[3/3,v2] net: smsc911x: add wake-up event interrupt support

The SMSC911x have a line out of the chip called "PME",
Power Management Event. When connected to an asynchronous
interrupt controller this is able to wake the system up
from sleep in response to certain network events.

This is the first attempt to support this in the Linux
driver: the Qualcomm APQ8060 Dragonboard has this line
routed to a GPIO line on the primary SoC padring, and as
such it can be armed as a wakeup interrupt.

The patch is inspired by the wakeup code in the RTC
subsystem.

The code looks for an additional interrupt - apart from the
ordinary device interrupt - and in case that is present,
we register an interrupt handler to respons to this,
and flag the device and this interrupt as a wakeup.

Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Call pm_wakeup_event() in the wakeup IRQ thread to
  account for the wakeup event.
- Drop the enable/disable_irq_wake() calls from suspend/resume:
  this is handled from the irq core when you call
  dev_pm_set_wake_irq() as we do.
---
 drivers/net/ethernet/smsc/smsc911x.c | 42 ++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

* Linus Walleij <linus.walleij@linaro.org> [160824 06:00]:
> The SMSC911x have a line out of the chip called "PME",
> Power Management Event. When connected to an asynchronous
> interrupt controller this is able to wake the system up
> from sleep in response to certain network events.
> 
> This is the first attempt to support this in the Linux
> driver: the Qualcomm APQ8060 Dragonboard has this line
> routed to a GPIO line on the primary SoC padring, and as
> such it can be armed as a wakeup interrupt.
> 
> The patch is inspired by the wakeup code in the RTC
> subsystem.
> 
> The code looks for an additional interrupt - apart from the
> ordinary device interrupt - and in case that is present,
> we register an interrupt handler to respons to this,
> and flag the device and this interrupt as a wakeup.
> 
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - Call pm_wakeup_event() in the wakeup IRQ thread to
>   account for the wakeup event.
> - Drop the enable/disable_irq_wake() calls from suspend/resume:
>   this is handled from the irq core when you call
>   dev_pm_set_wake_irq() as we do.

Looks OK to me:

Acked-by: Tony Lindgren <tony@atomide.com>

Hi Linus,


On 08/24/2016 07:59 AM, Linus Walleij wrote:
> The SMSC911x have a line out of the chip called "PME",
> Power Management Event. When connected to an asynchronous
> interrupt controller this is able to wake the system up
> from sleep in response to certain network events.
>
> This is the first attempt to support this in the Linux
> driver: the Qualcomm APQ8060 Dragonboard has this line
> routed to a GPIO line on the primary SoC padring, and as
> such it can be armed as a wakeup interrupt.
>
> The patch is inspired by the wakeup code in the RTC
> subsystem.
>
> The code looks for an additional interrupt - apart from the
> ordinary device interrupt - and in case that is present,
> we register an interrupt handler to respons to this,
> and flag the device and this interrupt as a wakeup.
>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - Call pm_wakeup_event() in the wakeup IRQ thread to
>   account for the wakeup event.
> - Drop the enable/disable_irq_wake() calls from suspend/resume:
>   this is handled from the irq core when you call
>   dev_pm_set_wake_irq() as we do.
> ---
>  drivers/net/ethernet/smsc/smsc911x.c | 42 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>
> diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
> index 8ab8d4b9614b..8fffc1dc2bdd 100644
> --- a/drivers/net/ethernet/smsc/smsc911x.c
> +++ b/drivers/net/ethernet/smsc/smsc911x.c
> @@ -63,6 +63,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  #include <linux/gpio/consumer.h>
> +#include <linux/pm_wakeirq.h>
>
>  #include "smsc911x.h"
>
> @@ -151,6 +152,9 @@ struct smsc911x_data {
>  	/* Reset GPIO */
>  	struct gpio_desc *reset_gpiod;
>
> +	/* PME interrupt */
> +	int pme_irq;
> +
>  	/* clock */
>  	struct clk *clk;
>  };
> @@ -1881,6 +1885,19 @@ static irqreturn_t smsc911x_irqhandler(int irq, void *dev_id)
>  	return serviced;
>  }
>
> +static irqreturn_t smsc911x_pme_irq_thread(int irq, void *dev_id)
> +{
> +	struct net_device *dev = dev_id;
> +	struct smsc911x_data *pdata __maybe_unused = netdev_priv(dev);
> +
> +	SMSC_TRACE(pdata, pm, "wakeup event");
> +	pm_wakeup_event(&dev->dev, 50);
> +	/* This signal is active for 50 ms, wait for it to deassert */
> +	usleep_range(50000, 100000);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  #ifdef CONFIG_NET_POLL_CONTROLLER
>  static void smsc911x_poll_controller(struct net_device *dev)
>  {
> @@ -2501,6 +2518,31 @@ static int smsc911x_drv_probe(struct platform_device *pdev)
>  		goto out_disable_resources;
>  	}
>
> +	irq = platform_get_irq(pdev, 1);
> +	if (irq == -EPROBE_DEFER) {
> +		retval = -EPROBE_DEFER;
> +		goto out_disable_resources;
> +	/* It's perfectly fine to not have a PME IRQ */
> +	} else if (irq > 0) {
> +		/*
> +		 * The Power Management Event (PME) IRQ appears as
> +		 * a pulse waking up the system from sleep in response to  a
> +		 * network event.
> +		 */
> +		retval = request_threaded_irq(irq, NULL,
> +					      smsc911x_pme_irq_thread,
> +					      IRQF_ONESHOT, "smsc911x-pme",
> +					      dev);
> +		if (retval) {
> +			SMSC_WARN(pdata, probe,
> +			"Unable to claim requested PME irq: %d", irq);
> +			goto out_disable_resources;
> +		}
> +		pdata->pme_irq = irq;
> +		device_init_wakeup(&pdev->dev, true);
> +		dev_pm_set_wake_irq(&pdev->dev, irq);
> +	}
> +
>  	netif_carrier_off(dev);
>
>  	retval = register_netdev(dev);
>


The cleanup code in drv_remove seems to be missing, am I missing something?

Also, do you want the wake-up to be active if the interface is downed?


Thanks,

Hi,

On 08/24/2016 07:59 AM, Linus Walleij wrote:
> The SMSC911x have a line out of the chip called "PME",
> Power Management Event. When connected to an asynchronous
> interrupt controller this is able to wake the system up
> from sleep in response to certain network events.
>
> This is the first attempt to support this in the Linux
> driver: the Qualcomm APQ8060 Dragonboard has this line
> routed to a GPIO line on the primary SoC padring, and as
> such it can be armed as a wakeup interrupt.
>
> The patch is inspired by the wakeup code in the RTC
> subsystem.
>
> The code looks for an additional interrupt - apart from the
> ordinary device interrupt - and in case that is present,
> we register an interrupt handler to respons to this,
> and flag the device and this interrupt as a wakeup.


Having looked at a couple of the supported smsc chips, it seems they can 
route the wakeup through the chip's interrupt as well. If you add code 
to support this, it should work on a lot of the smsc911x devices rather 
than just the dragonboard.


Thanks,




>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Tony Lindgren <tony@atomide.com>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - Call pm_wakeup_event() in the wakeup IRQ thread to
>   account for the wakeup event.
> - Drop the enable/disable_irq_wake() calls from suspend/resume:
>   this is handled from the irq core when you call
>   dev_pm_set_wake_irq() as we do.
> ---
>  drivers/net/ethernet/smsc/smsc911x.c | 42 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
>
> diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
> index 8ab8d4b9614b..8fffc1dc2bdd 100644
> --- a/drivers/net/ethernet/smsc/smsc911x.c
> +++ b/drivers/net/ethernet/smsc/smsc911x.c
> @@ -63,6 +63,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  #include <linux/gpio/consumer.h>
> +#include <linux/pm_wakeirq.h>
>
>  #include "smsc911x.h"
>
> @@ -151,6 +152,9 @@ struct smsc911x_data {
>  	/* Reset GPIO */
>  	struct gpio_desc *reset_gpiod;
>
> +	/* PME interrupt */
> +	int pme_irq;
> +
>  	/* clock */
>  	struct clk *clk;
>  };
> @@ -1881,6 +1885,19 @@ static irqreturn_t smsc911x_irqhandler(int irq, void *dev_id)
>  	return serviced;
>  }
>
> +static irqreturn_t smsc911x_pme_irq_thread(int irq, void *dev_id)
> +{
> +	struct net_device *dev = dev_id;
> +	struct smsc911x_data *pdata __maybe_unused = netdev_priv(dev);
> +
> +	SMSC_TRACE(pdata, pm, "wakeup event");
> +	pm_wakeup_event(&dev->dev, 50);
> +	/* This signal is active for 50 ms, wait for it to deassert */
> +	usleep_range(50000, 100000);
> +
> +	return IRQ_HANDLED;
> +}
> +
>  #ifdef CONFIG_NET_POLL_CONTROLLER
>  static void smsc911x_poll_controller(struct net_device *dev)
>  {
> @@ -2501,6 +2518,31 @@ static int smsc911x_drv_probe(struct platform_device *pdev)
>  		goto out_disable_resources;
>  	}
>
> +	irq = platform_get_irq(pdev, 1);
> +	if (irq == -EPROBE_DEFER) {
> +		retval = -EPROBE_DEFER;
> +		goto out_disable_resources;
> +	/* It's perfectly fine to not have a PME IRQ */
> +	} else if (irq > 0) {
> +		/*
> +		 * The Power Management Event (PME) IRQ appears as
> +		 * a pulse waking up the system from sleep in response to  a
> +		 * network event.
> +		 */
> +		retval = request_threaded_irq(irq, NULL,
> +					      smsc911x_pme_irq_thread,
> +					      IRQF_ONESHOT, "smsc911x-pme",
> +					      dev);
> +		if (retval) {
> +			SMSC_WARN(pdata, probe,
> +			"Unable to claim requested PME irq: %d", irq);
> +			goto out_disable_resources;
> +		}
> +		pdata->pme_irq = irq;
> +		device_init_wakeup(&pdev->dev, true);
> +		dev_pm_set_wake_irq(&pdev->dev, irq);
> +	}
> +
>  	netif_carrier_off(dev);
>
>  	retval = register_netdev(dev);
>

On Wed, Aug 31, 2016 at 5:27 PM, Jeremy Linton <jeremy.linton@arm.com> wrote:

> The cleanup code in drv_remove seems to be missing, am I missing something?

No you're right it's just my bad coding. Fixing it and thanks for noticing.

> Also, do you want the wake-up to be active if the interface is downed?

Hm! Good point.

It seems most other drivers call
device_set_wakeup_enable() on the device inside a
foo_set_wol() (wake-on-LAN) from the
.set_wol() callback in struct ethtool_ops.

This is in response to the ethtool calls from userspace.

So we need to implement this too.

I don't know whether that has anything to do with whether
the interface is up or not, it seems orthogonal actually.

I will hold this patch back until I can investigate and test
and just resend patches 1+2 right now. (Bindings should
still be OK to merge I guess, and I think the RESET patch
is sorted out.)

Yours,
Linus Walleij