146 lines
4.8 KiB
Diff
146 lines
4.8 KiB
Diff
--- /dev/null
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+++ b/drivers/char/hw_random/bcm2708-rng.c
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@@ -0,0 +1,117 @@
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+/**
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+ * Copyright (c) 2010-2012 Broadcom. All rights reserved.
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+ *
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+ * Redistribution and use in source and binary forms, with or without
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+ * modification, are permitted provided that the following conditions
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+ * are met:
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+ * 1. Redistributions of source code must retain the above copyright
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+ * notice, this list of conditions, and the following disclaimer,
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+ * without modification.
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+ * 2. Redistributions in binary form must reproduce the above copyright
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+ * notice, this list of conditions and the following disclaimer in the
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+ * documentation and/or other materials provided with the distribution.
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+ * 3. The names of the above-listed copyright holders may not be used
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+ * to endorse or promote products derived from this software without
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+ * specific prior written permission.
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+ *
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+ * ALTERNATIVELY, this software may be distributed under the terms of the
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+ * GNU General Public License ("GPL") version 2, as published by the Free
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+ * Software Foundation.
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+ *
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+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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+ */
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+
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+#include <linux/kernel.h>
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+#include <linux/module.h>
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+#include <linux/init.h>
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+#include <linux/hw_random.h>
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+#include <linux/printk.h>
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+
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+#include <asm/io.h>
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+#include <mach/hardware.h>
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+#include <mach/platform.h>
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+
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+#define RNG_CTRL (0x0)
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+#define RNG_STATUS (0x4)
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+#define RNG_DATA (0x8)
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+#define RNG_FF_THRESHOLD (0xc)
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+
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+/* enable rng */
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+#define RNG_RBGEN 0x1
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+/* double speed, less random mode */
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+#define RNG_RBG2X 0x2
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+
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+/* the initial numbers generated are "less random" so will be discarded */
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+#define RNG_WARMUP_COUNT 0x40000
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+
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+static int bcm2708_rng_data_read(struct hwrng *rng, u32 *buffer)
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+{
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+ void __iomem *rng_base = (void __iomem *)rng->priv;
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+ unsigned words;
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+ /* wait for a random number to be in fifo */
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+ do {
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+ words = __raw_readl(rng_base + RNG_STATUS)>>24;
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+ }
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+ while (words == 0);
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+ /* read the random number */
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+ *buffer = __raw_readl(rng_base + RNG_DATA);
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+ return 4;
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+}
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+
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+static struct hwrng bcm2708_rng_ops = {
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+ .name = "bcm2708",
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+ .data_read = bcm2708_rng_data_read,
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+};
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+
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+static int __init bcm2708_rng_init(void)
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+{
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+ void __iomem *rng_base;
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+ int err;
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+
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+ /* map peripheral */
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+ rng_base = ioremap(RNG_BASE, 0x10);
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+ pr_info("bcm2708_rng_init=%p\n", rng_base);
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+ if (!rng_base) {
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+ pr_err("bcm2708_rng_init failed to ioremap\n");
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+ return -ENOMEM;
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+ }
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+ bcm2708_rng_ops.priv = (unsigned long)rng_base;
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+ /* register driver */
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+ err = hwrng_register(&bcm2708_rng_ops);
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+ if (err) {
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+ pr_err("bcm2708_rng_init hwrng_register()=%d\n", err);
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+ iounmap(rng_base);
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+ } else {
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+ /* set warm-up count & enable */
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+ __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS);
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+ __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL);
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+ }
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+ return err;
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+}
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+
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+static void __exit bcm2708_rng_exit(void)
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+{
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+ void __iomem *rng_base = (void __iomem *)bcm2708_rng_ops.priv;
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+ pr_info("bcm2708_rng_exit\n");
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+ /* disable rng hardware */
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+ __raw_writel(0, rng_base + RNG_CTRL);
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+ /* unregister driver */
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+ hwrng_unregister(&bcm2708_rng_ops);
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+ iounmap(rng_base);
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+}
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+
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+module_init(bcm2708_rng_init);
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+module_exit(bcm2708_rng_exit);
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+
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+MODULE_DESCRIPTION("BCM2708 H/W Random Number Generator (RNG) driver");
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+MODULE_LICENSE("GPL and additional rights");
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--- a/drivers/char/hw_random/Kconfig
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+++ b/drivers/char/hw_random/Kconfig
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@@ -314,3 +314,15 @@ config HW_RANDOM_TPM
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module will be called tpm-rng.
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If unsure, say Y.
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+
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+config HW_RANDOM_BCM2708
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+ tristate "BCM2708 generic true random number generator support"
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+ depends on HW_RANDOM && ARCH_BCM2708
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+ ---help---
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+ This driver provides the kernel-side support for the BCM2708 hardware.
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+
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+ To compile this driver as a module, choose M here: the
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+ module will be called bcm2708-rng.
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+
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+ If unsure, say N.
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+
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--- a/drivers/char/hw_random/Makefile
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+++ b/drivers/char/hw_random/Makefile
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@@ -27,3 +27,4 @@ obj-$(CONFIG_HW_RANDOM_PSERIES) += pseri
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obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
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obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
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obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
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+obj-$(CONFIG_HW_RANDOM_BCM2708) += bcm2708-rng.o
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