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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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9d2c1a985b
This function call was found to be unnecessary as there is no equivalent platform_get_drvdata() call to access the private data of the driver. Also, the private data is defined in this driver, so there is no risk of it being accessed outside of this driver file. Signed-off-by: Andrei Coardos <aboutphysycs@gmail.com> Reviewed-by: Martin Kaiser <martin@kaiser.cx> Reviewed-by: Alexandru Ardelean <alex@shruggie.ro> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2016 HiSilicon Co., Ltd.
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*/
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/random.h>
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#define RNG_SEED 0x0
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#define RNG_CTRL 0x4
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#define RNG_SEED_SEL BIT(2)
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#define RNG_RING_EN BIT(1)
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#define RNG_EN BIT(0)
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#define RNG_RAN_NUM 0x10
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#define RNG_PHY_SEED 0x14
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#define to_hisi_rng(p) container_of(p, struct hisi_rng, rng)
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static int seed_sel;
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module_param(seed_sel, int, S_IRUGO);
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MODULE_PARM_DESC(seed_sel, "Auto reload seed. 0, use LFSR(default); 1, use ring oscillator.");
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struct hisi_rng {
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void __iomem *base;
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struct hwrng rng;
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};
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static int hisi_rng_init(struct hwrng *rng)
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{
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struct hisi_rng *hrng = to_hisi_rng(rng);
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int val = RNG_EN;
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u32 seed;
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/* get a random number as initial seed */
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get_random_bytes(&seed, sizeof(seed));
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writel_relaxed(seed, hrng->base + RNG_SEED);
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/**
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* The seed is reload periodically, there are two choice
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* of seeds, default seed using the value from LFSR, or
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* will use seed generated by ring oscillator.
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*/
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if (seed_sel == 1)
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val |= RNG_RING_EN | RNG_SEED_SEL;
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writel_relaxed(val, hrng->base + RNG_CTRL);
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return 0;
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}
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static void hisi_rng_cleanup(struct hwrng *rng)
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{
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struct hisi_rng *hrng = to_hisi_rng(rng);
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writel_relaxed(0, hrng->base + RNG_CTRL);
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}
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static int hisi_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
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{
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struct hisi_rng *hrng = to_hisi_rng(rng);
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u32 *data = buf;
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*data = readl_relaxed(hrng->base + RNG_RAN_NUM);
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return 4;
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}
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static int hisi_rng_probe(struct platform_device *pdev)
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{
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struct hisi_rng *rng;
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int ret;
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rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
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if (!rng)
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return -ENOMEM;
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rng->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(rng->base))
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return PTR_ERR(rng->base);
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rng->rng.name = pdev->name;
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rng->rng.init = hisi_rng_init;
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rng->rng.cleanup = hisi_rng_cleanup;
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rng->rng.read = hisi_rng_read;
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ret = devm_hwrng_register(&pdev->dev, &rng->rng);
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if (ret) {
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dev_err(&pdev->dev, "failed to register hwrng\n");
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return ret;
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}
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return 0;
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}
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static const struct of_device_id hisi_rng_dt_ids[] __maybe_unused = {
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{ .compatible = "hisilicon,hip04-rng" },
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{ .compatible = "hisilicon,hip05-rng" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, hisi_rng_dt_ids);
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static struct platform_driver hisi_rng_driver = {
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.probe = hisi_rng_probe,
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.driver = {
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.name = "hisi-rng",
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.of_match_table = of_match_ptr(hisi_rng_dt_ids),
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},
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};
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module_platform_driver(hisi_rng_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Kefeng Wang <wangkefeng.wang@huawei>");
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MODULE_DESCRIPTION("Hisilicon random number generator driver");
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