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Commit 3d85fb6f authored by Daniel Baluta's avatar Daniel Baluta Committed by Jonathan Cameron
Browse files

iio: dummy: Convert IIO dummy to configfs 



We register a new device type named "dummy", this will create a
configfs entry under:
	* /config/iio/devices/dummy.

Creating dummy devices is now as simple as:

$ mkdir /config/iio/devices/dummy/my_dummy_device

Signed-off-by: default avatarDaniel Baluta <daniel.baluta@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 0f3a8c3f

drivers/iio/dummy/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ config IIO_DUMMY_EVGEN 


config IIO_SIMPLE_DUMMY

       tristate "An example driver with no hardware requirements"

       depends on IIO_SW_DEVICE

       help

	 Driver intended mainly as documentation for how to write

	 a driver. May also be useful for testing userspace code

drivers/iio/dummy/iio_simple_dummy.c

+37 −65
Original line number Diff line number Diff line
@@ -17,26 +17,18 @@ 
#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/string.h>



#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/events.h>

#include <linux/iio/buffer.h>

#include <linux/iio/sw_device.h>

#include "iio_simple_dummy.h"



/*

 * A few elements needed to fake a bus for this driver

 * Note instances parameter controls how many of these

 * dummy devices are registered.

 */

static unsigned instances = 1;

module_param(instances, uint, 0);



/* Pointer array used to fake bus elements */

static struct iio_dev **iio_dummy_devs;



/* Fake a name for the part number, usually obtained from the id table */

static const char *iio_dummy_part_number = "iio_dummy_part_no";

static struct config_item_type iio_dummy_type = {

	.ct_owner = THIS_MODULE,

};



/**

 * struct iio_dummy_accel_calibscale - realworld to register mapping
@@ -572,12 +564,18 @@ static int iio_dummy_init_device(struct iio_dev *indio_dev) 
 *                      const struct i2c_device_id *id)

 * SPI: iio_dummy_probe(struct spi_device *spi)

 */

static int iio_dummy_probe(int index)

static struct iio_sw_device *iio_dummy_probe(const char *name)

{

	int ret;

	struct iio_dev *indio_dev;

	struct iio_dummy_state *st;

	struct iio_sw_device *swd;



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

	if (!swd) {

		ret = -ENOMEM;

		goto error_kzalloc;

	}

	/*

	 * Allocate an IIO device.

	 *
@@ -608,7 +606,7 @@ static int iio_dummy_probe(int index) 
	 * i2c_set_clientdata(client, indio_dev);

	 * spi_set_drvdata(spi, indio_dev);

	 */

	iio_dummy_devs[index] = indio_dev;

	swd->device = indio_dev;



	/*

	 * Set the device name.
@@ -619,7 +617,7 @@ static int iio_dummy_probe(int index) 
	 *    indio_dev->name = id->name;

	 *    indio_dev->name = spi_get_device_id(spi)->name;

	 */

	indio_dev->name = iio_dummy_part_number;

	indio_dev->name = kstrdup(name, GFP_KERNEL);



	/* Provide description of available channels */

	indio_dev->channels = iio_dummy_channels;
@@ -646,7 +644,9 @@ static int iio_dummy_probe(int index) 
	if (ret < 0)

		goto error_unconfigure_buffer;



	return 0;

	iio_swd_group_init_type_name(swd, name, &iio_dummy_type);



	return swd;

error_unconfigure_buffer:

	iio_simple_dummy_unconfigure_buffer(indio_dev);

error_unregister_events:
@@ -654,16 +654,18 @@ static int iio_dummy_probe(int index) 
error_free_device:

	iio_device_free(indio_dev);

error_ret:

	return ret;

	kfree(swd);

error_kzalloc:

	return ERR_PTR(ret);

}



/**

 * iio_dummy_remove() - device instance removal function

 * @index: device index.

 * @swd: pointer to software IIO device abstraction

 *

 * Parameters follow those of iio_dummy_probe for buses.

 */

static void iio_dummy_remove(int index)

static int iio_dummy_remove(struct iio_sw_device *swd)

{

	/*

	 * Get a pointer to the device instance iio_dev structure
@@ -671,7 +673,7 @@ static void iio_dummy_remove(int index) 
	 * struct iio_dev *indio_dev = i2c_get_clientdata(client);

	 * struct iio_dev *indio_dev = spi_get_drvdata(spi);

	 */

	struct iio_dev *indio_dev = iio_dummy_devs[index];

	struct iio_dev *indio_dev = swd->device;



	/* Unregister the device */

	iio_device_unregister(indio_dev);
@@ -684,11 +686,13 @@ static void iio_dummy_remove(int index) 
	iio_simple_dummy_events_unregister(indio_dev);



	/* Free all structures */

	kfree(indio_dev->name);

	iio_device_free(indio_dev);

}



	return 0;

}

/**

 * iio_dummy_init() -  device driver registration

 * module_iio_sw_device_driver() -  device driver registration

 *

 * Varies depending on bus type of the device. As there is no device

 * here, call probe directly. For information on device registration
@@ -697,50 +701,18 @@ static void iio_dummy_remove(int index) 
 * spi:

 * Documentation/spi/spi-summary

 */

static __init int iio_dummy_init(void)

{

	int i, ret;



	if (instances > 10) {

		instances = 1;

		return -EINVAL;

	}



	/* Fake a bus */

	iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs),

				 GFP_KERNEL);

	/* Here we have no actual device so call probe */

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

		ret = iio_dummy_probe(i);

		if (ret < 0)

			goto error_remove_devs;

	}

	return 0;



error_remove_devs:

	while (i--)

		iio_dummy_remove(i);



	kfree(iio_dummy_devs);

	return ret;

}

module_init(iio_dummy_init);

static const struct iio_sw_device_ops iio_dummy_device_ops = {

	.probe = iio_dummy_probe,

	.remove = iio_dummy_remove,

};



/**

 * iio_dummy_exit() - device driver removal

 *

 * Varies depending on bus type of the device.

 * As there is no device here, call remove directly.

 */

static __exit void iio_dummy_exit(void)

{

	int i;

static struct iio_sw_device_type iio_dummy_device = {

	.name = "dummy",

	.owner = THIS_MODULE,

	.ops = &iio_dummy_device_ops,

};



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

		iio_dummy_remove(i);

	kfree(iio_dummy_devs);

}

module_exit(iio_dummy_exit);

module_iio_sw_device_driver(iio_dummy_device);



MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");

MODULE_DESCRIPTION("IIO dummy driver");