From 0ce2081817af689905843885c9a32f4ec50fbd23 Mon Sep 17 00:00:00 2001
From: Francisco Molina <femolina@uc.cl>
Date: Fri, 9 Aug 2019 08:59:54 +0200
Subject: [PATCH] cpu/kinetis: re-enable HWRNG for k64f

- Fix SCGx used for RNGA since RNGA is not mapped
  to SCG3 for K64F.
---
 cpu/kinetis/Makefile.features            |  2 --
 cpu/kinetis/include/cpu_conf_kinetis.h   | 16 ++++++++++------
 cpu/kinetis/include/cpu_conf_kinetis_k.h | 13 +++++++++++++
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/cpu/kinetis/Makefile.features b/cpu/kinetis/Makefile.features
index d8b43c087c..5c0199efe0 100644
--- a/cpu/kinetis/Makefile.features
+++ b/cpu/kinetis/Makefile.features
@@ -3,8 +3,6 @@ FEATURES_PROVIDED += periph_cpuid
 # HACK Do not define 'hwrng' if the board does not supports it
 # A whitelist on CPU_MODEL would be better but this information/variable is not
 # available yet.
-# HWRNG uses the wrong hwrng register for the frdm-k64f board/cpu_model
-_KINETIS_BOARDS_WITHOUT_HWRNG += frdm-k64f
 # TRNG driver is not implemented for 'CPU_MODEL == mkw41z512vht4'
 _KINETIS_BOARDS_WITHOUT_HWRNG += frdm-kw41z phynode-kw41z usb-kw41z
 # No HWRNG in MK20D7 devices
diff --git a/cpu/kinetis/include/cpu_conf_kinetis.h b/cpu/kinetis/include/cpu_conf_kinetis.h
index dfd3e171de..421b9e7408 100644
--- a/cpu/kinetis/include/cpu_conf_kinetis.h
+++ b/cpu/kinetis/include/cpu_conf_kinetis.h
@@ -154,15 +154,19 @@ extern "C"
  * @name Hardware random number generator module configuration
  * @{
  */
-#if !defined(HWRNG_CLKEN) && defined(RNG) && !defined(RNG_CMD_ST_MASK)
-#define KINETIS_RNGA RNG
+#if !defined(HWRNG_CLK_REG) && !defined(HWRNG_CLK_REG_SHIFT)
 #if defined(SIM_SCGC3_RNGA_SHIFT)
-#define HWRNG_CLKEN()       (bit_set32(&SIM->SCGC3, SIM_SCGC3_RNGA_SHIFT))
-#define HWRNG_CLKDIS()      (bit_clear32(&SIM->SCGC3, SIM_SCGC3_RNGA_SHIFT))
+#define HWRNG_CLK_REG           SIM->SCGC3
+#define HWRNG_CLK_REG_SHIFT     SIM_SCGC3_RNGA_SHIFT
 #elif defined(SIM_SCGC6_RNGA_SHIFT)
-#define HWRNG_CLKEN()       (bit_set32(&SIM->SCGC6, SIM_SCGC6_RNGA_SHIFT))
-#define HWRNG_CLKDIS()      (bit_clear32(&SIM->SCGC6, SIM_SCGC6_RNGA_SHIFT))
+#define HWRNG_CLK_REG           SIM->SCGC6
+#define HWRNG_CLK_REG_SHIFT     SIM_SCGC6_RNGA_SHIFT
 #endif
+#endif
+#if defined(RNG)
+#define KINETIS_RNGA RNG
+#define HWRNG_CLKEN()       (bit_set32(&HWRNG_CLK_REG, HWRNG_CLK_REG_SHIFT))
+#define HWRNG_CLKDIS()      (bit_clear32(&HWRNG_CLK_REG, HWRNG_CLK_REG_SHIFT))
 #endif /* KINETIS_RNGA */
 /** @} */
 
diff --git a/cpu/kinetis/include/cpu_conf_kinetis_k.h b/cpu/kinetis/include/cpu_conf_kinetis_k.h
index 58de7ee115..3897c77ded 100644
--- a/cpu/kinetis/include/cpu_conf_kinetis_k.h
+++ b/cpu/kinetis/include/cpu_conf_kinetis_k.h
@@ -119,6 +119,19 @@
     defined(CPU_MODEL_MK64FX512VLQ12) || \
     defined(CPU_MODEL_MK64FX512VMD12)
 #include "vendor/MK64F12.h"
+
+/**
+ * @name Hardware random number generator module configuration
+ *
+ *       For K64F SCG3 or SCG6 can be used depending on if the the
+ *       peripheral is accessed through AIPS-lite0 or AIPS-lite1.
+ *       For K64F RNGA is only mapped to SCG6.
+ * @{
+ */
+#define HWRNG_CLK_REG           (SIM->SCGC6)
+#define HWRNG_CLK_REG_SHIFT     (SIM_SCGC6_RNGA_SHIFT)
+/** @} */
+
 #endif
 #endif /* (KINETIS_SUBFAMILY == y) */
 #endif /* (KINETIS_FAMILY == x) */