^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (c) 2010-2012 Broadcom. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (c) 2013 Lubomir Rintel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/hw_random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/of_address.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/of_platform.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/printk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/clk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #define RNG_CTRL 0x0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define RNG_STATUS 0x4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #define RNG_DATA 0x8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #define RNG_INT_MASK 0x10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) /* enable rng */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #define RNG_RBGEN 0x1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /* the initial numbers generated are "less random" so will be discarded */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #define RNG_WARMUP_COUNT 0x40000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #define RNG_INT_OFF 0x1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct bcm2835_rng_priv {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct hwrng rng;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) void __iomem *base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) bool mask_interrupts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) struct clk *clk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) return container_of(rng, struct bcm2835_rng_priv, rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /* MIPS chips strapped for BE will automagically configure the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * peripheral registers for CPU-native byte order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return __raw_readl(priv->base + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return readl(priv->base + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) u32 offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) __raw_writel(val, priv->base + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) writel(val, priv->base + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) bool wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) struct bcm2835_rng_priv *priv = to_rng_priv(rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) u32 max_words = max / sizeof(u32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) u32 num_words, count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) if (!wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) cpu_relax();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) num_words = rng_readl(priv, RNG_STATUS) >> 24;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (num_words > max_words)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) num_words = max_words;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) for (count = 0; count < num_words; count++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) ((u32 *)buf)[count] = rng_readl(priv, RNG_DATA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return num_words * sizeof(u32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) static int bcm2835_rng_init(struct hwrng *rng)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) struct bcm2835_rng_priv *priv = to_rng_priv(rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) u32 val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) if (!IS_ERR(priv->clk)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) ret = clk_prepare_enable(priv->clk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (priv->mask_interrupts) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) /* mask the interrupt */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) val = rng_readl(priv, RNG_INT_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) val |= RNG_INT_OFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) rng_writel(priv, val, RNG_INT_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) /* set warm-up count & enable */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) rng_writel(priv, RNG_RBGEN, RNG_CTRL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) static void bcm2835_rng_cleanup(struct hwrng *rng)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) struct bcm2835_rng_priv *priv = to_rng_priv(rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /* disable rng hardware */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) rng_writel(priv, 0, RNG_CTRL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (!IS_ERR(priv->clk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) clk_disable_unprepare(priv->clk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) struct bcm2835_rng_of_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) bool mask_interrupts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) static const struct bcm2835_rng_of_data nsp_rng_of_data = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) .mask_interrupts = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) static const struct of_device_id bcm2835_rng_of_match[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) { .compatible = "brcm,bcm2835-rng"},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) { .compatible = "brcm,bcm-nsp-rng", .data = &nsp_rng_of_data },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) { .compatible = "brcm,bcm5301x-rng", .data = &nsp_rng_of_data },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) { .compatible = "brcm,bcm6368-rng"},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static int bcm2835_rng_probe(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) const struct bcm2835_rng_of_data *of_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) struct device *dev = &pdev->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) const struct of_device_id *rng_id;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) struct bcm2835_rng_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) if (!priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) platform_set_drvdata(pdev, priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /* map peripheral */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) priv->base = devm_platform_ioremap_resource(pdev, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (IS_ERR(priv->base))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) return PTR_ERR(priv->base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /* Clock is optional on most platforms */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) priv->clk = devm_clk_get(dev, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) if (PTR_ERR(priv->clk) == -EPROBE_DEFER)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) return -EPROBE_DEFER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) priv->rng.name = pdev->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) priv->rng.init = bcm2835_rng_init;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) priv->rng.read = bcm2835_rng_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) priv->rng.cleanup = bcm2835_rng_cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) if (dev_of_node(dev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) rng_id = of_match_node(bcm2835_rng_of_match, dev->of_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) if (!rng_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) /* Check for rng init function, execute it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) of_data = rng_id->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) if (of_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) priv->mask_interrupts = of_data->mask_interrupts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) /* register driver */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) err = devm_hwrng_register(dev, &priv->rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) dev_err(dev, "hwrng registration failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) dev_info(dev, "hwrng registered\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) static const struct platform_device_id bcm2835_rng_devtype[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) { .name = "bcm2835-rng" },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) { .name = "bcm63xx-rng" },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) { /* sentinel */ }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) MODULE_DEVICE_TABLE(platform, bcm2835_rng_devtype);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) static struct platform_driver bcm2835_rng_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) .name = "bcm2835-rng",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) .of_match_table = bcm2835_rng_of_match,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) .probe = bcm2835_rng_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) .id_table = bcm2835_rng_devtype,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) module_platform_driver(bcm2835_rng_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) MODULE_DESCRIPTION("BCM2835 Random Number Generator (RNG) driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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