From patchwork Wed Nov 5 09:33:15 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris BREZILLON X-Patchwork-Id: 5233031 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E11B8C11AC for ; Wed, 5 Nov 2014 09:36:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0CBD320179 for ; Wed, 5 Nov 2014 09:36:15 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1580920108 for ; Wed, 5 Nov 2014 09:36:14 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xlwyf-0000M4-3O; Wed, 05 Nov 2014 09:34:09 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xlwyb-0000Gg-0h for linux-arm-kernel@bombadil.infradead.org; Wed, 05 Nov 2014 09:34:05 +0000 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by casper.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XlwyY-0003qA-Vp for linux-arm-kernel@lists.infradead.org; Wed, 05 Nov 2014 09:34:03 +0000 Received: by mail.free-electrons.com (Postfix, from userid 106) id B46C24B7; Wed, 5 Nov 2014 10:33:20 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from localhost.localdomain (col31-4-88-188-83-94.fbx.proxad.net [88.188.83.94]) by mail.free-electrons.com (Postfix) with ESMTPSA id 1B33F41C; Wed, 5 Nov 2014 10:33:20 +0100 (CET) From: Boris Brezillon To: Mike Turquette Subject: [PATCH 2/2] clk: at91: usb: fix at91sam9x5 recalc, round and set rate Date: Wed, 5 Nov 2014 10:33:15 +0100 Message-Id: <1415179995-25062-3-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1415179995-25062-1-git-send-email-boris.brezillon@free-electrons.com> References: <1415179995-25062-1-git-send-email-boris.brezillon@free-electrons.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141105_093403_053556_7B0EB216 X-CRM114-Status: GOOD ( 13.73 ) X-Spam-Score: -1.8 (-) Cc: Boris Brezillon , Nicolas Ferre , Alexandre Belloni , Andreas Henriksson , Jean-Christophe Plagniol-Villard , Andrew Victor , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 First check for rate == 0 in set_rate and round_rate to avoid div by zero. Then, in order to get the closest rate, round all divisions to the closest result instead of rounding them down. Signed-off-by: Boris Brezillon --- drivers/clk/at91/clk-usb.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c index 5b3b63c..7980e8c 100644 --- a/drivers/clk/at91/clk-usb.c +++ b/drivers/clk/at91/clk-usb.c @@ -52,7 +52,8 @@ static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw, tmp = pmc_read(pmc, AT91_PMC_USB); usbdiv = (tmp & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT; - return parent_rate / (usbdiv + 1); + + return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1)); } static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate, @@ -62,19 +63,19 @@ static long at91sam9x5_clk_usb_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long bestrate; unsigned long tmp; + if (!rate) + return DIV_ROUND_CLOSEST(*parent_rate, SAM9X5_USB_MAX_DIV + 1); + if (rate >= *parent_rate) return *parent_rate; - div = *parent_rate / rate; - if (div >= SAM9X5_USB_MAX_DIV) - return *parent_rate / (SAM9X5_USB_MAX_DIV + 1); + div = DIV_ROUND_CLOSEST(*parent_rate, rate); + if (div > SAM9X5_USB_MAX_DIV + 1) + div = SAM9X5_USB_MAX_DIV + 1; + else if (!div) + div = 1; - bestrate = *parent_rate / div; - tmp = *parent_rate / (div + 1); - if (bestrate - rate > rate - tmp) - bestrate = tmp; - - return bestrate; + return DIV_ROUND_CLOSEST(*parent_rate, div); } static int at91sam9x5_clk_usb_set_parent(struct clk_hw *hw, u8 index) @@ -106,9 +107,13 @@ static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate, u32 tmp; struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw); struct at91_pmc *pmc = usb->pmc; - unsigned long div = parent_rate / rate; + unsigned long div; - if (parent_rate % rate || div < 1 || div >= SAM9X5_USB_MAX_DIV) + if (!rate) + return -EINVAL; + + div = DIV_ROUND_CLOSEST(parent_rate, rate); + if (div > SAM9X5_USB_MAX_DIV + 1 || !div) return -EINVAL; tmp = pmc_read(pmc, AT91_PMC_USB) & ~AT91_PMC_OHCIUSBDIV;