From patchwork Fri Nov 16 01:52:49 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shinya Kuribayashi X-Patchwork-Id: 1752421 Return-Path: X-Original-To: patchwork-linux-sh@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id B0166DF2AB for ; Fri, 16 Nov 2012 01:52:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751209Ab2KPBwv (ORCPT ); Thu, 15 Nov 2012 20:52:51 -0500 Received: from relmlor3.renesas.com ([210.160.252.173]:47223 "EHLO relmlor3.renesas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750937Ab2KPBwu (ORCPT ); Thu, 15 Nov 2012 20:52:50 -0500 Received: from relmlir3.idc.renesas.com ([10.200.68.153]) by relmlor3.idc.renesas.com ( SJSMS) with ESMTP id <0MDK009M0581B650@relmlor3.idc.renesas.com>; Fri, 16 Nov 2012 10:52:49 +0900 (JST) Received: from relmlac2.idc.renesas.com ([10.200.69.22]) by relmlir3.idc.renesas.com ( SJSMS) with ESMTP id <0MDK009EU581ZH40@relmlir3.idc.renesas.com>; Fri, 16 Nov 2012 10:52:49 +0900 (JST) Received: by relmlac2.idc.renesas.com (Postfix, from userid 0) id A7A29280A4; Fri, 16 Nov 2012 10:52:49 +0900 (JST) Received: from relmlac2.idc.renesas.com (localhost [127.0.0.1]) by relmlac2.idc.renesas.com (Postfix) with ESMTP id A1086280A0; Fri, 16 Nov 2012 10:52:49 +0900 (JST) Received: from relmlii2.idc.renesas.com [10.200.68.66] by relmlac2.idc.renesas.com with ESMTP id LAZ20558; Fri, 16 Nov 2012 10:52:49 +0900 X-IronPort-AV: E=Sophos; i="4.83,261,1352041200"; d="scan'208"; a="106495110" Received: from unknown (HELO [10.161.64.55]) ([10.161.64.55]) by relmlii2.idc.renesas.com with ESMTP; Fri, 16 Nov 2012 10:52:49 +0900 Message-id: <50A59C71.3010900@renesas.com> Date: Fri, 16 Nov 2012 10:52:49 +0900 From: Shinya Kuribayashi User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:16.0) Gecko/20121026 Thunderbird/16.0.2 MIME-version: 1.0 To: lethal@linux-sh.org, magnus.damm@gmail.com, takashi.yoshii.zj@renesas.com, alan@linux.intel.com, gregkh@linuxfoundation.org Cc: rjw@sisk.pl, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org Subject: [PATCH v2 06/10] serial: sh-sci: support lower baud rate References: <509A0658.1010503@renesas.com> <509A0B4E.1030801@renesas.com> <20121116010107.GA6068@kroah.com> <50A59B9B.2010501@renesas.com> In-reply-to: <50A59B9B.2010501@renesas.com> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org From: Takashi Yoshii Support prescaler 1/16 and 1/64, in addition to current 1 and 1/4. Supporting below 2400bps was dropped long time ago in mainline. Since then, setting lower rate has been resulting in erroneous register value, without indicating any errors through API. This patch adds more prescaler to support lower rates again. This still doesn't check range, but we won't hit the case because even 50bps at 48MHz clock is now supported. Signed-off-by: Takashi Yoshii Signed-off-by: Shinya Kuribayashi --- drivers/tty/serial/sh-sci.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index ffeca65..3021912 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1814,7 +1814,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, { struct sci_port *s = to_sci_port(port); struct plat_sci_reg *reg; - unsigned int baud, smr_val, max_baud; + unsigned int baud, smr_val, max_baud, cks; int t = -1; /* @@ -1848,21 +1848,18 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); - serial_port_out(port, SCSMR, smr_val); + for (cks = 0; t >= 256 && cks <= 3; cks++) + t >>= 2; - dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t, - s->cfg->scscr); + dev_dbg(port->dev, "%s: SMR %x, cks %x, t %x, SCSCR %x\n", + __func__, smr_val, cks, t, s->cfg->scscr); if (t >= 0) { - if (t >= 256) { - serial_port_out(port, SCSMR, (serial_port_in(port, SCSMR) & ~3) | 1); - t >>= 2; - } else - serial_port_out(port, SCSMR, serial_port_in(port, SCSMR) & ~3); - + serial_port_out(port, SCSMR, (smr_val & ~3) | cks); serial_port_out(port, SCBRR, t); udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */ - } + } else + serial_port_out(port, SCSMR, smr_val); sci_init_pins(port, termios->c_cflag);