From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754518Ab3COM4X (ORCPT ); Fri, 15 Mar 2013 08:56:23 -0400 Received: from mga01.intel.com ([192.55.52.88]:28046 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754221Ab3COM4U (ORCPT ); Fri, 15 Mar 2013 08:56:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,850,1355126400"; d="scan'208";a="307131338" Date: Fri, 15 Mar 2013 14:56:15 +0200 From: Heikki Krogerus To: Maxime Ripard Cc: linux-arm-kernel@lists.infradead.org, kevin@allwinnertech.com, sunny@allwinnertech.com, shuge@allwinnertech.com, Emilio =?iso-8859-1?Q?L=F3pez?= , Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] serial: 8250_dw: add support for clocks property when using DeviceTree Message-ID: <20130315125615.GA27560@xps8300> References: <1362694460-1919-1-git-send-email-maxime.ripard@free-electrons.com> <1362694460-1919-2-git-send-email-maxime.ripard@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1362694460-1919-2-git-send-email-maxime.ripard@free-electrons.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Thu, Mar 07, 2013 at 11:14:15PM +0100, Maxime Ripard wrote: > From: Emilio López > > This commit implements support for using the "clocks" DT property, instead > of having to use clock-frequency. > > Signed-off-by: Emilio López > --- > drivers/tty/serial/8250/8250_dw.c | 32 ++++++++++++++++++++++---------- > 1 file changed, 22 insertions(+), 10 deletions(-) > @@ -137,8 +140,15 @@ static int dw8250_probe_of(struct uart_port *p) > p->regshift = val; > > if (of_property_read_u32(np, "clock-frequency", &val)) { > - dev_err(p->dev, "no clock-frequency property set\n"); > - return -EINVAL; > + /* Get clk rate through clk driver if present */ > + data->clk = clk_get(p->dev, NULL); > + if (IS_ERR(data->clk)) { > + dev_err(p->dev, "clk or clock-frequency not defined\n"); > + return -EINVAL; > + } > + > + clk_prepare_enable(data->clk); > + val = clk_get_rate(data->clk); Don't get the clk here.. > } > p->uartclk = val; > > @@ -300,6 +310,12 @@ static int dw8250_probe(struct platform_device *pdev) Get it here so it is then handled for also others besides DT users. And prefer devm_clk_get(). Something like this: ... uart.port.membase = ioremap(regs->start, resource_size(regs)); if (!uart.port.membase) return -ENOMEM; + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->clk = devm_clk_get(&pdev->dev, NULL); + clk_prepare_enable(data->clk); + uart.port.iotype = UPIO_MEM; uart.port.serial_in = dw8250_serial_in; uart.port.serial_out = dw8250_serial_out; + uart.port.private_data = data; + uart.port.uartclk = clk_get_rate(data->clk); dw8250_setup_port(&uart); ... Then in dw8250_probe_of() you need to use the "clock-frequency" property only when p->uartclk is 0. Thanks, -- heikki