateRandomNumber(&obj->handle, &dummy) != HAL_OK) {
+        error("trng_init: HAL_RNG_GenerateRandomNumber\n");
+    }
+
+#if defined(CFG_HW_RNG_SEMID)
+    LL_HSEM_ReleaseLock(HSEM, CFG_HW_RNG_SEMID, 0);
+#endif
+}
+
+
+void trng_free(trng_t *obj)
+{
+#if defined(CFG_HW_RNG_SEMID)
+    /*  In case RNG is a shared ressource, get the HW semaphore first */
+    while (LL_HSEM_1StepLock(HSEM, CFG_HW_RNG_SEMID));
+#endif
+    /*Disable the RNG peripheral */
+    HAL_RNG_DeInit(&obj->handle);
+
+#if defined(CFG_HW_RNG_SEMID)
+    /*  In case RNG is a shared ressource, get the HW semaphore first */
+    LL_HSEM_ReleaseLock(HSEM, CFG_HW_RNG_SEMID, 0);
+#else
+    /* RNG Peripheral clock disable - assume we're the only users of RNG  */
+    __HAL_RCC_RNG_CLK_DISABLE();
+#endif
+}
+
+
+int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
+{
+    int ret = 0;
+    volatile uint8_t random[4];
+    *output_length = 0;
+
+#if defined(CFG_HW_RNG_SEMID)
+    /*  In case RNG is a shared ressource, get the HW semaphore first */
+    while (LL_HSEM_1StepLock(HSEM, CFG_HW_RNG_SEMID));
+#endif
+
+#if defined(TARGET_STM32WB)
+    /* M0+ could have disabled RNG */
+    __HAL_RNG_ENABLE(&obj->handle);
+#endif // TARGET_STM32WB
+
+    /* Get Random byte */
+    while ((*output_length < length) && (ret == 0)) {
+        if (HAL_RNG_GenerateRandomNumber(&obj->handle, (uint32_t *)random) != HAL_OK) {
+            ret = -1;
+        } else {
+            for (uint8_t i = 0; (i < 4) && (*output_length < length) ; i++) {
+                *output++ = random[i];
+                *output_length += 1;
+                random[i] = 0;
+            }
+        }
+    }
+
+    /* Just be extra sure that we didn't do it wrong */
+    if ((__HAL_RNG_GET_FLAG(&obj->handle, (RNG_FLAG_CECS | RNG_FLAG_SECS))) != 0) {
+        ret = -1;
+    }
+
+#if defined(CFG_HW_RNG_SEMID)
+    /*  In case RNG is a shared ressource, get the HW semaphore first */
+    LL_HSEM_ReleaseLock(HSEM, CFG_HW_RNG_SEMID, 0);
+#endif
+
+    return (ret);
+}
+
+#endif