Re: [PATCH v5] tty: serial: imx: Allow UART to be a source for wakeup

From: Richard Zhao <richard.zhao@freescale.com>
To: Fabio Estevam <festevam@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org,
	Fabio Estevam <fabio.estevam@freescale.com>,
	linux-serial@vger.kernel.org, shawn.guo@freescale.com,
	kernel@pengutronix.de, alan@linux.intel.com
Subject: Re: [PATCH v5] tty: serial: imx: Allow UART to be a source for wakeup
Date: Wed, 14 Dec 2011 08:44:06 +0800	[thread overview]
Message-ID: <20111214004405.GI28768@b20223-02.ap.freescale.net> (raw)
In-Reply-To: <1323746628-25163-1-git-send-email-festevam@gmail.com>

On Tue, Dec 13, 2011 at 01:23:48AM -0200, Fabio Estevam wrote:
> Allow UART to be a source for wakeup from low power mode.
> 
> Tested on a MX27PDK by doing:
> 
> echo enabled > /sys/devices/platform/imx21-uart.0/tty/ttymxc0/power/wakeup
> 
> echo mem > /sys/power/state
> 
> and then pressing a key in the console will wakeup the sytem.
> 
> Suggested-by: Shawn Guo <shawn.guo@freescale.com>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
For imx6q sabrelite,
Tested-by: Richard Zhao <richard.zhao@freescale.com>
> ---
> Changes since v4:
> - Let serial core handle device_init_wakeup/device_set_wakeup_enable.
> Changes since v3:
> - Remove IMXUART_CANWAKE flag. Let userspace write in /sys/ file
> in order to enable UART wakeup source.
> Changes since v2:
> - Remove incorrect enable_irq_wake from serial_imx_resume
> Changes since v1:
> - Pass the can-wake property via DT correctly
>  drivers/tty/serial/imx.c |   15 +++++++++++++++
>  1 files changed, 15 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 163fc90..0022bbd 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -566,6 +566,9 @@ static irqreturn_t imx_int(int irq, void *dev_id)
>  	if (sts & USR1_RTSD)
>  		imx_rtsint(irq, dev_id);
>  
> +	if (sts & USR1_AWAKE)
> +		writel(USR1_AWAKE, sport->port.membase + USR1);
> +
>  	return IRQ_HANDLED;
>  }
>  
> @@ -1269,6 +1272,12 @@ static struct uart_driver imx_reg = {
>  static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
>  {
>  	struct imx_port *sport = platform_get_drvdata(dev);
> +	unsigned int val;
> +
> +	/* enable wakeup from i.MX UART */
> +	val = readl(sport->port.membase + UCR3);
> +	val |= UCR3_AWAKEN;
> +	writel(val, sport->port.membase + UCR3);
>  
>  	if (sport)
>  		uart_suspend_port(&imx_reg, &sport->port);
> @@ -1279,7 +1288,13 @@ static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
>  static int serial_imx_resume(struct platform_device *dev)
>  {
>  	struct imx_port *sport = platform_get_drvdata(dev);
> +	unsigned int val;
>  
> +	/* disable wakeup from i.MX UART */
> +	val = readl(sport->port.membase + UCR3);
> +	val &= ~UCR3_AWAKEN;
> +	writel(val, sport->port.membase + UCR3);
> +
>  	if (sport)
>  		uart_resume_port(&imx_reg, &sport->port);
>  
> -- 
> 1.7.1
> 
> 
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