15 files changed, 433 insertions, 24 deletions

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 0ad17efc96df..f976a49e1fb5 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -74,6 +74,16 @@ config HW_RANDOM_ATMEL
 
 	  If unsure, say Y.
 
+config HW_RANDOM_BA431
+	tristate "Silex Insight BA431 Random Number Generator support"
+	depends on HAS_IOMEM
+	help
+	  This driver provides kernel-side support for the Random Number
+	  Generator hardware based on Silex Insight BA431 IP.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ba431-rng.
+
 config HW_RANDOM_BCM2835
 	tristate "Broadcom BCM2835/BCM63xx Random Number Generator support"
 	depends on ARCH_BCM2835 || ARCH_BCM_NSP || ARCH_BCM_5301X || \
@@ -245,7 +255,7 @@ config HW_RANDOM_MXC_RNGA
 config HW_RANDOM_IMX_RNGC
 	tristate "Freescale i.MX RNGC Random Number Generator"
 	depends on HAS_IOMEM && HAVE_CLK
-	depends on SOC_IMX25 || COMPILE_TEST
+	depends on SOC_IMX25 || SOC_IMX6SL || SOC_IMX6SLL || SOC_IMX6UL || COMPILE_TEST
 	default HW_RANDOM
 	help
 	  This driver provides kernel-side support for the Random Number
@@ -257,6 +267,21 @@ config HW_RANDOM_IMX_RNGC
 
 	  If unsure, say Y.
 
+config HW_RANDOM_INGENIC_RNG
+	tristate "Ingenic Random Number Generator support"
+	depends on HW_RANDOM
+	depends on MACH_JZ4780 || MACH_X1000
+	default HW_RANDOM
+	help
+	  This driver provides kernel-side support for the Random Number Generator
+	  hardware found in ingenic JZ4780 and X1000 SoC. MIPS Creator CI20 uses
+	  JZ4780 SoC, YSH & ATIL CU1000-Neo uses X1000 SoC.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ingenic-rng.
+
+	  If unsure, say Y.
+
 config HW_RANDOM_NOMADIK
 	tristate "ST-Ericsson Nomadik Random Number Generator support"
 	depends on ARCH_NOMADIK
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 2c6724735345..26ae06844f09 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -9,6 +9,7 @@ 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-$(CONFIG_HW_RANDOM_BA431) += ba431-rng.o
 obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
 obj-$(CONFIG_HW_RANDOM_N2RNG) += n2-rng.o
 n2-rng-y := n2-drv.o n2-asm.o
@@ -22,6 +23,7 @@ obj-$(CONFIG_HW_RANDOM_VIRTIO) += virtio-rng.o
 obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
 obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
 obj-$(CONFIG_HW_RANDOM_IMX_RNGC) += imx-rngc.o
+obj-$(CONFIG_HW_RANDOM_INGENIC_RNG) += ingenic-rng.o
 obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
 obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
 obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
diff --git a/drivers/char/hw_random/ba431-rng.c b/drivers/char/hw_random/ba431-rng.c
new file mode 100644
index 000000000000..410b50b05e21
--- /dev/null
+++ b/drivers/char/hw_random/ba431-rng.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Silex Insight
+
+#include <linux/delay.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+
+#define BA431_RESET_DELAY			1 /* usec */
+#define BA431_RESET_READ_STATUS_TIMEOUT		1000 /* usec */
+#define BA431_RESET_READ_STATUS_INTERVAL	10 /* usec */
+#define BA431_READ_RETRY_INTERVAL		1 /* usec */
+
+#define BA431_REG_CTRL				0x00
+#define BA431_REG_FIFO_LEVEL			0x04
+#define BA431_REG_STATUS			0x30
+#define BA431_REG_FIFODATA			0x80
+
+#define BA431_CTRL_ENABLE			BIT(0)
+#define BA431_CTRL_SOFTRESET			BIT(8)
+
+#define BA431_STATUS_STATE_MASK			(BIT(1) | BIT(2) | BIT(3))
+#define BA431_STATUS_STATE_OFFSET		1
+
+enum ba431_state {
+	BA431_STATE_RESET,
+	BA431_STATE_STARTUP,
+	BA431_STATE_FIFOFULLON,
+	BA431_STATE_FIFOFULLOFF,
+	BA431_STATE_RUNNING,
+	BA431_STATE_ERROR
+};
+
+struct ba431_trng {
+	struct device *dev;
+	void __iomem *base;
+	struct hwrng rng;
+	atomic_t reset_pending;
+	struct work_struct reset_work;
+};
+
+static inline u32 ba431_trng_read_reg(struct ba431_trng *ba431, u32 reg)
+{
+	return ioread32(ba431->base + reg);
+}
+
+static inline void ba431_trng_write_reg(struct ba431_trng *ba431, u32 reg,
+					u32 val)
+{
+	iowrite32(val, ba431->base + reg);
+}
+
+static inline enum ba431_state ba431_trng_get_state(struct ba431_trng *ba431)
+{
+	u32 status = ba431_trng_read_reg(ba431, BA431_REG_STATUS);
+
+	return (status & BA431_STATUS_STATE_MASK) >> BA431_STATUS_STATE_OFFSET;
+}
+
+static int ba431_trng_is_in_error(struct ba431_trng *ba431)
+{
+	enum ba431_state state = ba431_trng_get_state(ba431);
+
+	if ((state < BA431_STATE_STARTUP) ||
+	    (state >= BA431_STATE_ERROR))
+		return 1;
+
+	return 0;
+}
+
+static int ba431_trng_reset(struct ba431_trng *ba431)
+{
+	int ret;
+
+	/* Disable interrupts, random generation and enable the softreset */
+	ba431_trng_write_reg(ba431, BA431_REG_CTRL, BA431_CTRL_SOFTRESET);
+	udelay(BA431_RESET_DELAY);
+	ba431_trng_write_reg(ba431, BA431_REG_CTRL, BA431_CTRL_ENABLE);
+
+	/* Wait until the state changed */
+	if (readx_poll_timeout(ba431_trng_is_in_error, ba431, ret, !ret,
+			       BA431_RESET_READ_STATUS_INTERVAL,
+			       BA431_RESET_READ_STATUS_TIMEOUT)) {
+		dev_err(ba431->dev, "reset failed (state: %d)\n",
+			ba431_trng_get_state(ba431));
+		return -ETIMEDOUT;
+	}
+
+	dev_info(ba431->dev, "reset done\n");
+
+	return 0;
+}
+
+static void ba431_trng_reset_work(struct work_struct *work)
+{
+	struct ba431_trng *ba431 = container_of(work, struct ba431_trng,
+						reset_work);
+	ba431_trng_reset(ba431);
+	atomic_set(&ba431->reset_pending, 0);
+}
+
+static void ba431_trng_schedule_reset(struct ba431_trng *ba431)
+{
+	if (atomic_cmpxchg(&ba431->reset_pending, 0, 1))
+		return;
+
+	schedule_work(&ba431->reset_work);
+}
+
+static int ba431_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct ba431_trng *ba431 = container_of(rng, struct ba431_trng, rng);
+	u32 *data = buf;
+	unsigned int level, i;
+	int n = 0;
+
+	while (max > 0) {
+		level = ba431_trng_read_reg(ba431, BA431_REG_FIFO_LEVEL);
+		if (!level) {
+			if (ba431_trng_is_in_error(ba431)) {
+				ba431_trng_schedule_reset(ba431);
+				break;
+			}
+
+			if (!wait)
+				break;
+
+			udelay(BA431_READ_RETRY_INTERVAL);
+			continue;
+		}
+
+		i = level;
+		do {
+			data[n++] = ba431_trng_read_reg(ba431,
+							BA431_REG_FIFODATA);
+			max -= sizeof(*data);
+		} while (--i && (max > 0));
+
+		if (ba431_trng_is_in_error(ba431)) {
+			n -= (level - i);
+			ba431_trng_schedule_reset(ba431);
+			break;
+		}
+	}
+
+	n *= sizeof(data);
+	return (n || !wait) ? n : -EIO;
+}
+
+static void ba431_trng_cleanup(struct hwrng *rng)
+{
+	struct ba431_trng *ba431 = container_of(rng, struct ba431_trng, rng);
+
+	ba431_trng_write_reg(ba431, BA431_REG_CTRL, 0);
+	cancel_work_sync(&ba431->reset_work);
+}
+
+static int ba431_trng_init(struct hwrng *rng)
+{
+	struct ba431_trng *ba431 = container_of(rng, struct ba431_trng, rng);
+
+	return ba431_trng_reset(ba431);
+}
+
+static int ba431_trng_probe(struct platform_device *pdev)
+{
+	struct ba431_trng *ba431;
+	struct resource *res;
+	int ret;
+
+	ba431 = devm_kzalloc(&pdev->dev, sizeof(*ba431), GFP_KERNEL);
+	if (!ba431)
+		return -ENOMEM;
+
+	ba431->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ba431->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ba431->base))
+		return PTR_ERR(ba431->base);
+
+	atomic_set(&ba431->reset_pending, 0);
+	INIT_WORK(&ba431->reset_work, ba431_trng_reset_work);
+	ba431->rng.name = pdev->name;
+	ba431->rng.init = ba431_trng_init;
+	ba431->rng.cleanup = ba431_trng_cleanup;
+	ba431->rng.read = ba431_trng_read;
+
+	platform_set_drvdata(pdev, ba431);
+
+	ret = hwrng_register(&ba431->rng);
+	if (ret) {
+		dev_err(&pdev->dev, "BA431 registration failed (%d)\n", ret);
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "BA431 TRNG registered\n");
+
+	return 0;
+}
+
+static int ba431_trng_remove(struct platform_device *pdev)
+{
+	struct ba431_trng *ba431 = platform_get_drvdata(pdev);
+
+	hwrng_unregister(&ba431->rng);
+
+	return 0;
+}
+
+static const struct of_device_id ba431_trng_dt_ids[] = {
+	{ .compatible = "silex-insight,ba431-rng", .data = NULL },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ba431_trng_dt_ids);
+
+static struct platform_driver ba431_trng_driver = {
+	.driver = {
+		.name = "ba431-rng",
+		.of_match_table = ba431_trng_dt_ids,
+	},
+	.probe = ba431_trng_probe,
+	.remove = ba431_trng_remove,
+};
+
+module_platform_driver(ba431_trng_driver);
+
+MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
+MODULE_DESCRIPTION("TRNG driver for Silex Insight BA431");
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index cbf5eaea662c..1a7c43b43c6b 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -139,7 +139,6 @@ 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;
 	const struct of_device_id *rng_id;
 	struct bcm2835_rng_priv *priv;
 	int err;
@@ -166,7 +165,7 @@ static int bcm2835_rng_probe(struct platform_device *pdev)
 	priv->rng.cleanup = bcm2835_rng_cleanup;
 
 	if (dev_of_node(dev)) {
-		rng_id = of_match_node(bcm2835_rng_of_match, np);
+		rng_id = of_match_node(bcm2835_rng_of_match, dev->of_node);
 		if (!rng_id)
 			return -EINVAL;
 
@@ -188,7 +187,7 @@ static int bcm2835_rng_probe(struct platform_device *pdev)
 
 MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match);
 
-static struct platform_device_id bcm2835_rng_devtype[] = {
+static const struct platform_device_id bcm2835_rng_devtype[] = {
 	{ .name = "bcm2835-rng" },
 	{ .name = "bcm63xx-rng" },
 	{ /* sentinel */ }
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index d2d7a42d7e0d..8c1c47dd9f46 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -611,7 +611,7 @@ EXPORT_SYMBOL_GPL(devm_hwrng_unregister);
 
 static int __init hwrng_modinit(void)
 {
-	int ret = -ENOMEM;
+	int ret;
 
 	/* kmalloc makes this safe for virt_to_page() in virtio_rng.c */
 	rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL);
diff --git a/drivers/char/hw_random/hisi-rng.c b/drivers/char/hw_random/hisi-rng.c
index 6815e17a9834..96438f85cafa 100644
--- a/drivers/char/hw_random/hisi-rng.c
+++ b/drivers/char/hw_random/hisi-rng.c
@@ -99,7 +99,7 @@ static int hisi_rng_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id hisi_rng_dt_ids[] = {
+static const struct of_device_id hisi_rng_dt_ids[] __maybe_unused = {
 	{ .compatible = "hisilicon,hip04-rng" },
 	{ .compatible = "hisilicon,hip05-rng" },
 	{ }
diff --git a/drivers/char/hw_random/ingenic-rng.c b/drivers/char/hw_random/ingenic-rng.c
new file mode 100644
index 000000000000..d704cef64b64
--- /dev/null
+++ b/drivers/char/hw_random/ingenic-rng.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ingenic Random Number Generator driver
+ * Copyright (c) 2017 PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
+ * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* RNG register offsets */
+#define RNG_REG_ERNG_OFFSET		0x0
+#define RNG_REG_RNG_OFFSET		0x4
+
+/* bits within the ERND register */
+#define ERNG_READY				BIT(31)
+#define ERNG_ENABLE				BIT(0)
+
+enum ingenic_rng_version {
+	ID_JZ4780,
+	ID_X1000,
+};
+
+/* Device associated memory */
+struct ingenic_rng {
+	enum ingenic_rng_version version;
+
+	void __iomem *base;
+	struct hwrng rng;
+};
+
+static int ingenic_rng_init(struct hwrng *rng)
+{
+	struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
+
+	writel(ERNG_ENABLE, priv->base + RNG_REG_ERNG_OFFSET);
+
+	return 0;
+}
+
+static void ingenic_rng_cleanup(struct hwrng *rng)
+{
+	struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
+
+	writel(0, priv->base + RNG_REG_ERNG_OFFSET);
+}
+
+static int ingenic_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
+	u32 *data = buf;
+	u32 status;
+	int ret;
+
+	if (priv->version >= ID_X1000) {
+		ret = readl_poll_timeout(priv->base + RNG_REG_ERNG_OFFSET, status,
+					 status & ERNG_READY, 10, 1000);
+		if (ret == -ETIMEDOUT) {
+			pr_err("%s: Wait for RNG data ready timeout\n", __func__);
+			return ret;
+		}
+	} else {
+		/*
+		 * A delay is required so that the current RNG data is not bit shifted
+		 * version of previous RNG data which could happen if random data is
+		 * read continuously from this device.
+		 */
+		udelay(20);
+	}
+
+	*data = readl(priv->base + RNG_REG_RNG_OFFSET);
+
+	return 4;
+}
+
+static int ingenic_rng_probe(struct platform_device *pdev)
+{
+	struct ingenic_rng *priv;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base)) {
+		pr_err("%s: Failed to map RNG registers\n", __func__);
+		ret = PTR_ERR(priv->base);
+		goto err_free_rng;
+	}
+
+	priv->version = (enum ingenic_rng_version)of_device_get_match_data(&pdev->dev);
+
+	priv->rng.name = pdev->name;
+	priv->rng.init = ingenic_rng_init;
+	priv->rng.cleanup = ingenic_rng_cleanup;
+	priv->rng.read = ingenic_rng_read;
+
+	ret = hwrng_register(&priv->rng);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register hwrng\n");
+		goto err_free_rng;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	dev_info(&pdev->dev, "Ingenic RNG driver registered\n");
+	return 0;
+
+err_free_rng:
+	kfree(priv);
+	return ret;
+}
+
+static int ingenic_rng_remove(struct platform_device *pdev)
+{
+	struct ingenic_rng *priv = platform_get_drvdata(pdev);
+
+	hwrng_unregister(&priv->rng);
+
+	writel(0, priv->base + RNG_REG_ERNG_OFFSET);
+
+	return 0;
+}
+
+static const struct of_device_id ingenic_rng_of_match[] = {
+	{ .compatible = "ingenic,jz4780-rng", .data = (void *) ID_JZ4780 },
+	{ .compatible = "ingenic,x1000-rng", .data = (void *) ID_X1000 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ingenic_rng_of_match);
+
+static struct platform_driver ingenic_rng_driver = {
+	.probe		= ingenic_rng_probe,
+	.remove		= ingenic_rng_remove,
+	.driver		= {
+		.name	= "ingenic-rng",
+		.of_match_table = ingenic_rng_of_match,
+	},
+};
+
+module_platform_driver(ingenic_rng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>");
+MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>");
+MODULE_DESCRIPTION("Ingenic Random Number Generator driver");
diff --git a/drivers/char/hw_random/ks-sa-rng.c b/drivers/char/hw_random/ks-sa-rng.c
index 001617033d6a..8f1d47ff9799 100644
--- a/drivers/char/hw_random/ks-sa-rng.c
+++ b/drivers/char/hw_random/ks-sa-rng.c
@@ -2,7 +2,7 @@
 /*
  * Random Number Generator driver for the Keystone SOC
  *
- * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com
+ * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com
  *
  * Authors:	Sandeep Nair
  *		Vitaly Andrianov
diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c
index 74ed29f42e4f..b0ded41eb865 100644
--- a/drivers/char/hw_random/nomadik-rng.c
+++ b/drivers/char/hw_random/nomadik-rng.c
@@ -76,7 +76,7 @@ static int nmk_rng_remove(struct amba_device *dev)
 	return 0;
 }
 
-static struct amba_id nmk_rng_ids[] = {
+static const struct amba_id nmk_rng_ids[] = {
 	{
 		.id	= 0x000805e1,
 		.mask	= 0x000fffff, /* top bits are rev and cfg: accept all */
diff --git a/drivers/char/hw_random/npcm-rng.c b/drivers/char/hw_random/npcm-rng.c
index 01d04404d8c0..5d0d13f891b7 100644
--- a/drivers/char/hw_random/npcm-rng.c
+++ b/drivers/char/hw_random/npcm-rng.c
@@ -161,7 +161,7 @@ static const struct dev_pm_ops npcm_rng_pm_ops = {
 				pm_runtime_force_resume)
 };
 
-static const struct of_device_id rng_dt_id[] = {
+static const struct of_device_id rng_dt_id[] __maybe_unused = {
 	{ .compatible = "nuvoton,npcm750-rng",  },
 	{},
 };
diff --git a/drivers/char/hw_random/octeon-rng.c b/drivers/char/hw_random/octeon-rng.c
index 7be8067ac4e8..8561a09b4681 100644
--- a/drivers/char/hw_random/octeon-rng.c
+++ b/drivers/char/hw_random/octeon-rng.c
@@ -33,7 +33,7 @@ static int octeon_rng_init(struct hwrng *rng)
 	ctl.u64 = 0;
 	ctl.s.ent_en = 1; /* Enable the entropy source.  */
 	ctl.s.rng_en = 1; /* Enable the RNG hardware.  */
-	cvmx_write_csr((u64)p->control_status, ctl.u64);
+	cvmx_write_csr((__force u64)p->control_status, ctl.u64);
 	return 0;
 }
 
@@ -44,14 +44,14 @@ static void octeon_rng_cleanup(struct hwrng *rng)
 
 	ctl.u64 = 0;
 	/* Disable everything.  */
-	cvmx_write_csr((u64)p->control_status, ctl.u64);
+	cvmx_write_csr((__force u64)p->control_status, ctl.u64);
 }
 
 static int octeon_rng_data_read(struct hwrng *rng, u32 *data)
 {
 	struct octeon_rng *p = container_of(rng, struct octeon_rng, ops);
 
-	*data = cvmx_read64_uint32((u64)p->result);
+	*data = cvmx_read64_uint32((__force u64)p->result);
 	return sizeof(u32);
 }
 
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index 7290c603fcb8..5cc5fc504968 100644
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -22,6 +22,7 @@
 #include <linux/platform_device.h>
 #include <linux/hw_random.h>
 #include <linux/delay.h>
+#include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
@@ -243,7 +244,6 @@ static struct omap_rng_pdata omap2_rng_pdata = {
 	.cleanup	= omap2_rng_cleanup,
 };
 
-#if defined(CONFIG_OF)
 static inline u32 omap4_rng_data_present(struct omap_rng_dev *priv)
 {
 	return omap_rng_read(priv, RNG_STATUS_REG) & RNG_REG_STATUS_RDY;
@@ -358,7 +358,7 @@ static struct omap_rng_pdata eip76_rng_pdata = {
 	.cleanup	= omap4_rng_cleanup,
 };
 
-static const struct of_device_id omap_rng_of_match[] = {
+static const struct of_device_id omap_rng_of_match[] __maybe_unused = {
 		{
 			.compatible	= "ti,omap2-rng",
 			.data		= &omap2_rng_pdata,
@@ -418,13 +418,6 @@ static int of_get_omap_rng_device_details(struct omap_rng_dev *priv,
 	}
 	return 0;
 }
-#else
-static int of_get_omap_rng_device_details(struct omap_rng_dev *omap_rng,
-					  struct platform_device *pdev)
-{
-	return -EINVAL;
-}
-#endif
 
 static int get_omap_rng_device_details(struct omap_rng_dev *omap_rng)
 {
diff --git a/drivers/char/hw_random/pic32-rng.c b/drivers/char/hw_random/pic32-rng.c
index 81080cb2294e..e8210c1715cf 100644
--- a/drivers/char/hw_random/pic32-rng.c
+++ b/drivers/char/hw_random/pic32-rng.c
@@ -119,7 +119,7 @@ static int pic32_rng_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id pic32_rng_of_match[] = {
+static const struct of_device_id pic32_rng_of_match[] __maybe_unused = {
 	{ .compatible	= "microchip,pic32mzda-rng", },
 	{ /* sentinel */ }
 };
diff --git a/drivers/char/hw_random/st-rng.c b/drivers/char/hw_random/st-rng.c
index 783c24e3f8b7..15ba1e6fae4d 100644
--- a/drivers/char/hw_random/st-rng.c
+++ b/drivers/char/hw_random/st-rng.c
@@ -12,6 +12,7 @@
 #include <linux/delay.h>
 #include <linux/hw_random.h>
 #include <linux/io.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
@@ -121,7 +122,7 @@ static int st_rng_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id st_rng_match[] = {
+static const struct of_device_id st_rng_match[] __maybe_unused = {
 	{ .compatible = "st,rng" },
 	{},
 };
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 79a6e47b5fbc..a90001e02bf7 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -195,7 +195,7 @@ static int virtrng_restore(struct virtio_device *vdev)
 }
 #endif
 
-static struct virtio_device_id id_table[] = {
+static const struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_RNG, VIRTIO_DEV_ANY_ID },
 	{ 0 },
 };