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Commit fd2bb310 authored by Cristina Opriceana's avatar Cristina Opriceana Committed by Jonathan Cameron
Browse files

Staging: iio: Move evgen interrupt generation to irq_work 



Enhance interrupt generation in the dummy driver and expand its usage
by introducing the irq_work infrastructure to trigger an interrupt.

This way, the irq_work_queue() wrapper permits calling both of the top
half and threaded part from a hard irq context, unlike handle_nested_irq(),
which only calls the threaded part.

As an outcome, the driver succeeds in simulating real hardware
interrupts, while keeping the normal interrupt flow.

Signed-off-by: default avatarCristina Opriceana <cristina.opriceana@gmail.com>
Acked-by: default avatarDaniel Baluta <daniel.baluta@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent cd8d9777

drivers/staging/iio/iio_dummy_evgen.c

+25 −1
Original line number Diff line number Diff line
@@ -24,9 +24,21 @@ 
#include "iio_dummy_evgen.h"

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/irq_work.h>



/* Fiddly bit of faking and irq without hardware */

#define IIO_EVENTGEN_NO 10



/**

 * struct iio_dummy_handle_irq - helper struct to simulate interrupt generation

 * @work: irq_work used to run handlers from hardirq context

 * @irq: fake irq line number to trigger an interrupt

 */

struct iio_dummy_handle_irq {

	struct irq_work work;

	int irq;

};



/**

 * struct iio_dummy_evgen - evgen state

 * @chip: irq chip we are faking
@@ -35,6 +47,7 @@ 
 * @inuse: mask of which irqs are connected

 * @regs: irq regs we are faking

 * @lock: protect the evgen state

 * @handler: helper for a 'hardware-like' interrupt simulation

 */

struct iio_dummy_eventgen {

	struct irq_chip chip;
@@ -43,6 +56,7 @@ struct iio_dummy_eventgen { 
	bool inuse[IIO_EVENTGEN_NO];

	struct iio_dummy_regs regs[IIO_EVENTGEN_NO];

	struct mutex lock;

	struct iio_dummy_handle_irq handler;

};



/* We can only ever have one instance of this 'device' */
@@ -67,6 +81,14 @@ static void iio_dummy_event_irqunmask(struct irq_data *d) 
	evgen->enabled[d->irq - evgen->base] = true;

}



static void iio_dummy_work_handler(struct irq_work *work)

{

	struct iio_dummy_handle_irq *irq_handler;



	irq_handler = container_of(work, struct iio_dummy_handle_irq, work);

	handle_simple_irq(irq_handler->irq, irq_to_desc(irq_handler->irq));

}



static int iio_dummy_evgen_create(void)

{

	int ret, i;
@@ -91,6 +113,7 @@ static int iio_dummy_evgen_create(void) 
				  IRQ_NOREQUEST | IRQ_NOAUTOEN,

				  IRQ_NOPROBE);

	}

	init_irq_work(&iio_evgen->handler.work, iio_dummy_work_handler);

	mutex_init(&iio_evgen->lock);

	return 0;

}
@@ -169,8 +192,9 @@ static ssize_t iio_evgen_poke(struct device *dev, 
	iio_evgen->regs[this_attr->address].reg_id   = this_attr->address;

	iio_evgen->regs[this_attr->address].reg_data = event;



	iio_evgen->handler.irq = iio_evgen->base + this_attr->address;

	if (iio_evgen->enabled[this_attr->address])

		handle_nested_irq(iio_evgen->base + this_attr->address);

		irq_work_queue(&iio_evgen->handler.work);



	return len;

}

drivers/staging/iio/iio_simple_dummy.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct iio_dummy_state { 
	int event_irq;

	int event_val;

	bool event_en;

	s64 event_timestamp;

#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */

};

drivers/staging/iio/iio_simple_dummy_events.c

+14 −5
Original line number Diff line number Diff line
@@ -153,6 +153,15 @@ int iio_simple_dummy_write_event_value(struct iio_dev *indio_dev, 
	return 0;

}



static irqreturn_t iio_simple_dummy_get_timestamp(int irq, void *private)

{

	struct iio_dev *indio_dev = private;

	struct iio_dummy_state *st = iio_priv(indio_dev);



	st->event_timestamp = iio_get_time_ns();

	return IRQ_HANDLED;

}



/**

 * iio_simple_dummy_event_handler() - identify and pass on event

 * @irq: irq of event line
@@ -177,7 +186,7 @@ static irqreturn_t iio_simple_dummy_event_handler(int irq, void *private) 
			       IIO_EVENT_CODE(IIO_VOLTAGE, 0, 0,

					      IIO_EV_DIR_RISING,

					      IIO_EV_TYPE_THRESH, 0, 0, 0),

			       iio_get_time_ns());

			       st->event_timestamp);

		break;

	case 1:

		if (st->activity_running > st->event_val)
@@ -187,7 +196,7 @@ static irqreturn_t iio_simple_dummy_event_handler(int irq, void *private) 
						      IIO_EV_DIR_RISING,

						      IIO_EV_TYPE_THRESH,

						      0, 0, 0),

				       iio_get_time_ns());

				       st->event_timestamp);

		break;

	case 2:

		if (st->activity_walking < st->event_val)
@@ -197,14 +206,14 @@ static irqreturn_t iio_simple_dummy_event_handler(int irq, void *private) 
						      IIO_EV_DIR_FALLING,

						      IIO_EV_TYPE_THRESH,

						      0, 0, 0),

				       iio_get_time_ns());

				       st->event_timestamp);

		break;

	case 3:

		iio_push_event(indio_dev,

			       IIO_EVENT_CODE(IIO_STEPS, 0, IIO_NO_MOD,

					      IIO_EV_DIR_NONE,

					      IIO_EV_TYPE_CHANGE, 0, 0, 0),

			       iio_get_time_ns());

			       st->event_timestamp);

		break;

	default:

		break;
@@ -238,7 +247,7 @@ int iio_simple_dummy_events_register(struct iio_dev *indio_dev) 
	st->regs = iio_dummy_evgen_get_regs(st->event_irq);



	ret = request_threaded_irq(st->event_irq,

				   NULL,

				   &iio_simple_dummy_get_timestamp,

				   &iio_simple_dummy_event_handler,

				   IRQF_ONESHOT,

				   "iio_simple_event",