Merge branch 'master' of https://gitlab.denx.de/u-boot/custodians/u-boot-samsung

14 files changed, 506 insertions, 6 deletions

diff --git a/arch/arm/dts/exynos850-e850-96-u-boot.dtsi b/arch/arm/dts/exynos850-e850-96-u-boot.dtsi
index 6d7148f..3aa5d8b 100644
--- a/arch/arm/dts/exynos850-e850-96-u-boot.dtsi
+++ b/arch/arm/dts/exynos850-e850-96-u-boot.dtsi
@@ -3,6 +3,17 @@
  * Copyright (c) 2023 Linaro Ltd.
  */
 
+&soc {
+	/* TODO: Remove this node once it appears in upstream dts */
+	trng: rng@12081400 {
+		compatible = "samsung,exynos850-trng";
+		reg = <0x12081400 0x100>;
+		clocks = <&cmu_core CLK_GOUT_SSS_ACLK>,
+			 <&cmu_core CLK_GOUT_SSS_PCLK>;
+		clock-names = "secss", "pclk";
+	};
+};
+
 &pmu_system_controller {
 	bootph-all;
 	samsung,uart-debug-1;
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index cad8bb0..3fee5a4 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -250,6 +250,8 @@ config TARGET_E850_96
 	select PINCTRL
 	select PINCTRL_EXYNOS850
 	imply OF_UPSTREAM
+	imply DM_RNG
+	imply RNG_EXYNOS
 
 endchoice
 endif
diff --git a/board/samsung/e850-96/Makefile b/board/samsung/e850-96/Makefile
index 301c223..71d46ea 100644
--- a/board/samsung/e850-96/Makefile
+++ b/board/samsung/e850-96/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0+
 #
-# Copyright (C) 2020, Linaro Limited
+# Copyright (C) 2024, Linaro Limited
 # Sam Protsenko <semen.protsenko@linaro.org>
 
-obj-y	:= e850-96.o
+obj-y	:= e850-96.o fw.o
diff --git a/board/samsung/e850-96/e850-96.c b/board/samsung/e850-96/e850-96.c
index a00d81b..c5cef6f 100644
--- a/board/samsung/e850-96/e850-96.c
+++ b/board/samsung/e850-96/e850-96.c
@@ -1,10 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Copyright (C) 2020, Linaro Limited
- * Sam Protsenko <semen.protsenko@linaro.org>
+ * Copyright (c) 2024, Linaro Ltd.
+ * Author: Sam Protsenko <semen.protsenko@linaro.org>
  */
 
 #include <init.h>
+#include "fw.h"
 
 int dram_init(void)
 {
@@ -18,5 +19,6 @@ int dram_init_banksize(void)
 
 int board_init(void)
 {
+	load_ldfw();
 	return 0;
 }
diff --git a/board/samsung/e850-96/e850-96.env b/board/samsung/e850-96/e850-96.env
new file mode 100644
index 0000000..f36f90b
--- /dev/null
+++ b/board/samsung/e850-96/e850-96.env
@@ -0,0 +1,26 @@
+partitions=
+	uuid_disk=${uuid_gpt_disk};
+	name=efs,start=512K,size=20M,uuid=${uuid_gpt_efs};
+	name=env,size=16K,uuid=${uuid_gpt_env};
+	name=kernel,size=30M,uuid=${uuid_gpt_kernel};
+	name=ramdisk,size=26M,uuid=${uuid_gpt_ramdisk};
+	name=dtbo,size=1M,uuid=${uuid_gpt_dtbo};
+	name=ldfw,size=4016K,uuid=${uuid_gpt_ldfw};
+	name=keystorage,size=8K,uuid=${uuid_gpt_keystorage};
+	name=tzsw,size=1M,uuid=${uuid_gpt_tzsw};
+	name=harx,size=2M,uuid=${uuid_gpt_harx};
+	name=harx_rkp,size=2M,uuid=${uuid_gpt_harx_rkp};
+	name=logo,size=40M,uuid=${uuid_gpt_logo};
+	name=super,size=3600M,uuid=${uuid_gpt_super};
+	name=cache,size=300M,uuid=${uuid_gpt_cache};
+	name=modem,size=100M,uuid=${uuid_gpt_modem};
+	name=boot,size=100M,uuid=${uuid_gpt_boot};
+	name=persist,size=30M,uuid=${uuid_gpt_persist};
+	name=recovery,size=40M,uuid=${uuid_gpt_recovery};
+	name=misc,size=40M,uuid=${uuid_gpt_misc};
+	name=mnv,size=20M,uuid=${uuid_gpt_mnv};
+	name=frp,size=512K,uuid=${uuid_gpt_frp};
+	name=vbmeta,size=64K,uuid=${uuid_gpt_vbmeta};
+	name=metadata,size=16M,uuid=${uuid_gpt_metadata};
+	name=dtb,size=1M,uuid=${uuid_gpt_dtb};
+	name=userdata,size=-,uuid=${uuid_gpt_userdata}
diff --git a/board/samsung/e850-96/fw.c b/board/samsung/e850-96/fw.c
new file mode 100644
index 0000000..82a0b22
--- /dev/null
+++ b/board/samsung/e850-96/fw.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Linaro Ltd.
+ * Author: Sam Protsenko <semen.protsenko@linaro.org>
+ *
+ * Firmware loading code.
+ */
+
+#include <part.h>
+#include <linux/arm-smccc.h>
+#include "fw.h"
+
+#define EMMC_IFACE		"mmc"
+#define EMMC_DEV_NUM		0
+
+/* LDFW constants */
+#define LDFW_PART_NAME		"ldfw"
+#define LDFW_NWD_ADDR		0x88000000
+#define LDFW_MAGIC		0x10adab1e
+#define SMC_CMD_LOAD_LDFW	-0x500
+#define SDM_HW_RESET_STATUS	0x1230
+#define SDM_SW_RESET_STATUS	0x1231
+#define SB_ERROR_PREFIX		0xfdaa0000
+
+struct ldfw_header {
+	u32 magic;
+	u32 size;
+	u32 init_entry;
+	u32 entry_point;
+	u32 suspend_entry;
+	u32 resume_entry;
+	u32 start_smc_id;
+	u32 version;
+	u32 set_runtime_entry;
+	u32 reserved[3];
+	char fw_name[16];
+};
+
+static int read_fw(const char *part_name, void *buf)
+{
+	struct blk_desc *blk_desc;
+	struct disk_partition part;
+	unsigned long cnt;
+	int part_num;
+
+	blk_desc = blk_get_dev(EMMC_IFACE, EMMC_DEV_NUM);
+	if (!blk_desc) {
+		debug("%s: Can't get eMMC device\n", __func__);
+		return -ENODEV;
+	}
+
+	part_num = part_get_info_by_name(blk_desc, part_name, &part);
+	if (part_num < 0) {
+		debug("%s: Can't get LDWF partition\n", __func__);
+		return -ENOENT;
+	}
+
+	cnt = blk_dread(blk_desc, part.start, part.size, buf);
+	if (cnt != part.size) {
+		debug("%s: Can't read LDFW partition\n", __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int load_ldfw(void)
+{
+	const phys_addr_t addr = (phys_addr_t)LDFW_NWD_ADDR;
+	struct ldfw_header *hdr;
+	struct arm_smccc_res res;
+	void *buf = (void *)addr;
+	u64 size = 0;
+	int err, i;
+
+	/* Load LDFW from the block device partition into RAM buffer */
+	err = read_fw(LDFW_PART_NAME, buf);
+	if (err)
+		return err;
+
+	/* Validate LDFW by magic number in its header */
+	hdr = buf;
+	if (hdr->magic != LDFW_MAGIC) {
+		debug("%s: Wrong LDFW magic; is LDFW flashed?\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Calculate actual total size of all LDFW blobs */
+	for (i = 0; hdr->magic == LDFW_MAGIC; ++i) {
+#ifdef DEBUG
+		char name[17] = { 0 };
+
+		strncpy(name, hdr->fw_name, 16);
+		debug("%s: ldfw #%d: version = 0x%x, name = %s\n", __func__, i,
+		      hdr->version, name);
+#endif
+
+		size += (u64)hdr->size;
+		hdr = (struct ldfw_header *)((u64)hdr + (u64)hdr->size);
+	}
+	debug("%s: The whole size of all LDFWs: 0x%llx\n", __func__, size);
+
+	/* Load LDFW firmware to SWD (Secure World) memory via EL3 monitor */
+	arm_smccc_smc(SMC_CMD_LOAD_LDFW, addr, size, 0, 0, 0, 0, 0, &res);
+	err = (int)res.a0;
+	if (err == -1 || err == SDM_HW_RESET_STATUS) {
+		debug("%s: Can't load LDFW in dump_gpr state\n", __func__);
+		return -EIO;
+	} else if (err == SDM_SW_RESET_STATUS) {
+		debug("%s: Can't load LDFW in kernel panic (SW RESET) state\n",
+		      __func__);
+		return -EIO;
+	} else if (err < 0 && (err & 0xffff0000) == SB_ERROR_PREFIX) {
+		debug("%s: LDFW signature is corrupted! ret=0x%x\n", __func__,
+		      (u32)err);
+		return -EIO;
+	} else if (err == 0) {
+		debug("%s: No LDFW is inited\n", __func__);
+		return -EIO;
+	}
+
+#ifdef DEBUG
+	u32 tried = res.a0 & 0xffff;
+	u32 failed = (res.a0 >> 16) & 0xffff;
+
+	debug("%s: %d/%d LDFWs have been loaded successfully\n", __func__,
+	      tried - failed, tried);
+#endif
+
+	return 0;
+}
diff --git a/board/samsung/e850-96/fw.h b/board/samsung/e850-96/fw.h
new file mode 100644
index 0000000..472664e
--- /dev/null
+++ b/board/samsung/e850-96/fw.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2024 Linaro Ltd.
+ * Sam Protsenko <semen.protsenko@linaro.org>
+ */
+
+#ifndef __E850_96_FW_H
+#define __E850_96_FW_H
+
+int load_ldfw(void);
+
+#endif /* __E850_96_FW_H */
diff --git a/board/samsung/odroid/Makefile b/board/samsung/odroid/Makefile
index 5bf4831..615c99f 100644
--- a/board/samsung/odroid/Makefile
+++ b/board/samsung/odroid/Makefile
@@ -3,4 +3,4 @@
 # Copyright (c) 2014 Samsung Electronics Co., Ltd. All rights reserved.
 # Przemyslaw Marczak <p.marczak@samsung.com>
 
-obj-y	:= odroid.o
+obj-$(CONFIG_TARGET_ODROID)	:= odroid.o
diff --git a/board/samsung/smdk5420/Kconfig b/board/samsung/smdk5420/Kconfig
index a9d62ff..37d6bbb 100644
--- a/board/samsung/smdk5420/Kconfig
+++ b/board/samsung/smdk5420/Kconfig
@@ -1,7 +1,7 @@
 if TARGET_ODROID_XU3
 
 config SYS_BOARD
-	default "smdk5420"
+	default "odroid"
 
 config SYS_VENDOR
 	default "samsung"
diff --git a/configs/e850-96_defconfig b/configs/e850-96_defconfig
index 38b9968..2949da2 100644
--- a/configs/e850-96_defconfig
+++ b/configs/e850-96_defconfig
@@ -11,6 +11,7 @@ CONFIG_DEFAULT_DEVICE_TREE="exynos/exynos850-e850-96"
 CONFIG_SYS_LOAD_ADDR=0x80000000
 # CONFIG_AUTOBOOT is not set
 # CONFIG_DISPLAY_CPUINFO is not set
+CONFIG_CMD_RNG=y
 # CONFIG_NET is not set
 CONFIG_CLK_EXYNOS850=y
 # CONFIG_MMC is not set
diff --git a/drivers/clk/exynos/clk-exynos850.c b/drivers/clk/exynos/clk-exynos850.c
index 0c09ba0..8cbc626 100644
--- a/drivers/clk/exynos/clk-exynos850.c
+++ b/drivers/clk/exynos/clk-exynos850.c
@@ -323,14 +323,18 @@ U_BOOT_DRIVER(exynos850_cmu_peri) = {
 /* Register Offset definitions for CMU_CORE (0x12000000) */
 #define PLL_CON0_MUX_CLKCMU_CORE_BUS_USER	0x0600
 #define PLL_CON0_MUX_CLKCMU_CORE_MMC_EMBD_USER	0x0620
+#define PLL_CON0_MUX_CLKCMU_CORE_SSS_USER	0x0630
 #define CLK_CON_DIV_DIV_CLK_CORE_BUSP		0x1800
 #define CLK_CON_GAT_GOUT_CORE_MMC_EMBD_I_ACLK	0x20e8
 #define CLK_CON_GAT_GOUT_CORE_MMC_EMBD_SDCLKIN	0x20ec
+#define CLK_CON_GAT_GOUT_CORE_SSS_I_ACLK	0x2128
+#define CLK_CON_GAT_GOUT_CORE_SSS_I_PCLK	0x212c
 
 /* List of parent clocks for Muxes in CMU_CORE */
 PNAME(mout_core_bus_user_p)		= { "clock-oscclk", "dout_core_bus" };
 PNAME(mout_core_mmc_embd_user_p)	= { "clock-oscclk",
 					    "dout_core_mmc_embd" };
+PNAME(mout_core_sss_user_p)		= { "clock-oscclk", "dout_core_sss" };
 
 static const struct samsung_mux_clock core_mux_clks[] = {
 	MUX(CLK_MOUT_CORE_BUS_USER, "mout_core_bus_user", mout_core_bus_user_p,
@@ -338,6 +342,8 @@ static const struct samsung_mux_clock core_mux_clks[] = {
 	MUX_F(CLK_MOUT_CORE_MMC_EMBD_USER, "mout_core_mmc_embd_user",
 	      mout_core_mmc_embd_user_p, PLL_CON0_MUX_CLKCMU_CORE_MMC_EMBD_USER,
 	      4, 1, CLK_SET_RATE_PARENT, 0),
+	MUX(CLK_MOUT_CORE_SSS_USER, "mout_core_sss_user", mout_core_sss_user_p,
+	    PLL_CON0_MUX_CLKCMU_CORE_SSS_USER, 4, 1),
 };
 
 static const struct samsung_div_clock core_div_clks[] = {
@@ -351,6 +357,10 @@ static const struct samsung_gate_clock core_gate_clks[] = {
 	GATE(CLK_GOUT_MMC_EMBD_SDCLKIN, "gout_mmc_embd_sdclkin",
 	     "mout_core_mmc_embd_user", CLK_CON_GAT_GOUT_CORE_MMC_EMBD_SDCLKIN,
 	     21, CLK_SET_RATE_PARENT, 0),
+	GATE(CLK_GOUT_SSS_ACLK, "gout_sss_aclk", "mout_core_sss_user",
+	     CLK_CON_GAT_GOUT_CORE_SSS_I_ACLK, 21, 0, 0),
+	GATE(CLK_GOUT_SSS_PCLK, "gout_sss_pclk", "dout_core_busp",
+	     CLK_CON_GAT_GOUT_CORE_SSS_I_PCLK, 21, 0, 0),
 };
 
 static const struct samsung_clk_group core_cmu_clks[] = {
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
index 5758ae1..b35d8c6 100644
--- a/drivers/rng/Kconfig
+++ b/drivers/rng/Kconfig
@@ -120,4 +120,17 @@ config RNG_TURRIS_RWTM
 	  on other Armada-3700 devices (like EspressoBin) if Secure
 	  Firmware from CZ.NIC is used.
 
+config RNG_EXYNOS
+	bool "Samsung Exynos True Random Number Generator support"
+	depends on DM_RNG
+	help
+	  Enable support for True Random Number Generator (TRNG) available on
+	  Exynos SoCs.
+
+	  On some chips (like Exynos850) TRNG registers are protected with TZPC
+	  (TrustZone Protection Control). For such chips the driver provides an
+	  implementation based on SMC calls to EL3 monitor program. In that
+	  case the LDFW (Loadable Firmware) has to be loaded first, as it
+	  actually implements TRNG SMC calls.
+
 endif
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
index c1f1c61..30553c9 100644
--- a/drivers/rng/Makefile
+++ b/drivers/rng/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_RNG_ARM_RNDR) += arm_rndr.o
 obj-$(CONFIG_TPM_RNG) += tpm_rng.o
 obj-$(CONFIG_RNG_JH7110) += jh7110_rng.o
 obj-$(CONFIG_RNG_TURRIS_RWTM) += turris_rwtm_rng.o
+obj-$(CONFIG_RNG_EXYNOS) += exynos-trng.o
diff --git a/drivers/rng/exynos-trng.c b/drivers/rng/exynos-trng.c
new file mode 100644
index 0000000..d2479d2
--- /dev/null
+++ b/drivers/rng/exynos-trng.c
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024 Linaro Ltd.
+ * Author: Sam Protsenko <semen.protsenko@linaro.org>
+ *
+ * Samsung Exynos TRNG driver (True Random Number Generator).
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <rng.h>
+#include <dm/device.h>
+#include <dm/device_compat.h>
+#include <asm/io.h>
+#include <linux/arm-smccc.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+#include <linux/time.h>
+
+#define EXYNOS_TRNG_CLKDIV		0x0
+#define EXYNOS_TRNG_CLKDIV_MASK		GENMASK(15, 0)
+#define EXYNOS_TRNG_CLOCK_RATE		500000
+
+#define EXYNOS_TRNG_CTRL		0x20
+#define EXYNOS_TRNG_CTRL_RNGEN		BIT(31)
+
+#define EXYNOS_TRNG_POST_CTRL		0x30
+#define EXYNOS_TRNG_ONLINE_CTRL		0x40
+#define EXYNOS_TRNG_ONLINE_STAT		0x44
+#define EXYNOS_TRNG_ONLINE_MAXCHI2	0x48
+#define EXYNOS_TRNG_FIFO_CTRL		0x50
+#define EXYNOS_TRNG_FIFO_0		0x80
+#define EXYNOS_TRNG_FIFO_1		0x84
+#define EXYNOS_TRNG_FIFO_2		0x88
+#define EXYNOS_TRNG_FIFO_3		0x8c
+#define EXYNOS_TRNG_FIFO_4		0x90
+#define EXYNOS_TRNG_FIFO_5		0x94
+#define EXYNOS_TRNG_FIFO_6		0x98
+#define EXYNOS_TRNG_FIFO_7		0x9c
+#define EXYNOS_TRNG_FIFO_LEN		8
+#define EXYNOS_TRNG_FIFO_TIMEOUT	(1 * USEC_PER_SEC)
+
+#define EXYNOS_SMC_CALL_VAL(func_num)			\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
+			   ARM_SMCCC_SMC_32,		\
+			   ARM_SMCCC_OWNER_SIP,		\
+			   func_num)
+
+/* SMC command for DTRNG access */
+#define SMC_CMD_RANDOM			EXYNOS_SMC_CALL_VAL(0x1012)
+
+/* SMC_CMD_RANDOM: arguments */
+#define HWRNG_INIT			0x0
+#define HWRNG_EXIT			0x1
+#define HWRNG_GET_DATA			0x2
+
+/* SMC_CMD_RANDOM: return values */
+#define HWRNG_RET_OK			0x0
+#define HWRNG_RET_RETRY_ERROR		0x2
+
+#define HWRNG_MAX_TRIES			100
+
+/**
+ * struct exynos_trng_variant - Chip specific data
+ *
+ * @smc: Set "true" if TRNG block has to be accessed via SMC calls
+ * @init: (Optional) TRNG initialization function to call on probe
+ * @exit: (Optional) TRNG deinitialization function to call on remove
+ * @read: Function to read the random data from TRNG block
+ */
+struct exynos_trng_variant {
+	bool smc;
+	int (*init)(struct udevice *dev);
+	void (*exit)(struct udevice *dev);
+	int (*read)(struct udevice *dev, void *data, size_t len);
+};
+
+/**
+ * struct exynos_trng_priv - Driver's private data
+ *
+ * @base: Base address of MMIO registers of TRNG block
+ * @clk: Operating clock (needed for TRNG block functioning)
+ * @pclk: Bus clock (needed for interfacing the TRNG block registers)
+ * @data: Chip specific data
+ */
+struct exynos_trng_priv {
+	void __iomem *base;
+	struct clk *clk;
+	struct clk *pclk;
+	const struct exynos_trng_variant *data;
+};
+
+static int exynos_trng_read_reg(struct udevice *dev, void *data, size_t len)
+{
+	struct exynos_trng_priv *trng = dev_get_priv(dev);
+	int val;
+
+	len = min_t(size_t, len, EXYNOS_TRNG_FIFO_LEN * 4);
+	writel_relaxed(len * 8, trng->base + EXYNOS_TRNG_FIFO_CTRL);
+	val = readl_poll_timeout(trng->base + EXYNOS_TRNG_FIFO_CTRL, val,
+				 val == 0, EXYNOS_TRNG_FIFO_TIMEOUT);
+	if (val < 0)
+		return val;
+
+	memcpy_fromio(data, trng->base + EXYNOS_TRNG_FIFO_0, len);
+
+	return 0;
+}
+
+static int exynos_trng_read_smc(struct udevice *dev, void *data, size_t len)
+{
+	struct arm_smccc_res res;
+	unsigned int copied = 0;
+	u32 *buf = data;
+	int tries = 0;
+
+	while (copied < len) {
+		arm_smccc_smc(SMC_CMD_RANDOM, HWRNG_GET_DATA, 0, 0, 0, 0, 0, 0,
+			      &res);
+		switch (res.a0) {
+		case HWRNG_RET_OK:
+			*buf++ = res.a2;
+			*buf++ = res.a3;
+			copied += 8;
+			tries = 0;
+			break;
+		case HWRNG_RET_RETRY_ERROR:
+			if (++tries >= HWRNG_MAX_TRIES)
+				return -EIO;
+			udelay(10);
+			break;
+		default:
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int exynos_trng_init_reg(struct udevice *dev)
+{
+	const u32 max_div = EXYNOS_TRNG_CLKDIV_MASK;
+	struct exynos_trng_priv *trng = dev_get_priv(dev);
+	unsigned long sss_rate;
+	u32 div;
+
+	sss_rate = clk_get_rate(trng->clk);
+
+	/*
+	 * For most TRNG circuits the clock frequency of under 500 kHz is safe.
+	 * The clock divider should be an even number.
+	 */
+	div = sss_rate / EXYNOS_TRNG_CLOCK_RATE;
+	div -= div % 2; /* make sure it's even */
+	if (div > max_div) {
+		dev_err(dev, "Clock divider too large: %u", div);
+		return -ERANGE;
+	}
+	writel_relaxed(div, trng->base + EXYNOS_TRNG_CLKDIV);
+
+	/* Enable the generator */
+	writel_relaxed(EXYNOS_TRNG_CTRL_RNGEN, trng->base + EXYNOS_TRNG_CTRL);
+
+	/* Disable post-processing */
+	writel_relaxed(0, trng->base + EXYNOS_TRNG_POST_CTRL);
+
+	return 0;
+}
+
+static int exynos_trng_init_smc(struct udevice *dev)
+{
+	struct arm_smccc_res res;
+	int ret = 0;
+
+	arm_smccc_smc(SMC_CMD_RANDOM, HWRNG_INIT, 0, 0, 0, 0, 0, 0, &res);
+	if (res.a0 != HWRNG_RET_OK) {
+		dev_err(dev, "SMC command for TRNG init failed (%d)\n",
+			(int)res.a0);
+		ret = -EIO;
+	}
+	if ((int)res.a0 == -1)
+		dev_info(dev, "Make sure LDFW is loaded\n");
+
+	return ret;
+}
+
+static void exynos_trng_exit_smc(struct udevice *dev)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(SMC_CMD_RANDOM, HWRNG_EXIT, 0, 0, 0, 0, 0, 0, &res);
+}
+
+static int exynos_trng_read(struct udevice *dev, void *data, size_t len)
+{
+	struct exynos_trng_priv *trng = dev_get_priv(dev);
+
+	return trng->data->read(dev, data, len);
+}
+
+static int exynos_trng_of_to_plat(struct udevice *dev)
+{
+	struct exynos_trng_priv *trng = dev_get_priv(dev);
+
+	trng->data = (struct exynos_trng_variant *)dev_get_driver_data(dev);
+	if (!trng->data->smc) {
+		trng->base = dev_read_addr_ptr(dev);
+		if (!trng->base)
+			return -EINVAL;
+	}
+
+	trng->clk = devm_clk_get(dev, "secss");
+	if (IS_ERR(trng->clk))
+		return PTR_ERR(trng->clk);
+
+	trng->pclk = devm_clk_get_optional(dev, "pclk");
+	if (IS_ERR(trng->pclk))
+		return PTR_ERR(trng->pclk);
+
+	return 0;
+}
+
+static int exynos_trng_probe(struct udevice *dev)
+{
+	struct exynos_trng_priv *trng = dev_get_priv(dev);
+	int ret;
+
+	ret = clk_enable(trng->pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(trng->clk);
+	if (ret)
+		return ret;
+
+	if (trng->data->init)
+		ret = trng->data->init(dev);
+
+	return ret;
+}
+
+static int exynos_trng_remove(struct udevice *dev)
+{
+	struct exynos_trng_priv *trng = dev_get_priv(dev);
+
+	if (trng->data->exit)
+		trng->data->exit(dev);
+
+	/* Keep SSS clocks enabled, they are needed for EL3_MON and kernel */
+
+	return 0;
+}
+
+static const struct dm_rng_ops exynos_trng_ops = {
+	.read	= exynos_trng_read,
+};
+
+static const struct exynos_trng_variant exynos5250_trng_data = {
+	.init	= exynos_trng_init_reg,
+	.read	= exynos_trng_read_reg,
+};
+
+static const struct exynos_trng_variant exynos850_trng_data = {
+	.smc	= true,
+	.init	= exynos_trng_init_smc,
+	.exit	= exynos_trng_exit_smc,
+	.read	= exynos_trng_read_smc,
+};
+
+static const struct udevice_id exynos_trng_match[] = {
+	{
+		.compatible = "samsung,exynos5250-trng",
+		.data = (ulong)&exynos5250_trng_data,
+	}, {
+		.compatible = "samsung,exynos850-trng",
+		.data = (ulong)&exynos850_trng_data,
+	},
+	{ },
+};
+
+U_BOOT_DRIVER(exynos_trng) = {
+	.name		= "exynos-trng",
+	.id		= UCLASS_RNG,
+	.of_match	= exynos_trng_match,
+	.of_to_plat	= exynos_trng_of_to_plat,
+	.probe		= exynos_trng_probe,
+	.remove		= exynos_trng_remove,
+	.ops		= &exynos_trng_ops,
+	.priv_auto	= sizeof(struct exynos_trng_priv),
+};