cregit-Linux how code gets into the kernel

Release 4.7 drivers/iio/dummy/iio_simple_dummy.c

/**
 * 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; }

Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron28363.03%350.00%
daniel balutadaniel baluta16436.53%116.67%
lars-peter clausenlars-peter clausen10.22%116.67%
alison schofieldalison schofield10.22%116.67%
Total449100.00%6100.00%

/** * 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; } }

Contributors

PersonTokensPropCommitsCommitProp
daniel balutadaniel baluta19348.01%125.00%
jonathan cameronjonathan cameron17944.53%125.00%
jin fengjin feng297.21%125.00%
lars-peter clausenlars-peter clausen10.25%125.00%
Total402100.00%4100.00%

/* * 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; }

Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron7881.25%150.00%
daniel balutadaniel baluta1818.75%150.00%
Total96100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron18897.41%350.00%
lars-peter clausenlars-peter clausen42.07%233.33%
cristina opriceanacristina opriceana10.52%116.67%
Total193100.00%6100.00%

/** * 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); }

Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron4295.45%360.00%
vladimirs ambrosovsvladimirs ambrosovs12.27%120.00%
lars-peter clausenlars-peter clausen12.27%120.00%
Total44100.00%5100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron7574.26%133.33%
vladimirs ambrosovsvladimirs ambrosovs2322.77%133.33%
thomas meyerthomas meyer32.97%133.33%
Total101100.00%3100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron35100.00%1100.00%
Total35100.00%1100.00%

module_exit(iio_dummy_exit); MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); MODULE_DESCRIPTION("IIO dummy driver"); MODULE_LICENSE("GPL v2");

Overall Contributors

PersonTokensPropCommitsCommitProp
jonathan cameronjonathan cameron144765.53%932.14%
daniel balutadaniel baluta60327.31%13.57%
lars-peter clausenlars-peter clausen853.85%725.00%
jin fengjin feng351.59%13.57%
vladimirs ambrosovsvladimirs ambrosovs251.13%310.71%
alison schofieldalison schofield50.23%27.14%
thomas meyerthomas meyer30.14%13.57%
peter meerwaldpeter meerwald20.09%13.57%
alexander steinalexander stein10.05%13.57%
cristina opriceanacristina opriceana10.05%13.57%
irina tirdeairina tirdea10.05%13.57%
Total2208100.00%28100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}