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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/char/hw_random/meson-rng.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/char/hw_random/meson-rng.c')
-rw-r--r-- | drivers/char/hw_random/meson-rng.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c new file mode 100644 index 000000000..8bb30282c --- /dev/null +++ b/drivers/char/hw_random/meson-rng.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +/* + * Copyright (c) 2016 BayLibre, SAS. + * Author: Neil Armstrong <narmstrong@baylibre.com> + * Copyright (C) 2014 Amlogic, Inc. + */ +#include <linux/err.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/hw_random.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/of.h> +#include <linux/clk.h> + +#define RNG_DATA 0x00 + +struct meson_rng_data { + void __iomem *base; + struct platform_device *pdev; + struct hwrng rng; + struct clk *core_clk; +}; + +static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct meson_rng_data *data = + container_of(rng, struct meson_rng_data, rng); + + *(u32 *)buf = readl_relaxed(data->base + RNG_DATA); + + return sizeof(u32); +} + +static void meson_rng_clk_disable(void *data) +{ + clk_disable_unprepare(data); +} + +static int meson_rng_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct meson_rng_data *data; + int ret; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->pdev = pdev; + + data->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(data->base)) + return PTR_ERR(data->base); + + data->core_clk = devm_clk_get_optional(dev, "core"); + if (IS_ERR(data->core_clk)) + return dev_err_probe(dev, PTR_ERR(data->core_clk), + "Failed to get core clock\n"); + + if (data->core_clk) { + ret = clk_prepare_enable(data->core_clk); + if (ret) + return ret; + ret = devm_add_action_or_reset(dev, meson_rng_clk_disable, + data->core_clk); + if (ret) + return ret; + } + + data->rng.name = pdev->name; + data->rng.read = meson_rng_read; + + platform_set_drvdata(pdev, data); + + return devm_hwrng_register(dev, &data->rng); +} + +static const struct of_device_id meson_rng_of_match[] = { + { .compatible = "amlogic,meson-rng", }, + {}, +}; +MODULE_DEVICE_TABLE(of, meson_rng_of_match); + +static struct platform_driver meson_rng_driver = { + .probe = meson_rng_probe, + .driver = { + .name = "meson-rng", + .of_match_table = meson_rng_of_match, + }, +}; + +module_platform_driver(meson_rng_driver); + +MODULE_DESCRIPTION("Meson H/W Random Number Generator driver"); +MODULE_AUTHOR("Lawrence Mok <lawrence.mok@amlogic.com>"); +MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>"); +MODULE_LICENSE("Dual BSD/GPL"); |