// SPDX-License-Identifier: GPL-2.0 /* * exynos-rng.c - Random Number Generator driver for the Exynos * * Copyright (c) 2017 Krzysztof Kozlowski <[email protected]> * * Loosely based on old driver from drivers/char/hw_random/exynos-rng.c: * Copyright (C) 2012 Samsung Electronics * Jonghwa Lee <[email protected]> */ #include <linux/clk.h> #include <linux/crypto.h> #include <linux/err.h> #include <linux/io.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> #include <linux/platform_device.h> #include <crypto/internal/rng.h> #define EXYNOS_RNG_CONTROL … #define EXYNOS_RNG_STATUS … #define EXYNOS_RNG_SEED_CONF … #define EXYNOS_RNG_GEN_PRNG … #define EXYNOS_RNG_SEED_BASE … #define EXYNOS_RNG_SEED(n) … #define EXYNOS_RNG_OUT_BASE … #define EXYNOS_RNG_OUT(n) … /* EXYNOS_RNG_CONTROL bit fields */ #define EXYNOS_RNG_CONTROL_START … /* EXYNOS_RNG_STATUS bit fields */ #define EXYNOS_RNG_STATUS_SEED_SETTING_DONE … #define EXYNOS_RNG_STATUS_RNG_DONE … /* Five seed and output registers, each 4 bytes */ #define EXYNOS_RNG_SEED_REGS … #define EXYNOS_RNG_SEED_SIZE … enum exynos_prng_type { … }; /* * Driver re-seeds itself with generated random numbers to hinder * backtracking of the original seed. * * Time for next re-seed in ms. */ #define EXYNOS_RNG_RESEED_TIME … #define EXYNOS_RNG_RESEED_BYTES … /* * In polling mode, do not wait infinitely for the engine to finish the work. */ #define EXYNOS_RNG_WAIT_RETRIES … /* Context for crypto */ struct exynos_rng_ctx { … }; /* Device associated memory */ struct exynos_rng_dev { … }; static struct exynos_rng_dev *exynos_rng_dev; static u32 exynos_rng_readl(struct exynos_rng_dev *rng, u32 offset) { … } static void exynos_rng_writel(struct exynos_rng_dev *rng, u32 val, u32 offset) { … } static int exynos_rng_set_seed(struct exynos_rng_dev *rng, const u8 *seed, unsigned int slen) { … } /* * Start the engine and poll for finish. Then read from output registers * filling the 'dst' buffer up to 'dlen' bytes or up to size of generated * random data (EXYNOS_RNG_SEED_SIZE). * * On success: return 0 and store number of read bytes under 'read' address. * On error: return -ERRNO. */ static int exynos_rng_get_random(struct exynos_rng_dev *rng, u8 *dst, unsigned int dlen, unsigned int *read) { … } /* Re-seed itself from time to time */ static void exynos_rng_reseed(struct exynos_rng_dev *rng) { … } static int exynos_rng_generate(struct crypto_rng *tfm, const u8 *src, unsigned int slen, u8 *dst, unsigned int dlen) { … } static int exynos_rng_seed(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) { … } static int exynos_rng_kcapi_init(struct crypto_tfm *tfm) { … } static struct rng_alg exynos_rng_alg = …; static int exynos_rng_probe(struct platform_device *pdev) { … } static void exynos_rng_remove(struct platform_device *pdev) { … } static int __maybe_unused exynos_rng_suspend(struct device *dev) { … } static int __maybe_unused exynos_rng_resume(struct device *dev) { … } static SIMPLE_DEV_PM_OPS(exynos_rng_pm_ops, exynos_rng_suspend, exynos_rng_resume); static const struct of_device_id exynos_rng_dt_match[] = …; MODULE_DEVICE_TABLE(of, exynos_rng_dt_match); static struct platform_driver exynos_rng_driver = …; module_platform_driver(…) …; MODULE_DESCRIPTION(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …;
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