HiSTB TRNG are found on some HiSilicon STB SoCs.
Signed-off-by: David Yang <mmyangfl@xxxxxxxxx>
---
v2: fix typo
v3: add option for post process depth, adjust timeout
drivers/crypto/hisilicon/Kconfig | 7 +
drivers/crypto/hisilicon/Makefile | 2 +-
drivers/crypto/hisilicon/trng/Makefile | 3 +
drivers/crypto/hisilicon/trng/trng-stb.c | 171 +++++++++++++++++++++++
4 files changed, 182 insertions(+), 1 deletion(-)
create mode 100644 drivers/crypto/hisilicon/trng/trng-stb.c
diff --git a/drivers/crypto/hisilicon/Kconfig b/drivers/crypto/hisilicon/Kconfig
index 4137a8bf131f..e8690c223584 100644
--- a/drivers/crypto/hisilicon/Kconfig
+++ b/drivers/crypto/hisilicon/Kconfig
@@ -82,3 +82,10 @@ config CRYPTO_DEV_HISI_TRNG
select CRYPTO_RNG
help
Support for HiSilicon TRNG Driver.
+
+config CRYPTO_DEV_HISTB_TRNG
+ tristate "Support for HiSTB TRNG Driver"
+ depends on ARCH_HISI || COMPILE_TEST
+ select HW_RANDOM
+ help
+ Support for HiSTB TRNG Driver.
diff --git a/drivers/crypto/hisilicon/Makefile b/drivers/crypto/hisilicon/Makefile
index 8595a5a5d228..fc51e0edec69 100644
--- a/drivers/crypto/hisilicon/Makefile
+++ b/drivers/crypto/hisilicon/Makefile
@@ -5,4 +5,4 @@ obj-$(CONFIG_CRYPTO_DEV_HISI_SEC2) += sec2/
obj-$(CONFIG_CRYPTO_DEV_HISI_QM) += hisi_qm.o
hisi_qm-objs = qm.o sgl.o debugfs.o
obj-$(CONFIG_CRYPTO_DEV_HISI_ZIP) += zip/
-obj-$(CONFIG_CRYPTO_DEV_HISI_TRNG) += trng/
+obj-y += trng/
diff --git a/drivers/crypto/hisilicon/trng/Makefile b/drivers/crypto/hisilicon/trng/Makefile
index d909079f351c..cf20b057c66b 100644
--- a/drivers/crypto/hisilicon/trng/Makefile
+++ b/drivers/crypto/hisilicon/trng/Makefile
@@ -1,2 +1,5 @@
obj-$(CONFIG_CRYPTO_DEV_HISI_TRNG) += hisi-trng-v2.o
hisi-trng-v2-objs = trng.o
+
+obj-$(CONFIG_CRYPTO_DEV_HISTB_TRNG) += histb-trng.o
+histb-trng-objs += trng-stb.o
diff --git a/drivers/crypto/hisilicon/trng/trng-stb.c b/drivers/crypto/hisilicon/trng/trng-stb.c
new file mode 100644
index 000000000000..44ee071fd348
--- /dev/null
+++ b/drivers/crypto/hisilicon/trng/trng-stb.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Device driver for True RNG in HiSTB SoCs
+ *
+ * Copyright (c) 2023 David Yang
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/timekeeping.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 */
+
+/*
+ * Observed:
+ * depth = 1 -> ~1ms
+ * depth = 255 -> ~16ms
+ */
+static int histb_trng_wait(struct hwrng *rng)
+{
+ void __iomem *base = (void __iomem *) rng->priv;
+ u32 val;
+
+ return readl_relaxed_poll_timeout(base + HISTB_TRNG_STAT,
+ val, val & DATA_COUNT, 1000,
+ 30 * 1000);
+}
+
+static void histb_trng_init(struct hwrng *rng, unsigned int depth)
+{
+ void __iomem *base = (void __iomem *) rng->priv;
+ 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)
+{
+ void __iomem *base = (void __iomem *) rng->priv;
+ size_t i;
+
+ for (i = 0; i < max; i += sizeof(u32)) {
+ if (!(readl_relaxed(base + HISTB_TRNG_STAT) & DATA_COUNT)) {
+ if (!wait)
+ break;
+ if (histb_trng_wait(rng)) {
+ pr_err("failed to generate random number, generated %zu\n",
+ i);
+ if (i)
+ break;
+ return -ETIMEDOUT;
+ }
+ }
+ *(u32 *) (data + i) = readl_relaxed(base + HISTB_TRNG_NUMBER);
+ }
+
+ return i;
+}
+
+static unsigned int histb_trng_get_depth(struct hwrng *rng)
+{
+ void __iomem *base = (void __iomem *) rng->priv;
+ u32 val = readl_relaxed(base + HISTB_TRNG_CTRL);
+
+ return (val & POST_PROCESS_DEPTH) >> 8;
+}
+
+static ssize_t
+depth_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct hwrng *rng = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%d\n", histb_trng_get_depth(rng));
+}
+
+static ssize_t
+depth_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct hwrng *rng = dev_get_drvdata(dev);
+ unsigned int depth;
+
+ if (kstrtouint(buf, 0, &depth))
+ return -ERANGE;
+
+ histb_trng_init(rng, 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 hwrng *rng;
+ int ret;
+
+ rng = devm_kzalloc(dev, sizeof(*rng), GFP_KERNEL);
+ if (!rng)
+ return -ENOMEM;
+
+ rng->priv = (unsigned long) devm_platform_ioremap_resource(pdev, 0);
+ if (rng->priv <= 0)
+ return -ENOMEM;
+
+ histb_trng_init(rng, 144);
+ if (histb_trng_wait(rng))
+ return -ENODEV;
+
+ rng->name = KBUILD_MODNAME;
+ rng->read = histb_trng_read;
+
+ ret = devm_hwrng_register(dev, rng);
+ if (ret) {
+ dev_err(dev, "failed to register %s (%d)\n", rng->name, ret);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, rng);
+ dev_set_drvdata(dev, rng);
+ 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 = of_match_ptr(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");
--
2.39.2
