From patchwork Wed Feb 7 21:17:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Jernej_=C5=A0krabec?= X-Patchwork-Id: 10206069 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B74D660327 for ; Wed, 7 Feb 2018 21:17:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A6D61286F3 for ; Wed, 7 Feb 2018 21:17:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9ABBF2874E; Wed, 7 Feb 2018 21:17:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 12064286F3 for ; Wed, 7 Feb 2018 21:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=yu9w1wOl9dzCG+0NMWnWdOWTyzo59FDj2w2FVcLY8/M=; b=TOadiHgvoCYBVacesGAnlzpWyw SH+MvCzC6GNBWI+TMgCnDdQR4d4B68U3DEm3i3jOTa7TFMX58m0TzIfT/LtdnrlYwiAUg/Urlt94V RhfR8oT+fgs+XFW+91DMaQBLyiqIIZlv+mTkO63IH+MbuY4vDrx+jNKwLRt4i/WjPd76Gov+/E7pw 68+4HQoc6+ZBDita8xyJ3avdAN3u6xHfEI79x0o/Xk3g0/QTwJEs9wpU5E4xPaSHP339s+uSRVrOj 3DJPSdmbMPe4ZfL2KzBQVNBfLjnEpnsQHXrxMT7OQpZdF1+Tb677QQCwZIqWl0S+A7Nuyd9yZH6Ko kMoN1QQQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.89 #1 (Red Hat Linux)) id 1ejX69-0002uu-RV; Wed, 07 Feb 2018 21:17:45 +0000 Received: from mailoutvs4.siol.net ([213.250.19.137] helo=mail.siol.net) by bombadil.infradead.org with esmtps (Exim 4.89 #1 (Red Hat Linux)) id 1ejX65-0002tI-Fm for linux-arm-kernel@lists.infradead.org; Wed, 07 Feb 2018 21:17:43 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.siol.net (Postfix) with ESMTP id DD8FB522DEA; Wed, 7 Feb 2018 22:17:28 +0100 (CET) X-Virus-Scanned: amavisd-new at psrvmta10.zcs-production.pri Received: from mail.siol.net ([127.0.0.1]) by localhost (psrvmta10.zcs-production.pri [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id kC4E_lF9DCh3; Wed, 7 Feb 2018 22:17:28 +0100 (CET) Received: from mail.siol.net (localhost [127.0.0.1]) by mail.siol.net (Postfix) with ESMTPS id 472A6522E36; Wed, 7 Feb 2018 22:17:28 +0100 (CET) Received: from localhost.localdomain (cpe-86-58-68-135.ftth.triera.net [86.58.68.135]) (Authenticated sender: 031275009) by mail.siol.net (Postfix) with ESMTPSA id 8E35E522DEA; Wed, 7 Feb 2018 22:17:25 +0100 (CET) From: Jernej Skrabec To: maxime.ripard@free-electrons.com, wens@csie.org, airlied@linux.ie, robh+dt@kernel.org, mark.rutland@arm.com, mturquette@baylibre.com, sboyd@kernel.org, architt@codeaurora.org, a.hajda@samsung.com, Laurent.pinchart@ideasonboard.com, narmstrong@baylibre.com, Jose.Abreu@synopsys.com Subject: [PATCH v4 02/12] clk: sunxi-ng: Use u64 for calculation of nkmp rate Date: Wed, 7 Feb 2018 22:17:03 +0100 Message-Id: <20180207211713.3638-3-jernej.skrabec@siol.net> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180207211713.3638-1-jernej.skrabec@siol.net> References: <20180207211713.3638-1-jernej.skrabec@siol.net> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, jernej.skrabec@siol.net, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-sunxi@googlegroups.com, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When parent rate is 24MHz and multiplier N >= 180, intermediate clock rate doesn't fit in 32 bit variable anymore. Because of that, introduce function for calculating clock rate which uses 64 bit variable for intermediate result. Signed-off-by: Jernej Skrabec Acked-by: Maxime Ripard --- drivers/clk/sunxi-ng/ccu_nkmp.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c index a99068a08315..c3f6fe7be565 100644 --- a/drivers/clk/sunxi-ng/ccu_nkmp.c +++ b/drivers/clk/sunxi-ng/ccu_nkmp.c @@ -20,6 +20,18 @@ struct _ccu_nkmp { unsigned long p, min_p, max_p; }; +static unsigned long ccu_nkmp_calc_rate(unsigned long parent, + unsigned long n, unsigned long k, + unsigned long m, unsigned long p) +{ + u64 rate = parent; + + rate *= n * k; + do_div(rate, m * p); + + return rate; +} + static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, struct _ccu_nkmp *nkmp) { @@ -33,7 +45,9 @@ static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate, for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) { unsigned long tmp_rate; - tmp_rate = parent * _n * _k / (_m * _p); + tmp_rate = ccu_nkmp_calc_rate(parent, + _n, _k, + _m, _p); if (tmp_rate > rate) continue; @@ -107,7 +121,7 @@ static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw, p = reg >> nkmp->p.shift; p &= (1 << nkmp->p.width) - 1; - return (parent_rate * n * k >> p) / m; + return ccu_nkmp_calc_rate(parent_rate, n, k, m, 1 << p); } static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, @@ -127,7 +141,8 @@ static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate, ccu_nkmp_find_best(*parent_rate, rate, &_nkmp); - return *parent_rate * _nkmp.n * _nkmp.k / (_nkmp.m * _nkmp.p); + return ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k, + _nkmp.m, _nkmp.p); } static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate,