From patchwork Tue Aug 11 17:21:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Valentin X-Patchwork-Id: 6993901 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 37D569F344 for ; Tue, 11 Aug 2015 17:22:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4492920490 for ; Tue, 11 Aug 2015 17:22:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2EC8C2060A for ; Tue, 11 Aug 2015 17:22:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754396AbbHKRVm (ORCPT ); Tue, 11 Aug 2015 13:21:42 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:34339 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755534AbbHKRVi (ORCPT ); Tue, 11 Aug 2015 13:21:38 -0400 Received: by pawu10 with SMTP id u10so168460138paw.1; Tue, 11 Aug 2015 10:21:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=/wLAQzaP06Tt/D/QqoHhhDH5Q8Cin1/oo2nlYxV65R4=; b=LydcDusYBdqqF3RbSW4S2Agb34cmv5UVvYbFtN8V+aP184lerlFHg0Amd+kKvLd44p gRCwmoigLDYAUUhCcArBiWV4ZoAZ51MN3nBA4CUcoCoTORwmC6tTjtiHWvYCqYTYBRrf FDifvPtjshkPTVMWTqN8aoqSoW6rywMskmm4BaW5soN9hGaxqUAZhNr3cjUEyrgeVK5G 12n60f3E66ed3NmQfdjE37wAx02eTiJui4GP1+bfMIsjazAqqYm9EfbeBb9UsSHT7gcw ZUDeIELgKQ30ADeS2/u2drosBErUX6Xzt9gihGvhNKP9j7xZdKcXF970yN0tva7vRfas oVEw== X-Received: by 10.68.200.40 with SMTP id jp8mr59663008pbc.16.1439313698187; Tue, 11 Aug 2015 10:21:38 -0700 (PDT) Received: from localhost (amazon.gigabitethernet4-0-6.asr1.snv2.gblx.net. [64.211.110.86]) by smtp.gmail.com with ESMTPSA id y2sm3382751pdp.0.2015.08.11.10.21.37 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Tue, 11 Aug 2015 10:21:37 -0700 (PDT) From: Eduardo Valentin To: Greg Kroah-Hartman , Jiri Slaby , Fabio Estevam Cc: Sascha Hauer , Linux PM , linux-serial@vger.kernel.org, LKML , Eduardo Valentin Subject: [PATCHv3 4/8] serial: imx: save and restore context in the suspend path Date: Tue, 11 Aug 2015 10:21:23 -0700 Message-Id: <1439313687-28502-5-git-send-email-edubezval@gmail.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1439313687-28502-1-git-send-email-edubezval@gmail.com> References: <1439313687-28502-1-git-send-email-edubezval@gmail.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.0 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, 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 This change teaches the imx serial driver to save its context and restore it across suspend and resume path. To do so, it introduces serial_imx_restore_context() and serial_imx_save_context() functions. They use a shadow set of registers to save key registers and restore them accordingly. These functions can be reused on other situations, when the device context is lost. Cc: Fabio Estevam Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Eduardo Valentin --- drivers/tty/serial/imx.c | 58 ++++++++++++++++++++++++++++++------------------ 1 file changed, 37 insertions(+), 21 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 167dea1..fe3d41c 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -217,6 +217,7 @@ struct imx_port { unsigned int dma_tx_nents; wait_queue_head_t dma_wait; unsigned int saved_reg[10]; + bool context_saved; }; struct imx_port_ucrs { @@ -1972,6 +1973,40 @@ static int serial_imx_remove(struct platform_device *pdev) return uart_remove_one_port(&imx_reg, &sport->port); } +static void serial_imx_restore_context(struct imx_port *sport) +{ + if (!sport->context_saved) + return; + + writel(sport->saved_reg[4], sport->port.membase + UFCR); + writel(sport->saved_reg[5], sport->port.membase + UESC); + writel(sport->saved_reg[6], sport->port.membase + UTIM); + writel(sport->saved_reg[7], sport->port.membase + UBIR); + writel(sport->saved_reg[8], sport->port.membase + UBMR); + writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS); + writel(sport->saved_reg[0], sport->port.membase + UCR1); + writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2); + writel(sport->saved_reg[2], sport->port.membase + UCR3); + writel(sport->saved_reg[3], sport->port.membase + UCR4); + sport->context_saved = false; +} + +static void serial_imx_save_context(struct imx_port *sport) +{ + /* Save necessary regs */ + sport->saved_reg[0] = readl(sport->port.membase + UCR1); + sport->saved_reg[1] = readl(sport->port.membase + UCR2); + sport->saved_reg[2] = readl(sport->port.membase + UCR3); + sport->saved_reg[3] = readl(sport->port.membase + UCR4); + sport->saved_reg[4] = readl(sport->port.membase + UFCR); + sport->saved_reg[5] = readl(sport->port.membase + UESC); + sport->saved_reg[6] = readl(sport->port.membase + UTIM); + sport->saved_reg[7] = readl(sport->port.membase + UBIR); + sport->saved_reg[8] = readl(sport->port.membase + UBMR); + sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS); + sport->context_saved = true; +} + static void serial_imx_enable_wakeup(struct imx_port *sport, bool on) { unsigned int val; @@ -2001,17 +2036,7 @@ static int imx_serial_port_suspend_noirq(struct device *dev) if (ret) return ret; - /* Save necessary regs */ - sport->saved_reg[0] = readl(sport->port.membase + UCR1); - sport->saved_reg[1] = readl(sport->port.membase + UCR2); - sport->saved_reg[2] = readl(sport->port.membase + UCR3); - sport->saved_reg[3] = readl(sport->port.membase + UCR4); - sport->saved_reg[4] = readl(sport->port.membase + UFCR); - sport->saved_reg[5] = readl(sport->port.membase + UESC); - sport->saved_reg[6] = readl(sport->port.membase + UTIM); - sport->saved_reg[7] = readl(sport->port.membase + UBIR); - sport->saved_reg[8] = readl(sport->port.membase + UBMR); - sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS); + serial_imx_save_context(sport); clk_disable(sport->clk_ipg); @@ -2028,16 +2053,7 @@ static int imx_serial_port_resume_noirq(struct device *dev) if (ret) return ret; - writel(sport->saved_reg[4], sport->port.membase + UFCR); - writel(sport->saved_reg[5], sport->port.membase + UESC); - writel(sport->saved_reg[6], sport->port.membase + UTIM); - writel(sport->saved_reg[7], sport->port.membase + UBIR); - writel(sport->saved_reg[8], sport->port.membase + UBMR); - writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS); - writel(sport->saved_reg[0], sport->port.membase + UCR1); - writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2); - writel(sport->saved_reg[2], sport->port.membase + UCR3); - writel(sport->saved_reg[3], sport->port.membase + UCR4); + serial_imx_restore_context(sport); clk_disable(sport->clk_ipg);