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52140993d4
The Broadcom BCM5301x SoCs (Northstar) utilize the same random number generator peripheral as Northstar Plus and BCM2835, but just like the NSP SoC, we need to enable the interrupt. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
147 lines
3.5 KiB
C
147 lines
3.5 KiB
C
/**
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* Copyright (c) 2010-2012 Broadcom. All rights reserved.
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* Copyright (c) 2013 Lubomir Rintel
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License ("GPL")
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* version 2, as published by the Free Software Foundation.
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*/
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_address.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <linux/printk.h>
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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_INT_MASK 0x10
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/* enable rng */
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#define RNG_RBGEN 0x1
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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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#define RNG_INT_OFF 0x1
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static void __init nsp_rng_init(void __iomem *base)
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{
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u32 val;
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/* mask the interrupt */
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val = readl(base + RNG_INT_MASK);
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val |= RNG_INT_OFF;
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writel(val, base + RNG_INT_MASK);
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}
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static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
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bool wait)
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{
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void __iomem *rng_base = (void __iomem *)rng->priv;
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u32 max_words = max / sizeof(u32);
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u32 num_words, count;
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while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) {
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if (!wait)
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return 0;
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cpu_relax();
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}
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num_words = readl(rng_base + RNG_STATUS) >> 24;
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if (num_words > max_words)
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num_words = max_words;
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for (count = 0; count < num_words; count++)
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((u32 *)buf)[count] = readl(rng_base + RNG_DATA);
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return num_words * sizeof(u32);
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}
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static struct hwrng bcm2835_rng_ops = {
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.name = "bcm2835",
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.read = bcm2835_rng_read,
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};
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static const struct of_device_id bcm2835_rng_of_match[] = {
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{ .compatible = "brcm,bcm2835-rng"},
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{ .compatible = "brcm,bcm-nsp-rng", .data = nsp_rng_init},
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{ .compatible = "brcm,bcm5301x-rng", .data = nsp_rng_init},
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{},
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};
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static int bcm2835_rng_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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void (*rng_setup)(void __iomem *base);
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const struct of_device_id *rng_id;
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void __iomem *rng_base;
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int err;
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/* map peripheral */
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rng_base = of_iomap(np, 0);
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if (!rng_base) {
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dev_err(dev, "failed to remap rng regs");
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return -ENODEV;
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}
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bcm2835_rng_ops.priv = (unsigned long)rng_base;
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rng_id = of_match_node(bcm2835_rng_of_match, np);
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if (!rng_id)
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return -EINVAL;
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/* Check for rng init function, execute it */
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rng_setup = rng_id->data;
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if (rng_setup)
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rng_setup(rng_base);
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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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/* register driver */
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err = hwrng_register(&bcm2835_rng_ops);
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if (err) {
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dev_err(dev, "hwrng registration failed\n");
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iounmap(rng_base);
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} else
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dev_info(dev, "hwrng registered\n");
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return err;
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}
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static int bcm2835_rng_remove(struct platform_device *pdev)
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{
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void __iomem *rng_base = (void __iomem *)bcm2835_rng_ops.priv;
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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(&bcm2835_rng_ops);
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iounmap(rng_base);
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return 0;
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}
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MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match);
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static struct platform_driver bcm2835_rng_driver = {
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.driver = {
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.name = "bcm2835-rng",
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.of_match_table = bcm2835_rng_of_match,
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},
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.probe = bcm2835_rng_probe,
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.remove = bcm2835_rng_remove,
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};
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module_platform_driver(bcm2835_rng_driver);
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MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
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MODULE_DESCRIPTION("BCM2835 Random Number Generator (RNG) driver");
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MODULE_LICENSE("GPL v2");
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