From patchwork Tue Jul 4 17:32:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Kaiser X-Patchwork-Id: 699015 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 B96B9C001DB for ; Tue, 4 Jul 2023 17:33:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231642AbjGDRd5 (ORCPT ); Tue, 4 Jul 2023 13:33:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231455AbjGDRdy (ORCPT ); Tue, 4 Jul 2023 13:33:54 -0400 Received: from viti.kaiser.cx (viti.kaiser.cx [IPv6:2a01:238:43fe:e600:cd0c:bd4a:7a3:8e9f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9C94DA; Tue, 4 Jul 2023 10:33:52 -0700 (PDT) Received: from ipservice-092-217-072-126.092.217.pools.vodafone-ip.de ([92.217.72.126] helo=martin-debian-2.paytec.ch) by viti.kaiser.cx with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1qGjuP-0000yT-Uj; Tue, 04 Jul 2023 19:33:50 +0200 From: Martin Kaiser To: Herbert Xu Cc: Joshua Henderson , linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Martin Kaiser Subject: [PATCH 4/4] hwrng: pic32 - enable TRNG only while it's used Date: Tue, 4 Jul 2023 19:32:03 +0200 Message-Id: <20230704173203.70706-5-martin@kaiser.cx> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230704173203.70706-1-martin@kaiser.cx> References: <20230704173203.70706-1-martin@kaiser.cx> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The probe function enables the TRNG hardware before registering the driver. If registration fails, probe returns an error, but the TRNG remains enabled. Define init and cleanup functions, enable and disable the hardware there. Signed-off-by: Martin Kaiser --- drivers/char/hw_random/pic32-rng.c | 41 ++++++++++++++---------------- 1 file changed, 19 insertions(+), 22 deletions(-) diff --git a/drivers/char/hw_random/pic32-rng.c b/drivers/char/hw_random/pic32-rng.c index c1b3f5915f03..1902f4389a3f 100644 --- a/drivers/char/hw_random/pic32-rng.c +++ b/drivers/char/hw_random/pic32-rng.c @@ -38,6 +38,15 @@ struct pic32_rng { */ #define RNG_TIMEOUT 500 +static int pic32_rng_init(struct hwrng *rng) +{ + struct pic32_rng *priv = container_of(rng, struct pic32_rng, rng); + + /* enable TRNG in enhanced mode */ + writel(TRNGEN | TRNGMOD, priv->base + RNGCON); + return 0; +} + static int pic32_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { @@ -59,12 +68,17 @@ static int pic32_rng_read(struct hwrng *rng, void *buf, size_t max, return -EIO; } +static void pic32_rng_cleanup(struct hwrng *rng) +{ + struct pic32_rng *priv = container_of(rng, struct pic32_rng, rng); + + writel(0, priv->base + RNGCON); +} + static int pic32_rng_probe(struct platform_device *pdev) { struct pic32_rng *priv; struct clk *clk; - u32 v; - int ret; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -78,28 +92,12 @@ static int pic32_rng_probe(struct platform_device *pdev) if (IS_ERR(clk)) return PTR_ERR(clk); - /* enable TRNG in enhanced mode */ - v = TRNGEN | TRNGMOD; - writel(v, priv->base + RNGCON); - priv->rng.name = pdev->name; + priv->rng.init = pic32_rng_init; priv->rng.read = pic32_rng_read; + priv->rng.cleanup = pic32_rng_cleanup; - ret = devm_hwrng_register(&pdev->dev, &priv->rng); - if (ret) - return ret; - - platform_set_drvdata(pdev, priv); - - return 0; -} - -static int pic32_rng_remove(struct platform_device *pdev) -{ - struct pic32_rng *rng = platform_get_drvdata(pdev); - - writel(0, rng->base + RNGCON); - return 0; + return devm_hwrng_register(&pdev->dev, &priv->rng); } static const struct of_device_id pic32_rng_of_match[] __maybe_unused = { @@ -110,7 +108,6 @@ MODULE_DEVICE_TABLE(of, pic32_rng_of_match); static struct platform_driver pic32_rng_driver = { .probe = pic32_rng_probe, - .remove = pic32_rng_remove, .driver = { .name = "pic32-rng", .of_match_table = of_match_ptr(pic32_rng_of_match),