周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Ingenic True Random Number Generator driver |
| 4 | * Copyright (c) 2019 漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com> |
| 5 | * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com> |
| 6 | */ |
| 7 | |
| 8 | #include <linux/clk.h> |
| 9 | #include <linux/err.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/hw_random.h> |
| 12 | #include <linux/io.h> |
| 13 | #include <linux/iopoll.h> |
Rob Herring | 0788257 | 2023-07-28 07:48:27 -0600 | [diff] [blame] | 14 | #include <linux/mod_devicetable.h> |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 15 | #include <linux/module.h> |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/slab.h> |
| 18 | |
| 19 | /* DTRNG register offsets */ |
| 20 | #define TRNG_REG_CFG_OFFSET 0x00 |
| 21 | #define TRNG_REG_RANDOMNUM_OFFSET 0x04 |
| 22 | #define TRNG_REG_STATUS_OFFSET 0x08 |
| 23 | |
| 24 | /* bits within the CFG register */ |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 25 | #define CFG_GEN_EN BIT(0) |
| 26 | |
| 27 | /* bits within the STATUS register */ |
| 28 | #define STATUS_RANDOM_RDY BIT(0) |
| 29 | |
| 30 | struct ingenic_trng { |
| 31 | void __iomem *base; |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 32 | struct hwrng rng; |
| 33 | }; |
| 34 | |
| 35 | static int ingenic_trng_init(struct hwrng *rng) |
| 36 | { |
| 37 | struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng); |
| 38 | unsigned int ctrl; |
| 39 | |
| 40 | ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET); |
| 41 | ctrl |= CFG_GEN_EN; |
| 42 | writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET); |
| 43 | |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 47 | static void ingenic_trng_cleanup(struct hwrng *rng) |
| 48 | { |
| 49 | struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng); |
| 50 | unsigned int ctrl; |
| 51 | |
| 52 | ctrl = readl(trng->base + TRNG_REG_CFG_OFFSET); |
| 53 | ctrl &= ~CFG_GEN_EN; |
| 54 | writel(ctrl, trng->base + TRNG_REG_CFG_OFFSET); |
| 55 | } |
| 56 | |
| 57 | static int ingenic_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait) |
| 58 | { |
| 59 | struct ingenic_trng *trng = container_of(rng, struct ingenic_trng, rng); |
| 60 | u32 *data = buf; |
| 61 | u32 status; |
| 62 | int ret; |
| 63 | |
| 64 | ret = readl_poll_timeout(trng->base + TRNG_REG_STATUS_OFFSET, status, |
| 65 | status & STATUS_RANDOM_RDY, 10, 1000); |
| 66 | if (ret == -ETIMEDOUT) { |
| 67 | pr_err("%s: Wait for DTRNG data ready timeout\n", __func__); |
| 68 | return ret; |
| 69 | } |
| 70 | |
| 71 | *data = readl(trng->base + TRNG_REG_RANDOMNUM_OFFSET); |
| 72 | |
| 73 | return 4; |
| 74 | } |
| 75 | |
| 76 | static int ingenic_trng_probe(struct platform_device *pdev) |
| 77 | { |
| 78 | struct ingenic_trng *trng; |
Martin Kaiser | e4ab6e7 | 2023-07-10 22:27:30 +0200 | [diff] [blame] | 79 | struct clk *clk; |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 80 | int ret; |
| 81 | |
| 82 | trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL); |
| 83 | if (!trng) |
| 84 | return -ENOMEM; |
| 85 | |
| 86 | trng->base = devm_platform_ioremap_resource(pdev, 0); |
Martin Kaiser | 6257490 | 2023-07-10 22:27:31 +0200 | [diff] [blame] | 87 | if (IS_ERR(trng->base)) |
| 88 | return dev_err_probe(&pdev->dev, PTR_ERR(trng->base), |
| 89 | "%s: Failed to map DTRNG registers\n", __func__); |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 90 | |
Martin Kaiser | e4ab6e7 | 2023-07-10 22:27:30 +0200 | [diff] [blame] | 91 | clk = devm_clk_get_enabled(&pdev->dev, NULL); |
Martin Kaiser | 6257490 | 2023-07-10 22:27:31 +0200 | [diff] [blame] | 92 | if (IS_ERR(clk)) |
| 93 | return dev_err_probe(&pdev->dev, PTR_ERR(clk), |
| 94 | "%s: Cannot get and enable DTRNG clock\n", __func__); |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 95 | |
| 96 | trng->rng.name = pdev->name; |
| 97 | trng->rng.init = ingenic_trng_init; |
| 98 | trng->rng.cleanup = ingenic_trng_cleanup; |
| 99 | trng->rng.read = ingenic_trng_read; |
| 100 | |
Martin Kaiser | a40be5e | 2023-07-10 22:27:33 +0200 | [diff] [blame] | 101 | ret = devm_hwrng_register(&pdev->dev, &trng->rng); |
Martin Kaiser | 6257490 | 2023-07-10 22:27:31 +0200 | [diff] [blame] | 102 | if (ret) |
| 103 | return dev_err_probe(&pdev->dev, ret, "Failed to register hwrng\n"); |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 104 | |
| 105 | platform_set_drvdata(pdev, trng); |
| 106 | |
| 107 | dev_info(&pdev->dev, "Ingenic DTRNG driver registered\n"); |
| 108 | return 0; |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 109 | } |
| 110 | |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 111 | static const struct of_device_id ingenic_trng_of_match[] = { |
| 112 | { .compatible = "ingenic,x1830-dtrng" }, |
| 113 | { /* sentinel */ } |
| 114 | }; |
| 115 | MODULE_DEVICE_TABLE(of, ingenic_trng_of_match); |
| 116 | |
| 117 | static struct platform_driver ingenic_trng_driver = { |
| 118 | .probe = ingenic_trng_probe, |
周琰杰 (Zhou Yanjie) | 406346d | 2020-09-14 00:10:21 +0800 | [diff] [blame] | 119 | .driver = { |
| 120 | .name = "ingenic-trng", |
| 121 | .of_match_table = ingenic_trng_of_match, |
| 122 | }, |
| 123 | }; |
| 124 | |
| 125 | module_platform_driver(ingenic_trng_driver); |
| 126 | |
| 127 | MODULE_LICENSE("GPL"); |
| 128 | MODULE_AUTHOR("漆鹏振 (Qi Pengzhen) <aric.pzqi@ingenic.com>"); |
| 129 | MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>"); |
| 130 | MODULE_DESCRIPTION("Ingenic True Random Number Generator driver"); |