[PATCH v3 2/3] hwrng: add Rockchip SoC hwrng driver

[Philipp Zabel]

Hi,

On Fr, 2024-06-21 at 02:25 +0100, Daniel Golle wrote:
> From: Aurelien Jarno <aurelien at aurel32.net>
> 
> Rockchip SoCs used to have a random number generator as part of their
> crypto device, and support for it has to be added to the corresponding
> driver. However newer Rockchip SoCs like the RK356x have an independent
> True Random Number Generator device. This patch adds a driver for it,
> greatly inspired from the downstream driver.
> 
> The TRNG device does not seem to have a signal conditionner and the FIPS
> 140-2 test returns a lot of failures. They can be reduced by increasing
> RK_RNG_SAMPLE_CNT, in a tradeoff between quality and speed. This value
> has been adjusted to get ~90% of successes and the quality value has
> been set accordingly.
> 
> Signed-off-by: Aurelien Jarno <aurelien at aurel32.net>
> [daniel at makrotpia.org: code style fixes]
> Signed-off-by: Daniel Golle <daniel at makrotopia.org>
> ---
>  MAINTAINERS                           |   1 +
>  drivers/char/hw_random/Kconfig        |  14 ++
>  drivers/char/hw_random/Makefile       |   1 +
>  drivers/char/hw_random/rockchip-rng.c | 229 ++++++++++++++++++++++++++
>  4 files changed, 245 insertions(+)
>  create mode 100644 drivers/char/hw_random/rockchip-rng.c
> 
[...]
> diff --git a/drivers/char/hw_random/rockchip-rng.c b/drivers/char/hw_random/rockchip-rng.c
> new file mode 100644
> index 000000000000..6070abb73847
> --- /dev/null
> +++ b/drivers/char/hw_random/rockchip-rng.c
> @@ -0,0 +1,229 @@
[...]
> 
> +static int rk_rng_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct rk_rng *rk_rng;
> +	int ret;
> +
> +	rk_rng = devm_kzalloc(dev, sizeof(*rk_rng), GFP_KERNEL);
> +	if (!rk_rng)
> +		return -ENOMEM;
> +
> +	rk_rng->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(rk_rng->base))
> +		return PTR_ERR(rk_rng->base);
> +
> +	rk_rng->clk_num = devm_clk_bulk_get_all(dev, &rk_rng->clk_bulks);
> +	if (rk_rng->clk_num < 0)
> +		return dev_err_probe(dev, rk_rng->clk_num,
> +				     "Failed to get clks property\n");
> +
> +	rk_rng->rst = devm_reset_control_array_get(&pdev->dev, false, false);

Please use devm_reset_control_array_get_exclusive() instead.


regards
Philipp