Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755557AbbHKRVn (ORCPT ); Tue, 11 Aug 2015 13:21:43 -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 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4667 Lines: 117 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); -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/