From patchwork Fri Sep 8 16:51:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gatien CHEVALLIER X-Patchwork-Id: 720953 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7CC1CCFA0A for ; Fri, 8 Sep 2023 16:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245323AbjIHQy7 (ORCPT ); Fri, 8 Sep 2023 12:54:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245288AbjIHQyw (ORCPT ); Fri, 8 Sep 2023 12:54:52 -0400 Received: from mx08-00178001.pphosted.com (mx08-00178001.pphosted.com [91.207.212.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E3A21FF9; Fri, 8 Sep 2023 09:54:18 -0700 (PDT) Received: from pps.filterd (m0369457.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 388DhjCH020949; Fri, 8 Sep 2023 18:53:56 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s= selector1; bh=UVCzEPUOFYm/fUt81a6TTT6V/OGVngLPpT/Z+K3A1yM=; b=LP Jtn1rL/3sIxf6cY0F/ys1+r4om4vrHzdd4iPE3z4l2B/R7BhBPwtO94aYRwgdSdq ewAdtyPlLVHM2TCZqunJkkv1gWjF3WWX2aSC1xjkA74yjZFaWJ7V0q7Tc4YK4mVS biOckH+RdKEKYYDOzGgGNWoiPHlza9glJ+GrV7y/yQWYn1/ZUT80kE1aIdIs/UMP OtWS6EkSMbXpHF7OtAGDqeDjiTgPrFEKx0g58SCA3brJ17YYplq9bgHvr0t+Tgl/ 9HpB7jc8cKYmX9/eMmh34iyLzYyVSFd413hWO3jqvm5kH1O14mj12UhTWaFIjezX zOOHyuTXDipmhaOsDrgw== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3sy88wgdyq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 08 Sep 2023 18:53:56 +0200 (MEST) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id DA57A10005B; Fri, 8 Sep 2023 18:53:55 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node1.st.com [10.75.129.69]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id D0CF4209EFC; Fri, 8 Sep 2023 18:53:55 +0200 (CEST) Received: from localhost (10.201.20.32) by SHFDAG1NODE1.st.com (10.75.129.69) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Fri, 8 Sep 2023 18:53:55 +0200 From: Gatien Chevallier To: Olivia Mackall , Herbert Xu , Rob Herring , Krzysztof Kozlowski , Maxime Coquelin , Alexandre Torgue CC: Lionel Debieve , , , , , , Gatien Chevallier Subject: [PATCH 09/10] hwrng: stm32 - rework power management sequences Date: Fri, 8 Sep 2023 18:51:19 +0200 Message-ID: <20230908165120.730867-10-gatien.chevallier@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230908165120.730867-1-gatien.chevallier@foss.st.com> References: <20230908165120.730867-1-gatien.chevallier@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.201.20.32] X-ClientProxiedBy: EQNCAS1NODE4.st.com (10.75.129.82) To SHFDAG1NODE1.st.com (10.75.129.69) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-09-08_12,2023-09-05_01,2023-05-22_02 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Implement stm32_rng_suspend()/stm32_rng_resume() low-power APIs called when the hardware block context will be lost. There is no need to save the RNG_CR register in stm32_rng_runtime_suspend() as the context is not lost. Therefore, only enable/disable the RNG in the runtime sequences. Signed-off-by: Gatien Chevallier --- drivers/char/hw_random/stm32-rng.c | 100 +++++++++++++++++++++++++++-- 1 file changed, 93 insertions(+), 7 deletions(-) diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 0243b889ac54..3ac6712324c7 100644 --- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -55,11 +55,25 @@ struct stm32_rng_data { bool has_cond_reset; }; +/** + * struct stm32_rng_config - RNG configuration data + * + * @cr: RNG configuration. 0 means default hardware RNG configuration + * @nscr: Noise sources control configuration. + * @htcr: Health tests configuration. + */ +struct stm32_rng_config { + u32 cr; + u32 nscr; + u32 htcr; +}; + struct stm32_rng_private { struct hwrng rng; void __iomem *base; struct clk *clk; struct reset_control *rst; + struct stm32_rng_config pm_conf; const struct stm32_rng_data *data; bool ced; bool lock_conf; @@ -355,11 +369,10 @@ static int stm32_rng_remove(struct platform_device *ofdev) return 0; } -#ifdef CONFIG_PM static int stm32_rng_runtime_suspend(struct device *dev) { - u32 reg; struct stm32_rng_private *priv = dev_get_drvdata(dev); + u32 reg; reg = readl_relaxed(priv->base + RNG_CR); reg &= ~RNG_CR_RNGEN; @@ -369,25 +382,98 @@ static int stm32_rng_runtime_suspend(struct device *dev) return 0; } +static int __maybe_unused stm32_rng_suspend(struct device *dev) +{ + struct stm32_rng_private *priv = dev_get_drvdata(dev); + + if (priv->data->has_cond_reset) { + priv->pm_conf.nscr = readl_relaxed(priv->base + RNG_NSCR); + priv->pm_conf.htcr = readl_relaxed(priv->base + RNG_HTCR); + } + + /* Do not save that RNG is enabled as it will be handled at resume */ + priv->pm_conf.cr = readl_relaxed(priv->base + RNG_CR) & ~RNG_CR_RNGEN; + + writel_relaxed(priv->pm_conf.cr, priv->base + RNG_CR); + + clk_disable_unprepare(priv->clk); + + return 0; +} + static int stm32_rng_runtime_resume(struct device *dev) { - u32 reg; struct stm32_rng_private *priv = dev_get_drvdata(dev); + int err; + u32 reg; + + err = clk_prepare_enable(priv->clk); + if (err) + return err; + + /* Clean error indications */ + writel_relaxed(0, priv->base + RNG_SR); - clk_prepare_enable(priv->clk); reg = readl_relaxed(priv->base + RNG_CR); reg |= RNG_CR_RNGEN; writel_relaxed(reg, priv->base + RNG_CR); return 0; } -#endif + +static int __maybe_unused stm32_rng_resume(struct device *dev) +{ + struct stm32_rng_private *priv = dev_get_drvdata(dev); + int err; + u32 reg; + + err = clk_prepare_enable(priv->clk); + if (err) + return err; + + /* Clean error indications */ + writel_relaxed(0, priv->base + RNG_SR); + + if (priv->data->has_cond_reset) { + /* + * Correct configuration in bits [29:4] must be set in the same + * access that set RNG_CR_CONDRST bit. Else config setting is + * not taken into account. CONFIGLOCK bit must also be unset but + * it is not handled at the moment. + */ + writel_relaxed(priv->pm_conf.cr | RNG_CR_CONDRST, priv->base + RNG_CR); + + writel_relaxed(priv->pm_conf.nscr, priv->base + RNG_NSCR); + writel_relaxed(priv->pm_conf.htcr, priv->base + RNG_HTCR); + + reg = readl_relaxed(priv->base + RNG_CR); + reg |= RNG_CR_RNGEN; + reg &= ~RNG_CR_CONDRST; + writel_relaxed(reg, priv->base + RNG_CR); + + err = readl_relaxed_poll_timeout_atomic(priv->base + RNG_CR, reg, + reg & ~RNG_CR_CONDRST, 10, 100000); + + if (err) { + clk_disable_unprepare(priv->clk); + dev_err((struct device *)priv->rng.priv, + "%s: timeout:%x CR: %x!\n", __func__, err, reg); + return -EINVAL; + } + } else { + reg = priv->pm_conf.cr; + reg |= RNG_CR_RNGEN; + writel_relaxed(reg, priv->base + RNG_CR); + } + + return 0; +} static const struct dev_pm_ops stm32_rng_pm_ops = { SET_RUNTIME_PM_OPS(stm32_rng_runtime_suspend, stm32_rng_runtime_resume, NULL) - SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, - pm_runtime_force_resume) + SET_SYSTEM_SLEEP_PM_OPS(stm32_rng_suspend, + stm32_rng_resume) }; static const struct stm32_rng_data stm32mp13_rng_data = {