Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756139AbcCaLmM (ORCPT ); Thu, 31 Mar 2016 07:42:12 -0400 Received: from mail.kernel.org ([198.145.29.136]:45601 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750849AbcCaLmK (ORCPT ); Thu, 31 Mar 2016 07:42:10 -0400 Date: Thu, 31 Mar 2016 19:41:48 +0800 From: Shawn Guo To: Stefan Agner Cc: mturquette@baylibre.com, sboyd@codeaurora.org, kernel@pengutronix.de, sergeimir@emcraft.com, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org Subject: Re: [PATCH 10/18] tty: serial: fsl_lpuart: support suspend/resume Message-ID: <20160331114148.GC18833@tiger> References: <1457576219-7971-1-git-send-email-stefan@agner.ch> <1457576219-7971-11-git-send-email-stefan@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1457576219-7971-11-git-send-email-stefan@agner.ch> 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 Content-Length: 4119 Lines: 97 On Wed, Mar 09, 2016 at 06:16:51PM -0800, Stefan Agner wrote: > In order to allow wake support in STOP sleep mode, clocks are > needed. Use imx_clk_gate2_cgr to disable automatic clock gating > in low power mode STOP. This allows to enable wake by UART using: > echo enabled > /sys/class/tty/ttyLP0/power/wakeup > > However, if wake is not enabled, the driver should disable the > clocks explicitly to save power. > > Signed-off-by: Stefan Agner > --- > drivers/clk/imx/clk-vf610.c | 12 ++++++------ It should go to a separate patch. Shawn > drivers/tty/serial/fsl_lpuart.c | 16 ++++++++++++++-- > 2 files changed, 20 insertions(+), 8 deletions(-) > > diff --git a/drivers/clk/imx/clk-vf610.c b/drivers/clk/imx/clk-vf610.c > index e2e2c43..170a96c 100644 > --- a/drivers/clk/imx/clk-vf610.c > +++ b/drivers/clk/imx/clk-vf610.c > @@ -315,12 +315,12 @@ static void __init vf610_clocks_init(struct device_node *ccm_node) > > clk[VF610_CLK_PIT] = imx_clk_gate2("pit", "ipg_bus", CCM_CCGR1, CCM_CCGRx_CGn(7)); > > - clk[VF610_CLK_UART0] = imx_clk_gate2("uart0", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(7)); > - clk[VF610_CLK_UART1] = imx_clk_gate2("uart1", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(8)); > - clk[VF610_CLK_UART2] = imx_clk_gate2("uart2", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(9)); > - clk[VF610_CLK_UART3] = imx_clk_gate2("uart3", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(10)); > - clk[VF610_CLK_UART4] = imx_clk_gate2("uart4", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(9)); > - clk[VF610_CLK_UART5] = imx_clk_gate2("uart5", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(10)); > + clk[VF610_CLK_UART0] = imx_clk_gate2_cgr("uart0", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(7), 0x2); > + clk[VF610_CLK_UART1] = imx_clk_gate2_cgr("uart1", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(8), 0x2); > + clk[VF610_CLK_UART2] = imx_clk_gate2_cgr("uart2", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(9), 0x2); > + clk[VF610_CLK_UART3] = imx_clk_gate2_cgr("uart3", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(10), 0x2); > + clk[VF610_CLK_UART4] = imx_clk_gate2_cgr("uart4", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(9), 0x2); > + clk[VF610_CLK_UART5] = imx_clk_gate2_cgr("uart5", "ipg_bus", CCM_CCGR6, CCM_CCGRx_CGn(10), 0x2); > > clk[VF610_CLK_I2C0] = imx_clk_gate2("i2c0", "ipg_bus", CCM_CCGR4, CCM_CCGRx_CGn(6)); > clk[VF610_CLK_I2C1] = imx_clk_gate2("i2c1", "ipg_bus", CCM_CCGR4, CCM_CCGRx_CGn(7)); > diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c > index 3d79003..94e29ba 100644 > --- a/drivers/tty/serial/fsl_lpuart.c > +++ b/drivers/tty/serial/fsl_lpuart.c > @@ -483,9 +483,8 @@ static void lpuart_dma_rx_complete(void *arg) > spin_unlock_irqrestore(&sport->port.lock, flags); > } > > -static void lpuart_timer_func(unsigned long data) > +static void lpuart_dma_rx_terminate(struct lpuart_port *sport) > { > - struct lpuart_port *sport = (struct lpuart_port *)data; > struct tty_port *port = &sport->port.state->port; > struct dma_tx_state state; > unsigned long flags; > @@ -510,6 +509,11 @@ static void lpuart_timer_func(unsigned long data) > spin_unlock_irqrestore(&sport->port.lock, flags); > } > > +static void lpuart_timer_func(unsigned long data) > +{ > + lpuart_dma_rx_terminate((struct lpuart_port *)data); > +} > + > static inline void lpuart_prepare_rx(struct lpuart_port *sport) > { > unsigned long flags; > @@ -1915,7 +1919,12 @@ static int lpuart_suspend(struct device *dev) > writeb(temp, sport->port.membase + UARTCR2); > } > > + if (sport->dma_rx_in_progress) > + lpuart_dma_rx_terminate(sport); > + > uart_suspend_port(&lpuart_reg, &sport->port); > + if (sport->port.suspended && !sport->port.irq_wake) > + clk_disable_unprepare(sport->clk); > > return 0; > } > @@ -1925,6 +1934,9 @@ static int lpuart_resume(struct device *dev) > struct lpuart_port *sport = dev_get_drvdata(dev); > unsigned long temp; > > + if (sport->port.suspended && !sport->port.irq_wake) > + clk_prepare_enable(sport->clk); > + > if (sport->lpuart32) { > lpuart32_setup_watermark(sport); > temp = lpuart32_read(sport->port.membase + UARTCTRL); > -- > 2.7.2 > >