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Commit e6477000 authored by Jonathan Cameron's avatar Jonathan Cameron Committed by Greg Kroah-Hartman
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staging:iio:dummy Add event support + fake event generator 



The event generator is not very pretty but does the job and
allows this driver to look a lot more like a normal driver
than it otherwise would.

Signed-off-by: default avatarJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3a84331d

drivers/staging/iio/Kconfig

+17 −3
Original line number Diff line number Diff line
@@ -70,12 +70,26 @@ source "drivers/staging/iio/meter/Kconfig" 
source "drivers/staging/iio/resolver/Kconfig"

source "drivers/staging/iio/trigger/Kconfig"



config IIO_DUMMY_EVGEN

       tristate



config IIO_SIMPLE_DUMMY

       tristate "An example driver with no hardware requirements"

       select IIO_SIMPLE_DUMMY_EVGEN if IIO_SIMPLE_DUMMY_EVENTS

       help

	 Driver intended mainly as documentation for how to write

	 a driver. May also be useful for testing userspace code

	 without hardward.



if IIO_SIMPLE_DUMMY



config IIO_SIMPLE_DUMMY_EVENTS

       boolean "Event generation support"

       select IIO_DUMMY_EVGEN

       help

         Add some dummy events to the simple dummy driver.





endif # IIO_SIMPLE_DUMMY



endif # IIO

drivers/staging/iio/Makefile

+5 −1
Original line number Diff line number Diff line
@@ -10,7 +10,11 @@ industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o 
obj-$(CONFIG_IIO_SW_RING) += ring_sw.o

obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o



obj-$(CONFIG_IIO_SIMPLE_DUMMY) += iio_simple_dummy.o

obj-$(CONFIG_IIO_SIMPLE_DUMMY) += iio_dummy.o

iio_dummy-y := iio_simple_dummy.o

iio_dummy-$(CONFIG_IIO_SIMPLE_DUMMY_EVENTS) += iio_simple_dummy_events.o



obj-$(CONFIG_IIO_DUMMY_EVGEN) += iio_dummy_evgen.o



obj-y += accel/

obj-y += adc/

drivers/staging/iio/iio_dummy_evgen.c

0 → 100644
+217 −0
Original line number Diff line number Diff line 
/**

 * Copyright (c) 2011 Jonathan Cameron

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published by

 * the Free Software Foundation.

 *

 * Companion module to the iio simple dummy example driver.

 * The purpose of this is to generate 'fake' event interrupts thus

 * allowing that driver's code to be as close as possible to that of

 * a normal driver talking to hardware.  The approach used here

 * is not intended to be general and just happens to work for this

 * particular use case.

 */



#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/mutex.h>

#include <linux/module.h>

#include <linux/sysfs.h>



#include "iio_dummy_evgen.h"

#include "iio.h"

#include "sysfs.h"



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

#define IIO_EVENTGEN_NO 10

/**

 * struct iio_dummy_evgen - evgen state

 * @chip: irq chip we are faking

 * @base: base of irq range

 * @enabled: mask of which irqs are enabled

 * @inuse: mask of which irqs actually have anyone connected

 * @lock: protect the evgen state

 */

struct iio_dummy_eventgen {

	struct irq_chip chip;

	int base;

	bool enabled[IIO_EVENTGEN_NO];

	bool inuse[IIO_EVENTGEN_NO];

	struct mutex lock;

};



/* We can only ever have one instance of this 'device' */

static struct iio_dummy_eventgen *iio_evgen;

static const char *iio_evgen_name = "iio_dummy_evgen";



static void iio_dummy_event_irqmask(struct irq_data *d)

{

	struct irq_chip *chip = irq_data_get_irq_chip(d);

	struct iio_dummy_eventgen *evgen =

		container_of(chip, struct iio_dummy_eventgen, chip);



	evgen->enabled[d->irq - evgen->base] = false;

}



static void iio_dummy_event_irqunmask(struct irq_data *d)

{

	struct irq_chip *chip = irq_data_get_irq_chip(d);

	struct iio_dummy_eventgen *evgen =

		container_of(chip, struct iio_dummy_eventgen, chip);



	evgen->enabled[d->irq - evgen->base] = true;

}



static int iio_dummy_evgen_create(void)

{

	int ret, i;



	iio_evgen = kzalloc(sizeof(*iio_evgen), GFP_KERNEL);

	if (iio_evgen == NULL)

		return -ENOMEM;



	iio_evgen->base = irq_alloc_descs(-1, 0, IIO_EVENTGEN_NO, 0);

	if (iio_evgen->base < 0) {

		ret = iio_evgen->base;

		kfree(iio_evgen);

		return ret;

	}

	iio_evgen->chip.name = iio_evgen_name;

	iio_evgen->chip.irq_mask = &iio_dummy_event_irqmask;

	iio_evgen->chip.irq_unmask = &iio_dummy_event_irqunmask;

	for (i = 0; i < IIO_EVENTGEN_NO; i++) {

		irq_set_chip(iio_evgen->base + i, &iio_evgen->chip);

		irq_set_handler(iio_evgen->base + i, &handle_simple_irq);

		irq_modify_status(iio_evgen->base + i,

				  IRQ_NOREQUEST | IRQ_NOAUTOEN,

				  IRQ_NOPROBE);

	}

	mutex_init(&iio_evgen->lock);

	return 0;

}



/**

 * iio_dummy_evgen_get_irq() - get an evgen provided irq for a device

 *

 * This function will give a free allocated irq to a client device.

 * That irq can then be caused to 'fire' by using the associated sysfs file.

 */

int iio_dummy_evgen_get_irq(void)

{

	int i, ret = 0;

	mutex_lock(&iio_evgen->lock);

	for (i = 0; i < IIO_EVENTGEN_NO; i++)

		if (iio_evgen->inuse[i] == false) {

			ret = iio_evgen->base + i;

			iio_evgen->inuse[i] = true;

			break;

		}

	mutex_unlock(&iio_evgen->lock);

	if (i == IIO_EVENTGEN_NO)

		return -ENOMEM;

	return ret;

}

EXPORT_SYMBOL_GPL(iio_dummy_evgen_get_irq);



/**

 * iio_dummy_evgen_release_irq() - give the irq back.

 * @irq: irq being returned to the pool

 *

 * Used by client driver instances to give the irqs back when they disconnect

 */

int iio_dummy_evgen_release_irq(int irq)

{

	mutex_lock(&iio_evgen->lock);

	iio_evgen->inuse[irq - iio_evgen->base] = false;

	mutex_unlock(&iio_evgen->lock);



	return 0;

}

EXPORT_SYMBOL_GPL(iio_dummy_evgen_release_irq);



static void iio_dummy_evgen_free(void)

{

	irq_free_descs(iio_evgen->base, IIO_EVENTGEN_NO);

	kfree(iio_evgen);

}



static void iio_evgen_release(struct device *dev)

{

	iio_dummy_evgen_free();

}



static ssize_t iio_evgen_poke(struct device *dev,

			      struct device_attribute *attr,

			      const char *buf,

			      size_t len)

{

	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);



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

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



	return len;

}



static IIO_DEVICE_ATTR(poke_ev0, S_IWUSR, NULL, &iio_evgen_poke, 0);

static IIO_DEVICE_ATTR(poke_ev1, S_IWUSR, NULL, &iio_evgen_poke, 1);

static IIO_DEVICE_ATTR(poke_ev2, S_IWUSR, NULL, &iio_evgen_poke, 2);

static IIO_DEVICE_ATTR(poke_ev3, S_IWUSR, NULL, &iio_evgen_poke, 3);

static IIO_DEVICE_ATTR(poke_ev4, S_IWUSR, NULL, &iio_evgen_poke, 4);

static IIO_DEVICE_ATTR(poke_ev5, S_IWUSR, NULL, &iio_evgen_poke, 5);

static IIO_DEVICE_ATTR(poke_ev6, S_IWUSR, NULL, &iio_evgen_poke, 6);

static IIO_DEVICE_ATTR(poke_ev7, S_IWUSR, NULL, &iio_evgen_poke, 7);

static IIO_DEVICE_ATTR(poke_ev8, S_IWUSR, NULL, &iio_evgen_poke, 8);

static IIO_DEVICE_ATTR(poke_ev9, S_IWUSR, NULL, &iio_evgen_poke, 9);



static struct attribute *iio_evgen_attrs[] = {

	&iio_dev_attr_poke_ev0.dev_attr.attr,

	&iio_dev_attr_poke_ev1.dev_attr.attr,

	&iio_dev_attr_poke_ev2.dev_attr.attr,

	&iio_dev_attr_poke_ev3.dev_attr.attr,

	&iio_dev_attr_poke_ev4.dev_attr.attr,

	&iio_dev_attr_poke_ev5.dev_attr.attr,

	&iio_dev_attr_poke_ev6.dev_attr.attr,

	&iio_dev_attr_poke_ev7.dev_attr.attr,

	&iio_dev_attr_poke_ev8.dev_attr.attr,

	&iio_dev_attr_poke_ev9.dev_attr.attr,

	NULL,

};



static const struct attribute_group iio_evgen_group = {

	.attrs = iio_evgen_attrs,

};



static const struct attribute_group *iio_evgen_groups[] = {

	&iio_evgen_group,

	NULL

};



static struct device iio_evgen_dev = {

	.bus = &iio_bus_type,

	.groups = iio_evgen_groups,

	.release = &iio_evgen_release,

};

static __init int iio_dummy_evgen_init(void)

{

	int ret = iio_dummy_evgen_create();

	if (ret < 0)

		return ret;

	device_initialize(&iio_evgen_dev);

	dev_set_name(&iio_evgen_dev, "iio_evgen");

	return device_add(&iio_evgen_dev);

}

module_init(iio_dummy_evgen_init);



static __exit void iio_dummy_evgen_exit(void)

{

	device_unregister(&iio_evgen_dev);

}

module_exit(iio_dummy_evgen_exit);



MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");

MODULE_DESCRIPTION("IIO dummy driver");

MODULE_LICENSE("GPL v2");

drivers/staging/iio/iio_dummy_evgen.h

0 → 100644
+2 −0
Original line number Diff line number Diff line 
int iio_dummy_evgen_get_irq(void);

int iio_dummy_evgen_release_irq(int irq);

drivers/staging/iio/iio_simple_dummy.c

+31 −22
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#include <linux/moduleparam.h>



#include "iio.h"

#include "sysfs.h"

#include "iio_simple_dummy.h"



/*

 * A few elements needed to fake a bus for this driver
@@ -53,26 +55,6 @@ static const struct iio_dummy_accel_calibscale dummy_scales[] = { 
	{ 733, 13, 0x9 }, /* 733.00013 */

};



/**

 * struct iio_dummy_state - device instance specific state.

 * @dac_val:			cache for dac value

 * @single_ended_adc_val:	cache for single ended adc value

 * @differential_adc_val:	cache for differential adc value

 * @accel_val:			cache for acceleration value

 * @accel_calibbias:		cache for acceleration calibbias

 * @accel_calibscale:		cache for acceleration calibscale

 * @lock:			lock to ensure state is consistent

 */

struct iio_dummy_state {

	int dac_val;

	int single_ended_adc_val;

	int differential_adc_val[2];

	int accel_val;

	int accel_calibbias;

	const struct iio_dummy_accel_calibscale *accel_calibscale;

	struct mutex lock;

};



/*

 * iio_dummy_channels - Description of available channels

 *
@@ -101,6 +83,14 @@ static struct iio_chan_spec iio_dummy_channels[] = { 
		 */

		(1 << IIO_CHAN_INFO_SCALE_SEPARATE),



#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS

		/*

		 * simple event - triggered when value rises above

		 * a threshold

		 */

		.event_mask = IIO_EV_BIT(IIO_EV_TYPE_THRESH,

					 IIO_EV_DIR_RISING),

#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */

	},

	/* Differential ADC channel in_voltage1-voltage2_raw etc*/

	{
@@ -296,6 +286,12 @@ static const struct iio_info iio_dummy_info = { 
	.driver_module = THIS_MODULE,

	.read_raw = &iio_dummy_read_raw,

	.write_raw = &iio_dummy_write_raw,

#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS

	.read_event_config = &iio_simple_dummy_read_event_config,

	.write_event_config = &iio_simple_dummy_write_event_config,

	.read_event_value = &iio_simple_dummy_read_event_value,

	.write_event_value = &iio_simple_dummy_write_event_value,

#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */

};



/**
@@ -392,11 +388,16 @@ static int __devinit iio_dummy_probe(int index) 
	/* Specify that device provides sysfs type interfaces */

	indio_dev->modes = INDIO_DIRECT_MODE;



	ret = iio_device_register(indio_dev);

	ret = iio_simple_dummy_events_register(indio_dev);

	if (ret < 0)

		goto error_free_device;

	ret = iio_device_register(indio_dev);

	if (ret < 0)

		goto error_unregister_events;



	return 0;

error_unregister_events:

	iio_simple_dummy_events_unregister(indio_dev);

error_free_device:

	/* Note free device should only be called, before registration

	 * has succeeded. */
@@ -413,6 +414,7 @@ static int __devinit iio_dummy_probe(int index) 
 */

static int iio_dummy_remove(int index)

{

	int ret;

	/*

	 * Get a pointer to the device instance iio_dev structure

	 * from the bus subsystem. E.g.
@@ -421,15 +423,22 @@ static int iio_dummy_remove(int index) 
	 */

	struct iio_dev *indio_dev = iio_dummy_devs[index];





	/* Unregister the device */

	iio_device_unregister(indio_dev);



	/* Device specific code to power down etc */





	ret = iio_simple_dummy_events_unregister(indio_dev);

	if (ret)

		goto error_ret;



	/* Free all structures */

	iio_free_device(indio_dev);



	return 0;

error_ret:

	return ret;

}



/**