[PATCH 0/3] hwrng: add support for Xiphera XIP8001B

[PATCH 0/3] hwrng: add support for Xiphera XIP8001B

[Atte Tommiska]

This patchset introduces a linux driver for Xiphera's XIP8001B IP.
The IP is an FPGA-based TRNG which can be used in various FPGA families.
The IP is in use in multiple customer projects and in Xiphera's own products.

Atte Tommiska (3):
  dt-bindings: vendor-prefixes: Add Xiphera vendor prefix
  dt-bindings: rng: add bindings for Xiphera XIP8001B hwnrg
  hwrng: xiphera-trng: add support for XIP8001B hwrng

 .../bindings/rng/xiphera,xip8001b-trng.yaml   |  30 ++++
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 drivers/char/hw_random/Kconfig                |  10 ++
 drivers/char/hw_random/Makefile               |   1 +
 drivers/char/hw_random/xiphera-trng.c         | 151 ++++++++++++++++++
 5 files changed, 194 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml
 create mode 100644 drivers/char/hw_random/xiphera-trng.c


base-commit: 9123e3a74ec7b934a4a099e98af6a61c2f80bbf5
-- 
2.28.0

[PATCH 1/3] dt-bindings: vendor-prefixes: Add Xiphera vendor prefix

[Atte Tommiska]

Xiphera is an FPGA-based cryptographic solutions provider based in
Finland.
Website of the company: https://xiphera.com/

Signed-off-by: Atte Tommiska <atte.tommiska@xiphera.com>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 2baee2c817c1..28ae913682b5 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1174,6 +1174,8 @@ patternProperties:
     description: Shenzhen Xingbangda Display Technology Co., Ltd
   "^xinpeng,.*":
     description: Shenzhen Xinpeng Technology Co., Ltd
+  "^xiphera,.*":
+    description: Xiphera Ltd.
   "^xlnx,.*":
     description: Xilinx
   "^xnano,.*":
-- 
2.28.0

[PATCH 2/3] dt-bindings: rng: add bindings for Xiphera XIP8001B hwnrg

[Atte Tommiska]

Document the device tree bindings of Xiphera's XIP8001B-trng IP.

Signed-off-by: Atte Tommiska <atte.tommiska@xiphera.com>
---
 .../bindings/rng/xiphera,xip8001b-trng.yaml   | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml

diff --git a/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml b/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml
new file mode 100644
index 000000000000..24ce44b8fe2d
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rng/xiphera,xip8001b-trng.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xiphera XIP8001B-trng bindings
+
+description: |
+  Xiphera FPGA-based true random number generator intellectual property core.
+
+properties:
+  compatible:
+    const: xiphera,xip8001b-trng
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    rng@43c00000 {
+        compatible = "xiphera,xip8001b-trng";
+        reg = <0x43c00000 0x10000>;
+    };
-- 
2.28.0

[PATCH 3/3] hwrng: xiphera-trng: add support for XIP8001B hwrng

[Atte Tommiska]

Xiphera XIP8001B is an FPGA-based True Random Number Generator
Intellectual Property (IP) Core which can be instantiated in
multiple FPGA families. This driver adds Linux support for it through
the hwrng interface.

Signed-off-by: Atte Tommiska <atte.tommiska@xiphera.com>
---
 drivers/char/hw_random/Kconfig        |  10 ++
 drivers/char/hw_random/Makefile       |   1 +
 drivers/char/hw_random/xiphera-trng.c | 151 ++++++++++++++++++++++++++
 3 files changed, 162 insertions(+)
 create mode 100644 drivers/char/hw_random/xiphera-trng.c

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index f976a49e1fb5..007d765a9253 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -512,6 +512,16 @@ config HW_RANDOM_CCTRNG
 	  will be called cctrng.
 	  If unsure, say 'N'.
 
+config HW_RANDOM_XIPHERA
+	tristate "Xiphera FPGA based True Random Number Generator support"
+	depends on HAS_IOMEM
+	help
+	  This driver provides kernel-side support for Xiphera True Random
+	  Number Generator Intellectual Property Core.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called xiphera-trng.
+
 endif # HW_RANDOM
 
 config UML_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 26ae06844f09..dfdcac81e384 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -44,3 +44,4 @@ obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o
 obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o
 obj-$(CONFIG_HW_RANDOM_NPCM) += npcm-rng.o
 obj-$(CONFIG_HW_RANDOM_CCTRNG) += cctrng.o
+obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o
diff --git a/drivers/char/hw_random/xiphera-trng.c b/drivers/char/hw_random/xiphera-trng.c
new file mode 100644
index 000000000000..2f082eb8e8a5
--- /dev/null
+++ b/drivers/char/hw_random/xiphera-trng.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2020 Xiphera Ltd. */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/hw_random.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+
+#define CONTROL_REG			0x00000000
+#define STATUS_REG			0x00000004
+#define RAND_REG			0x00000000
+
+#define HOST_TO_TRNG_RESET		0x00000001
+#define HOST_TO_TRNG_RELEASE_RESET	0x00000002
+#define HOST_TO_TRNG_ENABLE		0x80000000
+#define HOST_TO_TRNG_ZEROIZE		0x80000004
+#define HOST_TO_TRNG_ACK_ZEROIZE	0x80000008
+#define HOST_TO_TRNG_READ		0x8000000F
+
+/* trng statuses */
+#define TRNG_ACK_RESET			0x000000AC
+#define TRNG_SUCCESSFUL_STARTUP		0x00000057
+#define TRNG_FAILED_STARTUP		0x000000FA
+#define TRNG_NEW_RAND_AVAILABLE		0x000000ED
+
+struct xiphera_trng {
+	void __iomem *mem;
+	struct hwrng rng;
+};
+
+static int xiphera_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+	struct xiphera_trng *trng = container_of(rng, struct xiphera_trng, rng);
+	int ret = 0;
+
+	while (max >= sizeof(u32)) {
+		/* check for data */
+		if (readl(trng->mem + STATUS_REG) == TRNG_NEW_RAND_AVAILABLE) {
+			*(u32 *)buf = readl(trng->mem + RAND_REG);
+			/*
+			 * Inform the trng of the read
+			 * and re-enable it to produce a new random number
+			 */
+			writel(HOST_TO_TRNG_READ, trng->mem + CONTROL_REG);
+			writel(HOST_TO_TRNG_ENABLE, trng->mem + CONTROL_REG);
+			ret += sizeof(u32);
+			buf += sizeof(u32);
+			max -= sizeof(u32);
+		} else {
+			break;
+		}
+	}
+	return ret;
+}
+
+static int xiphera_trng_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct xiphera_trng *trng;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+
+	trng = devm_kzalloc(dev, sizeof(*trng), GFP_KERNEL);
+	if (!trng)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	trng->mem = devm_ioremap_resource(dev, res);
+	if (IS_ERR(trng->mem))
+		return PTR_ERR(trng->mem);
+
+	/*
+	 * the trng needs to be reset first which might not happen in time,
+	 * hence we incorporate a small delay to ensure proper behaviour
+	 */
+	writel(HOST_TO_TRNG_RESET, trng->mem + CONTROL_REG);
+	usleep_range(100, 200);
+
+	if (readl(trng->mem + STATUS_REG) != TRNG_ACK_RESET) {
+		/*
+		 * there is a small chance the trng is just not ready yet,
+		 * so we try one more time. If the second time fails, we give up
+		 */
+		usleep_range(100, 200);
+		if (readl(trng->mem + STATUS_REG) != TRNG_ACK_RESET) {
+			dev_err(dev, "failed to reset the trng ip\n");
+			return -ENODEV;
+		}
+	}
+
+	/*
+	 * once again, to ensure proper behaviour we sleep
+	 * for a while after zeroizing the trng
+	 */
+	writel(HOST_TO_TRNG_RELEASE_RESET, trng->mem + CONTROL_REG);
+	writel(HOST_TO_TRNG_ENABLE, trng->mem + CONTROL_REG);
+	writel(HOST_TO_TRNG_ZEROIZE, trng->mem + CONTROL_REG);
+	msleep(20);
+
+	if (readl(trng->mem + STATUS_REG) != TRNG_SUCCESSFUL_STARTUP) {
+		/* diagnose the reason for the failure */
+		if (readl(trng->mem + STATUS_REG) == TRNG_FAILED_STARTUP) {
+			dev_err(dev, "trng ip startup-tests failed\n");
+			return -ENODEV;
+		}
+		dev_err(dev, "startup-tests yielded no response\n");
+		return -ENODEV;
+	}
+
+	writel(HOST_TO_TRNG_ACK_ZEROIZE, trng->mem + CONTROL_REG);
+
+	trng->rng.name = pdev->name;
+	trng->rng.read = xiphera_trng_read;
+	trng->rng.quality = 900;
+
+	ret = devm_hwrng_register(dev, &trng->rng);
+	if (ret) {
+		dev_err(dev, "failed to register rng device: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, trng);
+
+	return 0;
+}
+
+static const struct of_device_id xiphera_trng_of_match[] = {
+	{ .compatible = "xiphera,xip8001b-trng", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, xiphera_trng_of_match);
+
+static struct platform_driver xiphera_trng_driver = {
+	.driver = {
+		.name = "xiphera-trng",
+		.owner = THIS_MODULE,
+		.of_match_table	= xiphera_trng_of_match,
+	},
+	.probe = xiphera_trng_probe,
+};
+
+module_platform_driver(xiphera_trng_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Atte Tommiska");
+MODULE_DESCRIPTION("Xiphera FPGA-based true random number generator driver");
-- 
2.28.0

Re: [PATCH 2/3] dt-bindings: rng: add bindings for Xiphera XIP8001B hwnrg

[Rob Herring]

On Wed, 19 Aug 2020 15:21:34 +0300, Atte Tommiska wrote:
> Document the device tree bindings of Xiphera's XIP8001B-trng IP.
> 
> Signed-off-by: Atte Tommiska <atte.tommiska@xiphera.com>
> ---
>  .../bindings/rng/xiphera,xip8001b-trng.yaml   | 30 +++++++++++++++++++
>  1 file changed, 30 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml
> 


My bot found errors running 'make dt_binding_check' on your patch:

/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml: 'maintainers' is a required property
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml: ignoring, error in schema: 
warning: no schema found in file: ./Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml


See https://patchwork.ozlabs.org/patch/1347768

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure dt-schema is up to date:

pip3 install git+https://github.com/devicetree-org/dt-schema.git@master --upgrade

Please check and re-submit.

Re: [PATCH 2/3] dt-bindings: rng: add bindings for Xiphera XIP8001B hwnrg

[Atte Tommiska]

On 20/08/2020 01:37, Rob Herring wrote:
> On Wed, 19 Aug 2020 15:21:34 +0300, Atte Tommiska wrote:
>> Document the device tree bindings of Xiphera's XIP8001B-trng IP.
>>
>> Signed-off-by: Atte Tommiska <atte.tommiska@xiphera.com>
>> ---
>>  .../bindings/rng/xiphera,xip8001b-trng.yaml   | 30 +++++++++++++++++++
>>  1 file changed, 30 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml
>>
> 
> 
> My bot found errors running 'make dt_binding_check' on your patch:
> 
> /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml: 'maintainers' is a required property
> /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml: ignoring, error in schema: 
> warning: no schema found in file: ./Documentation/devicetree/bindings/rng/xiphera,xip8001b-trng.yaml
> 
> 
> See https://patchwork.ozlabs.org/patch/1347768
> 
> If you already ran 'make dt_binding_check' and didn't see the above
> error(s), then make sure dt-schema is up to date:
> 
> pip3 install git+https://github.com/devicetree-org/dt-schema.git@master --upgrade
> 
> Please check and re-submit.
> 

Thank you.

Fixed and submitted v2 of the patch.