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-rw-r--r--drivers/rng/Kconfig9
-rw-r--r--drivers/rng/Makefile1
-rw-r--r--drivers/rng/tpm_rng.c23
3 files changed, 33 insertions, 0 deletions
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 21a9ff0195..16143681da 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -74,4 +74,13 @@ config RNG_SMCCC_TRNG
Enable random number generator for platforms that support Arm
SMCCC TRNG interface.
+config TPM_RNG
+ bool "Enable random number generator on TPM device"
+ depends on TPM
+ default y
+ help
+ The TPM device has an inbuilt random number generator
+ functionality. Enable random number generator on TPM
+ devices.
+
endif
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index 2494717d7c..78f61051ac 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o
obj-$(CONFIG_RNG_ROCKCHIP) += rockchip_rng.o
obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o
obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o
+obj-$(CONFIG_TPM_RNG) += tpm_rng.o
diff --git a/drivers/rng/tpm_rng.c b/drivers/rng/tpm_rng.c
new file mode 100644
index 0000000000..1a5e9e2e4b
--- /dev/null
+++ b/drivers/rng/tpm_rng.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022, Linaro Limited
+ */
+
+#include <dm.h>
+#include <rng.h>
+#include <tpm_api.h>
+
+static int rng_tpm_random_read(struct udevice *dev, void *data, size_t count)
+{
+ return tpm_get_random(dev_get_parent(dev), data, count);
+}
+
+static const struct dm_rng_ops tpm_rng_ops = {
+ .read = rng_tpm_random_read,
+};
+
+U_BOOT_DRIVER(tpm_rng) = {
+ .name = "tpm-rng",
+ .id = UCLASS_RNG,
+ .ops = &tpm_rng_ops,
+};