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98 lines
2.2 KiB
98 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause |
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/* |
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* Copyright (c) 2016 BayLibre, SAS. |
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* Author: Neil Armstrong <[email protected]> |
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* Copyright (C) 2014 Amlogic, Inc. |
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*/ |
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#include <linux/err.h> |
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#include <linux/module.h> |
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#include <linux/io.h> |
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#include <linux/platform_device.h> |
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#include <linux/hw_random.h> |
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#include <linux/slab.h> |
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#include <linux/types.h> |
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#include <linux/of.h> |
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#include <linux/clk.h> |
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#define RNG_DATA 0x00 |
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struct meson_rng_data { |
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void __iomem *base; |
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struct platform_device *pdev; |
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struct hwrng rng; |
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struct clk *core_clk; |
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}; |
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static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) |
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{ |
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struct meson_rng_data *data = |
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container_of(rng, struct meson_rng_data, rng); |
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*(u32 *)buf = readl_relaxed(data->base + RNG_DATA); |
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return sizeof(u32); |
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} |
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static void meson_rng_clk_disable(void *data) |
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{ |
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clk_disable_unprepare(data); |
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} |
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static int meson_rng_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct meson_rng_data *data; |
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int ret; |
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); |
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if (!data) |
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return -ENOMEM; |
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data->pdev = pdev; |
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data->base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(data->base)) |
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return PTR_ERR(data->base); |
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data->core_clk = devm_clk_get(dev, "core"); |
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if (IS_ERR(data->core_clk)) |
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data->core_clk = NULL; |
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if (data->core_clk) { |
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ret = clk_prepare_enable(data->core_clk); |
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if (ret) |
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return ret; |
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ret = devm_add_action_or_reset(dev, meson_rng_clk_disable, |
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data->core_clk); |
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if (ret) |
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return ret; |
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} |
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data->rng.name = pdev->name; |
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data->rng.read = meson_rng_read; |
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platform_set_drvdata(pdev, data); |
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return devm_hwrng_register(dev, &data->rng); |
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} |
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static const struct of_device_id meson_rng_of_match[] = { |
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{ .compatible = "amlogic,meson-rng", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, meson_rng_of_match); |
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static struct platform_driver meson_rng_driver = { |
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.probe = meson_rng_probe, |
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.driver = { |
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.name = "meson-rng", |
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.of_match_table = meson_rng_of_match, |
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}, |
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}; |
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module_platform_driver(meson_rng_driver); |
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MODULE_DESCRIPTION("Meson H/W Random Number Generator driver"); |
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MODULE_AUTHOR("Lawrence Mok <[email protected]>"); |
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MODULE_AUTHOR("Neil Armstrong <[email protected]>"); |
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MODULE_LICENSE("Dual BSD/GPL");
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