Add support for the Amlogic Meson SoCs Hardware Random generator as a hw_random char driver.
The generator is a single 32bit wide register.
Also adds the Meson GXBB SoC DTSI node and corresponding DT bindings.
Neil Armstrong (3):
char: hw_random: Add Amlogic Meson Hardware Random Generator
dt-bindings: hwrng: Add Amlogic Meson Hardware Random Generator
bindings
ARM64: dts: meson-gxbb: Add Hardware Random Generator node
.../devicetree/bindings/rng/amlogic,meson-rng.txt | 14 +++
arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 5 +
drivers/char/hw_random/Kconfig | 13 +++
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/meson-rng.c | 128 +++++++++++++++++++++
5 files changed, 161 insertions(+)
create mode 100644 Documentation/devicetree/bindings/rng/amlogic,meson-rng.txt
create mode 100644 drivers/char/hw_random/meson-rng.c
--
2.7.0
Signed-off-by: Neil Armstrong <[email protected]>
---
arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
index 832815d..8353621 100644
--- a/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb.dtsi
@@ -167,6 +167,11 @@
};
};
+ rng {
+ compatible = "amlogic,meson-rng";
+ reg = <0x0 0xc8834000 0x0 0x4>;
+ };
+
apb: apb@d0000000 {
compatible = "simple-bus";
reg = <0x0 0xd0000000 0x0 0x200000>;
--
2.7.0
Signed-off-by: Neil Armstrong <[email protected]>
---
.../devicetree/bindings/rng/amlogic,meson-rng.txt | 14 ++++++++++++++
1 file changed, 14 insertions(+)
create mode 100644 Documentation/devicetree/bindings/rng/amlogic,meson-rng.txt
diff --git a/Documentation/devicetree/bindings/rng/amlogic,meson-rng.txt b/Documentation/devicetree/bindings/rng/amlogic,meson-rng.txt
new file mode 100644
index 0000000..202f2d0
--- /dev/null
+++ b/Documentation/devicetree/bindings/rng/amlogic,meson-rng.txt
@@ -0,0 +1,14 @@
+Amlogic Meson Random number generator
+=====================================
+
+Required properties:
+
+- compatible : should be "amlogic,meson-rng"
+- reg : Specifies base physical address and size of the registers.
+
+Example:
+
+rng {
+ compatible = "amlogic,meson-rng";
+ reg = <0x0 0xc8834000 0x0 0x4>;
+};
--
2.7.0
Add support for the Amlogic Meson SoCs hardware random generator.
Signed-off-by: Neil Armstrong <[email protected]>
---
drivers/char/hw_random/Kconfig | 13 ++++
drivers/char/hw_random/Makefile | 1 +
drivers/char/hw_random/meson-rng.c | 128 +++++++++++++++++++++++++++++++++++++
3 files changed, 142 insertions(+)
create mode 100644 drivers/char/hw_random/meson-rng.c
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index ac51149..6f349bb 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -396,6 +396,19 @@ config HW_RANDOM_PIC32
If unsure, say Y.
+config HW_RANDOM_MESON
+ tristate "Amlogic Meson Random Number Generator support"
+ depends on HW_RANDOM && ARCH_MESON
+ default y
+ ---help---
+ This driver provides kernel-side support for the Random Number
+ Generator hardware found on Amlogic Meson SoCs.
+
+ To compile this driver as a module, choose M here. the
+ module will be called meson-rng.
+
+ If unsure, say Y.
+
endif # HW_RANDOM
config UML_RANDOM
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 63022b4..04bb0b0 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -34,3 +34,4 @@ obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o
obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o
obj-$(CONFIG_HW_RANDOM_STM32) += stm32-rng.o
obj-$(CONFIG_HW_RANDOM_PIC32) += pic32-rng.o
+obj-$(CONFIG_HW_RANDOM_MESON) += meson-rng.o
diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c
new file mode 100644
index 0000000..58bef39
--- /dev/null
+++ b/drivers/char/hw_random/meson-rng.c
@@ -0,0 +1,128 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <[email protected]>
+ * Copyright (C) 2014 Amlogic, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ *
+ * BSD LICENSE
+ *
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Neil Armstrong <[email protected]>
+ * Copyright (C) 2014 Amlogic, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/hw_random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of.h>
+
+#define RNG_DATA 0x00
+
+struct meson_rng_data {
+ void __iomem *base;
+ struct platform_device *pdev;
+ struct hwrng rng;
+};
+
+static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
+{
+ struct meson_rng_data *data =
+ container_of(rng, struct meson_rng_data, rng);
+
+ *(u32 *)buf = readl_relaxed(data->base + RNG_DATA);
+
+ return sizeof(u32);
+}
+
+static int meson_rng_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct meson_rng_data *data;
+ struct resource *res;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->pdev = pdev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(data->base))
+ return PTR_ERR(data->base);
+
+ data->rng.name = pdev->name;
+ data->rng.read = meson_rng_read;
+
+ platform_set_drvdata(pdev, data);
+
+ return devm_hwrng_register(dev, &data->rng);
+}
+
+static const struct of_device_id meson_rng_of_match[] = {
+ { .compatible = "amlogic,meson-rng", },
+ {},
+};
+
+static struct platform_driver meson_rng_driver = {
+ .probe = meson_rng_probe,
+ .driver = {
+ .name = "meson-rng",
+ .of_match_table = meson_rng_of_match,
+ },
+};
+
+module_platform_driver(meson_rng_driver);
+
+MODULE_ALIAS("platform:meson-rng");
+MODULE_DESCRIPTION("Meson H/W Random Number Generator driver");
+MODULE_AUTHOR("Lawrence Mok <[email protected]>");
+MODULE_AUTHOR("Neil Armstrong <[email protected]>");
+MODULE_LICENSE("Dual BSD/GPL");
--
2.7.0
Hello
I have some minor comments below
> +config HW_RANDOM_MESON
> + tristate "Amlogic Meson Random Number Generator support"
> + depends on HW_RANDOM && ARCH_MESON
Perhaps you could change to:
depends on HW_RANDOM
depends on ARCH_MESON || COMPILE_TEST
> +
> +static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
> +{
> + struct meson_rng_data *data =
> + container_of(rng, struct meson_rng_data, rng);
> +
> + *(u32 *)buf = readl_relaxed(data->base + RNG_DATA);
> +
> + return sizeof(u32);
> +}
I think you need a test for max < sizeof(u32)
Regards
LABBE Corentin
On Fri, Jun 03, 2016 at 10:47:00AM +0200, Neil Armstrong wrote:
> Signed-off-by: Neil Armstrong <[email protected]>
> ---
> .../devicetree/bindings/rng/amlogic,meson-rng.txt | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/rng/amlogic,meson-rng.txt
Acked-by: Rob Herring <[email protected]>