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

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

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>