v4.19.13 snapshot.
diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c
new file mode 100644
index 0000000..9c85815
--- /dev/null
+++ b/drivers/char/hw_random/nomadik-rng.c
@@ -0,0 +1,106 @@
+/*
+ * Nomadik RNG support
+ * Copyright 2009 Alessandro Rubini
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/amba/bus.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+
+static struct clk *rng_clk;
+
+static int nmk_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
+{
+ void __iomem *base = (void __iomem *)rng->priv;
+
+ /*
+ * The register is 32 bits and gives 16 random bits (low half).
+ * A subsequent read will delay the core for 400ns, so we just read
+ * once and accept the very unlikely very small delay, even if wait==0.
+ */
+ *(u16 *)data = __raw_readl(base + 8) & 0xffff;
+ return 2;
+}
+
+/* we have at most one RNG per machine, granted */
+static struct hwrng nmk_rng = {
+ .name = "nomadik",
+ .read = nmk_rng_read,
+};
+
+static int nmk_rng_probe(struct amba_device *dev, const struct amba_id *id)
+{
+ void __iomem *base;
+ int ret;
+
+ rng_clk = devm_clk_get(&dev->dev, NULL);
+ if (IS_ERR(rng_clk)) {
+ dev_err(&dev->dev, "could not get rng clock\n");
+ ret = PTR_ERR(rng_clk);
+ return ret;
+ }
+
+ clk_prepare_enable(rng_clk);
+
+ ret = amba_request_regions(dev, dev->dev.init_name);
+ if (ret)
+ goto out_clk;
+ ret = -ENOMEM;
+ base = devm_ioremap(&dev->dev, dev->res.start,
+ resource_size(&dev->res));
+ if (!base)
+ goto out_release;
+ nmk_rng.priv = (unsigned long)base;
+ ret = hwrng_register(&nmk_rng);
+ if (ret)
+ goto out_release;
+ return 0;
+
+out_release:
+ amba_release_regions(dev);
+out_clk:
+ clk_disable(rng_clk);
+ return ret;
+}
+
+static int nmk_rng_remove(struct amba_device *dev)
+{
+ hwrng_unregister(&nmk_rng);
+ amba_release_regions(dev);
+ clk_disable(rng_clk);
+ return 0;
+}
+
+static struct amba_id nmk_rng_ids[] = {
+ {
+ .id = 0x000805e1,
+ .mask = 0x000fffff, /* top bits are rev and cfg: accept all */
+ },
+ {0, 0},
+};
+
+MODULE_DEVICE_TABLE(amba, nmk_rng_ids);
+
+static struct amba_driver nmk_rng_driver = {
+ .drv = {
+ .owner = THIS_MODULE,
+ .name = "rng",
+ },
+ .probe = nmk_rng_probe,
+ .remove = nmk_rng_remove,
+ .id_table = nmk_rng_ids,
+};
+
+module_amba_driver(nmk_rng_driver);
+
+MODULE_LICENSE("GPL");