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

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

[Fabio Estevam]

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>
---
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

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

[Richard Zhao]

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
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

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

[Shawn Guo]

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>
> ---

I queued this for 3.3, and will send a pull-request to Greg.

-- 
Regards,
Shawn