diff mbox series

[v3,1/8] dm: rng: Add random number generator(rng) uclass

Message ID 1576221267-5948-2-git-send-email-sughosh.ganu@linaro.org
State Superseded, archived
Delegated to: Tom Rini
Headers show
Series Add a random number generator uclass | expand

Commit Message

Sughosh Ganu Dec. 13, 2019, 7:14 a.m. UTC 
Add a uclass for reading a random number seed from a random number
generator device.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
---
 drivers/Kconfig          |  2 ++
 drivers/Makefile         |  1 +
 drivers/rng/Kconfig      |  7 +++++++
 drivers/rng/Makefile     |  6 ++++++
 drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
 include/dm/uclass-id.h   |  1 +
 include/rng.h            | 30 ++++++++++++++++++++++++++++++
 7 files changed, 70 insertions(+)
 create mode 100644 drivers/rng/Kconfig
 create mode 100644 drivers/rng/Makefile
 create mode 100644 drivers/rng/rng-uclass.c
 create mode 100644 include/rng.h

Comments

Ilias Apalodimas Dec. 13, 2019, 12:21 p.m. UTC | #1 
On Fri, Dec 13, 2019 at 12:44:20PM +0530, Sughosh Ganu wrote:
> Add a uclass for reading a random number seed from a random number
> generator device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> ---
>  drivers/Kconfig          |  2 ++
>  drivers/Makefile         |  1 +
>  drivers/rng/Kconfig      |  7 +++++++
>  drivers/rng/Makefile     |  6 ++++++
>  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
>  include/dm/uclass-id.h   |  1 +
>  include/rng.h            | 30 ++++++++++++++++++++++++++++++
>  7 files changed, 70 insertions(+)
>  create mode 100644 drivers/rng/Kconfig
>  create mode 100644 drivers/rng/Makefile
>  create mode 100644 drivers/rng/rng-uclass.c
>  create mode 100644 include/rng.h
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 9d99ce0..e34a227 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
>  
>  source "drivers/reset/Kconfig"
>  
> +source "drivers/rng/Kconfig"
> +
>  source "drivers/rtc/Kconfig"
>  
>  source "drivers/scsi/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index e977f19..6c619b1 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
>  
>  obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
>  obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
> +obj-$(CONFIG_DM_RNG) += rng/
>  endif
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
> new file mode 100644
> index 0000000..dd44cc0
> --- /dev/null
> +++ b/drivers/rng/Kconfig
> @@ -0,0 +1,7 @@
> +config DM_RNG
> +	bool "Driver support for Random Number Generator devices"
> +	depends on DM
> +	help
> +	  Enable driver model for random number generator(rng) devices.
> +	  This interface is used to initialise the rng device and to
> +	  read the random seed from the device.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
> new file mode 100644
> index 0000000..311705b
> --- /dev/null
> +++ b/drivers/rng/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2019, Linaro Limited
> +#
> +
> +obj-$(CONFIG_DM_RNG) += rng-uclass.o
> diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c
> new file mode 100644
> index 0000000..b6af3b8
> --- /dev/null
> +++ b/drivers/rng/rng-uclass.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size)
> +{
> +	const struct dm_rng_ops *ops = device_get_ops(dev);
> +
> +	if (!ops->read)
> +		return -ENOSYS;
> +
> +	return ops->read(dev, buffer, size);
> +}
> +
> +UCLASS_DRIVER(rng) = {
> +	.name = "rng",
> +	.id = UCLASS_RNG,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 0c563d8..192202d 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -86,6 +86,7 @@ enum uclass_id {
>  	UCLASS_REGULATOR,	/* Regulator device */
>  	UCLASS_REMOTEPROC,	/* Remote Processor device */
>  	UCLASS_RESET,		/* Reset controller device */
> +	UCLASS_RNG,		/* Random Number Generator */
>  	UCLASS_RTC,		/* Real time clock device */
>  	UCLASS_SCSI,		/* SCSI device */
>  	UCLASS_SERIAL,		/* Serial UART */
> diff --git a/include/rng.h b/include/rng.h
> new file mode 100644
> index 0000000..61d5da9
> --- /dev/null
> +++ b/include/rng.h
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#if !defined _RNG_H_
> +#define _RNG_H_
> +
> +#include <dm.h>
> +
> +/**
> + * dm_rng_read() - read a random number seed from the rng device
> + * @buffer:	input buffer to put the read random seed into
> + * @size:	number of bytes of random seed read
> + *
> + */
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> +
> +/* struct dm_rng_ops - Operations for the hwrng uclass */
> +struct dm_rng_ops {
> +	/**
> +	 * @read() - read a random number seed
> +	 *
> +	 * @data:	input buffer to read the random seed
> +	 * @max:	total number of bytes to read
> +	 */
> +	int (*read)(struct udevice *dev, void *data, size_t max);
> +};
> +
> +#endif /* _RNG_H_ */
> -- 
> 2.7.4
> 

Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Patrick DELAUNAY Dec. 16, 2019, 11:59 a.m. UTC | #2 
Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add a uclass for reading a random number seed from a random number generator
> device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>

Thanks.

> ---
>  drivers/Kconfig          |  2 ++
>  drivers/Makefile         |  1 +
>  drivers/rng/Kconfig      |  7 +++++++
>  drivers/rng/Makefile     |  6 ++++++
>  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
>  include/dm/uclass-id.h   |  1 +
>  include/rng.h            | 30 ++++++++++++++++++++++++++++++
>  7 files changed, 70 insertions(+)
>  create mode 100644 drivers/rng/Kconfig
>  create mode 100644 drivers/rng/Makefile  create mode 100644 drivers/rng/rng-
> uclass.c  create mode 100644 include/rng.h
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig index 9d99ce0..e34a227 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
> 
>  source "drivers/reset/Kconfig"
> 
> +source "drivers/rng/Kconfig"
> +
>  source "drivers/rtc/Kconfig"
> 
>  source "drivers/scsi/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile index e977f19..6c619b1 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
> 
>  obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
>  obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
> +obj-$(CONFIG_DM_RNG) += rng/
>  endif
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig new file mode 100644 index
> 0000000..dd44cc0
> --- /dev/null
> +++ b/drivers/rng/Kconfig
> @@ -0,0 +1,7 @@
> +config DM_RNG
> +	bool "Driver support for Random Number Generator devices"
> +	depends on DM
> +	help
> +	  Enable driver model for random number generator(rng) devices.
> +	  This interface is used to initialise the rng device and to
> +	  read the random seed from the device.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile new file mode 100644 index
> 0000000..311705b
> --- /dev/null
> +++ b/drivers/rng/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2019, Linaro Limited
> +#
> +
> +obj-$(CONFIG_DM_RNG) += rng-uclass.o
> diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c new file mode
> 100644 index 0000000..b6af3b8
> --- /dev/null
> +++ b/drivers/rng/rng-uclass.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size) {
> +	const struct dm_rng_ops *ops = device_get_ops(dev);
> +
> +	if (!ops->read)
> +		return -ENOSYS;
> +
> +	return ops->read(dev, buffer, size);
> +}
> +
> +UCLASS_DRIVER(rng) = {
> +	.name = "rng",
> +	.id = UCLASS_RNG,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index
> 0c563d8..192202d 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -86,6 +86,7 @@ enum uclass_id {
>  	UCLASS_REGULATOR,	/* Regulator device */
>  	UCLASS_REMOTEPROC,	/* Remote Processor device */
>  	UCLASS_RESET,		/* Reset controller device */
> +	UCLASS_RNG,		/* Random Number Generator */
>  	UCLASS_RTC,		/* Real time clock device */
>  	UCLASS_SCSI,		/* SCSI device */
>  	UCLASS_SERIAL,		/* Serial UART */
> diff --git a/include/rng.h b/include/rng.h new file mode 100644 index
> 0000000..61d5da9
> --- /dev/null
> +++ b/include/rng.h
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#if !defined _RNG_H_
> +#define _RNG_H_
> +
> +#include <dm.h>
> +
> +/**
> + * dm_rng_read() - read a random number seed from the rng device
> + * @buffer:	input buffer to put the read random seed into
> + * @size:	number of bytes of random seed read
> + *
> + */
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> +
> +/* struct dm_rng_ops - Operations for the hwrng uclass */ struct
> +dm_rng_ops {
> +	/**
> +	 * @read() - read a random number seed
> +	 *
> +	 * @data:	input buffer to read the random seed
> +	 * @max:	total number of bytes to read
> +	 */
> +	int (*read)(struct udevice *dev, void *data, size_t max); };
> +
> +#endif /* _RNG_H_ */
> --
> 2.7.4
Patrick DELAUNAY Dec. 16, 2019, 12:13 p.m. UTC | #3 
Hi,

> From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> Sent: vendredi 13 décembre 2019 08:14
> 
> Add a uclass for reading a random number seed from a random number generator
> device.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> ---
>  drivers/Kconfig          |  2 ++
>  drivers/Makefile         |  1 +
>  drivers/rng/Kconfig      |  7 +++++++
>  drivers/rng/Makefile     |  6 ++++++
>  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
>  include/dm/uclass-id.h   |  1 +
>  include/rng.h            | 30 ++++++++++++++++++++++++++++++
>  7 files changed, 70 insertions(+)
>  create mode 100644 drivers/rng/Kconfig
>  create mode 100644 drivers/rng/Makefile  create mode 100644 drivers/rng/rng-
> uclass.c  create mode 100644 include/rng.h
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig index 9d99ce0..e34a227 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -90,6 +90,8 @@ source "drivers/remoteproc/Kconfig"
> 
>  source "drivers/reset/Kconfig"
> 
> +source "drivers/rng/Kconfig"
> +
>  source "drivers/rtc/Kconfig"
> 
>  source "drivers/scsi/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile index e977f19..6c619b1 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -115,4 +115,5 @@ obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
> 
>  obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
>  obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
> +obj-$(CONFIG_DM_RNG) += rng/
>  endif
> diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig new file mode 100644 index
> 0000000..dd44cc0
> --- /dev/null
> +++ b/drivers/rng/Kconfig
> @@ -0,0 +1,7 @@
> +config DM_RNG
> +	bool "Driver support for Random Number Generator devices"
> +	depends on DM
> +	help
> +	  Enable driver model for random number generator(rng) devices.
> +	  This interface is used to initialise the rng device and to
> +	  read the random seed from the device.
> diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile new file mode 100644 index
> 0000000..311705b
> --- /dev/null
> +++ b/drivers/rng/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (c) 2019, Linaro Limited
> +#
> +
> +obj-$(CONFIG_DM_RNG) += rng-uclass.o
> diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c new file mode
> 100644 index 0000000..b6af3b8
> --- /dev/null
> +++ b/drivers/rng/rng-uclass.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <rng.h>
> +
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size) {
> +	const struct dm_rng_ops *ops = device_get_ops(dev);
> +
> +	if (!ops->read)
> +		return -ENOSYS;
> +
> +	return ops->read(dev, buffer, size);
> +}
> +
> +UCLASS_DRIVER(rng) = {
> +	.name = "rng",
> +	.id = UCLASS_RNG,
> +};
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index
> 0c563d8..192202d 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -86,6 +86,7 @@ enum uclass_id {
>  	UCLASS_REGULATOR,	/* Regulator device */
>  	UCLASS_REMOTEPROC,	/* Remote Processor device */
>  	UCLASS_RESET,		/* Reset controller device */
> +	UCLASS_RNG,		/* Random Number Generator */
>  	UCLASS_RTC,		/* Real time clock device */
>  	UCLASS_SCSI,		/* SCSI device */
>  	UCLASS_SERIAL,		/* Serial UART */
> diff --git a/include/rng.h b/include/rng.h new file mode 100644 index
> 0000000..61d5da9
> --- /dev/null
> +++ b/include/rng.h
> @@ -0,0 +1,30 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2019, Linaro Limited
> + */
> +
> +#if !defined _RNG_H_
> +#define _RNG_H_
> +
> +#include <dm.h>
> +
> +/**
> + * dm_rng_read() - read a random number seed from the rng device
> + * @buffer:	input buffer to put the read random seed into
> + * @size:	number of bytes of random seed read

Missing return value here, I propose:

@return zero on success, or -ve error code.

> + *
> + */
> +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> +
> +/* struct dm_rng_ops - Operations for the hwrng uclass */ struct
> +dm_rng_ops {
> +	/**
> +	 * @read() - read a random number seed
> +	 *
> +	 * @data:	input buffer to read the random seed
> +	 * @max:	total number of bytes to read

Missing return value here, I propose: 

@return zero on success, or -ve error code.

> +	 */
> +	int (*read)(struct udevice *dev, void *data, size_t max); };
> +
> +#endif /* _RNG_H_ */
> --
> 2.7.4

Patrick
Sughosh Ganu Dec. 16, 2019, 6:55 p.m. UTC | #4 
hi Patrick,

On Mon, 16 Dec 2019 at 17:43, Patrick DELAUNAY <patrick.delaunay@st.com>
wrote:

> Hi,
>
> > From: U-Boot <u-boot-bounces@lists.denx.de> On Behalf Of Sughosh Ganu
> > Sent: vendredi 13 décembre 2019 08:14
> >
> > Add a uclass for reading a random number seed from a random number
> generator
> > device.
> >
> > Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> > Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
> > ---
> >  drivers/Kconfig          |  2 ++
> >  drivers/Makefile         |  1 +
> >  drivers/rng/Kconfig      |  7 +++++++
> >  drivers/rng/Makefile     |  6 ++++++
> >  drivers/rng/rng-uclass.c | 23 +++++++++++++++++++++++
> >  include/dm/uclass-id.h   |  1 +
> >  include/rng.h            | 30 ++++++++++++++++++++++++++++++
> >  7 files changed, 70 insertions(+)
> >  create mode 100644 drivers/rng/Kconfig
> >  create mode 100644 drivers/rng/Makefile  create mode 100644
> drivers/rng/rng-
> > uclass.c  create mode 100644 include/rng.h
>

<snip>


> > diff --git a/include/rng.h b/include/rng.h new file mode 100644 index
> > 0000000..61d5da9
> > --- /dev/null
> > +++ b/include/rng.h
> > @@ -0,0 +1,30 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (c) 2019, Linaro Limited
> > + */
> > +
> > +#if !defined _RNG_H_
> > +#define _RNG_H_
> > +
> > +#include <dm.h>
> > +
> > +/**
> > + * dm_rng_read() - read a random number seed from the rng device
> > + * @buffer:  input buffer to put the read random seed into
> > + * @size:    number of bytes of random seed read
>
> Missing return value here, I propose:
>
> @return zero on success, or -ve error code.
>

Ok. Will add.


>
> > + *
> > + */
> > +int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
> > +
> > +/* struct dm_rng_ops - Operations for the hwrng uclass */ struct
> > +dm_rng_ops {
> > +     /**
> > +      * @read() - read a random number seed
> > +      *
> > +      * @data:       input buffer to read the random seed
> > +      * @max:        total number of bytes to read
>
> Missing return value here, I propose:
>
> @return zero on success, or -ve error code.
>

Ok. Will add.

-sughosh
diff mbox series

Patch

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 9d99ce0..e34a227 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -90,6 +90,8 @@  source "drivers/remoteproc/Kconfig"
 
 source "drivers/reset/Kconfig"
 
+source "drivers/rng/Kconfig"
+
 source "drivers/rtc/Kconfig"
 
 source "drivers/scsi/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index e977f19..6c619b1 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -115,4 +115,5 @@  obj-$(CONFIG_W1_EEPROM) += w1-eeprom/
 
 obj-$(CONFIG_MACH_PIC32) += ddr/microchip/
 obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock/
+obj-$(CONFIG_DM_RNG) += rng/
 endif
diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig
new file mode 100644
index 0000000..dd44cc0
--- /dev/null
+++ b/drivers/rng/Kconfig
@@ -0,0 +1,7 @@ 
+config DM_RNG
+	bool "Driver support for Random Number Generator devices"
+	depends on DM
+	help
+	  Enable driver model for random number generator(rng) devices.
+	  This interface is used to initialise the rng device and to
+	  read the random seed from the device.
diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile
new file mode 100644
index 0000000..311705b
--- /dev/null
+++ b/drivers/rng/Makefile
@@ -0,0 +1,6 @@ 
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2019, Linaro Limited
+#
+
+obj-$(CONFIG_DM_RNG) += rng-uclass.o
diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c
new file mode 100644
index 0000000..b6af3b8
--- /dev/null
+++ b/drivers/rng/rng-uclass.c
@@ -0,0 +1,23 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <rng.h>
+
+int dm_rng_read(struct udevice *dev, void *buffer, size_t size)
+{
+	const struct dm_rng_ops *ops = device_get_ops(dev);
+
+	if (!ops->read)
+		return -ENOSYS;
+
+	return ops->read(dev, buffer, size);
+}
+
+UCLASS_DRIVER(rng) = {
+	.name = "rng",
+	.id = UCLASS_RNG,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 0c563d8..192202d 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -86,6 +86,7 @@  enum uclass_id {
 	UCLASS_REGULATOR,	/* Regulator device */
 	UCLASS_REMOTEPROC,	/* Remote Processor device */
 	UCLASS_RESET,		/* Reset controller device */
+	UCLASS_RNG,		/* Random Number Generator */
 	UCLASS_RTC,		/* Real time clock device */
 	UCLASS_SCSI,		/* SCSI device */
 	UCLASS_SERIAL,		/* Serial UART */
diff --git a/include/rng.h b/include/rng.h
new file mode 100644
index 0000000..61d5da9
--- /dev/null
+++ b/include/rng.h
@@ -0,0 +1,30 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019, Linaro Limited
+ */
+
+#if !defined _RNG_H_
+#define _RNG_H_
+
+#include <dm.h>
+
+/**
+ * dm_rng_read() - read a random number seed from the rng device
+ * @buffer:	input buffer to put the read random seed into
+ * @size:	number of bytes of random seed read
+ *
+ */
+int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+
+/* struct dm_rng_ops - Operations for the hwrng uclass */
+struct dm_rng_ops {
+	/**
+	 * @read() - read a random number seed
+	 *
+	 * @data:	input buffer to read the random seed
+	 * @max:	total number of bytes to read
+	 */
+	int (*read)(struct udevice *dev, void *data, size_t max);
+};
+
+#endif /* _RNG_H_ */