hwrng: hisi - add HiSilicon TRNG driver support

This series adds HiSilicon true random number generator(TRNG)
driver in hw_random subsystem.

Signed-off-by: Zaibo Xu <xuzaibo@huawei.com>
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 87a1c30e795875cd140083fda67d3d1a55541e7e..7c7fecfa2fb271e865b076467c3f5e647c94c21b 100644 (file)
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -308,6 +308,19 @@ config HW_RANDOM_HISI
 
          If unsure, say Y.
 
+config HW_RANDOM_HISI_V2
+       tristate "HiSilicon True Random Number Generator V2 support"
+       depends on HW_RANDOM && ARM64 && ACPI
+       default HW_RANDOM
+       help
+         This driver provides kernel-side support for the True Random Number
+         Generator V2 hardware found on HiSilicon Hi1620 SoC.
+
+         To compile this driver as a module, choose M here: the
+         module will be called hisi-trng-v2.
+
+         If unsure, say Y.
+
 config HW_RANDOM_ST
        tristate "ST Microelectronics HW Random Number Generator support"
        depends on HW_RANDOM && ARCH_STI

diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 17b6d4e6d5915ebe268b0f8b639b5f5acf662dca..a7801b49ce6c0f9859dc6eb7dc091ab7ed142572 100644 (file)
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
 obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
 obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
 obj-$(CONFIG_HW_RANDOM_HISI)   += hisi-rng.o
+obj-$(CONFIG_HW_RANDOM_HISI_V2) += hisi-trng-v2.o
 obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
 obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o
 obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o

diff --git a/drivers/char/hw_random/hisi-trng-v2.c b/drivers/char/hw_random/hisi-trng-v2.c
new file mode 100644 (file)
index 0000000..6a65b82
--- /dev/null
+++ b/drivers/char/hw_random/hisi-trng-v2.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 HiSilicon Limited. */
+
+#include <linux/acpi.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/platform_device.h>
+#include <linux/random.h>
+
+#define HISI_TRNG_REG          0x00F0
+#define HISI_TRNG_BYTES                4
+#define HISI_TRNG_QUALITY      512
+#define SLEEP_US               10
+#define TIMEOUT_US             10000
+
+struct hisi_trng {
+       void __iomem *base;
+       struct hwrng rng;
+};
+
+static int hisi_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+       struct hisi_trng *trng;
+       int currsize = 0;
+       u32 val = 0;
+       u32 ret;
+
+       trng = container_of(rng, struct hisi_trng, rng);
+
+       do {
+               ret = readl_poll_timeout(trng->base + HISI_TRNG_REG, val,
+                                        val, SLEEP_US, TIMEOUT_US);
+               if (ret)
+                       return currsize;
+
+               if (max - currsize >= HISI_TRNG_BYTES) {
+                       memcpy(buf + currsize, &val, HISI_TRNG_BYTES);
+                       currsize += HISI_TRNG_BYTES;
+                       if (currsize == max)
+                               return currsize;
+                       continue;
+               }
+
+               /* copy remaining bytes */
+               memcpy(buf + currsize, &val, max - currsize);
+               currsize = max;
+       } while (currsize < max);
+
+       return currsize;
+}
+
+static int hisi_trng_probe(struct platform_device *pdev)
+{
+       struct hisi_trng *trng;
+       int ret;
+
+       trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
+       if (!trng)
+               return -ENOMEM;
+
+       trng->base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(trng->base))
+               return PTR_ERR(trng->base);
+
+       trng->rng.name = pdev->name;
+       trng->rng.read = hisi_trng_read;
+       trng->rng.quality = HISI_TRNG_QUALITY;
+
+       ret = devm_hwrng_register(&pdev->dev, &trng->rng);
+       if (ret)
+               dev_err(&pdev->dev, "failed to register hwrng!\n");
+
+       return ret;
+}
+
+static const struct acpi_device_id hisi_trng_acpi_match[] = {
+       { "HISI02B3", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(acpi, hisi_trng_acpi_match);
+
+static struct platform_driver hisi_trng_driver = {
+       .probe          = hisi_trng_probe,
+       .driver         = {
+               .name   = "hisi-trng-v2",
+               .acpi_match_table = ACPI_PTR(hisi_trng_acpi_match),
+       },
+};
+
+module_platform_driver(hisi_trng_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Weili Qian <qianweili@huawei.com>");
+MODULE_AUTHOR("Zaibo Xu <xuzaibo@huawei.com>");
+MODULE_DESCRIPTION("HiSilicon true random number generator V2 driver");