diff options
Diffstat (limited to 'drivers/crypto/hisilicon/trng/trng-stb.c')
-rw-r--r-- | drivers/crypto/hisilicon/trng/trng-stb.c | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/drivers/crypto/hisilicon/trng/trng-stb.c b/drivers/crypto/hisilicon/trng/trng-stb.c deleted file mode 100644 index 29200a7d3d81..000000000000 --- a/drivers/crypto/hisilicon/trng/trng-stb.c +++ /dev/null @@ -1,176 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later OR MIT -/* - * Device driver for True RNG in HiSTB SoCs - * - * Copyright (c) 2023 David Yang - */ - -#include <crypto/internal/rng.h> -#include <linux/device.h> -#include <linux/err.h> -#include <linux/hw_random.h> -#include <linux/io.h> -#include <linux/iopoll.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/mutex.h> -#include <linux/of_device.h> - -#define HISTB_TRNG_CTRL 0x0 -#define RNG_SOURCE GENMASK(1, 0) -#define DROP_ENABLE BIT(5) -#define POST_PROCESS_ENABLE BIT(7) -#define POST_PROCESS_DEPTH GENMASK(15, 8) -#define HISTB_TRNG_NUMBER 0x4 -#define HISTB_TRNG_STAT 0x8 -#define DATA_COUNT GENMASK(2, 0) /* max 4 */ - -struct histb_trng_priv { - struct hwrng rng; - void __iomem *base; -}; - -/* - * Observed: - * depth = 1 -> ~1ms - * depth = 255 -> ~16ms - */ -static int histb_trng_wait(void __iomem *base) -{ - u32 val; - - return readl_relaxed_poll_timeout(base + HISTB_TRNG_STAT, val, - val & DATA_COUNT, 1000, 30 * 1000); -} - -static void histb_trng_init(void __iomem *base, unsigned int depth) -{ - u32 val; - - val = readl_relaxed(base + HISTB_TRNG_CTRL); - - val &= ~RNG_SOURCE; - val |= 2; - - val &= ~POST_PROCESS_DEPTH; - val |= min(depth, 0xffu) << 8; - - val |= POST_PROCESS_ENABLE; - val |= DROP_ENABLE; - - writel_relaxed(val, base + HISTB_TRNG_CTRL); -} - -static int histb_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) -{ - struct histb_trng_priv *priv = container_of(rng, typeof(*priv), rng); - void __iomem *base = priv->base; - - for (int i = 0; i < max; i += sizeof(u32)) { - if (!(readl_relaxed(base + HISTB_TRNG_STAT) & DATA_COUNT)) { - if (!wait) - return i; - if (histb_trng_wait(base)) { - pr_err("failed to generate random number, generated %d\n", - i); - return i ? i : -ETIMEDOUT; - } - } - *(u32 *) (data + i) = readl_relaxed(base + HISTB_TRNG_NUMBER); - } - - return max; -} - -static unsigned int histb_trng_get_depth(void __iomem *base) -{ - return (readl_relaxed(base + HISTB_TRNG_CTRL) & POST_PROCESS_DEPTH) >> 8; -} - -static ssize_t -depth_show(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct histb_trng_priv *priv = dev_get_drvdata(dev); - void __iomem *base = priv->base; - - return sprintf(buf, "%d\n", histb_trng_get_depth(base)); -} - -static ssize_t -depth_store(struct device *dev, struct device_attribute *attr, - const char *buf, size_t count) -{ - struct histb_trng_priv *priv = dev_get_drvdata(dev); - void __iomem *base = priv->base; - unsigned int depth; - - if (kstrtouint(buf, 0, &depth)) - return -ERANGE; - - histb_trng_init(base, depth); - return count; -} - -static DEVICE_ATTR_RW(depth); - -static struct attribute *histb_trng_attrs[] = { - &dev_attr_depth.attr, - NULL, -}; - -ATTRIBUTE_GROUPS(histb_trng); - -static int histb_trng_probe(struct platform_device *pdev) -{ - struct device *dev = &pdev->dev; - struct histb_trng_priv *priv; - void __iomem *base; - int ret; - - priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); - if (!priv) - return -ENOMEM; - - base = devm_platform_ioremap_resource(pdev, 0); - if (IS_ERR(base)) - return -ENOMEM; - - histb_trng_init(base, 144); - if (histb_trng_wait(base)) { - dev_err(dev, "cannot bring up device\n"); - return -ENODEV; - } - - priv->base = base; - priv->rng.name = pdev->name; - priv->rng.read = histb_trng_read; - ret = devm_hwrng_register(dev, &priv->rng); - if (ret) { - dev_err(dev, "failed to register hwrng: %d\n", ret); - return ret; - } - - platform_set_drvdata(pdev, priv); - dev_set_drvdata(dev, priv); - return 0; -} - -static const struct of_device_id histb_trng_of_match[] = { - { .compatible = "hisilicon,histb-trng", }, - { } -}; - -static struct platform_driver histb_trng_driver = { - .probe = histb_trng_probe, - .driver = { - .name = "histb-trng", - .of_match_table = histb_trng_of_match, - .dev_groups = histb_trng_groups, - }, -}; - -module_platform_driver(histb_trng_driver); - -MODULE_DESCRIPTION("HiSTB True RNG"); -MODULE_LICENSE("Dual MIT/GPL"); -MODULE_AUTHOR("David Yang <mmyangfl@gmail.com>"); |