From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758948AbdKHArp (ORCPT ); Tue, 7 Nov 2017 19:47:45 -0500 Received: from mail-qt0-f194.google.com ([209.85.216.194]:51792 "EHLO mail-qt0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934118AbdKHApS (ORCPT ); Tue, 7 Nov 2017 19:45:18 -0500 X-Google-Smtp-Source: ABhQp+TBiBoxV2u1idnVmiitGX55WvRs+utGJ2sITOnhkdMGgRQjYfPVH0I/8cvjfWrCjueENn4lgg== From: Florian Fainelli To: linux-kernel@vger.kernel.org Cc: Florian Fainelli , Matt Mackall , Herbert Xu , Rob Herring , Mark Rutland , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com (maintainer:BROADCOM BCM281XX/BCM11XXX/BCM216XX ARM ARCHITE...), Eric Anholt , Stefan Wahren , PrasannaKumar Muralidharan , Russell King , Krzysztof Kozlowski , Harald Freudenberger , Sean Wang , Martin Kaiser , Steffen Trumtrar , linux-crypto@vger.kernel.org (open list:HARDWARE RANDOM NUMBER GENERATOR CORE), devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS), linux-rpi-kernel@lists.infradead.org (moderated list:BROADCOM BCM2835 ARM ARCHITECTURE), linux-arm-kernel@lists.infradead.org (moderated list:BROADCOM BCM2835 ARM ARCHITECTURE) Subject: [PATCH v2 07/12] hwrng: bcm2835-rng: Manage an optional clock Date: Tue, 7 Nov 2017 16:44:44 -0800 Message-Id: <20171108004449.32730-8-f.fainelli@gmail.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20171108004449.32730-1-f.fainelli@gmail.com> References: <20171108004449.32730-1-f.fainelli@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org One of the last steps before bcm63xx-rng can be eliminated is to manage a clock during hwrng::init and hwrng::cleanup, so fetch it in the probe function, and manage it during these two steps when valid. Signed-off-by: Florian Fainelli --- drivers/char/hw_random/bcm2835-rng.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c index ed20e0b6b7ae..99b56fd5482c 100644 --- a/drivers/char/hw_random/bcm2835-rng.c +++ b/drivers/char/hw_random/bcm2835-rng.c @@ -15,6 +15,7 @@ #include #include #include +#include #define RNG_CTRL 0x0 #define RNG_STATUS 0x4 @@ -33,6 +34,7 @@ struct bcm2835_rng_priv { struct hwrng rng; void __iomem *base; bool mask_interrupts; + struct clk *clk; }; static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng) @@ -66,8 +68,15 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, static int bcm2835_rng_init(struct hwrng *rng) { struct bcm2835_rng_priv *priv = to_rng_priv(rng); + int ret = 0; u32 val; + if (!IS_ERR(priv->clk)) { + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + } + if (priv->mask_interrupts) { /* mask the interrupt */ val = readl(priv->base + RNG_INT_MASK); @@ -79,7 +88,7 @@ static int bcm2835_rng_init(struct hwrng *rng) __raw_writel(RNG_WARMUP_COUNT, priv->base + RNG_STATUS); __raw_writel(RNG_RBGEN, priv->base + RNG_CTRL); - return 0; + return ret; } static void bcm2835_rng_cleanup(struct hwrng *rng) @@ -88,6 +97,9 @@ static void bcm2835_rng_cleanup(struct hwrng *rng) /* disable rng hardware */ __raw_writel(0, priv->base + RNG_CTRL); + + if (!IS_ERR(priv->clk)) + clk_disable_unprepare(priv->clk); } struct bcm2835_rng_of_data { @@ -130,6 +142,9 @@ static int bcm2835_rng_probe(struct platform_device *pdev) return PTR_ERR(priv->base); } + /* Clock is optional on most platforms */ + priv->clk = devm_clk_get(dev, NULL); + priv->rng.name = "bcm2835-rng"; priv->rng.init = bcm2835_rng_init; priv->rng.read = bcm2835_rng_read; -- 2.9.3