From patchwork Tue Jul 30 16:11:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Golle X-Patchwork-Id: 13747593 X-Patchwork-Delegate: herbert@gondor.apana.org.au Received: from pidgin.makrotopia.org (pidgin.makrotopia.org [185.142.180.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BF84B1917EC; Tue, 30 Jul 2024 16:11:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.142.180.65 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722355882; cv=none; b=KhIwjJr0bFfd6qogtN4ijJZMmD1mKWXHwP27FxFWs3fvLIababfkOp45BQwXpqPlUYnXtFy4zm/Sy8+JhsTaweFsSals7cZUVwKQb5Ks3CbaFFoq5jJVd9vIj3kigG+BS7A6FOWubia1Ckfjq3wgBcoxLpoavhV4Uk0t6zzGxIk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722355882; c=relaxed/simple; bh=8Hra6Msh5RuH9SWqep6wwP7oAK6v3huO+m0XVJLtrhs=; h=Date:From:To:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RFLd8FpigqdjzmIFLkE8dngr+bOFm2YsNLbYFLoqD9H0FXtmWfvI/xAyc1xP2LYLw8S/2b+LIUEjRV1PoqssIl+gH608Iw1BBelrjKuDXKeHiGGgrq0OEcNooOwOo/B1zYpow2MBf4OkFYcpHyjxB2pVjT1zMKKjFd0Etk4LJH4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org; spf=pass smtp.mailfrom=makrotopia.org; arc=none smtp.client-ip=185.142.180.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=makrotopia.org Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.98) (envelope-from ) id 1sYpRL-000000002MR-3rqc; Tue, 30 Jul 2024 16:11:08 +0000 Date: Tue, 30 Jul 2024 17:11:04 +0100 From: Daniel Golle To: Daniel Golle , Aurelien Jarno , Olivia Mackall , Herbert Xu , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Philipp Zabel , Dragan Simic , Uwe =?iso-8859-1?q?Kleine-K=F6nig?= , Cristian Ciocaltea , Sascha Hauer , Francesco Dolcini , Ard Biesheuvel , linux-crypto@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 2/3] hwrng: add hwrng driver for Rockchip RK3568 SoC Message-ID: References: Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: From: Aurelien Jarno 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 RK3568 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 [daniel@makrotpia.org: code style fixes] Signed-off-by: Daniel Golle Acked-by: Krzysztof Kozlowski --- MAINTAINERS | 1 + drivers/char/hw_random/Kconfig | 14 ++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/rockchip-rng.c | 227 ++++++++++++++++++++++++++ 4 files changed, 243 insertions(+) create mode 100644 drivers/char/hw_random/rockchip-rng.c diff --git a/MAINTAINERS b/MAINTAINERS index 9b75626b54e16..369778c7ddcc4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -19727,6 +19727,7 @@ M: Daniel Golle M: Aurelien Jarno S: Maintained F: Documentation/devicetree/bindings/rng/rockchip,rk3568-rng.yaml +F: drivers/char/hw_random/rockchip-rng.c ROCKCHIP RASTER 2D GRAPHIC ACCELERATION UNIT DRIVER M: Jacob Chen diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 01e2e1ef82cf9..4a339c18a3ccc 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -572,6 +572,20 @@ config HW_RANDOM_JH7110 To compile this driver as a module, choose M here. The module will be called jh7110-trng. +config HW_RANDOM_ROCKCHIP + tristate "Rockchip True Random Number Generator" + depends on HW_RANDOM && (ARCH_ROCKCHIP || COMPILE_TEST) + depends on HAS_IOMEM + default HW_RANDOM + help + This driver provides kernel-side support for the True Random Number + Generator hardware found on some Rockchip SoC like RK3566 or RK3568. + + To compile this driver as a module, choose M here: the + module will be called rockchip-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 32549a1186dc5..01f012eab4400 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -48,4 +48,5 @@ obj-$(CONFIG_HW_RANDOM_XIPHERA) += xiphera-trng.o obj-$(CONFIG_HW_RANDOM_ARM_SMCCC_TRNG) += arm_smccc_trng.o obj-$(CONFIG_HW_RANDOM_CN10K) += cn10k-rng.o obj-$(CONFIG_HW_RANDOM_POLARFIRE_SOC) += mpfs-rng.o +obj-$(CONFIG_HW_RANDOM_ROCKCHIP) += rockchip-rng.o obj-$(CONFIG_HW_RANDOM_JH7110) += jh7110-trng.o diff --git a/drivers/char/hw_random/rockchip-rng.c b/drivers/char/hw_random/rockchip-rng.c new file mode 100644 index 0000000000000..a8ccaf14c2c27 --- /dev/null +++ b/drivers/char/hw_random/rockchip-rng.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * rockchip-rng.c True Random Number Generator driver for Rockchip RK3568 SoC + * + * Copyright (c) 2018, Fuzhou Rockchip Electronics Co., Ltd. + * Copyright (c) 2022, Aurelien Jarno + * Authors: + * Lin Jinhan + * Aurelien Jarno + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define RK_RNG_AUTOSUSPEND_DELAY 100 +#define RK_RNG_MAX_BYTE 32 +#define RK_RNG_POLL_PERIOD_US 100 +#define RK_RNG_POLL_TIMEOUT_US 10000 + +/* + * TRNG collects osc ring output bit every RK_RNG_SAMPLE_CNT time. The value is + * a tradeoff between speed and quality and has been adjusted to get a quality + * of ~900 (~87.5% of FIPS 140-2 successes). + */ +#define RK_RNG_SAMPLE_CNT 1000 + +/* TRNG registers from RK3568 TRM-Part2, section 5.4.1 */ +#define TRNG_RST_CTL 0x0004 +#define TRNG_RNG_CTL 0x0400 +#define TRNG_RNG_CTL_LEN_64_BIT (0x00 << 4) +#define TRNG_RNG_CTL_LEN_128_BIT (0x01 << 4) +#define TRNG_RNG_CTL_LEN_192_BIT (0x02 << 4) +#define TRNG_RNG_CTL_LEN_256_BIT (0x03 << 4) +#define TRNG_RNG_CTL_OSC_RING_SPEED_0 (0x00 << 2) +#define TRNG_RNG_CTL_OSC_RING_SPEED_1 (0x01 << 2) +#define TRNG_RNG_CTL_OSC_RING_SPEED_2 (0x02 << 2) +#define TRNG_RNG_CTL_OSC_RING_SPEED_3 (0x03 << 2) +#define TRNG_RNG_CTL_MASK GENMASK(15, 0) +#define TRNG_RNG_CTL_ENABLE BIT(1) +#define TRNG_RNG_CTL_START BIT(0) +#define TRNG_RNG_SAMPLE_CNT 0x0404 +#define TRNG_RNG_DOUT 0x0410 + +struct rk_rng { + struct hwrng rng; + void __iomem *base; + struct reset_control *rst; + int clk_num; + struct clk_bulk_data *clk_bulks; +}; + +/* The mask in the upper 16 bits determines the bits that are updated */ +static void rk_rng_write_ctl(struct rk_rng *rng, u32 val, u32 mask) +{ + writel((mask << 16) | val, rng->base + TRNG_RNG_CTL); +} + +static int rk_rng_init(struct hwrng *rng) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + int ret; + + /* start clocks */ + ret = clk_bulk_prepare_enable(rk_rng->clk_num, rk_rng->clk_bulks); + if (ret < 0) { + dev_err((struct device *) rk_rng->rng.priv, + "Failed to enable clks %d\n", ret); + return ret; + } + + /* set the sample period */ + writel(RK_RNG_SAMPLE_CNT, rk_rng->base + TRNG_RNG_SAMPLE_CNT); + + /* set osc ring speed and enable it */ + rk_rng_write_ctl(rk_rng, TRNG_RNG_CTL_LEN_256_BIT | + TRNG_RNG_CTL_OSC_RING_SPEED_0 | + TRNG_RNG_CTL_ENABLE, + TRNG_RNG_CTL_MASK); + + return 0; +} + +static void rk_rng_cleanup(struct hwrng *rng) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + + /* stop TRNG */ + rk_rng_write_ctl(rk_rng, 0, TRNG_RNG_CTL_MASK); + + /* stop clocks */ + clk_bulk_disable_unprepare(rk_rng->clk_num, rk_rng->clk_bulks); +} + +static int rk_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + struct rk_rng *rk_rng = container_of(rng, struct rk_rng, rng); + size_t to_read = min_t(size_t, max, RK_RNG_MAX_BYTE); + u32 reg; + int ret = 0; + + ret = pm_runtime_resume_and_get((struct device *) rk_rng->rng.priv); + if (ret < 0) + return ret; + + /* Start collecting random data */ + rk_rng_write_ctl(rk_rng, TRNG_RNG_CTL_START, TRNG_RNG_CTL_START); + + ret = readl_poll_timeout(rk_rng->base + TRNG_RNG_CTL, reg, + !(reg & TRNG_RNG_CTL_START), + RK_RNG_POLL_PERIOD_US, + RK_RNG_POLL_TIMEOUT_US); + if (ret < 0) + goto out; + + /* Read random data stored in the registers */ + memcpy_fromio(buf, rk_rng->base + TRNG_RNG_DOUT, to_read); +out: + pm_runtime_mark_last_busy((struct device *) rk_rng->rng.priv); + pm_runtime_put_sync_autosuspend((struct device *) rk_rng->rng.priv); + + return (ret < 0) ? ret : to_read; +} + +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_exclusive(&pdev->dev); + if (IS_ERR(rk_rng->rst)) + return dev_err_probe(dev, PTR_ERR(rk_rng->rst), + "Failed to get reset property\n"); + + reset_control_assert(rk_rng->rst); + udelay(2); + reset_control_deassert(rk_rng->rst); + + platform_set_drvdata(pdev, rk_rng); + + rk_rng->rng.name = dev_driver_string(dev); + if (!IS_ENABLED(CONFIG_PM)) { + rk_rng->rng.init = rk_rng_init; + rk_rng->rng.cleanup = rk_rng_cleanup; + } + rk_rng->rng.read = rk_rng_read; + rk_rng->rng.priv = (unsigned long) dev; + rk_rng->rng.quality = 900; + + pm_runtime_set_autosuspend_delay(dev, RK_RNG_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(dev); + devm_pm_runtime_enable(dev); + + ret = devm_hwrng_register(dev, &rk_rng->rng); + if (ret) + return dev_err_probe(&pdev->dev, ret, "Failed to register Rockchip hwrng\n"); + + return 0; +} + +static int __maybe_unused rk_rng_runtime_suspend(struct device *dev) +{ + struct rk_rng *rk_rng = dev_get_drvdata(dev); + + rk_rng_cleanup(&rk_rng->rng); + + return 0; +} + +static int __maybe_unused rk_rng_runtime_resume(struct device *dev) +{ + struct rk_rng *rk_rng = dev_get_drvdata(dev); + + return rk_rng_init(&rk_rng->rng); +} + +static const struct dev_pm_ops rk_rng_pm_ops = { + SET_RUNTIME_PM_OPS(rk_rng_runtime_suspend, + rk_rng_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) +}; + +static const struct of_device_id rk_rng_dt_match[] = { + { .compatible = "rockchip,rk3568-rng", }, + { /* sentinel */ }, +}; + +MODULE_DEVICE_TABLE(of, rk_rng_dt_match); + +static struct platform_driver rk_rng_driver = { + .driver = { + .name = "rockchip-rng", + .pm = &rk_rng_pm_ops, + .of_match_table = rk_rng_dt_match, + }, + .probe = rk_rng_probe, +}; + +module_platform_driver(rk_rng_driver); + +MODULE_DESCRIPTION("Rockchip RK3568 True Random Number Generator driver"); +MODULE_AUTHOR("Lin Jinhan "); +MODULE_AUTHOR("Aurelien Jarno "); +MODULE_AUTHOR("Daniel Golle "); +MODULE_LICENSE("GPL");