1190873a0S周琰杰 (Zhou Yanjie) // SPDX-License-Identifier: GPL-2.0
2190873a0S周琰杰 (Zhou Yanjie) /*
3190873a0S周琰杰 (Zhou Yanjie) * Ingenic Random Number Generator driver
4190873a0S周琰杰 (Zhou Yanjie) * Copyright (c) 2017 PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
5190873a0S周琰杰 (Zhou Yanjie) * Copyright (c) 2020 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
6190873a0S周琰杰 (Zhou Yanjie) */
7190873a0S周琰杰 (Zhou Yanjie)
8190873a0S周琰杰 (Zhou Yanjie) #include <linux/err.h>
9190873a0S周琰杰 (Zhou Yanjie) #include <linux/kernel.h>
10190873a0S周琰杰 (Zhou Yanjie) #include <linux/hw_random.h>
11190873a0S周琰杰 (Zhou Yanjie) #include <linux/io.h>
12190873a0S周琰杰 (Zhou Yanjie) #include <linux/iopoll.h>
13190873a0S周琰杰 (Zhou Yanjie) #include <linux/module.h>
14190873a0S周琰杰 (Zhou Yanjie) #include <linux/of_device.h>
15190873a0S周琰杰 (Zhou Yanjie) #include <linux/platform_device.h>
16190873a0S周琰杰 (Zhou Yanjie) #include <linux/slab.h>
17190873a0S周琰杰 (Zhou Yanjie)
18190873a0S周琰杰 (Zhou Yanjie) /* RNG register offsets */
19190873a0S周琰杰 (Zhou Yanjie) #define RNG_REG_ERNG_OFFSET 0x0
20190873a0S周琰杰 (Zhou Yanjie) #define RNG_REG_RNG_OFFSET 0x4
21190873a0S周琰杰 (Zhou Yanjie)
22190873a0S周琰杰 (Zhou Yanjie) /* bits within the ERND register */
23190873a0S周琰杰 (Zhou Yanjie) #define ERNG_READY BIT(31)
24190873a0S周琰杰 (Zhou Yanjie) #define ERNG_ENABLE BIT(0)
25190873a0S周琰杰 (Zhou Yanjie)
26190873a0S周琰杰 (Zhou Yanjie) enum ingenic_rng_version {
27190873a0S周琰杰 (Zhou Yanjie) ID_JZ4780,
28190873a0S周琰杰 (Zhou Yanjie) ID_X1000,
29190873a0S周琰杰 (Zhou Yanjie) };
30190873a0S周琰杰 (Zhou Yanjie)
31190873a0S周琰杰 (Zhou Yanjie) /* Device associated memory */
32190873a0S周琰杰 (Zhou Yanjie) struct ingenic_rng {
33190873a0S周琰杰 (Zhou Yanjie) enum ingenic_rng_version version;
34190873a0S周琰杰 (Zhou Yanjie)
35190873a0S周琰杰 (Zhou Yanjie) void __iomem *base;
36190873a0S周琰杰 (Zhou Yanjie) struct hwrng rng;
37190873a0S周琰杰 (Zhou Yanjie) };
38190873a0S周琰杰 (Zhou Yanjie)
ingenic_rng_init(struct hwrng * rng)39190873a0S周琰杰 (Zhou Yanjie) static int ingenic_rng_init(struct hwrng *rng)
40190873a0S周琰杰 (Zhou Yanjie) {
41190873a0S周琰杰 (Zhou Yanjie) struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
42190873a0S周琰杰 (Zhou Yanjie)
43190873a0S周琰杰 (Zhou Yanjie) writel(ERNG_ENABLE, priv->base + RNG_REG_ERNG_OFFSET);
44190873a0S周琰杰 (Zhou Yanjie)
45190873a0S周琰杰 (Zhou Yanjie) return 0;
46190873a0S周琰杰 (Zhou Yanjie) }
47190873a0S周琰杰 (Zhou Yanjie)
ingenic_rng_cleanup(struct hwrng * rng)48190873a0S周琰杰 (Zhou Yanjie) static void ingenic_rng_cleanup(struct hwrng *rng)
49190873a0S周琰杰 (Zhou Yanjie) {
50190873a0S周琰杰 (Zhou Yanjie) struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
51190873a0S周琰杰 (Zhou Yanjie)
52190873a0S周琰杰 (Zhou Yanjie) writel(0, priv->base + RNG_REG_ERNG_OFFSET);
53190873a0S周琰杰 (Zhou Yanjie) }
54190873a0S周琰杰 (Zhou Yanjie)
ingenic_rng_read(struct hwrng * rng,void * buf,size_t max,bool wait)55190873a0S周琰杰 (Zhou Yanjie) static int ingenic_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
56190873a0S周琰杰 (Zhou Yanjie) {
57190873a0S周琰杰 (Zhou Yanjie) struct ingenic_rng *priv = container_of(rng, struct ingenic_rng, rng);
58190873a0S周琰杰 (Zhou Yanjie) u32 *data = buf;
59190873a0S周琰杰 (Zhou Yanjie) u32 status;
60190873a0S周琰杰 (Zhou Yanjie) int ret;
61190873a0S周琰杰 (Zhou Yanjie)
62190873a0S周琰杰 (Zhou Yanjie) if (priv->version >= ID_X1000) {
63190873a0S周琰杰 (Zhou Yanjie) ret = readl_poll_timeout(priv->base + RNG_REG_ERNG_OFFSET, status,
64190873a0S周琰杰 (Zhou Yanjie) status & ERNG_READY, 10, 1000);
65190873a0S周琰杰 (Zhou Yanjie) if (ret == -ETIMEDOUT) {
66190873a0S周琰杰 (Zhou Yanjie) pr_err("%s: Wait for RNG data ready timeout\n", __func__);
67190873a0S周琰杰 (Zhou Yanjie) return ret;
68190873a0S周琰杰 (Zhou Yanjie) }
69190873a0S周琰杰 (Zhou Yanjie) } else {
70190873a0S周琰杰 (Zhou Yanjie) /*
71190873a0S周琰杰 (Zhou Yanjie) * A delay is required so that the current RNG data is not bit shifted
72190873a0S周琰杰 (Zhou Yanjie) * version of previous RNG data which could happen if random data is
73190873a0S周琰杰 (Zhou Yanjie) * read continuously from this device.
74190873a0S周琰杰 (Zhou Yanjie) */
75190873a0S周琰杰 (Zhou Yanjie) udelay(20);
76190873a0S周琰杰 (Zhou Yanjie) }
77190873a0S周琰杰 (Zhou Yanjie)
78190873a0S周琰杰 (Zhou Yanjie) *data = readl(priv->base + RNG_REG_RNG_OFFSET);
79190873a0S周琰杰 (Zhou Yanjie)
80190873a0S周琰杰 (Zhou Yanjie) return 4;
81190873a0S周琰杰 (Zhou Yanjie) }
82190873a0S周琰杰 (Zhou Yanjie)
ingenic_rng_probe(struct platform_device * pdev)83190873a0S周琰杰 (Zhou Yanjie) static int ingenic_rng_probe(struct platform_device *pdev)
84190873a0S周琰杰 (Zhou Yanjie) {
85190873a0S周琰杰 (Zhou Yanjie) struct ingenic_rng *priv;
86190873a0S周琰杰 (Zhou Yanjie) int ret;
87190873a0S周琰杰 (Zhou Yanjie)
88190873a0S周琰杰 (Zhou Yanjie) priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
89190873a0S周琰杰 (Zhou Yanjie) if (!priv)
90190873a0S周琰杰 (Zhou Yanjie) return -ENOMEM;
91190873a0S周琰杰 (Zhou Yanjie)
92190873a0S周琰杰 (Zhou Yanjie) priv->base = devm_platform_ioremap_resource(pdev, 0);
93190873a0S周琰杰 (Zhou Yanjie) if (IS_ERR(priv->base)) {
94190873a0S周琰杰 (Zhou Yanjie) pr_err("%s: Failed to map RNG registers\n", __func__);
9511a954eeSWei Yongjun return PTR_ERR(priv->base);
96190873a0S周琰杰 (Zhou Yanjie) }
97190873a0S周琰杰 (Zhou Yanjie)
98*1ce1cd82SRob Herring priv->version = (enum ingenic_rng_version)(uintptr_t)of_device_get_match_data(&pdev->dev);
99190873a0S周琰杰 (Zhou Yanjie)
100190873a0S周琰杰 (Zhou Yanjie) priv->rng.name = pdev->name;
101190873a0S周琰杰 (Zhou Yanjie) priv->rng.init = ingenic_rng_init;
102190873a0S周琰杰 (Zhou Yanjie) priv->rng.cleanup = ingenic_rng_cleanup;
103190873a0S周琰杰 (Zhou Yanjie) priv->rng.read = ingenic_rng_read;
104190873a0S周琰杰 (Zhou Yanjie)
105190873a0S周琰杰 (Zhou Yanjie) ret = hwrng_register(&priv->rng);
106190873a0S周琰杰 (Zhou Yanjie) if (ret) {
107190873a0S周琰杰 (Zhou Yanjie) dev_err(&pdev->dev, "Failed to register hwrng\n");
10811a954eeSWei Yongjun return ret;
109190873a0S周琰杰 (Zhou Yanjie) }
110190873a0S周琰杰 (Zhou Yanjie)
111190873a0S周琰杰 (Zhou Yanjie) platform_set_drvdata(pdev, priv);
112190873a0S周琰杰 (Zhou Yanjie)
113190873a0S周琰杰 (Zhou Yanjie) dev_info(&pdev->dev, "Ingenic RNG driver registered\n");
114190873a0S周琰杰 (Zhou Yanjie) return 0;
115190873a0S周琰杰 (Zhou Yanjie) }
116190873a0S周琰杰 (Zhou Yanjie)
ingenic_rng_remove(struct platform_device * pdev)117190873a0S周琰杰 (Zhou Yanjie) static int ingenic_rng_remove(struct platform_device *pdev)
118190873a0S周琰杰 (Zhou Yanjie) {
119190873a0S周琰杰 (Zhou Yanjie) struct ingenic_rng *priv = platform_get_drvdata(pdev);
120190873a0S周琰杰 (Zhou Yanjie)
121190873a0S周琰杰 (Zhou Yanjie) hwrng_unregister(&priv->rng);
122190873a0S周琰杰 (Zhou Yanjie)
123190873a0S周琰杰 (Zhou Yanjie) writel(0, priv->base + RNG_REG_ERNG_OFFSET);
124190873a0S周琰杰 (Zhou Yanjie)
125190873a0S周琰杰 (Zhou Yanjie) return 0;
126190873a0S周琰杰 (Zhou Yanjie) }
127190873a0S周琰杰 (Zhou Yanjie)
128190873a0S周琰杰 (Zhou Yanjie) static const struct of_device_id ingenic_rng_of_match[] = {
129190873a0S周琰杰 (Zhou Yanjie) { .compatible = "ingenic,jz4780-rng", .data = (void *) ID_JZ4780 },
130190873a0S周琰杰 (Zhou Yanjie) { .compatible = "ingenic,x1000-rng", .data = (void *) ID_X1000 },
131190873a0S周琰杰 (Zhou Yanjie) { /* sentinel */ }
132190873a0S周琰杰 (Zhou Yanjie) };
133190873a0S周琰杰 (Zhou Yanjie) MODULE_DEVICE_TABLE(of, ingenic_rng_of_match);
134190873a0S周琰杰 (Zhou Yanjie)
135190873a0S周琰杰 (Zhou Yanjie) static struct platform_driver ingenic_rng_driver = {
136190873a0S周琰杰 (Zhou Yanjie) .probe = ingenic_rng_probe,
137190873a0S周琰杰 (Zhou Yanjie) .remove = ingenic_rng_remove,
138190873a0S周琰杰 (Zhou Yanjie) .driver = {
139190873a0S周琰杰 (Zhou Yanjie) .name = "ingenic-rng",
140190873a0S周琰杰 (Zhou Yanjie) .of_match_table = ingenic_rng_of_match,
141190873a0S周琰杰 (Zhou Yanjie) },
142190873a0S周琰杰 (Zhou Yanjie) };
143190873a0S周琰杰 (Zhou Yanjie)
144190873a0S周琰杰 (Zhou Yanjie) module_platform_driver(ingenic_rng_driver);
145190873a0S周琰杰 (Zhou Yanjie)
146190873a0S周琰杰 (Zhou Yanjie) MODULE_LICENSE("GPL");
147190873a0S周琰杰 (Zhou Yanjie) MODULE_AUTHOR("PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>");
148190873a0S周琰杰 (Zhou Yanjie) MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>");
149190873a0S周琰杰 (Zhou Yanjie) MODULE_DESCRIPTION("Ingenic Random Number Generator driver");
150