From 54739069937954d759ebc02bed32d08457c90a15 Mon Sep 17 00:00:00 2001
From: Bogdan Davidoaia <bogdan.davidoaia@linaro.org>
Date: Tue, 28 Feb 2017 13:24:43 +0200
Subject: [PATCH] random: add MCUX TRNG driver

Provide a random driver wrapped around the MCUX TRNG driver.

Change-Id: Icbd7ab587aa18ecbd7eae52290aaa5d8ee504cf2
Origin: Original
Signed-off-by: Bogdan Davidoaia <bogdan.davidoaia@linaro.org>
---
 arch/arm/soc/nxp_kinetis/Kconfig  |  6 +++
 drivers/random/Kconfig.mcux       |  9 +++++
 drivers/random/Makefile           |  1 +
 drivers/random/random_mcux_trng.c | 64 +++++++++++++++++++++++++++++++
 ext/hal/nxp/mcux/drivers/Makefile |  1 +
 5 files changed, 81 insertions(+)
 create mode 100644 drivers/random/random_mcux_trng.c

diff --git a/arch/arm/soc/nxp_kinetis/Kconfig b/arch/arm/soc/nxp_kinetis/Kconfig
index d08870f84d5..f7bf5a30cb3 100644
--- a/arch/arm/soc/nxp_kinetis/Kconfig
+++ b/arch/arm/soc/nxp_kinetis/Kconfig
@@ -45,6 +45,12 @@ config HAS_RNGA
 	help
 	Set if the random number generator accelerator (RNGA) module is present in the SoC.
 
+config HAS_TRNG
+	bool
+	default n
+	help
+	Set if the true random number generator (TRNG) module is present in the SoC.
+
 config HAS_LPUART
 	bool
 	default n
diff --git a/drivers/random/Kconfig.mcux b/drivers/random/Kconfig.mcux
index 307c5b17969..1c53968705a 100644
--- a/drivers/random/Kconfig.mcux
+++ b/drivers/random/Kconfig.mcux
@@ -12,3 +12,12 @@ menuconfig RANDOM_MCUX_RNGA
 	help
 	  This option enables the random number generator accelerator (RNGA)
 	  driver based on the MCUX RNGA driver.
+
+menuconfig RANDOM_MCUX_TRNG
+	bool "MCUX TRNG driver"
+	depends on RANDOM_GENERATOR && HAS_TRNG
+	default n
+	select RANDOM_HAS_DRIVER
+	help
+	  This option enables the true random number generator (TRNG)
+	  driver based on the MCUX TRNG driver.
diff --git a/drivers/random/Makefile b/drivers/random/Makefile
index 9b42ce680f8..db1f6525990 100644
--- a/drivers/random/Makefile
+++ b/drivers/random/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_RANDOM_MCUX_RNGA) += random_mcux_rnga.o
+obj-$(CONFIG_RANDOM_MCUX_TRNG) += random_mcux_trng.o
 obj-$(CONFIG_TIMER_RANDOM_GENERATOR) = rand32_timer.o
 obj-$(CONFIG_X86_TSC_RANDOM_GENERATOR) += rand32_timestamp.o
diff --git a/drivers/random/random_mcux_trng.c b/drivers/random/random_mcux_trng.c
new file mode 100644
index 00000000000..5679d170506
--- /dev/null
+++ b/drivers/random/random_mcux_trng.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2017 Linaro Limited.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <device.h>
+#include <random.h>
+#include <drivers/rand32.h>
+#include <init.h>
+
+#include "fsl_trng.h"
+
+static int random_mcux_trng_get_entropy(struct device *dev, uint8_t *buffer,
+					uint16_t length)
+{
+	status_t status;
+
+	ARG_UNUSED(dev);
+
+	status = TRNG_GetRandomData(TRNG0, buffer, length);
+	__ASSERT_NO_MSG(!status);
+
+	return 0;
+}
+
+static const struct random_driver_api random_mcux_trng_api_funcs = {
+	.get_entropy = random_mcux_trng_get_entropy
+};
+
+static int random_mcux_trng_init(struct device *);
+
+DEVICE_AND_API_INIT(random_mcux_trng, CONFIG_RANDOM_NAME,
+		    random_mcux_trng_init, NULL, NULL,
+		    PRE_KERNEL_2, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
+		    &random_mcux_trng_api_funcs);
+
+static int random_mcux_trng_init(struct device *dev)
+{
+	trng_config_t conf;
+	status_t status;
+
+	ARG_UNUSED(dev);
+
+	status = TRNG_GetDefaultConfig(&conf);
+	__ASSERT_NO_MSG(!status);
+
+	status = TRNG_Init(TRNG0, &conf);
+	__ASSERT_NO_MSG(!status);
+
+	return 0;
+}
+
+uint32_t sys_rand32_get(void)
+{
+	uint32_t output;
+	int rc;
+
+	rc = random_mcux_trng_get_entropy(DEVICE_GET(random_mcux_trng),
+					  (uint8_t *) &output, sizeof(output));
+	__ASSERT_NO_MSG(!rc);
+
+	return output;
+}
diff --git a/ext/hal/nxp/mcux/drivers/Makefile b/ext/hal/nxp/mcux/drivers/Makefile
index 36a908cf274..4a6d46b626d 100644
--- a/ext/hal/nxp/mcux/drivers/Makefile
+++ b/ext/hal/nxp/mcux/drivers/Makefile
@@ -7,6 +7,7 @@
 obj-$(CONFIG_ETH_MCUX) += fsl_enet.o
 obj-$(CONFIG_I2C_MCUX) += fsl_i2c.o
 obj-$(CONFIG_RANDOM_MCUX_RNGA) += fsl_rnga.o
+obj-$(CONFIG_RANDOM_MCUX_TRNG) += fsl_trng.o
 obj-$(CONFIG_SOC_FLASH_MCUX) += fsl_flash.o
 obj-$(CONFIG_SPI_MCUX) += fsl_dspi.o
 obj-$(CONFIG_UART_MCUX) += fsl_uart.o