Diff: targets/TARGET_ONSEMI/TARGET_NCS36510/ncs36510_trng_api.c

Revision:

150:02e0a0aed4ec

Child:

160:d5399cc887bb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_ONSEMI/TARGET_NCS36510/ncs36510_trng_api.c	Tue Nov 08 17:45:16 2016 +0000
@@ -0,0 +1,113 @@
+/**
+ ******************************************************************************
+ * @file trng_api.c
+ * @brief Implementation of TRNG functionality.
+ * @internal
+ * @author  ON Semiconductor.
+ * $Rev: $
+ * $Date: $
+ ******************************************************************************
+ * Copyright 2016 Semiconductor Components Industries LLC (d/b/a “ON Semiconductor”).
+ * All rights reserved.  This software and/or documentation is licensed by ON Semiconductor
+ * under limited terms and conditions.  The terms and conditions pertaining to the software
+ * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf
+ * (“ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software”) and
+ * if applicable the software license agreement.  Do not use this software and/or
+ * documentation unless you have carefully read and you agree to the limited terms and
+ * conditions.  By using this software and/or documentation, you agree to the limited
+ * terms and conditions.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
+ * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
+ * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,
+ * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
+ * @endinternal
+ *
+ * @ingroup TRNG
+ *
+ */
+#if DEVICE_TRNG
+
+/*************************************************************************************************
+*                                                                                                *
+*  Header files                                                                                  *
+*                                                                                                *
+*************************************************************************************************/
+#include "trng_api.h"
+#include "memory_map.h"
+#include "ncs36510_trng.h"
+#include "clock.h"
+#include "wait_api.h"
+
+/*************************************************************************************************
+*                                                                                                *
+*  Functions                                                                                     *
+*                                                                                                *
+*************************************************************************************************/
+
+
+void trng_init(trng_t *obj)
+{
+    /* Enable TRNG */
+    CLOCK_ENABLE(CLOCK_RAND);
+
+    /* Initialize TRNG */
+    RANDREG->CONTROL.WORD = False;
+
+    return;
+}
+void trng_free(trng_t *obj)
+{
+    /* Stop TRNG  */
+    RANDREG->CONTROL.WORD = False;
+
+    /* Disable TRNG */
+    CLOCK_DISABLE(CLOCK_RAND);
+
+    return;
+}
+
+int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
+{
+    uint32_t MSLRandom = 0, Index, TempLen, *TempPtr = (uint32_t*)output;
+        
+    RANDREG->CONTROL.BITS.METASTABLE_LATCH_EN = TRNG_ENABLE;        /* ENable MSL TRNG */
+    RANDREG->CONTROL.BITS.MEATSTABLE_SPEED    = TRNG_FAST_MODE;     /* Meta-stable Latch TRNG Speed Control */
+    RANDREG->CONTROL.BITS.MODE                = TRNG_ON_READ_EVENT; /* TRNG is only updated on a read event of the TRNG register */
+
+    wait_us(1); /* Wait till MSL generates random number after enable for the first time */
+    
+    TempLen = length / 4;
+
+    for(Index = 0; Index < TempLen; Index++)
+    {
+        MSLRandom = RANDREG->METASTABLE_LATCH_VAL;
+        *TempPtr++ = MSLRandom ;
+    }
+
+    TempLen = length % 4;
+    Index *= 4;
+
+    if(TempLen-- > 0)
+    {
+        MSLRandom = RANDREG->METASTABLE_LATCH_VAL;
+        *(output + Index++) = (MSLRandom >> 0) & 0xFF;
+        if(TempLen-- > 0)
+        {
+            *(output + Index++) = (MSLRandom >> 8) & 0xFF;
+            if(TempLen-- > 0)
+            {
+                *(output + Index++) = (MSLRandom >> 16) & 0xFF;
+            }
+        }
+    }
+
+    RANDREG->CONTROL.BITS.METASTABLE_LATCH_EN = TRNG_DISABLE;        /* Disable MSL */
+
+    *output_length = Index;
+
+    return 0; /* Success */
+}
+
+#endif /* DEVICE_TRNG */
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