Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto updates from Herbert Xu:
 "API:
   - Enforce the setting of keys for keyed aead/hash/skcipher
     algorithms.
   - Add multibuf speed tests in tcrypt.

  Algorithms:
   - Improve performance of sha3-generic.
   - Add native sha512 support on arm64.
   - Add v8.2 Crypto Extentions version of sha3/sm3 on arm64.
   - Avoid hmac nesting by requiring underlying algorithm to be unkeyed.
   - Add cryptd_max_cpu_qlen module parameter to cryptd.

  Drivers:
   - Add support for EIP97 engine in inside-secure.
   - Add inline IPsec support to chelsio.
   - Add RevB core support to crypto4xx.
   - Fix AEAD ICV check in crypto4xx.
   - Add stm32 crypto driver.
   - Add support for BCM63xx platforms in bcm2835 and remove bcm63xx.
   - Add Derived Key Protocol (DKP) support in caam.
   - Add Samsung Exynos True RNG driver.
   - Add support for Exynos5250+ SoCs in exynos PRNG driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (166 commits)
  crypto: picoxcell - Fix error handling in spacc_probe()
  crypto: arm64/sha512 - fix/improve new v8.2 Crypto Extensions code
  crypto: arm64/sm3 - new v8.2 Crypto Extensions implementation
  crypto: arm64/sha3 - new v8.2 Crypto Extensions implementation
  crypto: testmgr - add new testcases for sha3
  crypto: sha3-generic - export init/update/final routines
  crypto: sha3-generic - simplify code
  crypto: sha3-generic - rewrite KECCAK transform to help the compiler optimize
  crypto: sha3-generic - fixes for alignment and big endian operation
  crypto: aesni - handle zero length dst buffer
  crypto: artpec6 - remove select on non-existing CRYPTO_SHA384
  hwrng: bcm2835 - Remove redundant dev_err call in bcm2835_rng_probe()
  crypto: stm32 - remove redundant dev_err call in stm32_cryp_probe()
  crypto: axis - remove unnecessary platform_get_resource() error check
  crypto: testmgr - test misuse of result in ahash
  crypto: inside-secure - make function safexcel_try_push_requests static
  crypto: aes-generic - fix aes-generic regression on powerpc
  crypto: chelsio - Fix indentation warning
  crypto: arm64/sha1-ce - get rid of literal pool
  crypto: arm64/sha2-ce - move the round constant table to .rodata section
  ...

8 files changed, 377 insertions, 233 deletions

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 88044eda0ac6..4d0f571c15f9 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -73,26 +73,14 @@ config HW_RANDOM_ATMEL
 
 	  If unsure, say Y.
 
-config HW_RANDOM_BCM63XX
-	tristate "Broadcom BCM63xx Random Number Generator support"
-	depends on BCM63XX || BMIPS_GENERIC
-	default HW_RANDOM
-	---help---
-	  This driver provides kernel-side support for the Random Number
-	  Generator hardware found on the Broadcom BCM63xx SoCs.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called bcm63xx-rng
-
-	  If unusure, say Y.
-
 config HW_RANDOM_BCM2835
-	tristate "Broadcom BCM2835 Random Number Generator support"
-	depends on ARCH_BCM2835 || ARCH_BCM_NSP || ARCH_BCM_5301X
+	tristate "Broadcom BCM2835/BCM63xx Random Number Generator support"
+	depends on ARCH_BCM2835 || ARCH_BCM_NSP || ARCH_BCM_5301X || \
+		   ARCH_BCM_63XX || BCM63XX || BMIPS_GENERIC
 	default HW_RANDOM
 	---help---
 	  This driver provides kernel-side support for the Random Number
-	  Generator hardware found on the Broadcom BCM2835 SoCs.
+	  Generator hardware found on the Broadcom BCM2835 and BCM63xx SoCs.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called bcm2835-rng
@@ -436,6 +424,18 @@ config HW_RANDOM_S390
 
 	  If unsure, say Y.
 
+config HW_RANDOM_EXYNOS
+	tristate "Samsung Exynos True Random Number Generator support"
+	depends on ARCH_EXYNOS || COMPILE_TEST
+	default HW_RANDOM
+	---help---
+	  This driver provides support for the True Random Number
+	  Generator available in Exynos SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called exynos-trng.
+
+	  If unsure, say Y.
 endif # HW_RANDOM
 
 config UML_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 0ef05c61d9c8..b780370bd4eb 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -9,11 +9,11 @@ obj-$(CONFIG_HW_RANDOM_TIMERIOMEM) += timeriomem-rng.o
 obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
 obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
 obj-$(CONFIG_HW_RANDOM_ATMEL) += atmel-rng.o
-obj-$(CONFIG_HW_RANDOM_BCM63XX)	+= bcm63xx-rng.o
 obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
 obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
 n2-rng-y := n2-drv.o n2-asm.o
 obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
+obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-trng.o
 obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP3_ROM) += omap3-rom-rng.o
diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index 574211a49549..7a84cec30c3a 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -15,6 +15,7 @@
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/printk.h>
+#include <linux/clk.h>
 
 #define RNG_CTRL	0x0
 #define RNG_STATUS	0x4
@@ -29,116 +30,180 @@
 
 #define RNG_INT_OFF	0x1
 
-static void __init nsp_rng_init(void __iomem *base)
+struct bcm2835_rng_priv {
+	struct hwrng rng;
+	void __iomem *base;
+	bool mask_interrupts;
+	struct clk *clk;
+};
+
+static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
 {
-	u32 val;
+	return container_of(rng, struct bcm2835_rng_priv, rng);
+}
+
+static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset)
+{
+	/* MIPS chips strapped for BE will automagically configure the
+	 * peripheral registers for CPU-native byte order.
+	 */
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		return __raw_readl(priv->base + offset);
+	else
+		return readl(priv->base + offset);
+}
 
-	/* mask the interrupt */
-	val = readl(base + RNG_INT_MASK);
-	val |= RNG_INT_OFF;
-	writel(val, base + RNG_INT_MASK);
+static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val,
+			      u32 offset)
+{
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		__raw_writel(val, priv->base + offset);
+	else
+		writel(val, priv->base + offset);
 }
 
 static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 			       bool wait)
 {
-	void __iomem *rng_base = (void __iomem *)rng->priv;
+	struct bcm2835_rng_priv *priv = to_rng_priv(rng);
 	u32 max_words = max / sizeof(u32);
 	u32 num_words, count;
 
-	while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) {
+	while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) {
 		if (!wait)
 			return 0;
 		cpu_relax();
 	}
 
-	num_words = readl(rng_base + RNG_STATUS) >> 24;
+	num_words = rng_readl(priv, RNG_STATUS) >> 24;
 	if (num_words > max_words)
 		num_words = max_words;
 
 	for (count = 0; count < num_words; count++)
-		((u32 *)buf)[count] = readl(rng_base + RNG_DATA);
+		((u32 *)buf)[count] = rng_readl(priv, RNG_DATA);
 
 	return num_words * sizeof(u32);
 }
 
-static struct hwrng bcm2835_rng_ops = {
-	.name	= "bcm2835",
-	.read	= bcm2835_rng_read,
+static int bcm2835_rng_init(struct hwrng *rng)
+{
+	struct bcm2835_rng_priv *priv = to_rng_priv(rng);
+	int ret = 0;
+	u32 val;
+
+	if (!IS_ERR(priv->clk)) {
+		ret = clk_prepare_enable(priv->clk);
+		if (ret)
+			return ret;
+	}
+
+	if (priv->mask_interrupts) {
+		/* mask the interrupt */
+		val = rng_readl(priv, RNG_INT_MASK);
+		val |= RNG_INT_OFF;
+		rng_writel(priv, val, RNG_INT_MASK);
+	}
+
+	/* set warm-up count & enable */
+	rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS);
+	rng_writel(priv, RNG_RBGEN, RNG_CTRL);
+
+	return ret;
+}
+
+static void bcm2835_rng_cleanup(struct hwrng *rng)
+{
+	struct bcm2835_rng_priv *priv = to_rng_priv(rng);
+
+	/* disable rng hardware */
+	rng_writel(priv, 0, RNG_CTRL);
+
+	if (!IS_ERR(priv->clk))
+		clk_disable_unprepare(priv->clk);
+}
+
+struct bcm2835_rng_of_data {
+	bool mask_interrupts;
+};
+
+static const struct bcm2835_rng_of_data nsp_rng_of_data = {
+	.mask_interrupts = true,
 };
 
 static const struct of_device_id bcm2835_rng_of_match[] = {
 	{ .compatible = "brcm,bcm2835-rng"},
-	{ .compatible = "brcm,bcm-nsp-rng", .data = nsp_rng_init},
-	{ .compatible = "brcm,bcm5301x-rng", .data = nsp_rng_init},
+	{ .compatible = "brcm,bcm-nsp-rng", .data = &nsp_rng_of_data },
+	{ .compatible = "brcm,bcm5301x-rng", .data = &nsp_rng_of_data },
+	{ .compatible = "brcm,bcm6368-rng"},
 	{},
 };
 
 static int bcm2835_rng_probe(struct platform_device *pdev)
 {
+	const struct bcm2835_rng_of_data *of_data;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
-	void (*rng_setup)(void __iomem *base);
 	const struct of_device_id *rng_id;
-	void __iomem *rng_base;
+	struct bcm2835_rng_priv *priv;
+	struct resource *r;
 	int err;
 
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
 	/* map peripheral */
-	rng_base = of_iomap(np, 0);
-	if (!rng_base) {
-		dev_err(dev, "failed to remap rng regs");
-		return -ENODEV;
-	}
-	bcm2835_rng_ops.priv = (unsigned long)rng_base;
+	priv->base = devm_ioremap_resource(dev, r);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	/* Clock is optional on most platforms */
+	priv->clk = devm_clk_get(dev, NULL);
+
+	priv->rng.name = pdev->name;
+	priv->rng.init = bcm2835_rng_init;
+	priv->rng.read = bcm2835_rng_read;
+	priv->rng.cleanup = bcm2835_rng_cleanup;
 
 	rng_id = of_match_node(bcm2835_rng_of_match, np);
-	if (!rng_id) {
-		iounmap(rng_base);
+	if (!rng_id)
 		return -EINVAL;
-	}
-	/* Check for rng init function, execute it */
-	rng_setup = rng_id->data;
-	if (rng_setup)
-		rng_setup(rng_base);
 
-	/* set warm-up count & enable */
-	__raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
-	__raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
+	/* Check for rng init function, execute it */
+	of_data = rng_id->data;
+	if (of_data)
+		priv->mask_interrupts = of_data->mask_interrupts;
 
 	/* register driver */
-	err = hwrng_register(&bcm2835_rng_ops);
-	if (err) {
+	err = devm_hwrng_register(dev, &priv->rng);
+	if (err)
 		dev_err(dev, "hwrng registration failed\n");
-		iounmap(rng_base);
-	} else
+	else
 		dev_info(dev, "hwrng registered\n");
 
 	return err;
 }
 
-static int bcm2835_rng_remove(struct platform_device *pdev)
-{
-	void __iomem *rng_base = (void __iomem *)bcm2835_rng_ops.priv;
-
-	/* disable rng hardware */
-	__raw_writel(0, rng_base + RNG_CTRL);
-
-	/* unregister driver */
-	hwrng_unregister(&bcm2835_rng_ops);
-	iounmap(rng_base);
-
-	return 0;
-}
-
 MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match);
 
+static struct platform_device_id bcm2835_rng_devtype[] = {
+	{ .name = "bcm2835-rng" },
+	{ .name = "bcm63xx-rng" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, bcm2835_rng_devtype);
+
 static struct platform_driver bcm2835_rng_driver = {
 	.driver = {
 		.name = "bcm2835-rng",
 		.of_match_table = bcm2835_rng_of_match,
 	},
 	.probe		= bcm2835_rng_probe,
-	.remove		= bcm2835_rng_remove,
+	.id_table	= bcm2835_rng_devtype,
 };
 module_platform_driver(bcm2835_rng_driver);
 
diff --git a/drivers/char/hw_random/bcm63xx-rng.c b/drivers/char/hw_random/bcm63xx-rng.c
deleted file mode 100644
index 5132c9cde50d..000000000000
--- a/drivers/char/hw_random/bcm63xx-rng.c
+++ /dev/null
@@ -1,154 +0,0 @@
-/*
- * Broadcom BCM63xx Random Number Generator support
- *
- * Copyright (C) 2011, Florian Fainelli <florian@openwrt.org>
- * Copyright (C) 2009, Broadcom Corporation
- *
- */
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/io.h>
-#include <linux/err.h>
-#include <linux/clk.h>
-#include <linux/platform_device.h>
-#include <linux/hw_random.h>
-#include <linux/of.h>
-
-#define RNG_CTRL			0x00
-#define RNG_EN				(1 << 0)
-
-#define RNG_STAT			0x04
-#define RNG_AVAIL_MASK			(0xff000000)
-
-#define RNG_DATA			0x08
-#define RNG_THRES			0x0c
-#define RNG_MASK			0x10
-
-struct bcm63xx_rng_priv {
-	struct hwrng rng;
-	struct clk *clk;
-	void __iomem *regs;
-};
-
-#define to_rng_priv(rng)	container_of(rng, struct bcm63xx_rng_priv, rng)
-
-static int bcm63xx_rng_init(struct hwrng *rng)
-{
-	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
-	u32 val;
-	int error;
-
-	error = clk_prepare_enable(priv->clk);
-	if (error)
-		return error;
-
-	val = __raw_readl(priv->regs + RNG_CTRL);
-	val |= RNG_EN;
-	__raw_writel(val, priv->regs + RNG_CTRL);
-
-	return 0;
-}
-
-static void bcm63xx_rng_cleanup(struct hwrng *rng)
-{
-	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
-	u32 val;
-
-	val = __raw_readl(priv->regs + RNG_CTRL);
-	val &= ~RNG_EN;
-	__raw_writel(val, priv->regs + RNG_CTRL);
-
-	clk_disable_unprepare(priv->clk);
-}
-
-static int bcm63xx_rng_data_present(struct hwrng *rng, int wait)
-{
-	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
-
-	return __raw_readl(priv->regs + RNG_STAT) & RNG_AVAIL_MASK;
-}
-
-static int bcm63xx_rng_data_read(struct hwrng *rng, u32 *data)
-{
-	struct bcm63xx_rng_priv *priv = to_rng_priv(rng);
-
-	*data = __raw_readl(priv->regs + RNG_DATA);
-
-	return 4;
-}
-
-static int bcm63xx_rng_probe(struct platform_device *pdev)
-{
-	struct resource *r;
-	int ret;
-	struct bcm63xx_rng_priv *priv;
-
-	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!r) {
-		dev_err(&pdev->dev, "no iomem resource\n");
-		return -ENXIO;
-	}
-
-	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-
-	priv->rng.name = pdev->name;
-	priv->rng.init = bcm63xx_rng_init;
-	priv->rng.cleanup = bcm63xx_rng_cleanup;
-	priv->rng.data_present = bcm63xx_rng_data_present;
-	priv->rng.data_read = bcm63xx_rng_data_read;
-
-	priv->clk = devm_clk_get(&pdev->dev, "ipsec");
-	if (IS_ERR(priv->clk)) {
-		ret = PTR_ERR(priv->clk);
-		dev_err(&pdev->dev, "no clock for device: %d\n", ret);
-		return ret;
-	}
-
-	if (!devm_request_mem_region(&pdev->dev, r->start,
-					resource_size(r), pdev->name)) {
-		dev_err(&pdev->dev, "request mem failed");
-		return -EBUSY;
-	}
-
-	priv->regs = devm_ioremap_nocache(&pdev->dev, r->start,
-					resource_size(r));
-	if (!priv->regs) {
-		dev_err(&pdev->dev, "ioremap failed");
-		return -ENOMEM;
-	}
-
-	ret = devm_hwrng_register(&pdev->dev, &priv->rng);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to register rng device: %d\n",
-			ret);
-		return ret;
-	}
-
-	dev_info(&pdev->dev, "registered RNG driver\n");
-
-	return 0;
-}
-
-#ifdef CONFIG_OF
-static const struct of_device_id bcm63xx_rng_of_match[] = {
-	{ .compatible = "brcm,bcm6368-rng", },
-	{},
-};
-MODULE_DEVICE_TABLE(of, bcm63xx_rng_of_match);
-#endif
-
-static struct platform_driver bcm63xx_rng_driver = {
-	.probe		= bcm63xx_rng_probe,
-	.driver		= {
-		.name	= "bcm63xx-rng",
-		.of_match_table = of_match_ptr(bcm63xx_rng_of_match),
-	},
-};
-
-module_platform_driver(bcm63xx_rng_driver);
-
-MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
-MODULE_DESCRIPTION("Broadcom BCM63xx RNG driver");
-MODULE_LICENSE("GPL");
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 657b8770b6b9..91bb98c42a1c 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -306,6 +306,10 @@ static int enable_best_rng(void)
 		ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng));
 		if (!ret)
 			cur_rng_set_by_user = 0;
+	} else {
+		drop_current_rng();
+		cur_rng_set_by_user = 0;
+		ret = 0;
 	}
 
 	return ret;
diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
new file mode 100644
index 000000000000..1947aed7c044
--- /dev/null
+++ b/drivers/char/hw_random/exynos-trng.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RNG driver for Exynos TRNGs
+ *
+ * Author: Łukasz Stelmach <l.stelmach@samsung.com>
+ *
+ * Copyright 2017 (c) Samsung Electronics Software, Inc.
+ *
+ * Based on the Exynos PRNG driver drivers/crypto/exynos-rng by
+ * Krzysztof Kozłowski <krzk@kernel.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/crypto.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#define EXYNOS_TRNG_CLKDIV         (0x0)
+
+#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_CLOCK_RATE     (500000)
+
+
+struct exynos_trng_dev {
+	struct device    *dev;
+	void __iomem     *mem;
+	struct clk       *clk;
+	struct hwrng rng;
+};
+
+static int exynos_trng_do_read(struct hwrng *rng, void *data, size_t max,
+			       bool wait)
+{
+	struct exynos_trng_dev *trng;
+	int val;
+
+	max = min_t(size_t, max, (EXYNOS_TRNG_FIFO_LEN * 4));
+
+	trng = (struct exynos_trng_dev *)rng->priv;
+
+	writel_relaxed(max * 8, trng->mem + EXYNOS_TRNG_FIFO_CTRL);
+	val = readl_poll_timeout(trng->mem + EXYNOS_TRNG_FIFO_CTRL, val,
+				 val == 0, 200, 1000000);
+	if (val < 0)
+		return val;
+
+	memcpy_fromio(data, trng->mem + EXYNOS_TRNG_FIFO_0, max);
+
+	return max;
+}
+
+static int exynos_trng_init(struct hwrng *rng)
+{
+	struct exynos_trng_dev *trng = (struct exynos_trng_dev *)rng->priv;
+	unsigned long sss_rate;
+	u32 val;
+
+	sss_rate = clk_get_rate(trng->clk);
+
+	/*
+	 * For most TRNG circuits the clock frequency of under 500 kHz
+	 * is safe.
+	 */
+	val = sss_rate / (EXYNOS_TRNG_CLOCK_RATE * 2);
+	if (val > 0x7fff) {
+		dev_err(trng->dev, "clock divider too large: %d", val);
+		return -ERANGE;
+	}
+	val = val << 1;
+	writel_relaxed(val, trng->mem + EXYNOS_TRNG_CLKDIV);
+
+	/* Enable the generator. */
+	val = EXYNOS_TRNG_CTRL_RNGEN;
+	writel_relaxed(val, trng->mem + EXYNOS_TRNG_CTRL);
+
+	/*
+	 * Disable post-processing. /dev/hwrng is supposed to deliver
+	 * unprocessed data.
+	 */
+	writel_relaxed(0, trng->mem + EXYNOS_TRNG_POST_CTRL);
+
+	return 0;
+}
+
+static int exynos_trng_probe(struct platform_device *pdev)
+{
+	struct exynos_trng_dev *trng;
+	struct resource *res;
+	int ret = -ENOMEM;
+
+	trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
+	if (!trng)
+		return ret;
+
+	trng->rng.name = devm_kstrdup(&pdev->dev, dev_name(&pdev->dev),
+				      GFP_KERNEL);
+	if (!trng->rng.name)
+		return ret;
+
+	trng->rng.init = exynos_trng_init;
+	trng->rng.read = exynos_trng_do_read;
+	trng->rng.priv = (unsigned long) trng;
+
+	platform_set_drvdata(pdev, trng);
+	trng->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	trng->mem = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(trng->mem))
+		return PTR_ERR(trng->mem);
+
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Could not get runtime PM.\n");
+		goto err_pm_get;
+	}
+
+	trng->clk = devm_clk_get(&pdev->dev, "secss");
+	if (IS_ERR(trng->clk)) {
+		ret = PTR_ERR(trng->clk);
+		dev_err(&pdev->dev, "Could not get clock.\n");
+		goto err_clock;
+	}
+
+	ret = clk_prepare_enable(trng->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable the clk.\n");
+		goto err_clock;
+	}
+
+	ret = hwrng_register(&trng->rng);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register hwrng device.\n");
+		goto err_register;
+	}
+
+	dev_info(&pdev->dev, "Exynos True Random Number Generator.\n");
+
+	return 0;
+
+err_register:
+	clk_disable_unprepare(trng->clk);
+
+err_clock:
+	pm_runtime_put_sync(&pdev->dev);
+
+err_pm_get:
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int exynos_trng_remove(struct platform_device *pdev)
+{
+	struct exynos_trng_dev *trng =  platform_get_drvdata(pdev);
+
+	hwrng_unregister(&trng->rng);
+	clk_disable_unprepare(trng->clk);
+
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused exynos_trng_suspend(struct device *dev)
+{
+	pm_runtime_put_sync(dev);
+
+	return 0;
+}
+
+static int __maybe_unused exynos_trng_resume(struct device *dev)
+{
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "Could not get runtime PM.\n");
+		pm_runtime_put_noidle(dev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(exynos_trng_pm_ops, exynos_trng_suspend,
+			 exynos_trng_resume);
+
+static const struct of_device_id exynos_trng_dt_match[] = {
+	{
+		.compatible = "samsung,exynos5250-trng",
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, exynos_trng_dt_match);
+
+static struct platform_driver exynos_trng_driver = {
+	.driver = {
+		.name = "exynos-trng",
+		.pm = &exynos_trng_pm_ops,
+		.of_match_table = exynos_trng_dt_match,
+	},
+	.probe = exynos_trng_probe,
+	.remove = exynos_trng_remove,
+};
+
+module_platform_driver(exynos_trng_driver);
+MODULE_AUTHOR("Łukasz Stelmach");
+MODULE_DESCRIPTION("H/W TRNG driver for Exynos chips");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c
index 88db42d30760..eca87249bcff 100644
--- a/drivers/char/hw_random/imx-rngc.c
+++ b/drivers/char/hw_random/imx-rngc.c
@@ -282,8 +282,7 @@ static int __exit imx_rngc_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM
-static int imx_rngc_suspend(struct device *dev)
+static int __maybe_unused imx_rngc_suspend(struct device *dev)
 {
 	struct imx_rngc *rngc = dev_get_drvdata(dev);
 
@@ -292,7 +291,7 @@ static int imx_rngc_suspend(struct device *dev)
 	return 0;
 }
 
-static int imx_rngc_resume(struct device *dev)
+static int __maybe_unused imx_rngc_resume(struct device *dev)
 {
 	struct imx_rngc *rngc = dev_get_drvdata(dev);
 
@@ -301,11 +300,7 @@ static int imx_rngc_resume(struct device *dev)
 	return 0;
 }
 
-static const struct dev_pm_ops imx_rngc_pm_ops = {
-	.suspend	= imx_rngc_suspend,
-	.resume		= imx_rngc_resume,
-};
-#endif
+SIMPLE_DEV_PM_OPS(imx_rngc_pm_ops, imx_rngc_suspend, imx_rngc_resume);
 
 static const struct of_device_id imx_rngc_dt_ids[] = {
 	{ .compatible = "fsl,imx25-rngb", .data = NULL, },
@@ -316,9 +311,7 @@ MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids);
 static struct platform_driver imx_rngc_driver = {
 	.driver = {
 		.name = "imx_rngc",
-#ifdef CONFIG_PM
 		.pm = &imx_rngc_pm_ops,
-#endif
 		.of_match_table = imx_rngc_dt_ids,
 	},
 	.remove = __exit_p(imx_rngc_remove),
diff --git a/drivers/char/hw_random/mtk-rng.c b/drivers/char/hw_random/mtk-rng.c
index 8da7bcf54105..7f99cd52b40e 100644
--- a/drivers/char/hw_random/mtk-rng.c
+++ b/drivers/char/hw_random/mtk-rng.c
@@ -135,6 +135,7 @@ static int mtk_rng_probe(struct platform_device *pdev)
 #endif
 	priv->rng.read = mtk_rng_read;
 	priv->rng.priv = (unsigned long)&pdev->dev;
+	priv->rng.quality = 900;
 
 	priv->clk = devm_clk_get(&pdev->dev, "rng");
 	if (IS_ERR(priv->clk)) {