From patchwork Mon Sep 15 14:00:07 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frans Klaver X-Patchwork-Id: 4905921 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id ED8679F2EC for ; Mon, 15 Sep 2014 14:04:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E3CDE202A1 for ; Mon, 15 Sep 2014 14:06:55 +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 4152220274 for ; Mon, 15 Sep 2014 14:06:53 +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 1XTWtU-0006XW-JV; Mon, 15 Sep 2014 14:04:40 +0000 Received: from filter1.ibarracuda.nl ([83.247.7.10]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XTWsM-000475-Kn for linux-arm-kernel@lists.infradead.org; Mon, 15 Sep 2014 14:03:32 +0000 X-ASG-Debug-ID: 1410789665-0759e746c032220002-tbGyMd Received: from XSMCASSVR01.xsens-tech.local (rev-215.116.249.87.virtu.nl [87.249.116.215]) by filter1.ibarracuda.nl with ESMTP id AM7vml6nzubMcdRB (version=TLSv1 cipher=AES128-SHA bits=128 verify=NO); Mon, 15 Sep 2014 16:01:05 +0200 (CEST) X-Barracuda-Envelope-From: Frans.Klaver@xsens.com X-Barracuda-AUTH-User: xsenscom X-Barracuda-Apparent-Source-IP: 87.249.116.215 Received: from ci00147.xsens-tech.local (172.16.11.160) by XSMCASSVR01.xsens-tech.local (192.168.0.248) with Microsoft SMTP Server id 14.3.195.1; Mon, 15 Sep 2014 16:01:01 +0200 From: Frans Klaver To: Tony Lindgren Subject: [PATCH 1/4] tty: omap-serial: pull out calculation from baud_is_mode16 Date: Mon, 15 Sep 2014 16:00:07 +0200 X-ASG-Orig-Subj: [PATCH 1/4] tty: omap-serial: pull out calculation from baud_is_mode16 Message-ID: <1410789610-23059-2-git-send-email-frans.klaver@xsens.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1410789610-23059-1-git-send-email-frans.klaver@xsens.com> References: <1410789610-23059-1-git-send-email-frans.klaver@xsens.com> MIME-Version: 1.0 X-Originating-IP: [172.16.11.160] X-Barracuda-Connect: rev-215.116.249.87.virtu.nl[87.249.116.215] X-Barracuda-Start-Time: 1410789665 X-Barracuda-Encrypted: AES128-SHA X-Barracuda-URL: http://filter1.ibarracuda.nl:8000/cgi-mod/mark.cgi X-Virus-Scanned: by bsmtpd at ibarracuda.nl X-Barracuda-BRTS-Status: 1 X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=5.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.3.9505 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140915_070331_029472_1161E900 X-CRM114-Status: GOOD ( 11.30 ) X-Spam-Score: 0.0 (/) Cc: Mark Rutland , Frans Klaver , Alexey Pelykh , Pawel Moll , Ian Campbell , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Felipe Balbi , devicetree@vger.kernel.org, Rob Herring , linux-serial@vger.kernel.org, Kumar Gala , linux-omap@vger.kernel.org, Jiri Slaby , 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP To determine the correct divisor, we need to know the difference between the desired baud rate and the actual baud rate. The calculation for this difference is implemented twice within omap_serial_baud_is_mode16(). Pull out the calculation for easier maintenance. Signed-off-by: Frans Klaver --- drivers/tty/serial/omap-serial.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index d017cec..ae935ce 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -239,6 +239,22 @@ static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable) } /* + * Calculate the absolute difference between the desired and actual baud + * rate for the given mode. + */ +static inline int calculate_baud_abs_diff(struct uart_port *port, + unsigned int baud, unsigned int mode) +{ + unsigned int n = port->uartclk / (mode * baud); + int abs_diff = baud - (port->uartclk / (mode * n)); + + if (abs_diff < 0) + abs_diff = -abs_diff; + + return abs_diff; +} + +/* * serial_omap_baud_is_mode16 - check if baud rate is MODE16X * @port: uart port info * @baud: baudrate for which mode needs to be determined @@ -252,14 +268,8 @@ static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable) static bool serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud) { - unsigned int n13 = port->uartclk / (13 * baud); - unsigned int n16 = port->uartclk / (16 * baud); - int baudAbsDiff13 = baud - (port->uartclk / (13 * n13)); - int baudAbsDiff16 = baud - (port->uartclk / (16 * n16)); - if (baudAbsDiff13 < 0) - baudAbsDiff13 = -baudAbsDiff13; - if (baudAbsDiff16 < 0) - baudAbsDiff16 = -baudAbsDiff16; + int baudAbsDiff13 = calculate_baud_abs_diff(port, baud, 13); + int baudAbsDiff16 = calculate_baud_abs_diff(port, baud, 16); return (baudAbsDiff13 >= baudAbsDiff16); }