<div dir="ltr">Hi Vinod,<div><br></div><div>Thanks for your notification.</div><div><br></div><div>NPCM Hardware RNG is true RNG.</div><div><br></div><div>Tomer</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, 12 Sep 2019 at 19:47, Vinod Koul <<a href="mailto:vkoul@kernel.org">vkoul@kernel.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On 12-09-19, 12:01, Tomer Maimon wrote:<br>
> Add Nuvoton NPCM BMC Random Number Generator(RNG) driver.<br>
<br>
Is this a true RNG or a psedo RNG, in case of latter it should be added<br>
in drivers/crypto/. See crypto_register_rng()<br>
<br>
> <br>
> Signed-off-by: Tomer Maimon <<a href="mailto:tmaimon77@gmail.com" target="_blank">tmaimon77@gmail.com</a>><br>
> ---<br>
> drivers/char/hw_random/Kconfig | 13 +++<br>
> drivers/char/hw_random/Makefile | 1 +<br>
> drivers/char/hw_random/npcm-rng.c | 186 ++++++++++++++++++++++++++++++<br>
> 3 files changed, 200 insertions(+)<br>
> create mode 100644 drivers/char/hw_random/npcm-rng.c<br>
> <br>
> diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig<br>
> index 59f25286befe..87a1c30e7958 100644<br>
> --- a/drivers/char/hw_random/Kconfig<br>
> +++ b/drivers/char/hw_random/Kconfig<br>
> @@ -440,6 +440,19 @@ config HW_RANDOM_OPTEE<br>
> <br>
> If unsure, say Y.<br>
> <br>
> +config HW_RANDOM_NPCM<br>
> + tristate "NPCM Random Number Generator support"<br>
> + depends on ARCH_NPCM || COMPILE_TEST<br>
> + default HW_RANDOM<br>
> + help<br>
> + This driver provides support for the Random Number<br>
> + Generator hardware available in Nuvoton NPCM SoCs.<br>
> +<br>
> + To compile this driver as a module, choose M here: the<br>
> + module will be called npcm-rng.<br>
> +<br>
> + If unsure, say Y.<br>
> +<br>
> endif # HW_RANDOM<br>
> <br>
> config UML_RANDOM<br>
> diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile<br>
> index 7c9ef4a7667f..17b6d4e6d591 100644<br>
> --- a/drivers/char/hw_random/Makefile<br>
> +++ b/drivers/char/hw_random/Makefile<br>
> @@ -39,3 +39,4 @@ obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o<br>
> obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o<br>
> obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o<br>
> obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o<br>
> +obj-$(CONFIG_HW_RANDOM_NPCM) += npcm-rng.o<br>
> diff --git a/drivers/char/hw_random/npcm-rng.c b/drivers/char/hw_random/npcm-rng.c<br>
> new file mode 100644<br>
> index 000000000000..b7c8c7e13a49<br>
> --- /dev/null<br>
> +++ b/drivers/char/hw_random/npcm-rng.c<br>
> @@ -0,0 +1,186 @@<br>
> +// SPDX-License-Identifier: GPL-2.0<br>
> +// Copyright (c) 2019 Nuvoton Technology corporation.<br>
> +<br>
> +#include <linux/kernel.h><br>
> +#include <linux/module.h><br>
> +#include <linux/io.h><br>
> +#include <linux/iopoll.h><br>
> +#include <linux/init.h><br>
> +#include <linux/random.h><br>
> +#include <linux/err.h><br>
> +#include <linux/platform_device.h><br>
> +#include <linux/hw_random.h><br>
> +#include <linux/delay.h><br>
> +#include <linux/of_irq.h><br>
> +#include <linux/pm_runtime.h><br>
> +<br>
> +#define NPCM_RNGCS_REG 0x00 /* Control and status register */<br>
> +#define NPCM_RNGD_REG 0x04 /* Data register */<br>
> +#define NPCM_RNGMODE_REG 0x08 /* Mode register */<br>
> +<br>
> +#define NPCM_RNG_CLK_SET_25MHZ GENMASK(4, 3) /* 20-25 MHz */<br>
> +#define NPCM_RNG_DATA_VALID BIT(1)<br>
> +#define NPCM_RNG_ENABLE BIT(0)<br>
> +#define NPCM_RNG_M1ROSEL BIT(1)<br>
> +<br>
> +#define NPCM_RNG_TIMEOUT_USEC 20000<br>
> +#define NPCM_RNG_POLL_USEC 1000<br>
> +<br>
> +#define to_npcm_rng(p) container_of(p, struct npcm_rng, rng)<br>
> +<br>
> +struct npcm_rng {<br>
> + void __iomem *base;<br>
> + struct hwrng rng;<br>
> +};<br>
> +<br>
> +static int npcm_rng_init(struct hwrng *rng)<br>
> +{<br>
> + struct npcm_rng *priv = to_npcm_rng(rng);<br>
> +<br>
> + writel(NPCM_RNG_CLK_SET_25MHZ | NPCM_RNG_ENABLE,<br>
> + priv->base + NPCM_RNGCS_REG);<br>
> +<br>
> + return 0;<br>
> +}<br>
> +<br>
> +static void npcm_rng_cleanup(struct hwrng *rng)<br>
> +{<br>
> + struct npcm_rng *priv = to_npcm_rng(rng);<br>
> +<br>
> + writel(NPCM_RNG_CLK_SET_25MHZ, priv->base + NPCM_RNGCS_REG);<br>
> +}<br>
> +<br>
> +static int npcm_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)<br>
> +{<br>
> + struct npcm_rng *priv = to_npcm_rng(rng);<br>
> + int retval = 0;<br>
> + int ready;<br>
> +<br>
> + pm_runtime_get_sync((struct device *)priv->rng.priv);<br>
> +<br>
> + while (max >= sizeof(u32)) {<br>
> + if (wait) {<br>
> + if (readl_poll_timeout(priv->base + NPCM_RNGCS_REG,<br>
> + ready,<br>
> + ready & NPCM_RNG_DATA_VALID,<br>
> + NPCM_RNG_POLL_USEC,<br>
> + NPCM_RNG_TIMEOUT_USEC))<br>
> + break;<br>
> + } else {<br>
> + if ((readl(priv->base + NPCM_RNGCS_REG) &<br>
> + NPCM_RNG_DATA_VALID) == 0)<br>
> + break;<br>
> + }<br>
> +<br>
> + *(u32 *)buf = readl(priv->base + NPCM_RNGD_REG);<br>
> + retval += sizeof(u32);<br>
> + buf += sizeof(u32);<br>
> + max -= sizeof(u32);<br>
> + }<br>
> +<br>
> + pm_runtime_mark_last_busy((struct device *)priv->rng.priv);<br>
> + pm_runtime_put_sync_autosuspend((struct device *)priv->rng.priv);<br>
> +<br>
> + return retval || !wait ? retval : -EIO;<br>
> +}<br>
> +<br>
> +static int npcm_rng_probe(struct platform_device *pdev)<br>
> +{<br>
> + struct npcm_rng *priv;<br>
> + struct resource *res;<br>
> + int ret;<br>
> +<br>
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);<br>
> + if (!priv)<br>
> + return -ENOMEM;<br>
> +<br>
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);<br>
> + priv->base = devm_ioremap_resource(&pdev->dev, res);<br>
> + if (IS_ERR(priv->base))<br>
> + return PTR_ERR(priv->base);<br>
> +<br>
> + dev_set_drvdata(&pdev->dev, priv);<br>
> + pm_runtime_set_autosuspend_delay(&pdev->dev, 100);<br>
> + pm_runtime_use_autosuspend(&pdev->dev);<br>
> + pm_runtime_enable(&pdev->dev);<br>
> +<br>
> +#ifndef CONFIG_PM<br>
> + priv->rng.init = npcm_rng_init;<br>
> + priv->rng.cleanup = npcm_rng_cleanup;<br>
> +#endif<br>
> + priv-><a href="http://rng.name" rel="noreferrer" target="_blank">rng.name</a> = pdev->name;<br>
> + priv->rng.read = npcm_rng_read;<br>
> + priv->rng.priv = (unsigned long)&pdev->dev;<br>
> + priv->rng.quality = 1000;<br>
> +<br>
> + writel(NPCM_RNG_M1ROSEL, priv->base + NPCM_RNGMODE_REG);<br>
> +<br>
> + ret = devm_hwrng_register(&pdev->dev, &priv->rng);<br>
> + if (ret) {<br>
> + dev_err(&pdev->dev, "Failed to register rng device: %d\n",<br>
> + ret);<br>
> + pm_runtime_disable(&pdev->dev);<br>
> + pm_runtime_set_suspended(&pdev->dev);<br>
> + return ret;<br>
> + }<br>
> +<br>
> + return 0;<br>
> +}<br>
> +<br>
> +static int npcm_rng_remove(struct platform_device *pdev)<br>
> +{<br>
> + struct npcm_rng *priv = platform_get_drvdata(pdev);<br>
> +<br>
> + devm_hwrng_unregister(&pdev->dev, &priv->rng);<br>
> + pm_runtime_disable(&pdev->dev);<br>
> + pm_runtime_set_suspended(&pdev->dev);<br>
> +<br>
> + return 0;<br>
> +}<br>
> +<br>
> +#ifdef CONFIG_PM<br>
> +static int npcm_rng_runtime_suspend(struct device *dev)<br>
> +{<br>
> + struct npcm_rng *priv = dev_get_drvdata(dev);<br>
> +<br>
> + npcm_rng_cleanup(&priv->rng);<br>
> +<br>
> + return 0;<br>
> +}<br>
> +<br>
> +static int npcm_rng_runtime_resume(struct device *dev)<br>
> +{<br>
> + struct npcm_rng *priv = dev_get_drvdata(dev);<br>
> +<br>
> + return npcm_rng_init(&priv->rng);<br>
> +}<br>
> +#endif<br>
> +<br>
> +static const struct dev_pm_ops npcm_rng_pm_ops = {<br>
> + SET_RUNTIME_PM_OPS(npcm_rng_runtime_suspend,<br>
> + npcm_rng_runtime_resume, NULL)<br>
> + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,<br>
> + pm_runtime_force_resume)<br>
> +};<br>
> +<br>
> +static const struct of_device_id rng_dt_id[] = {<br>
> + { .compatible = "nuvoton,npcm750-rng", },<br>
> + {},<br>
> +};<br>
> +MODULE_DEVICE_TABLE(of, rng_dt_id);<br>
> +<br>
> +static struct platform_driver npcm_rng_driver = {<br>
> + .driver = {<br>
> + .name = "npcm-rng",<br>
> + .pm = &npcm_rng_pm_ops,<br>
> + .of_match_table = of_match_ptr(rng_dt_id),<br>
> + },<br>
> + .probe = npcm_rng_probe,<br>
> + .remove = npcm_rng_remove,<br>
> +};<br>
> +<br>
> +module_platform_driver(npcm_rng_driver);<br>
> +<br>
> +MODULE_DESCRIPTION("Nuvoton NPCM Random Number Generator Driver");<br>
> +MODULE_AUTHOR("Tomer Maimon <<a href="mailto:tomer.maimon@nuvoton.com" target="_blank">tomer.maimon@nuvoton.com</a>>");<br>
> +MODULE_LICENSE("GPL v2");<br>
> -- <br>
> 2.18.0<br>
<br>
-- <br>
~Vinod<br>
</blockquote></div>