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: 13301520 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 385BFEB64D9 for ; Tue, 4 Jul 2023 17:34:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vPbzeMby7CzHBDJql6frpLXNivunc76ZGmY4erPkoSM=; b=e2oNxna6RLCE3m heEBCPjrQZds+lu7iDFEoNFDpc8VT5rSAAwoqC0x/EiL4279zjVbnef0d9wADT+aS/W8BPlWf5F8R QiXAjCT0TcjQBgMSGHTByrgJIXwPikiJvyHkJx8iXBnNQoUuDyUEStOgtaLeyp2qdkMDd7eTHycaD bkfvaIIYjW6KghzQFskK+qPvU8v8Nyk629cEIg3QCSnIvssHXkLZjBEyAoH7e+1tlKwlr3bJpb9WJ 5/RJhVqguvNbAhcza5ZnsjmwpQSGoxGCLQGN0AbdasXJS0tD4S66hPgXqhmZfYR2hn0smppfLgquG CIVY+cmGym7CpXQzG84Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qGjuZ-00DwKc-0e; Tue, 04 Jul 2023 17:33:59 +0000 Received: from viti.kaiser.cx ([2a01:238:43fe:e600:cd0c:bd4a:7a3:8e9f]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qGjuV-00DwHb-27 for linux-arm-kernel@lists.infradead.org; Tue, 04 Jul 2023 17:33:57 +0000 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230704_103355_845021_8D523A68 X-CRM114-Status: GOOD ( 16.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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),