From patchwork Wed Aug 28 16:26:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomer Maimon X-Patchwork-Id: 11119369 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 64C2D14F7 for ; Wed, 28 Aug 2019 16:27:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44D0622CF5 for ; Wed, 28 Aug 2019 16:27:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726860AbfH1Q1f (ORCPT ); Wed, 28 Aug 2019 12:27:35 -0400 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:42163 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726407AbfH1Q1f (ORCPT ); Wed, 28 Aug 2019 12:27:35 -0400 Received: from taln60.nuvoton.co.il (ntil-fw [212.199.177.25]) by herzl.nuvoton.co.il (8.13.8/8.13.8) with ESMTP id x7SGQJeN004240; Wed, 28 Aug 2019 19:26:19 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 10070) id AB1A462CAA; Wed, 28 Aug 2019 19:26:19 +0300 (IDT) From: Tomer Maimon To: mpm@selenic.com, herbert@gondor.apana.org.au, arnd@arndb.de, gregkh@linuxfoundation.org, robh+dt@kernel.org, mark.rutland@arm.com, avifishman70@gmail.com, tali.perry1@gmail.com, venture@google.com, yuenn@google.com, benjaminfair@google.com, sumit.garg@linaro.org, jens.wiklander@linaro.org, vkoul@kernel.org, tglx@linutronix.de, joel@jms.id.au Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, openbmc@lists.ozlabs.org, Tomer Maimon Subject: [PATCH v1 2/2] hwrng: npcm: add NPCM RNG driver Date: Wed, 28 Aug 2019 19:26:17 +0300 Message-Id: <20190828162617.237398-3-tmaimon77@gmail.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190828162617.237398-1-tmaimon77@gmail.com> References: <20190828162617.237398-1-tmaimon77@gmail.com> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Add Nuvoton NPCM BMC Random Number Generator(RNG) driver. Signed-off-by: Tomer Maimon --- drivers/char/hw_random/Kconfig | 13 ++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/npcm-rng.c | 207 ++++++++++++++++++++++++++++++ 3 files changed, 221 insertions(+) create mode 100644 drivers/char/hw_random/npcm-rng.c diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 59f25286befe..87a1c30e7958 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -440,6 +440,19 @@ config HW_RANDOM_OPTEE If unsure, say Y. +config HW_RANDOM_NPCM + tristate "NPCM Random Number Generator support" + depends on ARCH_NPCM || COMPILE_TEST + default HW_RANDOM + help + This driver provides support for the Random Number + Generator hardware available in Nuvoton NPCM SoCs. + + To compile this driver as a module, choose M here: the + module will be called npcm-rng. + + If unsure, say Y. + endif # HW_RANDOM config UML_RANDOM diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 7c9ef4a7667f..17b6d4e6d591 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -39,3 +39,4 @@ obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o +obj-$(CONFIG_HW_RANDOM_NPCM) += npcm-rng.o diff --git a/drivers/char/hw_random/npcm-rng.c b/drivers/char/hw_random/npcm-rng.c new file mode 100644 index 000000000000..5b4b1b6cb362 --- /dev/null +++ b/drivers/char/hw_random/npcm-rng.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2019 Nuvoton Technology corporation. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define NPCM_RNGCS_REG 0x00 /* Control and status register */ +#define NPCM_RNGD_REG 0x04 /* Data register */ +#define NPCM_RNGMODE_REG 0x08 /* Mode register */ + +#define NPCM_RNG_CLK_SET_25MHZ GENMASK(4, 3) /* 20-25 MHz */ +#define NPCM_RNG_DATA_VALID BIT(1) +#define NPCM_RNG_ENABLE BIT(0) +#define NPCM_RNG_M1ROSEL BIT(1) + +#define NPCM_RNG_TIMEOUT_POLL 20 + +#define to_npcm_rng(p) container_of(p, struct npcm_rng, rng) + +struct npcm_rng { + void __iomem *base; + struct hwrng rng; +}; + +static int npcm_rng_init(struct hwrng *rng) +{ + struct npcm_rng *priv = to_npcm_rng(rng); + u32 val; + + val = readl(priv->base + NPCM_RNGCS_REG); + val |= NPCM_RNG_ENABLE; + writel(val, priv->base + NPCM_RNGCS_REG); + + return 0; +} + +static void npcm_rng_cleanup(struct hwrng *rng) +{ + struct npcm_rng *priv = to_npcm_rng(rng); + u32 val; + + val = readl(priv->base + NPCM_RNGCS_REG); + val &= ~NPCM_RNG_ENABLE; + writel(val, priv->base + NPCM_RNGCS_REG); +} + +static bool npcm_rng_wait_ready(struct hwrng *rng, bool wait) +{ + struct npcm_rng *priv = to_npcm_rng(rng); + int timeout_cnt = 0; + int ready; + + ready = readl(priv->base + NPCM_RNGCS_REG) & NPCM_RNG_DATA_VALID; + while ((ready == 0) && (timeout_cnt < NPCM_RNG_TIMEOUT_POLL)) { + usleep_range(500, 1000); + ready = readl(priv->base + NPCM_RNGCS_REG) & + NPCM_RNG_DATA_VALID; + timeout_cnt++; + } + + return !!ready; +} + +static int npcm_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct npcm_rng *priv = to_npcm_rng(rng); + int retval = 0; + + pm_runtime_get_sync((struct device *)priv->rng.priv); + + while (max >= sizeof(u32)) { + if (!npcm_rng_wait_ready(rng, wait)) + break; + + *(u32 *)buf = readl(priv->base + NPCM_RNGD_REG); + retval += sizeof(u32); + buf += sizeof(u32); + max -= sizeof(u32); + } + + pm_runtime_mark_last_busy((struct device *)priv->rng.priv); + pm_runtime_put_sync_autosuspend((struct device *)priv->rng.priv); + + return retval || !wait ? retval : -EIO; +} + +static int npcm_rng_probe(struct platform_device *pdev) +{ + struct npcm_rng *priv; + struct resource *res; + u32 quality; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->rng.name = pdev->name; +#ifndef CONFIG_PM + priv->rng.init = npcm_rng_init; + priv->rng.cleanup = npcm_rng_cleanup; +#endif + priv->rng.read = npcm_rng_read; + priv->rng.priv = (unsigned long)&pdev->dev; + if (of_property_read_u32(pdev->dev.of_node, "quality", &quality)) + priv->rng.quality = 1000; + else + priv->rng.quality = quality; + + writel(NPCM_RNG_M1ROSEL, priv->base + NPCM_RNGMODE_REG); +#ifndef CONFIG_PM + writel(NPCM_RNG_CLK_SET_25MHZ, priv->base + NPCM_RNGCS_REG); +#else + writel(NPCM_RNG_CLK_SET_25MHZ | NPCM_RNG_ENABLE, + priv->base + NPCM_RNGCS_REG); +#endif + + ret = devm_hwrng_register(&pdev->dev, &priv->rng); + if (ret) { + dev_err(&pdev->dev, "Failed to register rng device: %d\n", + ret); + return ret; + } + + dev_set_drvdata(&pdev->dev, priv); + pm_runtime_set_autosuspend_delay(&pdev->dev, 100); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + dev_info(&pdev->dev, "Random Number Generator Probed\n"); + + return 0; +} + +static int npcm_rng_remove(struct platform_device *pdev) +{ + struct npcm_rng *priv = platform_get_drvdata(pdev); + + hwrng_unregister(&priv->rng); + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + + return 0; +} + +#ifdef CONFIG_PM +static int npcm_rng_runtime_suspend(struct device *dev) +{ + struct npcm_rng *priv = dev_get_drvdata(dev); + + npcm_rng_cleanup(&priv->rng); + + return 0; +} + +static int npcm_rng_runtime_resume(struct device *dev) +{ + struct npcm_rng *priv = dev_get_drvdata(dev); + + return npcm_rng_init(&priv->rng); +} +#endif + +static const struct dev_pm_ops npcm_rng_pm_ops = { + SET_RUNTIME_PM_OPS(npcm_rng_runtime_suspend, + npcm_rng_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) +}; + +static const struct of_device_id rng_dt_id[] = { + { .compatible = "nuvoton,npcm750-rng", }, + {}, +}; +MODULE_DEVICE_TABLE(of, rng_dt_id); + +static struct platform_driver npcm_rng_driver = { + .driver = { + .name = "npcm-rng", + .pm = &npcm_rng_pm_ops, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(rng_dt_id), + }, + .probe = npcm_rng_probe, + .remove = npcm_rng_remove, +}; + +module_platform_driver(npcm_rng_driver); + +MODULE_DESCRIPTION("Nuvoton NPCM Random Number Generator Driver"); +MODULE_AUTHOR("Tomer Maimon "); +MODULE_LICENSE("GPL v2");