From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756751AbdKDNwH (ORCPT ); Sat, 4 Nov 2017 09:52:07 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:50540 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753304AbdKDNwE (ORCPT ); Sat, 4 Nov 2017 09:52:04 -0400 Date: Sat, 4 Nov 2017 14:50:54 +0100 (CET) From: Stefan Wahren To: Florian Fainelli Cc: Krzysztof Kozlowski , Ray Jui , Eric Anholt , Rob Herring , Steffen Trumtrar , Harald Freudenberger , Russell King , "moderated list:BROADCOM BCM2835 ARM ARCHITECTURE" , PrasannaKumar Muralidharan , Scott Branden , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Herbert Xu , Martin Kaiser , Matt Mackall , "maintainer:BROADCOM BCM281XX/BCM11XXX/BCM216XX ARM ARCHITE..." , Mark Rutland , "moderated list:BROADCOM BCM2835 ARM ARCHITECTURE" , linux-kernel@vger.kernel.org, Sean Wang , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" Message-ID: <944505791.223880.1509803454887@email.1und1.de> In-Reply-To: <20171102010408.27736-8-f.fainelli@gmail.com> References: <20171102010408.27736-1-f.fainelli@gmail.com> <20171102010408.27736-8-f.fainelli@gmail.com> Subject: Re: [PATCH 07/12] hwrng: bcm2835-rng: Manage an optional clock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Priority: 3 Importance: Medium X-Mailer: Open-Xchange Mailer v7.8.3-Rev35 X-Originating-Client: open-xchange-appsuite X-Provags-ID: V03:K0:qpeNMacHUyxIeU6bUMgTT6U91VWC9zl8P2DAspgwVZem/UUAV55 X2BShl1fu4Qqz/p/mGkyCt2UMeBMLpMZ3I2Es84IeIbSfiptTuDD9G5TDDCSZobNu9W7f2x l+Ke23v4FVBCmUjMnS9eacbsTMvTjkZYIh2n98mM0irOpB0oZVqEipRDJBp2O7wGbfwEjti fENYAvXqpDo/O9HkEY5Mw== X-UI-Out-Filterresults: notjunk:1;V01:K0:0qx9YxV1hK8=:xO6FX5+0N1wVpzo5nYlmXj xVq2zAvah3iAIIlY5lCoOjeRsoaRezLVT3+slOe3XZrTxoukdWhx805Rk9adTVYDS2JpQO6L7 UUu0eTTwbLn+5U+fLXmd63XPbpIWXIGTJcw4jiY91WORu1Gw5DakoR0W2Do+v6T2r1ajrzWSL 2Nixmok0OsyTV+KmrUkWUn9h5i2Yy+d4X9iKG0MVTaE3NGCMmyVpDjtWXJTKDsrKVP2CcRvVq AlbSCrq3xOorTNfuUFo/a3zUfk1djgcR3H7P0Ad4fGRD9FIZq/KwzxeY0FbcJZOBHQCav5ZSQ Phe5rE2LcV4wYUmz94SvasMsyI7bY3L3TbwxRP0quW6dLyq1/yHN2GMb0UWT75eI27FwYeJWi 2Lm8MOe73vLc4YYRZGJmZZ5kwGYl1ANc+WEIX3nEZANYiNvEg5RAMkmQeM1eVojMqV2aNXPBx rLHX6dCWI+joe4WLb/I/hjEoRktRefDv0B9lLkDy6LNrvk15YXjOt0TK7EEJaDm65qpymEVi/ 61SKgx2u8x4Yq5h2ebWfqpxmepJ1IPUJ8qZLIlmJd8OkGywpjvYO0mpLuMyg8/k3QLbrLf+Si Jr0L03CDbjDYth1H8OBevBrwbXh7Z4Blyp1Vb+18+EiGsmmfOw3jGu29zDpoMyg7soLWvvsSj 3j+iVXOWomonSnXB05I2jKTL6+mCYX085pdwybLtUvYPVNverxgPBimO1YI/p2w95b+Pz/Yle ns8Jr3C5CQhVkv2d8tfz6qC5jDnvPC8SBjK5VwLVRqeQF1M+29w/ClmXb6c= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Florian, > Florian Fainelli hat am 2. November 2017 um 02:04 geschrieben: > > > 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 | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c > index ed20e0b6b7ae..35928efb52e7 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) > @@ -67,6 +69,11 @@ static int bcm2835_rng_init(struct hwrng *rng) > { > struct bcm2835_rng_priv *priv = to_rng_priv(rng); > u32 val; > + int ret; > + > + ret = clk_prepare_enable(priv->clk); > + if (ret) > + return ret; > > if (priv->mask_interrupts) { > /* mask the interrupt */ > @@ -88,6 +95,8 @@ static void bcm2835_rng_cleanup(struct hwrng *rng) > > /* disable rng hardware */ > __raw_writel(0, priv->base + RNG_CTRL); > + > + clk_disable_unprepare(priv->clk); > } > > struct bcm2835_rng_of_data { > @@ -130,6 +139,11 @@ 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); > + if (IS_ERR(priv->clk)) > + priv->clk = NULL; at least in case of EPROBE_DEFERED this isn't the expected behavior. Maybe we should better trigger on non-existing clock? > + > priv->rng.name = "bcm2835-rng"; > priv->rng.init = bcm2835_rng_init; > priv->rng.read = bcm2835_rng_read; > -- > 2.9.3 >