3 files changed, 116 insertions, 0 deletions

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index c0df30faa66a..d31483c54883 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -186,3 +186,15 @@ config HW_RANDOM_MXC_RNGA
           module will be called mxc-rnga.
 
           If unsure, say Y.
+
+config HW_RANDOM_NOMADIK
+        tristate "ST-Ericsson Nomadik Random Number Generator support"
+        depends on HW_RANDOM && PLAT_NOMADIK
+        ---help---
+          This driver provides kernel-side support for the Random Number
+          Generator hardware found on ST-Ericsson SoCs (8815 and 8500).
+
+          To compile this driver as a module, choose M here: the
+          module will be called nomadik-rng.
+
+          If unsure, say Y.
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 5eeb1303f0d0..4273308aa1e3 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -18,3 +18,4 @@ 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_OCTEON) += octeon-rng.o
+obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c
new file mode 100644
index 000000000000..a8b4c4010144
--- /dev/null
+++ b/drivers/char/hw_random/nomadik-rng.c
@@ -0,0 +1,103 @@
+/*
+ * 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/init.h>
+#include <linux/device.h>
+#include <linux/amba/bus.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+
+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, struct amba_id *id)
+{
+        void __iomem *base;
+        int ret;
+
+        ret = amba_request_regions(dev, dev->dev.init_name);
+        if (ret)
+                return ret;
+        ret = -ENOMEM;
+        base = ioremap(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_unmap;
+        return 0;
+
+out_unmap:
+        iounmap(base);
+out_release:
+        amba_release_regions(dev);
+        return ret;
+}
+
+static int nmk_rng_remove(struct amba_device *dev)
+{
+        void __iomem *base = (void __iomem *)nmk_rng.priv;
+        hwrng_unregister(&nmk_rng);
+        iounmap(base);
+        amba_release_regions(dev);
+        return 0;
+}
+
+static struct amba_id nmk_rng_ids[] = {
+        {
+                .id     = 0x000805e1,
+                .mask   = 0x000fffff, /* top bits are rev and cfg: accept all */
+        },
+        {0, 0},
+};
+
+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,
+};
+
+static int __init nmk_rng_init(void)
+{
+        return amba_driver_register(&nmk_rng_driver);
+}
+
+static void __devexit nmk_rng_exit(void)
+{
+        amba_driver_unregister(&nmk_rng_driver);
+}
+
+module_init(nmk_rng_init);
+module_exit(nmk_rng_exit);
+
+MODULE_LICENSE("GPL");