Merge commit 'v2.6.30-rc5' into next

1 files changed, 182 insertions, 0 deletions

diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
new file mode 100644
index 000000000000..dcd352ad0e7f
--- /dev/null
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -0,0 +1,182 @@
+/*
+ * drivers/char/hw_random/timeriomem-rng.c
+ *
+ * Copyright (C) 2009 Alexander Clouter <alex@digriz.org.uk>
+ *
+ * Derived from drivers/char/hw_random/omap-rng.c
+ *   Copyright 2005 (c) MontaVista Software, Inc.
+ *   Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Overview:
+ *   This driver is useful for platforms that have an IO range that provides
+ *   periodic random data from a single IO memory address.  All the platform
+ *   has to do is provide the address and 'wait time' that new data becomes
+ *   available.
+ *
+ * TODO: add support for reading sizes other than 32bits and masking
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/timeriomem-rng.h>
+#include <linux/jiffies.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+
+static struct timeriomem_rng_data *timeriomem_rng_data;
+
+static void timeriomem_rng_trigger(unsigned long);
+static DEFINE_TIMER(timeriomem_rng_timer, timeriomem_rng_trigger, 0, 0);
+
+/*
+ * have data return 1, however return 0 if we have nothing
+ */
+static int timeriomem_rng_data_present(struct hwrng *rng, int wait)
+{
+        if (rng->priv == 0)
+                return 1;
+
+        if (!wait || timeriomem_rng_data->present)
+                return timeriomem_rng_data->present;
+
+        wait_for_completion(&timeriomem_rng_data->completion);
+
+        return 1;
+}
+
+static int timeriomem_rng_data_read(struct hwrng *rng, u32 *data)
+{
+        unsigned long cur;
+        s32 delay;
+
+        *data = readl(timeriomem_rng_data->address);
+
+        if (rng->priv != 0) {
+                cur = jiffies;
+
+                delay = cur - timeriomem_rng_timer.expires;
+                delay = rng->priv - (delay % rng->priv);
+
+                timeriomem_rng_timer.expires = cur + delay;
+                timeriomem_rng_data->present = 0;
+
+                init_completion(&timeriomem_rng_data->completion);
+                add_timer(&timeriomem_rng_timer);
+        }
+
+        return 4;
+}
+
+static void timeriomem_rng_trigger(unsigned long dummy)
+{
+        timeriomem_rng_data->present = 1;
+        complete(&timeriomem_rng_data->completion);
+}
+
+static struct hwrng timeriomem_rng_ops = {
+        .name           = "timeriomem",
+        .data_present   = timeriomem_rng_data_present,
+        .data_read      = timeriomem_rng_data_read,
+        .priv           = 0,
+};
+
+static int __init timeriomem_rng_probe(struct platform_device *pdev)
+{
+        struct resource *res, *mem;
+        int ret;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+        if (!res)
+                return -ENOENT;
+
+        mem = request_mem_region(res->start, res->end - res->start + 1,
+                                 pdev->name);
+        if (mem == NULL)
+                return -EBUSY;
+
+        dev_set_drvdata(&pdev->dev, mem);
+
+        timeriomem_rng_data = pdev->dev.platform_data;
+
+        timeriomem_rng_data->address = ioremap(res->start,
+                                                res->end - res->start + 1);
+        if (!timeriomem_rng_data->address) {
+                ret = -ENOMEM;
+                goto err_ioremap;
+        }
+
+        if (timeriomem_rng_data->period != 0
+                && usecs_to_jiffies(timeriomem_rng_data->period) > 0) {
+                timeriomem_rng_timer.expires = jiffies;
+
+                timeriomem_rng_ops.priv = usecs_to_jiffies(
+                                                timeriomem_rng_data->period);
+        }
+        timeriomem_rng_data->present = 1;
+
+        ret = hwrng_register(&timeriomem_rng_ops);
+        if (ret)
+                goto err_register;
+
+        dev_info(&pdev->dev, "32bits from 0x%p @ %dus\n",
+                        timeriomem_rng_data->address,
+                        timeriomem_rng_data->period);
+
+        return 0;
+
+err_register:
+        dev_err(&pdev->dev, "problem registering\n");
+        iounmap(timeriomem_rng_data->address);
+err_ioremap:
+        release_resource(mem);
+
+        return ret;
+}
+
+static int __devexit timeriomem_rng_remove(struct platform_device *pdev)
+{
+        struct resource *mem = dev_get_drvdata(&pdev->dev);
+
+        del_timer_sync(&timeriomem_rng_timer);
+        hwrng_unregister(&timeriomem_rng_ops);
+
+        iounmap(timeriomem_rng_data->address);
+        release_resource(mem);
+
+        return 0;
+}
+
+static struct platform_driver timeriomem_rng_driver = {
+        .driver = {
+                .name           = "timeriomem_rng",
+                .owner          = THIS_MODULE,
+        },
+        .probe          = timeriomem_rng_probe,
+        .remove         = __devexit_p(timeriomem_rng_remove),
+};
+
+static int __init timeriomem_rng_init(void)
+{
+        return platform_driver_register(&timeriomem_rng_driver);
+}
+
+static void __exit timeriomem_rng_exit(void)
+{
+        platform_driver_unregister(&timeriomem_rng_driver);
+}
+
+module_init(timeriomem_rng_init);
+module_exit(timeriomem_rng_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
+MODULE_DESCRIPTION("Timer IOMEM H/W RNG driver");