Andrew SaLoutos / mbed-dev-STM-lean

From Ben Katz mbed-dev library. Removed unnecessary target files to reduce the overall size by a factor of 10 to make it easier to import into the online IDE.

Dependents:   motor_driver motor_driver_screaming_fix

targets/TARGET_STM/trng_api.c@0:083111ae2a11, 2020-11-26 (annotated)

Committer:
saloutos
Date:
Thu Nov 26 04:08:56 2020 +0000
Revision:
0:083111ae2a11
first commit of leaned mbed dev lib

Who changed what in which revision?

UserRevisionLine numberNew contents of line
saloutos 0:083111ae2a11 1 /*
saloutos 0:083111ae2a11 2 * Hardware entropy collector for the STM32 families
saloutos 0:083111ae2a11 3 *
saloutos 0:083111ae2a11 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
saloutos 0:083111ae2a11 5 * SPDX-License-Identifier: Apache-2.0
saloutos 0:083111ae2a11 6 *
saloutos 0:083111ae2a11 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
saloutos 0:083111ae2a11 8 * not use this file except in compliance with the License.
saloutos 0:083111ae2a11 9 * You may obtain a copy of the License at
saloutos 0:083111ae2a11 10 *
saloutos 0:083111ae2a11 11 * http://www.apache.org/licenses/LICENSE-2.0
saloutos 0:083111ae2a11 12 *
saloutos 0:083111ae2a11 13 * Unless required by applicable law or agreed to in writing, software
saloutos 0:083111ae2a11 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
saloutos 0:083111ae2a11 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
saloutos 0:083111ae2a11 16 * See the License for the specific language governing permissions and
saloutos 0:083111ae2a11 17 * limitations under the License.
saloutos 0:083111ae2a11 18 *
saloutos 0:083111ae2a11 19 */
saloutos 0:083111ae2a11 20
saloutos 0:083111ae2a11 21 #if defined(DEVICE_TRNG)
saloutos 0:083111ae2a11 22
saloutos 0:083111ae2a11 23 #include <stdlib.h>
saloutos 0:083111ae2a11 24 #include "cmsis.h"
saloutos 0:083111ae2a11 25 #include "trng_api.h"
saloutos 0:083111ae2a11 26
saloutos 0:083111ae2a11 27 /** trng_get_byte
saloutos 0:083111ae2a11 28 * @brief Get one byte of entropy from the RNG, assuming it is up and running.
saloutos 0:083111ae2a11 29 * @param obj TRNG obj
saloutos 0:083111ae2a11 30 * @param pointer to the hardware generated random byte.
saloutos 0:083111ae2a11 31 */
saloutos 0:083111ae2a11 32 static void trng_get_byte(trng_t *obj, unsigned char *byte )
saloutos 0:083111ae2a11 33 {
saloutos 0:083111ae2a11 34 *byte = (unsigned char)HAL_RNG_GetRandomNumber(&obj->handle);
saloutos 0:083111ae2a11 35 }
saloutos 0:083111ae2a11 36
saloutos 0:083111ae2a11 37 void trng_init(trng_t *obj)
saloutos 0:083111ae2a11 38 {
saloutos 0:083111ae2a11 39 #if defined(TARGET_STM32L4)
saloutos 0:083111ae2a11 40 RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;
saloutos 0:083111ae2a11 41
saloutos 0:083111ae2a11 42 /*Select PLLQ output as RNG clock source */
saloutos 0:083111ae2a11 43 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_RNG;
saloutos 0:083111ae2a11 44 PeriphClkInitStruct.RngClockSelection = RCC_RNGCLKSOURCE_PLL;
saloutos 0:083111ae2a11 45 HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
saloutos 0:083111ae2a11 46 #endif
saloutos 0:083111ae2a11 47
saloutos 0:083111ae2a11 48 /* RNG Peripheral clock enable */
saloutos 0:083111ae2a11 49 __HAL_RCC_RNG_CLK_ENABLE();
saloutos 0:083111ae2a11 50
saloutos 0:083111ae2a11 51 /* Initialize RNG instance */
saloutos 0:083111ae2a11 52 obj->handle.Instance = RNG;
saloutos 0:083111ae2a11 53 HAL_RNG_Init(&obj->handle);
saloutos 0:083111ae2a11 54
saloutos 0:083111ae2a11 55 /* first random number generated after setting the RNGEN bit should not be used */
saloutos 0:083111ae2a11 56 HAL_RNG_GetRandomNumber(&obj->handle);
saloutos 0:083111ae2a11 57
saloutos 0:083111ae2a11 58 }
saloutos 0:083111ae2a11 59
saloutos 0:083111ae2a11 60 void trng_free(trng_t *obj)
saloutos 0:083111ae2a11 61 {
saloutos 0:083111ae2a11 62 /*Disable the RNG peripheral */
saloutos 0:083111ae2a11 63 HAL_RNG_DeInit(&obj->handle);
saloutos 0:083111ae2a11 64 /* RNG Peripheral clock disable - assume we're the only users of RNG */
saloutos 0:083111ae2a11 65 __HAL_RCC_RNG_CLK_DISABLE();
saloutos 0:083111ae2a11 66 }
saloutos 0:083111ae2a11 67
saloutos 0:083111ae2a11 68 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
saloutos 0:083111ae2a11 69 {
saloutos 0:083111ae2a11 70 int ret;
saloutos 0:083111ae2a11 71
saloutos 0:083111ae2a11 72 /* Get Random byte */
saloutos 0:083111ae2a11 73 for( uint32_t i = 0; i < length; i++ ){
saloutos 0:083111ae2a11 74 trng_get_byte(obj, output + i );
saloutos 0:083111ae2a11 75 }
saloutos 0:083111ae2a11 76
saloutos 0:083111ae2a11 77 *output_length = length;
saloutos 0:083111ae2a11 78 /* Just be extra sure that we didn't do it wrong */
saloutos 0:083111ae2a11 79 if( ( __HAL_RNG_GET_FLAG(&obj->handle, (RNG_FLAG_CECS | RNG_FLAG_SECS)) ) != 0 ) {
saloutos 0:083111ae2a11 80 ret = -1;
saloutos 0:083111ae2a11 81 } else {
saloutos 0:083111ae2a11 82 ret = 0;
saloutos 0:083111ae2a11 83 }
saloutos 0:083111ae2a11 84
saloutos 0:083111ae2a11 85 return( ret );
saloutos 0:083111ae2a11 86 }
saloutos 0:083111ae2a11 87
saloutos 0:083111ae2a11 88 #endif