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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 | // SPDX-License-Identifier: GPL-2.0 /* * Ingenic True Random Number Generator driver * Copyright (c) 2019 漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com> * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com> */ #include <linux/clk.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/hw_random.h> #include <linux/io.h> #include <linux/iopoll.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/slab.h> /* DTRNG register offsets */ #define TRNG_REG_CFG_OFFSET 0x00 #define TRNG_REG_RANDOMNUM_OFFSET 0x04 #define TRNG_REG_STATUS_OFFSET 0x08 /* bits within the CFG register */ #define CFG_RDY_CLR BIT(12) #define CFG_INT_MASK BIT(11) #define CFG_GEN_EN BIT(0) /* bits within the STATUS register */ #define STATUS_RANDOM_RDY BIT(0) struct ingenic_trng { void __iomem *base; struct clk *clk; struct hwrng rng; }; static int ingenic_trng_init(struct hwrng *rng) { struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng); unsigned int ctrl; ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET); ctrl |= CFG_GEN_EN; writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET); return 0; } static void ingenic_trng_cleanup(struct hwrng *rng) { struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng); unsigned int ctrl; ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET); ctrl &= ~CFG_GEN_EN; writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET); } static int ingenic_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng); u32 *data = buf; u32 status; int ret; ret = readl_poll_timeout(trng->base + TRNG_REG_STATUS_OFFSET, status, status & STATUS_RANDOM_RDY, 10, 1000); if (ret == -ETIMEDOUT) { pr_err("%s: Wait for DTRNG data ready timeout\n", __func__); return ret; } *data = readl(trng->base + TRNG_REG_RANDOMNUM_OFFSET); return 4; } static int ingenic_trng_probe(struct platform_device *pdev) { struct ingenic_trng *trng; int ret; trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL); if (!trng) return -ENOMEM; trng->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(trng->base)) { pr_err("%s: Failed to map DTRNG registers\n", __func__); ret = PTR_ERR(trng->base); return PTR_ERR(trng->base); } trng->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(trng->clk)) { ret = PTR_ERR(trng->clk); pr_crit("%s: Cannot get DTRNG clock\n", __func__); return PTR_ERR(trng->clk); } ret = clk_prepare_enable(trng->clk); if (ret) { pr_crit("%s: Unable to enable DTRNG clock\n", __func__); return ret; } trng->rng.name = pdev->name; trng->rng.init = ingenic_trng_init; trng->rng.cleanup = ingenic_trng_cleanup; trng->rng.read = ingenic_trng_read; ret = hwrng_register(&trng->rng); if (ret) { dev_err(&pdev->dev, "Failed to register hwrng\n"); goto err_unprepare_clk; } platform_set_drvdata(pdev, trng); dev_info(&pdev->dev, "Ingenic DTRNG driver registered\n"); return 0; err_unprepare_clk: clk_disable_unprepare(trng->clk); return ret; } static int ingenic_trng_remove(struct platform_device *pdev) { struct ingenic_trng *trng = platform_get_drvdata(pdev); unsigned int ctrl; hwrng_unregister(&trng->rng); ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET); ctrl &= ~CFG_GEN_EN; writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET); clk_disable_unprepare(trng->clk); return 0; } static const struct of_device_id ingenic_trng_of_match[] = { { .compatible = "ingenic,x1830-dtrng" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, ingenic_trng_of_match); static struct platform_driver ingenic_trng_driver = { .probe = ingenic_trng_probe, .remove = ingenic_trng_remove, .driver = { .name = "ingenic-trng", .of_match_table = ingenic_trng_of_match, }, }; module_platform_driver(ingenic_trng_driver); MODULE_LICENSE("GPL"); MODULE_AUTHOR("漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com>"); MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>"); MODULE_DESCRIPTION("Ingenic True Random Number Generator driver"); |