Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d562853d authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

greybus: svc watchdog: allow it to be enabled/disabled from userspace 



Sometimes you want to disable the SVC watchdog without having to patch
your kernel, so provide a sysfs file to do this.  This can let us do
power measurements, and let the firmware developers not go crazy
worrying that the kernel is going to reset their chips with no notice.

Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent 7030f924

drivers/staging/greybus/Documentation/sysfs-bus-greybus

+8 −0
Original line number Diff line number Diff line
@@ -163,3 +163,11 @@ KernelVersion: 4.XX 
Contact:	Greg Kroah-Hartman <greg@kroah.com>

Description:

		The version number of the firmware in the SVC device.



What:		/sys/bus/greybus/device/N-svc/watchdog

Date:		October 2016

KernelVersion:	4.XX

Contact:	Greg Kroah-Hartman <greg@kroah.com>

Description:

		If the SVC watchdog is enabled or not.  Writing 0 to this

		file will disable the watchdog, writing 1 will enable it.

drivers/staging/greybus/svc.c

+32 −0
Original line number Diff line number Diff line
@@ -70,10 +70,42 @@ static ssize_t intf_eject_store(struct device *dev, 
}

static DEVICE_ATTR_WO(intf_eject);



static ssize_t watchdog_show(struct device *dev, struct device_attribute *attr,

			     char *buf)

{

	struct gb_svc *svc = to_gb_svc(dev);



	return sprintf(buf, "%s\n",

		       gb_svc_watchdog_enabled(svc) ? "enabled" : "disabled");

}



static ssize_t watchdog_store(struct device *dev,

			      struct device_attribute *attr, const char *buf,

			      size_t len)

{

	struct gb_svc *svc = to_gb_svc(dev);

	int retval;

	bool user_request;



	retval = strtobool(buf, &user_request);

	if (retval)

		return retval;



	if (user_request)

		retval = gb_svc_watchdog_enable(svc);

	else

		retval = gb_svc_watchdog_disable(svc);

	if (retval)

		return retval;

	return len;

}

static DEVICE_ATTR_RW(watchdog);



static struct attribute *svc_attrs[] = {

	&dev_attr_endo_id.attr,

	&dev_attr_ap_intf_id.attr,

	&dev_attr_intf_eject.attr,

	&dev_attr_watchdog.attr,

	NULL,

};

ATTRIBUTE_GROUPS(svc);

drivers/staging/greybus/svc.h

+3 −0
Original line number Diff line number Diff line
@@ -61,6 +61,9 @@ int gb_svc_intf_set_power_mode(struct gb_svc *svc, u8 intf_id, u8 hs_series, 
int gb_svc_ping(struct gb_svc *svc);

int gb_svc_watchdog_create(struct gb_svc *svc);

void gb_svc_watchdog_destroy(struct gb_svc *svc);

bool gb_svc_watchdog_enabled(struct gb_svc *svc);

int gb_svc_watchdog_enable(struct gb_svc *svc);

int gb_svc_watchdog_disable(struct gb_svc *svc);



int gb_svc_protocol_init(void);

void gb_svc_protocol_exit(void);

drivers/staging/greybus/svc_watchdog.c

+51 −9
Original line number Diff line number Diff line
@@ -15,7 +15,7 @@ 
struct gb_svc_watchdog {

	struct delayed_work	work;

	struct gb_svc		*svc;

	bool			finished;

	bool			enabled;

};



static struct delayed_work reset_work;
@@ -65,11 +65,16 @@ static void do_work(struct work_struct *work) 


		INIT_DELAYED_WORK(&reset_work, greybus_reset);

		queue_delayed_work(system_wq, &reset_work, HZ/2);

		return;



		/*

		 * Disable ourselves, we don't want to trip again unless

		 * userspace wants us to.

		 */

		watchdog->enabled = false;

	}



	/* resubmit our work to happen again, if we are still "alive" */

	if (!watchdog->finished)

	if (watchdog->enabled)

		queue_delayed_work(system_wq, &watchdog->work,

				   SVC_WATCHDOG_PERIOD);

}
@@ -85,14 +90,12 @@ int gb_svc_watchdog_create(struct gb_svc *svc) 
	if (!watchdog)

		return -ENOMEM;



	watchdog->finished = false;

	watchdog->enabled = false;

	watchdog->svc = svc;

	INIT_DELAYED_WORK(&watchdog->work, do_work);

	svc->watchdog = watchdog;



	queue_delayed_work(system_wq, &watchdog->work,

			   SVC_WATCHDOG_PERIOD);

	return 0;

	return gb_svc_watchdog_enable(svc);

}



void gb_svc_watchdog_destroy(struct gb_svc *svc)
@@ -102,8 +105,47 @@ void gb_svc_watchdog_destroy(struct gb_svc *svc) 
	if (!watchdog)

		return;



	watchdog->finished = true;

	cancel_delayed_work_sync(&watchdog->work);

	gb_svc_watchdog_disable(svc);

	svc->watchdog = NULL;

	kfree(watchdog);

}



bool gb_svc_watchdog_enabled(struct gb_svc *svc)

{

	if (!svc || !svc->watchdog)

		return false;

	return svc->watchdog->enabled;

}



int gb_svc_watchdog_enable(struct gb_svc *svc)

{

	struct gb_svc_watchdog *watchdog;



	if (!svc->watchdog)

		return -ENODEV;



	watchdog = svc->watchdog;

	if (watchdog->enabled)

		return 0;



	watchdog->enabled = true;

	queue_delayed_work(system_wq, &watchdog->work,

			   SVC_WATCHDOG_PERIOD);

	return 0;

}



int gb_svc_watchdog_disable(struct gb_svc *svc)

{

	struct gb_svc_watchdog *watchdog;



	if (!svc->watchdog)

		return -ENODEV;



	watchdog = svc->watchdog;

	if (!watchdog->enabled)

		return 0;



	watchdog->enabled = false;

	cancel_delayed_work_sync(&watchdog->work);

	return 0;

}