| /** |
| **************************************************************************************** |
| * |
| * @file hw_trng.c |
| * |
| * @brief Implementation of the True Random Number Generator Low Level Driver. |
| * |
| * Copyright (c) 2016, Dialog Semiconductor |
| * 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 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 the copyright holder nor the names of its contributors |
| * may be used to endorse or promote products derived from this software without |
| * specific prior written permission. |
| * |
| * 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. |
| * |
| * |
| **************************************************************************************** |
| */ |
| |
| #if dg_configUSE_HW_TRNG |
| |
| #include <hw_trng.h> |
| |
| #if (dg_configSYSTEMVIEW) |
| # include "SEGGER_SYSVIEW_FreeRTOS.h" |
| #else |
| # define SEGGER_SYSTEMVIEW_ISR_ENTER() |
| # define SEGGER_SYSTEMVIEW_ISR_EXIT() |
| #endif |
| |
| #define HW_TRNG_FIFO_DEPTH (32) |
| |
| static hw_trng_cb trng_cb; |
| |
| void hw_trng_disable_clk(void) |
| { |
| GLOBAL_INT_DISABLE(); |
| REG_CLR_BIT(CRG_TOP, CLK_AMBA_REG, TRNG_CLK_ENABLE); |
| GLOBAL_INT_RESTORE(); |
| } |
| |
| void hw_trng_clear_pending(void) |
| { |
| uint32_t dummy __attribute__((unused)); |
| /* read TRNG_FIFOLVL_REG to clear level-sensitive source. */ |
| dummy = TRNG->TRNG_FIFOLVL_REG; |
| NVIC_ClearPendingIRQ(TRNG_IRQn); |
| } |
| |
| void hw_trng_enable(hw_trng_cb callback) |
| { |
| if (callback != NULL) |
| { |
| trng_cb = callback; |
| hw_trng_clear_pending(); |
| NVIC_EnableIRQ(TRNG_IRQn); |
| } |
| |
| GLOBAL_INT_DISABLE(); |
| REG_SET_BIT(CRG_TOP, CLK_AMBA_REG, TRNG_CLK_ENABLE); |
| GLOBAL_INT_RESTORE(); |
| REG_SET_BIT(TRNG, TRNG_CTRL_REG, TRNG_ENABLE); |
| } |
| |
| void hw_trng_get_numbers(uint32_t *buffer, uint8_t size) |
| { |
| if (size > HW_TRNG_FIFO_DEPTH) |
| { |
| size = HW_TRNG_FIFO_DEPTH; |
| } |
| |
| for (int i = 0; i < size ; i++) |
| { |
| buffer[i] = hw_trng_get_number(); |
| } |
| } |
| |
| __RETAINED_CODE uint8_t hw_trng_get_fifo_level(void) |
| { |
| return (TRNG->TRNG_FIFOLVL_REG) & (REG_MSK(TRNG, TRNG_FIFOLVL_REG, TRNG_FIFOLVL) | |
| REG_MSK(TRNG, TRNG_FIFOLVL_REG, TRNG_FIFOFULL)); |
| } |
| |
| void hw_trng_disable_interrupt(void) |
| { |
| NVIC_DisableIRQ(TRNG_IRQn); |
| trng_cb = NULL; |
| } |
| |
| void hw_trng_disable(void) |
| { |
| hw_trng_stop(); |
| hw_trng_disable_interrupt(); |
| hw_trng_clear_pending(); |
| hw_trng_disable_clk(); |
| } |
| |
| void TRNG_Handler(void) |
| { |
| uint32_t dummy __attribute__((unused)); |
| |
| SEGGER_SYSTEMVIEW_ISR_ENTER(); |
| |
| if (trng_cb != NULL) |
| { |
| trng_cb(); |
| } |
| |
| /* read TRNG_FIFOLVL_REG to clear level-sensitive source. */ |
| dummy = TRNG->TRNG_FIFOLVL_REG; |
| |
| SEGGER_SYSTEMVIEW_ISR_EXIT(); |
| } |
| |
| #endif /* dg_configUSE_HW_TRNG */ |