Re: [PATCH 1/1] drivers/rng: add Amlogic hardware RNG driver

Hi,

Le 24/02/2020 à 23:21, Heinrich Schuchardt a écrit :

Add support for the hardware random number generator of Amlogic SOCs.

Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de

drivers/rng/Kconfig | 8 +++ drivers/rng/Makefile | 1 + drivers/rng/meson-rng.c | 120 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+) create mode 100644 drivers/rng/meson-rng.c

diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index c1aa43b823..edb6152bb9 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -8,6 +8,14 @@ config DM_RNG

if DM_RNG

+config RNG_MESON

• bool "Amlogic Meson Random Number Generator support"
• depends on ARCH_MESON
• default y
• help

•  Enable support for hardware random number generator
  

•  of Amlogic Meson SoCs.
  

config RNG_SANDBOX bool "Sandbox random number generator" depends on SANDBOX diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 3517005541..6a8a66779b 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -4,5 +4,6 @@ #

obj-$(CONFIG_DM_RNG) += rng-uclass.o +obj-$(CONFIG_RNG_MESON) += meson-rng.o obj-$(CONFIG_RNG_SANDBOX) += sandbox_rng.o obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o diff --git a/drivers/rng/meson-rng.c b/drivers/rng/meson-rng.c new file mode 100644 index 0000000000..4b81a62353 --- /dev/null +++ b/drivers/rng/meson-rng.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*

• • Copyright 2020, Heinrich Schuchardt xypron.glpk@gmx.de
• • Driver for Amlogic hardware random number generator
• */

+#include <common.h> +#include <clk.h> +#include <dm.h> +#include <rng.h> +#include <asm/io.h>

+struct meson_rng_platdata {

• fdt_addr_t base;
• struct clk clk;

+};

+/**

• • meson_rng_read() - fill buffer with random bytes
• • @buffer: buffer to receive data
• • @size: size of buffer
• • Return: 0
• */

+static int meson_rng_read(struct udevice *dev, void *data, size_t len) +{

• struct meson_rng_platdata *pdata = dev_get_platdata(dev);
• char *buffer = (char *)data;
• while (len) {

• u32 rand = readl(pdata->base);
  

• size_t step;
  

• if (len >= 4)
  

• 	step = 4;
  

• else
  

• 	step = len;
  

• memcpy(buffer, &rand, step);
  

• buffer += step;
  

• len -= step;
  

• }
• return 0;

+}

+/**

• • meson_rng_probe() - probe rng device
• • @dev: device
• • Return: 0 if ok
• */

+static int meson_rng_probe(struct udevice *dev) +{

• struct meson_rng_platdata *pdata = dev_get_platdata(dev);
• int err;
• err = clk_enable(&pdata->clk);
• if (err)

• return err;
  

• return 0;

+}

+/**

• • meson_rng_remove() - deinitialize rng device
• • @dev: device
• • Return: 0 if ok
• */

+static int meson_rng_remove(struct udevice *dev) +{

• struct meson_rng_platdata *pdata = dev_get_platdata(dev);
• return clk_disable(&pdata->clk);

+}

+/**

• • meson_rng_ofdata_to_platdata() - transfer device tree data to plaform data
• • @dev: device
• • Return: 0 if ok
• */

+static int meson_rng_ofdata_to_platdata(struct udevice *dev) +{

• struct meson_rng_platdata *pdata = dev_get_platdata(dev);
• int err;
• pdata->base = dev_read_addr(dev);
• if (!pdata->base)

• return -ENODEV;
  

• err = clk_get_by_name(dev, "core", &pdata->clk);
• if (err)

• return err;
  

• return 0;

+}

+static const struct dm_rng_ops meson_rng_ops = {

• .read = meson_rng_read,

+};

+static const struct udevice_id meson_rng_match[] = {

• {

• .compatible = "amlogic,meson-rng",
  

• },
• {},

+};

+U_BOOT_DRIVER(meson_rng) = {

• .name = "meson-rng",
• .id = UCLASS_RNG,
• .of_match = meson_rng_match,
• .ops = &meson_rng_ops,
• .probe = meson_rng_probe,
• .remove = meson_rng_remove,
• .platdata_auto_alloc_size = sizeof(struct meson_rng_platdata),
• .ofdata_to_platdata = meson_rng_ofdata_to_platdata,

+};

2.20.1

Reviewed-by: Neil Armstrong narmstrong@baylibre.com

Thanks, looks fine.

I suspect this will help adding EFI RNG data for Linux early random seed, right ?

Is there a RNG maintainer or should I apply it myself ?

Neil