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 --- Changes since V5: * Handle review comments from Heinrich Schuchardt to read all the bytes requested in the individual drivers.
arch/sandbox/dts/test.dts | 4 ++++ drivers/rng/Kconfig | 8 +++++++ drivers/rng/Makefile | 1 + drivers/rng/sandbox_rng.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 69 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@0 { + compatible = "sandbox,sandbox-rng"; + }; + rproc_1: rproc@1 { compatible = "sandbox,test-processor"; remoteproc-name = "remoteproc-test-dev1"; diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index c9c4751..35a3bd1 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -6,6 +6,14 @@ 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 + select CONFIG_LIB_RAND + 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..cd0b0ac --- /dev/null +++ b/drivers/rng/sandbox_rng.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2019, Linaro Limited + */ + +#include <common.h> +#include <dm.h> +#include <rng.h> + +#include <linux/string.h> + +static int sandbox_rng_read(struct udevice *dev, void *data, size_t len) +{ + unsigned int i, seed, random; + unsigned char *buf = data; + size_t nrem, nloops; + + if (!len) + return 0; + + nloops = len / sizeof(random); + seed = get_timer(0) ^ rand(); + srand(seed); + + for (i = 0, nrem = len; i < nloops; i++) { + random = rand(); + memcpy(buf, &random, sizeof(random)); + buf += sizeof(random); + nrem -= sizeof(random); + } + + if (nrem) { + random = rand(); + memcpy(buf, &random, nrem); + } + + return 0; +} + +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, +};