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path: root/drivers/iio/dummy/iio_simple_dummy.c
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-rw-r--r--drivers/iio/dummy/iio_simple_dummy.c747
1 files changed, 747 insertions, 0 deletions
diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c
new file mode 100644
index 000000000000..43fe4ba7d0dc
--- /dev/null
+++ b/drivers/iio/dummy/iio_simple_dummy.c
@@ -0,0 +1,747 @@
+/**
+ * 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.
+ *
+ * A reference industrial I/O driver to illustrate the functionality available.
+ *
+ * There are numerous real drivers to illustrate the finer points.
+ * The purpose of this driver is to provide a driver with far more comments
+ * and explanatory notes than any 'real' driver would have.
+ * Anyone starting out writing an IIO driver should first make sure they
+ * understand all of this driver except those bits specifically marked
+ * as being present to allow us to 'fake' the presence of hardware.
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/buffer.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";
+
+/**
+ * struct iio_dummy_accel_calibscale - realworld to register mapping
+ * @val: first value in read_raw - here integer part.
+ * @val2: second value in read_raw etc - here micro part.
+ * @regval: register value - magic device specific numbers.
+ */
+struct iio_dummy_accel_calibscale {
+ int val;
+ int val2;
+ int regval; /* what would be written to hardware */
+};
+
+static const struct iio_dummy_accel_calibscale dummy_scales[] = {
+ { 0, 100, 0x8 }, /* 0.000100 */
+ { 0, 133, 0x7 }, /* 0.000133 */
+ { 733, 13, 0x9 }, /* 733.000013 */
+};
+
+#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
+
+/*
+ * simple event - triggered when value rises above
+ * a threshold
+ */
+static const struct iio_event_spec iio_dummy_event = {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+};
+
+/*
+ * simple step detect event - triggered when a step is detected
+ */
+static const struct iio_event_spec step_detect_event = {
+ .type = IIO_EV_TYPE_CHANGE,
+ .dir = IIO_EV_DIR_NONE,
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+};
+
+/*
+ * simple transition event - triggered when the reported running confidence
+ * value rises above a threshold value
+ */
+static const struct iio_event_spec iio_running_event = {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+};
+
+/*
+ * simple transition event - triggered when the reported walking confidence
+ * value falls under a threshold value
+ */
+static const struct iio_event_spec iio_walking_event = {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_FALLING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE),
+};
+#endif
+
+/*
+ * iio_dummy_channels - Description of available channels
+ *
+ * This array of structures tells the IIO core about what the device
+ * actually provides for a given channel.
+ */
+static const struct iio_chan_spec iio_dummy_channels[] = {
+ /* indexed ADC channel in_voltage0_raw etc */
+ {
+ .type = IIO_VOLTAGE,
+ /* Channel has a numeric index of 0 */
+ .indexed = 1,
+ .channel = 0,
+ /* What other information is available? */
+ .info_mask_separate =
+ /*
+ * in_voltage0_raw
+ * Raw (unscaled no bias removal etc) measurement
+ * from the device.
+ */
+ BIT(IIO_CHAN_INFO_RAW) |
+ /*
+ * in_voltage0_offset
+ * Offset for userspace to apply prior to scale
+ * when converting to standard units (microvolts)
+ */
+ BIT(IIO_CHAN_INFO_OFFSET) |
+ /*
+ * in_voltage0_scale
+ * Multipler for userspace to apply post offset
+ * when converting to standard units (microvolts)
+ */
+ BIT(IIO_CHAN_INFO_SCALE),
+ /*
+ * sampling_frequency
+ * The frequency in Hz at which the channels are sampled
+ */
+ .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ /* The ordering of elements in the buffer via an enum */
+ .scan_index = DUMMY_INDEX_VOLTAGE_0,
+ .scan_type = { /* Description of storage in buffer */
+ .sign = 'u', /* unsigned */
+ .realbits = 13, /* 13 bits */
+ .storagebits = 16, /* 16 bits used for storage */
+ .shift = 0, /* zero shift */
+ },
+#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
+ .event_spec = &iio_dummy_event,
+ .num_event_specs = 1,
+#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
+ },
+ /* Differential ADC channel in_voltage1-voltage2_raw etc*/
+ {
+ .type = IIO_VOLTAGE,
+ .differential = 1,
+ /*
+ * Indexing for differential channels uses channel
+ * for the positive part, channel2 for the negative.
+ */
+ .indexed = 1,
+ .channel = 1,
+ .channel2 = 2,
+ /*
+ * in_voltage1-voltage2_raw
+ * Raw (unscaled no bias removal etc) measurement
+ * from the device.
+ */
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ /*
+ * in_voltage-voltage_scale
+ * Shared version of scale - shared by differential
+ * input channels of type IIO_VOLTAGE.
+ */
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+ /*
+ * sampling_frequency
+ * The frequency in Hz at which the channels are sampled
+ */
+ .scan_index = DUMMY_INDEX_DIFFVOLTAGE_1M2,
+ .scan_type = { /* Description of storage in buffer */
+ .sign = 's', /* signed */
+ .realbits = 12, /* 12 bits */
+ .storagebits = 16, /* 16 bits used for storage */
+ .shift = 0, /* zero shift */
+ },
+ },
+ /* Differential ADC channel in_voltage3-voltage4_raw etc*/
+ {
+ .type = IIO_VOLTAGE,
+ .differential = 1,
+ .indexed = 1,
+ .channel = 3,
+ .channel2 = 4,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .scan_index = DUMMY_INDEX_DIFFVOLTAGE_3M4,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 11,
+ .storagebits = 16,
+ .shift = 0,
+ },
+ },
+ /*
+ * 'modified' (i.e. axis specified) acceleration channel
+ * in_accel_z_raw
+ */
+ {
+ .type = IIO_ACCEL,
+ .modified = 1,
+ /* Channel 2 is use for modifiers */
+ .channel2 = IIO_MOD_X,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ /*
+ * Internal bias and gain correction values. Applied
+ * by the hardware or driver prior to userspace
+ * seeing the readings. Typically part of hardware
+ * calibration.
+ */
+ BIT(IIO_CHAN_INFO_CALIBSCALE) |
+ BIT(IIO_CHAN_INFO_CALIBBIAS),
+ .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .scan_index = DUMMY_INDEX_ACCELX,
+ .scan_type = { /* Description of storage in buffer */
+ .sign = 's', /* signed */
+ .realbits = 16, /* 16 bits */
+ .storagebits = 16, /* 16 bits used for storage */
+ .shift = 0, /* zero shift */
+ },
+ },
+ /*
+ * Convenience macro for timestamps. 4 is the index in
+ * the buffer.
+ */
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+ /* DAC channel out_voltage0_raw */
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .scan_index = -1, /* No buffer support */
+ .output = 1,
+ .indexed = 1,
+ .channel = 0,
+ },
+ {
+ .type = IIO_STEPS,
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_ENABLE) |
+ BIT(IIO_CHAN_INFO_CALIBHEIGHT),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .scan_index = -1, /* No buffer support */
+#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
+ .event_spec = &step_detect_event,
+ .num_event_specs = 1,
+#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
+ },
+ {
+ .type = IIO_ACTIVITY,
+ .modified = 1,
+ .channel2 = IIO_MOD_RUNNING,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .scan_index = -1, /* No buffer support */
+#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
+ .event_spec = &iio_running_event,
+ .num_event_specs = 1,
+#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
+ },
+ {
+ .type = IIO_ACTIVITY,
+ .modified = 1,
+ .channel2 = IIO_MOD_WALKING,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .scan_index = -1, /* No buffer support */
+#ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
+ .event_spec = &iio_walking_event,
+ .num_event_specs = 1,
+#endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */
+ },
+};
+
+/**
+ * iio_dummy_read_raw() - data read function.
+ * @indio_dev: the struct iio_dev associated with this device instance
+ * @chan: the channel whose data is to be read
+ * @val: first element of returned value (typically INT)
+ * @val2: second element of returned value (typically MICRO)
+ * @mask: what we actually want to read as per the info_mask_*
+ * in iio_chan_spec.
+ */
+static int iio_dummy_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long mask)
+{
+ struct iio_dummy_state *st = iio_priv(indio_dev);
+ int ret = -EINVAL;
+
+ mutex_lock(&st->lock);
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW: /* magic value - channel value read */
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ if (chan->output) {
+ /* Set integer part to cached value */
+ *val = st->dac_val;
+ ret = IIO_VAL_INT;
+ } else if (chan->differential) {
+ if (chan->channel == 1)
+ *val = st->differential_adc_val[0];
+ else
+ *val = st->differential_adc_val[1];
+ ret = IIO_VAL_INT;
+ } else {
+ *val = st->single_ended_adc_val;
+ ret = IIO_VAL_INT;
+ }
+ break;
+ case IIO_ACCEL:
+ *val = st->accel_val;
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ break;
+ }
+ break;
+ case IIO_CHAN_INFO_PROCESSED:
+ switch (chan->type) {
+ case IIO_STEPS:
+ *val = st->steps;
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_ACTIVITY:
+ switch (chan->channel2) {
+ case IIO_MOD_RUNNING:
+ *val = st->activity_running;
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_MOD_WALKING:
+ *val = st->activity_walking;
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ break;
+ case IIO_CHAN_INFO_OFFSET:
+ /* only single ended adc -> 7 */
+ *val = 7;
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ switch (chan->differential) {
+ case 0:
+ /* only single ended adc -> 0.001333 */
+ *val = 0;
+ *val2 = 1333;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ case 1:
+ /* all differential adc -> 0.000001344 */
+ *val = 0;
+ *val2 = 1344;
+ ret = IIO_VAL_INT_PLUS_NANO;
+ }
+ break;
+ default:
+ break;
+ }
+ break;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ /* only the acceleration axis - read from cache */
+ *val = st->accel_calibbias;
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_CHAN_INFO_CALIBSCALE:
+ *val = st->accel_calibscale->val;
+ *val2 = st->accel_calibscale->val2;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = 3;
+ *val2 = 33;
+ ret = IIO_VAL_INT_PLUS_NANO;
+ break;
+ case IIO_CHAN_INFO_ENABLE:
+ switch (chan->type) {
+ case IIO_STEPS:
+ *val = st->steps_enabled;
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ break;
+ }
+ break;
+ case IIO_CHAN_INFO_CALIBHEIGHT:
+ switch (chan->type) {
+ case IIO_STEPS:
+ *val = st->height;
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ default:
+ break;
+ }
+ mutex_unlock(&st->lock);
+ return ret;
+}
+
+/**
+ * iio_dummy_write_raw() - data write function.
+ * @indio_dev: the struct iio_dev associated with this device instance
+ * @chan: the channel whose data is to be written
+ * @val: first element of value to set (typically INT)
+ * @val2: second element of value to set (typically MICRO)
+ * @mask: what we actually want to write as per the info_mask_*
+ * in iio_chan_spec.
+ *
+ * Note that all raw writes are assumed IIO_VAL_INT and info mask elements
+ * are assumed to be IIO_INT_PLUS_MICRO unless the callback write_raw_get_fmt
+ * in struct iio_info is provided by the driver.
+ */
+static int iio_dummy_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long mask)
+{
+ int i;
+ int ret = 0;
+ struct iio_dummy_state *st = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ if (chan->output == 0)
+ return -EINVAL;
+
+ /* Locking not required as writing single value */
+ mutex_lock(&st->lock);
+ st->dac_val = val;
+ mutex_unlock(&st->lock);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_PROCESSED:
+ switch (chan->type) {
+ case IIO_STEPS:
+ mutex_lock(&st->lock);
+ st->steps = val;
+ mutex_unlock(&st->lock);
+ return 0;
+ case IIO_ACTIVITY:
+ if (val < 0)
+ val = 0;
+ if (val > 100)
+ val = 100;
+ switch (chan->channel2) {
+ case IIO_MOD_RUNNING:
+ st->activity_running = val;
+ return 0;
+ case IIO_MOD_WALKING:
+ st->activity_walking = val;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_CALIBSCALE:
+ mutex_lock(&st->lock);
+ /* Compare against table - hard matching here */
+ for (i = 0; i < ARRAY_SIZE(dummy_scales); i++)
+ if (val == dummy_scales[i].val &&
+ val2 == dummy_scales[i].val2)
+ break;
+ if (i == ARRAY_SIZE(dummy_scales))
+ ret = -EINVAL;
+ else
+ st->accel_calibscale = &dummy_scales[i];
+ mutex_unlock(&st->lock);
+ return ret;
+ case IIO_CHAN_INFO_CALIBBIAS:
+ mutex_lock(&st->lock);
+ st->accel_calibbias = val;
+ mutex_unlock(&st->lock);
+ return 0;
+ case IIO_CHAN_INFO_ENABLE:
+ switch (chan->type) {
+ case IIO_STEPS:
+ mutex_lock(&st->lock);
+ st->steps_enabled = val;
+ mutex_unlock(&st->lock);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_CALIBHEIGHT:
+ switch (chan->type) {
+ case IIO_STEPS:
+ st->height = val;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * Device type specific information.
+ */
+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 */
+};
+
+/**
+ * iio_dummy_init_device() - device instance specific init
+ * @indio_dev: the iio device structure
+ *
+ * Most drivers have one of these to set up default values,
+ * reset the device to known state etc.
+ */
+static int iio_dummy_init_device(struct iio_dev *indio_dev)
+{
+ struct iio_dummy_state *st = iio_priv(indio_dev);
+
+ st->dac_val = 0;
+ st->single_ended_adc_val = 73;
+ st->differential_adc_val[0] = 33;
+ st->differential_adc_val[1] = -34;
+ st->accel_val = 34;
+ st->accel_calibbias = -7;
+ st->accel_calibscale = &dummy_scales[0];
+ st->steps = 47;
+ st->activity_running = 98;
+ st->activity_walking = 4;
+
+ return 0;
+}
+
+/**
+ * iio_dummy_probe() - device instance probe
+ * @index: an id number for this instance.
+ *
+ * Arguments are bus type specific.
+ * I2C: iio_dummy_probe(struct i2c_client *client,
+ * const struct i2c_device_id *id)
+ * SPI: iio_dummy_probe(struct spi_device *spi)
+ */
+static int iio_dummy_probe(int index)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct iio_dummy_state *st;
+
+ /*
+ * Allocate an IIO device.
+ *
+ * This structure contains all generic state
+ * information about the device instance.
+ * It also has a region (accessed by iio_priv()
+ * for chip specific state information.
+ */
+ indio_dev = iio_device_alloc(sizeof(*st));
+ if (!indio_dev) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ st = iio_priv(indio_dev);
+ mutex_init(&st->lock);
+
+ iio_dummy_init_device(indio_dev);
+ /*
+ * With hardware: Set the parent device.
+ * indio_dev->dev.parent = &spi->dev;
+ * indio_dev->dev.parent = &client->dev;
+ */
+
+ /*
+ * Make the iio_dev struct available to remove function.
+ * Bus equivalents
+ * i2c_set_clientdata(client, indio_dev);
+ * spi_set_drvdata(spi, indio_dev);
+ */
+ iio_dummy_devs[index] = indio_dev;
+
+ /*
+ * Set the device name.
+ *
+ * This is typically a part number and obtained from the module
+ * id table.
+ * e.g. for i2c and spi:
+ * indio_dev->name = id->name;
+ * indio_dev->name = spi_get_device_id(spi)->name;
+ */
+ indio_dev->name = iio_dummy_part_number;
+
+ /* Provide description of available channels */
+ indio_dev->channels = iio_dummy_channels;
+ indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels);
+
+ /*
+ * Provide device type specific interface functions and
+ * constant data.
+ */
+ indio_dev->info = &iio_dummy_info;
+
+ /* Specify that device provides sysfs type interfaces */
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = iio_simple_dummy_events_register(indio_dev);
+ if (ret < 0)
+ goto error_free_device;
+
+ ret = iio_simple_dummy_configure_buffer(indio_dev);
+ if (ret < 0)
+ goto error_unregister_events;
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0)
+ goto error_unconfigure_buffer;
+
+ return 0;
+error_unconfigure_buffer:
+ iio_simple_dummy_unconfigure_buffer(indio_dev);
+error_unregister_events:
+ iio_simple_dummy_events_unregister(indio_dev);
+error_free_device:
+ iio_device_free(indio_dev);
+error_ret:
+ return ret;
+}
+
+/**
+ * iio_dummy_remove() - device instance removal function
+ * @index: device index.
+ *
+ * Parameters follow those of iio_dummy_probe for buses.
+ */
+static void iio_dummy_remove(int index)
+{
+ /*
+ * Get a pointer to the device instance iio_dev structure
+ * from the bus subsystem. E.g.
+ * 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];
+
+ /* Unregister the device */
+ iio_device_unregister(indio_dev);
+
+ /* Device specific code to power down etc */
+
+ /* Buffered capture related cleanup */
+ iio_simple_dummy_unconfigure_buffer(indio_dev);
+
+ iio_simple_dummy_events_unregister(indio_dev);
+
+ /* Free all structures */
+ iio_device_free(indio_dev);
+}
+
+/**
+ * iio_dummy_init() - 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
+ * i2c:
+ * Documentation/i2c/writing-clients
+ * 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);
+
+/**
+ * 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;
+
+ for (i = 0; i < instances; i++)
+ iio_dummy_remove(i);
+ kfree(iio_dummy_devs);
+}
+module_exit(iio_dummy_exit);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
+MODULE_DESCRIPTION("IIO dummy driver");
+MODULE_LICENSE("GPL v2");