summaryrefslogtreecommitdiff
path: root/drivers/char
diff options
context:
space:
mode:
authorKefeng Wang <wangkefeng.wang@huawei.com>2016-04-13 13:11:28 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2016-04-15 17:36:36 +0300
commitafc39d6e89b4f410f511f03dc6de8dc1d4952d42 (patch)
tree6ab5bee42fdebde12258e80dfd2626b5b962942e /drivers/char
parentc7995ee7ff60c1973a3a63e35b41c2393f47f760 (diff)
downloadlinux-afc39d6e89b4f410f511f03dc6de8dc1d4952d42.tar.xz
hwrng: hisi - Add support for Hisilicon SoC RNG
This adds the Hisilicon Random Number Generator(RNG) support, which is found in Hip04 and Hip05 soc. Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/hw_random/Kconfig13
-rw-r--r--drivers/char/hw_random/Makefile1
-rw-r--r--drivers/char/hw_random/hisi-rng.c126
3 files changed, 140 insertions, 0 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 3c5be60befce..c76a88da8d04 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -334,6 +334,19 @@ config HW_RANDOM_TPM
If unsure, say Y.
+config HW_RANDOM_HISI
+ tristate "Hisilicon Random Number Generator support"
+ depends on HW_RANDOM && ARCH_HISI
+ default HW_RANDOM
+ ---help---
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on Hisilicon Hip04 and Hip05 SoC.
+
+ To compile this driver as a module, choose M here: the
+ module will be called hisi-rng.
+
+ If unsure, say Y.
+
config HW_RANDOM_MSM
tristate "Qualcomm SoCs Random Number Generator support"
depends on HW_RANDOM && ARCH_QCOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index f5a6fa7690e7..e09305bb89e1 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o
+obj-$(CONFIG_HW_RANDOM_HISI) += hisi-rng.o
obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o
obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o
diff --git a/drivers/char/hw_random/hisi-rng.c b/drivers/char/hw_random/hisi-rng.c
new file mode 100644
index 000000000000..40d96572c591
--- /dev/null
+++ b/drivers/char/hw_random/hisi-rng.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2016 HiSilicon Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/random.h>
+
+#define RNG_SEED 0x0
+#define RNG_CTRL 0x4
+ #define RNG_SEED_SEL BIT(2)
+ #define RNG_RING_EN BIT(1)
+ #define RNG_EN BIT(0)
+#define RNG_RAN_NUM 0x10
+#define RNG_PHY_SEED 0x14
+
+#define to_hisi_rng(p) container_of(p, struct hisi_rng, rng)
+
+static int seed_sel;
+module_param(seed_sel, int, S_IRUGO);
+MODULE_PARM_DESC(seed_sel, "Auto reload seed. 0, use LFSR(default); 1, use ring oscillator.");
+
+struct hisi_rng {
+ void __iomem *base;
+ struct hwrng rng;
+};
+
+static int hisi_rng_init(struct hwrng *rng)
+{
+ struct hisi_rng *hrng = to_hisi_rng(rng);
+ int val = RNG_EN;
+ u32 seed;
+
+ /* get a random number as initial seed */
+ get_random_bytes(&seed, sizeof(seed));
+
+ writel_relaxed(seed, hrng->base + RNG_SEED);
+
+ /**
+ * The seed is reload periodically, there are two choice
+ * of seeds, default seed using the value from LFSR, or
+ * will use seed generated by ring oscillator.
+ */
+ if (seed_sel == 1)
+ val |= RNG_RING_EN | RNG_SEED_SEL;
+
+ writel_relaxed(val, hrng->base + RNG_CTRL);
+ return 0;
+}
+
+static void hisi_rng_cleanup(struct hwrng *rng)
+{
+ struct hisi_rng *hrng = to_hisi_rng(rng);
+
+ writel_relaxed(0, hrng->base + RNG_CTRL);
+}
+
+static int hisi_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+ struct hisi_rng *hrng = to_hisi_rng(rng);
+ u32 *data = buf;
+
+ *data = readl_relaxed(hrng->base + RNG_RAN_NUM);
+ return 4;
+}
+
+static int hisi_rng_probe(struct platform_device *pdev)
+{
+ struct hisi_rng *rng;
+ struct resource *res;
+ int ret;
+
+ rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
+ if (!rng)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, rng);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ rng->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(rng->base))
+ return PTR_ERR(rng->base);
+
+ rng->rng.name = pdev->name;
+ rng->rng.init = hisi_rng_init;
+ rng->rng.cleanup = hisi_rng_cleanup;
+ rng->rng.read = hisi_rng_read;
+
+ ret = devm_hwrng_register(&pdev->dev, &rng->rng);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register hwrng\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id hisi_rng_dt_ids[] = {
+ { .compatible = "hisilicon,hip04-rng" },
+ { .compatible = "hisilicon,hip05-rng" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, hisi_rng_dt_ids);
+
+static struct platform_driver hisi_rng_driver = {
+ .probe = hisi_rng_probe,
+ .driver = {
+ .name = "hisi-rng",
+ .of_match_table = of_match_ptr(hisi_rng_dt_ids),
+ },
+};
+
+module_platform_driver(hisi_rng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Kefeng Wang <wangkefeng.wang@huawei>");
+MODULE_DESCRIPTION("Hisilicon random number generator driver");