Add TRNG for NRF52832

Use SoftDevice API to get random numbers when present and active,
otherwise read random numbers directly from TRNG peripheral.

Author: Marcus Chang

targets/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF52832/sdk/nrf_drv_config.h

@@ -171,7 +171,7 @@
 #define NRF_MAXIMUM_LATENCY_US 2000
 
 /* RNG */
-#define RNG_ENABLED 0
+#define RNG_ENABLED 1
 
 #if (RNG_ENABLED == 1)
 #define RNG_CONFIG_ERROR_CORRECTION true

targets/TARGET_NORDIC/TARGET_NRF5/TARGET_SDK11/drivers_nrf/hal/nrf_rng.h

@@ -0,0 +1,281 @@
+/* 
+ * Copyright (c) 2014 Nordic Semiconductor ASA
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ * 
+ *   1. Redistributions of source code must retain the above copyright notice, this list 
+ *      of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA 
+ *      integrated circuit in a product or a software update for such product, must reproduce 
+ *      the above copyright notice, this list of conditions and the following disclaimer in 
+ *      the documentation and/or other materials provided with the distribution.
+ *
+ *   3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be 
+ *      used to endorse or promote products derived from this software without specific prior 
+ *      written permission.
+ *
+ *   4. This software, with or without modification, must only be used with a 
+ *      Nordic Semiconductor ASA integrated circuit.
+ *
+ *   5. Any software provided in binary or object form under this license must not be reverse 
+ *      engineered, decompiled, modified and/or disassembled. 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ */
+
+/**
+ * @file
+ * @brief RNG HAL API.
+ */
+
+#ifndef NRF_RNG_H__
+#define NRF_RNG_H__
+/**
+ * @defgroup nrf_rng_hal RNG HAL
+ * @{
+ * @ingroup nrf_rng
+ * @brief Hardware access layer for managing the random number generator (RNG).
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "nrf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define NRF_RNG_TASK_SET    (1UL)
+#define NRF_RNG_EVENT_CLEAR (0UL)
+/**
+ * @enum nrf_rng_task_t
+ * @brief RNG tasks.
+ */
+typedef enum /*lint -save -e30 -esym(628,__INTADDR__) */
+{
+    NRF_RNG_TASK_START = offsetof(NRF_RNG_Type, TASKS_START), /**< Start the random number generator. */
+    NRF_RNG_TASK_STOP  = offsetof(NRF_RNG_Type, TASKS_STOP)   /**< Stop the random number generator. */
+} nrf_rng_task_t;                                             /*lint -restore */
+
+/**
+ * @enum nrf_rng_event_t
+ * @brief RNG events.
+ */
+typedef enum /*lint -save -e30 -esym(628,__INTADDR__) */
+{
+    NRF_RNG_EVENT_VALRDY = offsetof(NRF_RNG_Type, EVENTS_VALRDY) /**< New random number generated event. */
+} nrf_rng_event_t;                                               /*lint -restore */
+
+/**
+ * @enum nrf_rng_int_mask_t
+ * @brief RNG interrupts.
+ */
+typedef enum
+{
+    NRF_RNG_INT_VALRDY_MASK = RNG_INTENSET_VALRDY_Msk /**< Mask for enabling or disabling an interrupt on VALRDY event.  */
+} nrf_rng_int_mask_t;
+
+/**
+ * @enum nrf_rng_short_mask_t
+ * @brief Types of RNG shortcuts.
+ */
+typedef enum
+{
+    NRF_RNG_SHORT_VALRDY_STOP_MASK = RNG_SHORTS_VALRDY_STOP_Msk /**<  Mask for setting shortcut between EVENT_VALRDY and TASK_STOP. */
+} nrf_rng_short_mask_t;
+
+/**
+ * @brief Function for enabling interrupts.
+ *
+ * @param[in]  rng_int_mask              Mask of interrupts.
+ */
+__STATIC_INLINE void nrf_rng_int_enable(uint32_t rng_int_mask);
+
+/**
+ * @brief Function for disabling interrupts.
+ *
+ * @param[in]  rng_int_mask              Mask of interrupts.
+ */
+__STATIC_INLINE void nrf_rng_int_disable(uint32_t rng_int_mask);
+
+/**
+ * @brief Function for getting the state of a specific interrupt.
+ *
+ * @param[in]  rng_int_mask              Interrupt.
+ *
+ * @retval     true                   If the interrupt is not enabled.
+ * @retval     false                  If the interrupt is enabled.
+ */
+__STATIC_INLINE bool nrf_rng_int_get(nrf_rng_int_mask_t rng_int_mask);
+
+/**
+ * @brief Function for getting the address of a specific task.
+ *
+ * This function can be used by the PPI module.
+ *
+ * @param[in]  rng_task              Task.
+ */
+__STATIC_INLINE uint32_t * nrf_rng_task_address_get(nrf_rng_task_t rng_task);
+
+/**
+ * @brief Function for setting a specific task.
+ *
+ * @param[in]  rng_task              Task.
+ */
+__STATIC_INLINE void nrf_rng_task_trigger(nrf_rng_task_t rng_task);
+
+/**
+ * @brief Function for getting address of a specific event.
+ *
+ * This function can be used by the PPI module.
+ *
+ * @param[in]  rng_event              Event.
+ */
+__STATIC_INLINE uint32_t * nrf_rng_event_address_get(nrf_rng_event_t rng_event);
+
+/**
+ * @brief Function for clearing a specific event.
+ *
+ * @param[in]  rng_event              Event.
+ */
+__STATIC_INLINE void nrf_rng_event_clear(nrf_rng_event_t rng_event);
+
+/**
+ * @brief Function for getting the state of a specific event.
+ *
+ * @param[in]  rng_event              Event.
+ *
+ * @retval     true               If the event is not set.
+ * @retval     false              If the event is set.
+ */
+__STATIC_INLINE bool nrf_rng_event_get(nrf_rng_event_t rng_event);
+
+/**
+ * @brief Function for setting shortcuts.
+ *
+ * @param[in]  rng_short_mask              Mask of shortcuts.
+ *
+ */
+__STATIC_INLINE void nrf_rng_shorts_enable(uint32_t rng_short_mask);
+
+/**
+ * @brief Function for clearing shortcuts.
+ *
+ * @param[in]  rng_short_mask              Mask of shortcuts.
+ *
+ */
+__STATIC_INLINE void nrf_rng_shorts_disable(uint32_t rng_short_mask);
+
+/**
+ * @brief Function for getting the previously generated random value.
+ *
+ * @return     Previously generated random value.
+ */
+__STATIC_INLINE uint8_t nrf_rng_random_value_get(void);
+
+/**
+ * @brief Function for enabling digital error correction.
+ */
+__STATIC_INLINE void nrf_rng_error_correction_enable(void);
+
+/**
+ * @brief Function for disabling digital error correction.
+ */
+__STATIC_INLINE void nrf_rng_error_correction_disable(void);
+
+/**
+ *@}
+ **/
+
+#ifndef SUPPRESS_INLINE_IMPLEMENTATION
+
+__STATIC_INLINE void nrf_rng_int_enable(uint32_t rng_int_mask)
+{
+    NRF_RNG->INTENSET = rng_int_mask;
+}
+
+__STATIC_INLINE void nrf_rng_int_disable(uint32_t rng_int_mask)
+{
+    NRF_RNG->INTENCLR = rng_int_mask;
+}
+
+__STATIC_INLINE bool nrf_rng_int_get(nrf_rng_int_mask_t rng_int_mask)
+{
+    return (bool)(NRF_RNG->INTENCLR & rng_int_mask);
+}
+
+__STATIC_INLINE uint32_t * nrf_rng_task_address_get(nrf_rng_task_t rng_task)
+{
+    return (uint32_t *)((uint8_t *)NRF_RNG + rng_task);
+}
+
+__STATIC_INLINE void nrf_rng_task_trigger(nrf_rng_task_t rng_task)
+{
+    *((volatile uint32_t *)((uint8_t *)NRF_RNG + rng_task)) = NRF_RNG_TASK_SET;
+}
+
+__STATIC_INLINE uint32_t * nrf_rng_event_address_get(nrf_rng_event_t rng_event)
+{
+    return (uint32_t *)((uint8_t *)NRF_RNG + rng_event);
+}
+
+__STATIC_INLINE void nrf_rng_event_clear(nrf_rng_event_t rng_event)
+{
+    *((volatile uint32_t *)((uint8_t *)NRF_RNG + rng_event)) = NRF_RNG_EVENT_CLEAR;
+#if __CORTEX_M == 0x04
+    volatile uint32_t dummy = *((volatile uint32_t *)((uint8_t *)NRF_RNG + rng_event));
+    (void)dummy;
+#endif
+}
+
+__STATIC_INLINE bool nrf_rng_event_get(nrf_rng_event_t rng_event)
+{
+    return (bool) * ((volatile uint32_t *)((uint8_t *)NRF_RNG + rng_event));
+}
+
+__STATIC_INLINE void nrf_rng_shorts_enable(uint32_t rng_short_mask)
+{
+     NRF_RNG->SHORTS |= rng_short_mask;
+}
+
+__STATIC_INLINE void nrf_rng_shorts_disable(uint32_t rng_short_mask)
+{
+     NRF_RNG->SHORTS &= ~rng_short_mask;
+}
+
+__STATIC_INLINE uint8_t nrf_rng_random_value_get(void)
+{
+    return (uint8_t)(NRF_RNG->VALUE & RNG_VALUE_VALUE_Msk);
+}
+
+__STATIC_INLINE void nrf_rng_error_correction_enable(void)
+{
+    NRF_RNG->CONFIG |= RNG_CONFIG_DERCEN_Msk;
+}
+
+__STATIC_INLINE void nrf_rng_error_correction_disable(void)
+{
+    NRF_RNG->CONFIG &= ~RNG_CONFIG_DERCEN_Msk;
+}
+
+#endif
+ 
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NRF_RNG_H__ */