[PATCH v3 5/8] sandbox: rng: Add a random number generator(rng) driver

Sughosh Ganu
2019-12-13T07:14:24Z

Add a sandbox driver for random number generation. Mostly aimed at
providing a unit test for rng uclass.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
arch/sandbox/dts/test.dts | 4 ++++
drivers/rng/Kconfig | 7 +++++++
drivers/rng/Makefile | 1 +
drivers/rng/sandbox_rng.c | 36 ++++++++++++++++++++++++++++++++++++
4 files changed, 48 insertions(+)
create mode 100644 drivers/rng/sandbox_rng.c

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index fdb08f2..2c85540 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -599,6 +599,10 @@
reset-names = "other", "test";
};

+ rng at 0 {
+ compatible = "sandbox,sandbox-rng";
+ };
+
rproc_1: rproc at 1 {
compatible = "sandbox,test-processor";
remoteproc-name = "remoteproc-test-dev1";
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 5fc11db..3a1d3f0 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -6,6 +6,13 @@ config DM_RNG
This interface is used to initialise the rng device and to
read the random seed from the device.

+config RNG_SANDBOX
+ bool "Sandbox random number generator"
+ depends on SANDBOX && DM_RNG
+ help
+ Enable random number generator for sandbox. This is an
+ emulation of a rng device.
+
config RNG_STM32MP1
bool "Enable random number generator for STM32MP1"
depends on ARCH_STM32MP && DM_RNG
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index 699beb3..3517005 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -4,4 +4,5 @@
#

obj-$(CONFIG_DM_RNG) += rng-uclass.o
+obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o
obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o
diff --git a/drivers/rng/sandbox_rng.c b/drivers/rng/sandbox_rng.c
new file mode 100644
index 0000000..c5be552
--- /dev/null
+++ b/drivers/rng/sandbox_rng.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+
+static unsigned long random = 0xdeadbeef;
+
+static int sandbox_rng_read(struct udevice *dev, void *data, size_t len)
+{
+ random ^= ~0UL;
+ *(unsigned long *)data = random;
+
+ return sizeof(random);
+}
+
+static const struct dm_rng_ops sandbox_rng_ops = {
+ .read = sandbox_rng_read,
+};
+
+static const struct udevice_id sandbox_rng_match[] = {
+ {
+ .compatible = "sandbox,sandbox-rng",
+ },
+ {},
+};
+
+U_BOOT_DRIVER(sandbox_rng) = {
+ .name = "sandbox-rng",
+ .id = UCLASS_RNG,
+ .of_match = sandbox_rng_match,
+ .ops = &sandbox_rng_ops,
+};
--
2.7.4