1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
new file mode 100644
index 000000000..8bb30282c
--- /dev/null
+++ b/drivers/char/hw_random/meson-rng.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2014 Amlogic, Inc.
+ */
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/hw_random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+
+#define RNG_DATA 0x00
+
+struct meson_rng_data {
+	void __iomem *base;
+	struct platform_device *pdev;
+	struct hwrng rng;
+	struct clk *core_clk;
+};
+
+static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct meson_rng_data *data =
+			container_of(rng, struct meson_rng_data, rng);
+
+	*(u32 *)buf = readl_relaxed(data->base + RNG_DATA);
+
+	return sizeof(u32);
+}
+
+static void meson_rng_clk_disable(void *data)
+{
+	clk_disable_unprepare(data);
+}
+
+static int meson_rng_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct meson_rng_data *data;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->pdev = pdev;
+
+	data->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(data->base))
+		return PTR_ERR(data->base);
+
+	data->core_clk = devm_clk_get_optional(dev, "core");
+	if (IS_ERR(data->core_clk))
+		return dev_err_probe(dev, PTR_ERR(data->core_clk),
+				     "Failed to get core clock\n");
+
+	if (data->core_clk) {
+		ret = clk_prepare_enable(data->core_clk);
+		if (ret)
+			return ret;
+		ret = devm_add_action_or_reset(dev, meson_rng_clk_disable,
+					       data->core_clk);
+		if (ret)
+			return ret;
+	}
+
+	data->rng.name = pdev->name;
+	data->rng.read = meson_rng_read;
+
+	platform_set_drvdata(pdev, data);
+
+	return devm_hwrng_register(dev, &data->rng);
+}
+
+static const struct of_device_id meson_rng_of_match[] = {
+	{ .compatible = "amlogic,meson-rng", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, meson_rng_of_match);
+
+static struct platform_driver meson_rng_driver = {
+	.probe	= meson_rng_probe,
+	.driver	= {
+		.name = "meson-rng",
+		.of_match_table = meson_rng_of_match,
+	},
+};
+
+module_platform_driver(meson_rng_driver);
+
+MODULE_DESCRIPTION("Meson H/W Random Number Generator driver");
+MODULE_AUTHOR("Lawrence Mok <lawrence.mok@amlogic.com>");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_LICENSE("Dual BSD/GPL");