xref: /linux/include/linux/iio/iio.h (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)

/* SPDX-License-Identifier: GPL-2.0-only */

/* The industrial I/O core
 *
 * Copyright (c) 2008 Jonathan Cameron
 */
#ifndef _INDUSTRIAL_IO_H_
#define _INDUSTRIAL_IO_H_

#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/cleanup.h>
#include <linux/slab.h>
#include <linux/iio/types.h>
/* IIO TODO LIST */
/*
 * Provide means of adjusting timer accuracy.
 * Currently assumes nano seconds.
 */

struct fwnode_reference_args;

enum iio_shared_by {
	IIO_SEPARATE,
	IIO_SHARED_BY_TYPE,
	IIO_SHARED_BY_DIR,
	IIO_SHARED_BY_ALL
};

enum iio_endian {
	IIO_CPU,
	IIO_BE,
	IIO_LE,
};

struct iio_chan_spec;
struct iio_dev;

/**
 * struct iio_chan_spec_ext_info - Extended channel info attribute
 * @name:	Info attribute name
 * @shared:	Whether this attribute is shared between all channels.
 * @read:	Read callback for this info attribute, may be NULL.
 * @write:	Write callback for this info attribute, may be NULL.
 * @private:	Data private to the driver.
 */
struct iio_chan_spec_ext_info {
	const char *name;
	enum iio_shared_by shared;
	ssize_t (*read)(struct iio_dev *, uintptr_t private,
			struct iio_chan_spec const *, char *buf);
	ssize_t (*write)(struct iio_dev *, uintptr_t private,
			 struct iio_chan_spec const *, const char *buf,
			 size_t len);
	uintptr_t private;
};

/**
 * struct iio_enum - Enum channel info attribute
 * @items:	An array of strings.
 * @num_items:	Length of the item array.
 * @set:	Set callback function, may be NULL.
 * @get:	Get callback function, may be NULL.
 *
 * The iio_enum struct can be used to implement enum style channel attributes.
 * Enum style attributes are those which have a set of strings which map to
 * unsigned integer values. The IIO enum helper code takes care of mapping
 * between value and string as well as generating a "_available" file which
 * contains a list of all available items. The set callback will be called when
 * the attribute is updated. The last parameter is the index to the newly
 * activated item. The get callback will be used to query the currently active
 * item and is supposed to return the index for it.
 */
struct iio_enum {
	const char * const *items;
	unsigned int num_items;
	int (*set)(struct iio_dev *, const struct iio_chan_spec *, unsigned int);
	int (*get)(struct iio_dev *, const struct iio_chan_spec *);
};

ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
ssize_t iio_enum_read(struct iio_dev *indio_dev,
	uintptr_t priv, const struct iio_chan_spec *chan, char *buf);
ssize_t iio_enum_write(struct iio_dev *indio_dev,
	uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
	size_t len);

/**
 * IIO_ENUM() - Initialize enum extended channel attribute
 * @_name:	Attribute name
 * @_shared:	Whether the attribute is shared between all channels
 * @_e:		Pointer to an iio_enum struct
 *
 * This should usually be used together with IIO_ENUM_AVAILABLE()
 */
#define IIO_ENUM(_name, _shared, _e) \
{ \
	.name = (_name), \
	.shared = (_shared), \
	.read = iio_enum_read, \
	.write = iio_enum_write, \
	.private = (uintptr_t)(_e), \
}

/**
 * IIO_ENUM_AVAILABLE() - Initialize enum available extended channel attribute
 * @_name:	Attribute name ("_available" will be appended to the name)
 * @_shared:	Whether the attribute is shared between all channels
 * @_e:		Pointer to an iio_enum struct
 *
 * Creates a read only attribute which lists all the available enum items in a
 * space separated list. This should usually be used together with IIO_ENUM()
 */
#define IIO_ENUM_AVAILABLE(_name, _shared, _e) \
{ \
	.name = (_name "_available"), \
	.shared = _shared, \
	.read = iio_enum_available_read, \
	.private = (uintptr_t)(_e), \
}

/**
 * struct iio_mount_matrix - iio mounting matrix
 * @rotation: 3 dimensional space rotation matrix defining sensor alignment with
 *            main hardware
 */
struct iio_mount_matrix {
	const char *rotation[9];
};

ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
			      const struct iio_chan_spec *chan, char *buf);
int iio_read_mount_matrix(struct device *dev, struct iio_mount_matrix *matrix);

typedef const struct iio_mount_matrix *
	(iio_get_mount_matrix_t)(const struct iio_dev *indio_dev,
				 const struct iio_chan_spec *chan);

/**
 * IIO_MOUNT_MATRIX() - Initialize mount matrix extended channel attribute
 * @_shared:	Whether the attribute is shared between all channels
 * @_get:	Pointer to an iio_get_mount_matrix_t accessor
 */
#define IIO_MOUNT_MATRIX(_shared, _get) \
{ \
	.name = "mount_matrix", \
	.shared = (_shared), \
	.read = iio_show_mount_matrix, \
	.private = (uintptr_t)(_get), \
}

/**
 * struct iio_event_spec - specification for a channel event
 * @type:		    Type of the event
 * @dir:		    Direction of the event
 * @mask_separate:	    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be registered per channel.
 * @mask_shared_by_type:    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be shared by channel type.
 * @mask_shared_by_dir:	    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be shared by channel type and
 *			    direction.
 * @mask_shared_by_all:	    Bit mask of enum iio_event_info values. Attributes
 *			    set in this mask will be shared by all channels.
 */
struct iio_event_spec {
	enum iio_event_type type;
	enum iio_event_direction dir;
	unsigned long mask_separate;
	unsigned long mask_shared_by_type;
	unsigned long mask_shared_by_dir;
	unsigned long mask_shared_by_all;
};

/**
 * struct iio_scan_type - specification for channel data format in buffer
 * @sign:		's' or 'u' to specify signed or unsigned
 * @realbits:		Number of valid bits of data
 * @storagebits:	Realbits + padding
 * @shift:		Shift right by this before masking out realbits.
 * @repeat:		Number of times real/storage bits repeats. When the
 *			repeat element is more than 1, then the type element in
 *			sysfs will show a repeat value. Otherwise, the number
 *			of repetitions is omitted.
 * @endianness:		little or big endian
 */
struct iio_scan_type {
	char	sign;
	u8	realbits;
	u8	storagebits;
	u8	shift;
	u8	repeat;
	enum iio_endian endianness;
};

/**
 * struct iio_chan_spec - specification of a single channel
 * @type:		What type of measurement is the channel making.
 * @channel:		What number do we wish to assign the channel.
 * @channel2:		If there is a second number for a differential
 *			channel then this is it. If modified is set then the
 *			value here specifies the modifier.
 * @address:		Driver specific identifier.
 * @scan_index:		Monotonic index to give ordering in scans when read
 *			from a buffer.
 * @scan_type:		struct describing the scan type - mutually exclusive
 *			with ext_scan_type.
 * @ext_scan_type:	Used in rare cases where there is more than one scan
 *			format for a channel. When this is used, the flag
 *			has_ext_scan_type must be set and the driver must
 *			implement get_current_scan_type in struct iio_info.
 * @num_ext_scan_type:	Number of elements in ext_scan_type.
 * @info_mask_separate: What information is to be exported that is specific to
 *			this channel.
 * @info_mask_separate_available: What availability information is to be
 *			exported that is specific to this channel.
 * @info_mask_shared_by_type: What information is to be exported that is shared
 *			by all channels of the same type.
 * @info_mask_shared_by_type_available: What availability information is to be
 *			exported that is shared by all channels of the same
 *			type.
 * @info_mask_shared_by_dir: What information is to be exported that is shared
 *			by all channels of the same direction.
 * @info_mask_shared_by_dir_available: What availability information is to be
 *			exported that is shared by all channels of the same
 *			direction.
 * @info_mask_shared_by_all: What information is to be exported that is shared
 *			by all channels.
 * @info_mask_shared_by_all_available: What availability information is to be
 *			exported that is shared by all channels.
 * @event_spec:		Array of events which should be registered for this
 *			channel.
 * @num_event_specs:	Size of the event_spec array.
 * @ext_info:		Array of extended info attributes for this channel.
 *			The array is NULL terminated, the last element should
 *			have its name field set to NULL.
 * @extend_name:	Allows labeling of channel attributes with an
 *			informative name. Note this has no effect codes etc,
 *			unlike modifiers.
 *			This field is deprecated in favour of providing
 *			iio_info->read_label() to override the label, which
 *			unlike @extend_name does not affect sysfs filenames.
 * @datasheet_name:	A name used in in-kernel mapping of channels. It should
 *			correspond to the first name that the channel is referred
 *			to by in the datasheet (e.g. IND), or the nearest
 *			possible compound name (e.g. IND-INC).
 * @modified:		Does a modifier apply to this channel. What these are
 *			depends on the channel type.  Modifier is set in
 *			channel2. Examples are IIO_MOD_X for axial sensors about
 *			the 'x' axis.
 * @indexed:		Specify the channel has a numerical index. If not,
 *			the channel index number will be suppressed for sysfs
 *			attributes but not for event codes.
 * @output:		Channel is output.
 * @differential:	Channel is differential.
 * @has_ext_scan_type:	True if ext_scan_type is used instead of scan_type.
 */
struct iio_chan_spec {
	enum iio_chan_type	type;
	int			channel;
	int			channel2;
	unsigned long		address;
	int			scan_index;
	union {
		struct iio_scan_type scan_type;
		struct {
			const struct iio_scan_type *ext_scan_type;
			unsigned int num_ext_scan_type;
		};
	};
	long			info_mask_separate;
	long			info_mask_separate_available;
	long			info_mask_shared_by_type;
	long			info_mask_shared_by_type_available;
	long			info_mask_shared_by_dir;
	long			info_mask_shared_by_dir_available;
	long			info_mask_shared_by_all;
	long			info_mask_shared_by_all_available;
	const struct iio_event_spec *event_spec;
	unsigned int		num_event_specs;
	const struct iio_chan_spec_ext_info *ext_info;
	const char		*extend_name;
	const char		*datasheet_name;
	unsigned		modified:1;
	unsigned		indexed:1;
	unsigned		output:1;
	unsigned		differential:1;
	unsigned		has_ext_scan_type:1;
};


/**
 * iio_channel_has_info() - Checks whether a channel supports a info attribute
 * @chan: The channel to be queried
 * @type: Type of the info attribute to be checked
 *
 * Returns true if the channels supports reporting values for the given info
 * attribute type, false otherwise.
 */
static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
	enum iio_chan_info_enum type)
{
	return (chan->info_mask_separate & BIT(type)) |
		(chan->info_mask_shared_by_type & BIT(type)) |
		(chan->info_mask_shared_by_dir & BIT(type)) |
		(chan->info_mask_shared_by_all & BIT(type));
}

/**
 * iio_channel_has_available() - Checks if a channel has an available attribute
 * @chan: The channel to be queried
 * @type: Type of the available attribute to be checked
 *
 * Returns true if the channel supports reporting available values for the
 * given attribute type, false otherwise.
 */
static inline bool iio_channel_has_available(const struct iio_chan_spec *chan,
					     enum iio_chan_info_enum type)
{
	return (chan->info_mask_separate_available & BIT(type)) |
		(chan->info_mask_shared_by_type_available & BIT(type)) |
		(chan->info_mask_shared_by_dir_available & BIT(type)) |
		(chan->info_mask_shared_by_all_available & BIT(type));
}

#define IIO_CHAN_SOFT_TIMESTAMP(_si) {					\
	.type = IIO_TIMESTAMP,						\
	.channel = -1,							\
	.scan_index = _si,						\
	.scan_type = {							\
		.sign = 's',						\
		.realbits = 64,					\
		.storagebits = 64,					\
		},							\
}

s64 iio_get_time_ns(const struct iio_dev *indio_dev);

/*
 * Device operating modes
 * @INDIO_DIRECT_MODE: There is an access to either:
 * a) The last single value available for devices that do not provide
 *    on-demand reads.
 * b) A new value after performing an on-demand read otherwise.
 * On most devices, this is a single-shot read. On some devices with data
 * streams without an 'on-demand' function, this might also be the 'last value'
 * feature. Above all, this mode internally means that we are not in any of the
 * other modes, and sysfs reads should work.
 * Device drivers should inform the core if they support this mode.
 * @INDIO_BUFFER_TRIGGERED: Common mode when dealing with kfifo buffers.
 * It indicates that an explicit trigger is required. This requests the core to
 * attach a poll function when enabling the buffer, which is indicated by the
 * _TRIGGERED suffix.
 * The core will ensure this mode is set when registering a triggered buffer
 * with iio_triggered_buffer_setup().
 * @INDIO_BUFFER_SOFTWARE: Another kfifo buffer mode, but not event triggered.
 * No poll function can be attached because there is no triggered infrastructure
 * we can use to cause capture. There is a kfifo that the driver will fill, but
 * not "only one scan at a time". Typically, hardware will have a buffer that
 * can hold multiple scans. Software may read one or more scans at a single time
 * and push the available data to a Kfifo. This means the core will not attach
 * any poll function when enabling the buffer.
 * The core will ensure this mode is set when registering a simple kfifo buffer
 * with devm_iio_kfifo_buffer_setup().
 * @INDIO_BUFFER_HARDWARE: For specific hardware, if unsure do not use this mode.
 * Same as above but this time the buffer is not a kfifo where we have direct
 * access to the data. Instead, the consumer driver must access the data through
 * non software visible channels (or DMA when there is no demux possible in
 * software)
 * The core will ensure this mode is set when registering a dmaengine buffer
 * with devm_iio_dmaengine_buffer_setup().
 * @INDIO_EVENT_TRIGGERED: Very unusual mode.
 * Triggers usually refer to an external event which will start data capture.
 * Here it is kind of the opposite as, a particular state of the data might
 * produce an event which can be considered as an event. We don't necessarily
 * have access to the data itself, but to the event produced. For example, this
 * can be a threshold detector. The internal path of this mode is very close to
 * the INDIO_BUFFER_TRIGGERED mode.
 * The core will ensure this mode is set when registering a triggered event.
 * @INDIO_HARDWARE_TRIGGERED: Very unusual mode.
 * Here, triggers can result in data capture and can be routed to multiple
 * hardware components, which make them close to regular triggers in the way
 * they must be managed by the core, but without the entire interrupts/poll
 * functions burden. Interrupts are irrelevant as the data flow is hardware
 * mediated and distributed.
 */
#define INDIO_DIRECT_MODE		0x01
#define INDIO_BUFFER_TRIGGERED		0x02
#define INDIO_BUFFER_SOFTWARE		0x04
#define INDIO_BUFFER_HARDWARE		0x08
#define INDIO_EVENT_TRIGGERED		0x10
#define INDIO_HARDWARE_TRIGGERED	0x20

#define INDIO_ALL_BUFFER_MODES					\
	(INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE)

#define INDIO_ALL_TRIGGERED_MODES	\
	(INDIO_BUFFER_TRIGGERED		\
	 | INDIO_EVENT_TRIGGERED	\
	 | INDIO_HARDWARE_TRIGGERED)

#define INDIO_MAX_RAW_ELEMENTS		4

struct iio_val_int_plus_micro {
	int integer;
	int micro;
};

struct iio_trigger; /* forward declaration */

/**
 * struct iio_info - constant information about device
 * @event_attrs:	event control attributes
 * @attrs:		general purpose device attributes
 * @read_raw:		function to request a value from the device.
 *			mask specifies which value. Note 0 means a reading of
 *			the channel in question.  Return value will specify the
 *			type of value returned by the device. val and val2 will
 *			contain the elements making up the returned value.
 * @read_raw_multi:	function to return values from the device.
 *			mask specifies which value. Note 0 means a reading of
 *			the channel in question.  Return value will specify the
 *			type of value returned by the device. vals pointer
 *			contain the elements making up the returned value.
 *			max_len specifies maximum number of elements
 *			vals pointer can contain. val_len is used to return
 *			length of valid elements in vals.
 * @read_avail:		function to return the available values from the device.
 *			mask specifies which value. Note 0 means the available
 *			values for the channel in question.  Return value
 *			specifies if a IIO_AVAIL_LIST or a IIO_AVAIL_RANGE is
 *			returned in vals. The type of the vals are returned in
 *			type and the number of vals is returned in length. For
 *			ranges, there are always three vals returned; min, step
 *			and max. For lists, all possible values are enumerated.
 * @write_raw:		function to write a value to the device.
 *			Parameters are the same as for read_raw.
 * @read_label:		function to request label name for a specified label,
 *			for better channel identification.
 * @write_raw_get_fmt:	callback function to query the expected
 *			format/precision. If not set by the driver, write_raw
 *			returns IIO_VAL_INT_PLUS_MICRO.
 * @read_event_config:	find out if the event is enabled.
 * @write_event_config:	set if the event is enabled.
 * @read_event_value:	read a configuration value associated with the event.
 * @write_event_value:	write a configuration value for the event.
 * @read_event_label:	function to request label name for a specified label,
 *			for better event identification.
 * @validate_trigger:	function to validate the trigger when the
 *			current trigger gets changed.
 * @get_current_scan_type: must be implemented by drivers that use ext_scan_type
 *			in the channel spec to return the index of the currently
 *			active ext_scan type for a channel.
 * @update_scan_mode:	function to configure device and scan buffer when
 *			channels have changed
 * @debugfs_reg_access:	function to read or write register value of device
 * @fwnode_xlate:	fwnode based function pointer to obtain channel specifier index.
 * @hwfifo_set_watermark: function pointer to set the current hardware
 *			fifo watermark level; see hwfifo_* entries in
 *			Documentation/ABI/testing/sysfs-bus-iio for details on
 *			how the hardware fifo operates
 * @hwfifo_flush_to_buffer: function pointer to flush the samples stored
 *			in the hardware fifo to the device buffer. The driver
 *			should not flush more than count samples. The function
 *			must return the number of samples flushed, 0 if no
 *			samples were flushed or a negative integer if no samples
 *			were flushed and there was an error.
 **/
struct iio_info {
	const struct attribute_group	*event_attrs;
	const struct attribute_group	*attrs;

	int (*read_raw)(struct iio_dev *indio_dev,
			struct iio_chan_spec const *chan,
			int *val,
			int *val2,
			long mask);

	int (*read_raw_multi)(struct iio_dev *indio_dev,
			struct iio_chan_spec const *chan,
			int max_len,
			int *vals,
			int *val_len,
			long mask);

	int (*read_avail)(struct iio_dev *indio_dev,
			  struct iio_chan_spec const *chan,
			  const int **vals,
			  int *type,
			  int *length,
			  long mask);

	int (*write_raw)(struct iio_dev *indio_dev,
			 struct iio_chan_spec const *chan,
			 int val,
			 int val2,
			 long mask);

	int (*read_label)(struct iio_dev *indio_dev,
			 struct iio_chan_spec const *chan,
			 char *label);

	int (*write_raw_get_fmt)(struct iio_dev *indio_dev,
			 struct iio_chan_spec const *chan,
			 long mask);

	int (*read_event_config)(struct iio_dev *indio_dev,
				 const struct iio_chan_spec *chan,
				 enum iio_event_type type,
				 enum iio_event_direction dir);

	int (*write_event_config)(struct iio_dev *indio_dev,
				  const struct iio_chan_spec *chan,
				  enum iio_event_type type,
				  enum iio_event_direction dir,
				  int state);

	int (*read_event_value)(struct iio_dev *indio_dev,
				const struct iio_chan_spec *chan,
				enum iio_event_type type,
				enum iio_event_direction dir,
				enum iio_event_info info, int *val, int *val2);

	int (*write_event_value)(struct iio_dev *indio_dev,
				 const struct iio_chan_spec *chan,
				 enum iio_event_type type,
				 enum iio_event_direction dir,
				 enum iio_event_info info, int val, int val2);

	int (*read_event_label)(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				enum iio_event_type type,
				enum iio_event_direction dir,
				char *label);

	int (*validate_trigger)(struct iio_dev *indio_dev,
				struct iio_trigger *trig);
	int (*get_current_scan_type)(const struct iio_dev *indio_dev,
				     const struct iio_chan_spec *chan);
	int (*update_scan_mode)(struct iio_dev *indio_dev,
				const unsigned long *scan_mask);
	int (*debugfs_reg_access)(struct iio_dev *indio_dev,
				  unsigned reg, unsigned writeval,
				  unsigned *readval);
	int (*fwnode_xlate)(struct iio_dev *indio_dev,
			    const struct fwnode_reference_args *iiospec);
	int (*hwfifo_set_watermark)(struct iio_dev *indio_dev, unsigned val);
	int (*hwfifo_flush_to_buffer)(struct iio_dev *indio_dev,
				      unsigned count);
};

/**
 * struct iio_buffer_setup_ops - buffer setup related callbacks
 * @preenable:		[DRIVER] function to run prior to marking buffer enabled
 * @postenable:		[DRIVER] function to run after marking buffer enabled
 * @predisable:		[DRIVER] function to run prior to marking buffer
 *			disabled
 * @postdisable:	[DRIVER] function to run after marking buffer disabled
 * @validate_scan_mask: [DRIVER] function callback to check whether a given
 *			scan mask is valid for the device.
 */
struct iio_buffer_setup_ops {
	int (*preenable)(struct iio_dev *);
	int (*postenable)(struct iio_dev *);
	int (*predisable)(struct iio_dev *);
	int (*postdisable)(struct iio_dev *);
	bool (*validate_scan_mask)(struct iio_dev *indio_dev,
				   const unsigned long *scan_mask);
};

/**
 * struct iio_dev - industrial I/O device
 * @modes:		[DRIVER] bitmask listing all the operating modes
 *			supported by the IIO device. This list should be
 *			initialized before registering the IIO device. It can
 *			also be filed up by the IIO core, as a result of
 *			enabling particular features in the driver
 *			(see iio_triggered_event_setup()).
 * @dev:		[DRIVER] device structure, should be assigned a parent
 *			and owner
 * @buffer:		[DRIVER] any buffer present
 * @scan_bytes:		[INTERN] num bytes captured to be fed to buffer demux
 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks. Sort the
 *			   array in order of preference, the most preferred
 *			   masks first.
 * @masklength:		[INTERN] the length of the mask established from
 *			channels
 * @active_scan_mask:	[INTERN] union of all scan masks requested by buffers
 * @scan_timestamp:	[INTERN] set if any buffers have requested timestamp
 * @trig:		[INTERN] current device trigger (buffer modes)
 * @pollfunc:		[DRIVER] function run on trigger being received
 * @pollfunc_event:	[DRIVER] function run on events trigger being received
 * @channels:		[DRIVER] channel specification structure table
 * @num_channels:	[DRIVER] number of channels specified in @channels.
 * @name:		[DRIVER] name of the device.
 * @label:              [DRIVER] unique name to identify which device this is
 * @info:		[DRIVER] callbacks and constant info from driver
 * @setup_ops:		[DRIVER] callbacks to call before and after buffer
 *			enable/disable
 * @priv:		[DRIVER] reference to driver's private information
 *			**MUST** be accessed **ONLY** via iio_priv() helper
 */
struct iio_dev {
	int				modes;
	struct device			dev;

	struct iio_buffer		*buffer;
	int				scan_bytes;

	const unsigned long		*available_scan_masks;
	unsigned			__private masklength;
	const unsigned long		*active_scan_mask;
	bool				scan_timestamp;
	struct iio_trigger		*trig;
	struct iio_poll_func		*pollfunc;
	struct iio_poll_func		*pollfunc_event;

	struct iio_chan_spec const	*channels;
	int				num_channels;

	const char			*name;
	const char			*label;
	const struct iio_info		*info;
	const struct iio_buffer_setup_ops	*setup_ops;

	void				*priv;
};

int iio_device_id(struct iio_dev *indio_dev);
int iio_device_get_current_mode(struct iio_dev *indio_dev);
bool iio_buffer_enabled(struct iio_dev *indio_dev);

const struct iio_chan_spec
*iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
/**
 * iio_device_register() - register a device with the IIO subsystem
 * @indio_dev:		Device structure filled by the device driver
 **/
#define iio_device_register(indio_dev) \
	__iio_device_register((indio_dev), THIS_MODULE)
int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod);
void iio_device_unregister(struct iio_dev *indio_dev);
/**
 * devm_iio_device_register - Resource-managed iio_device_register()
 * @dev:	Device to allocate iio_dev for
 * @indio_dev:	Device structure filled by the device driver
 *
 * Managed iio_device_register.  The IIO device registered with this
 * function is automatically unregistered on driver detach. This function
 * calls iio_device_register() internally. Refer to that function for more
 * information.
 *
 * RETURNS:
 * 0 on success, negative error number on failure.
 */
#define devm_iio_device_register(dev, indio_dev) \
	__devm_iio_device_register((dev), (indio_dev), THIS_MODULE)
int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
			       struct module *this_mod);
int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
int iio_device_claim_direct_mode(struct iio_dev *indio_dev);
void iio_device_release_direct_mode(struct iio_dev *indio_dev);

/*
 * This autocleanup logic is normally used via
 * iio_device_claim_direct_scoped().
 */
DEFINE_GUARD(iio_claim_direct, struct iio_dev *, iio_device_claim_direct_mode(_T),
	     iio_device_release_direct_mode(_T))

DEFINE_GUARD_COND(iio_claim_direct, _try, ({
			struct iio_dev *dev;
			int d = iio_device_claim_direct_mode(_T);

			if (d < 0)
				dev = NULL;
			else
				dev = _T;
			dev;
		}))

/**
 * iio_device_claim_direct_scoped() - Scoped call to iio_device_claim_direct.
 * @fail: What to do on failure to claim device.
 * @iio_dev: Pointer to the IIO devices structure
 */
#define iio_device_claim_direct_scoped(fail, iio_dev) \
	scoped_cond_guard(iio_claim_direct_try, fail, iio_dev)

int iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
void iio_device_release_buffer_mode(struct iio_dev *indio_dev);

extern const struct bus_type iio_bus_type;

/**
 * iio_device_put() - reference counted deallocation of struct device
 * @indio_dev: IIO device structure containing the device
 **/
static inline void iio_device_put(struct iio_dev *indio_dev)
{
	if (indio_dev)
		put_device(&indio_dev->dev);
}

clockid_t iio_device_get_clock(const struct iio_dev *indio_dev);
int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id);

/**
 * dev_to_iio_dev() - Get IIO device struct from a device struct
 * @dev: 		The device embedded in the IIO device
 *
 * Note: The device must be a IIO device, otherwise the result is undefined.
 */
static inline struct iio_dev *dev_to_iio_dev(struct device *dev)
{
	return container_of(dev, struct iio_dev, dev);
}

/**
 * iio_device_get() - increment reference count for the device
 * @indio_dev: 		IIO device structure
 *
 * Returns: The passed IIO device
 **/
static inline struct iio_dev *iio_device_get(struct iio_dev *indio_dev)
{
	return indio_dev ? dev_to_iio_dev(get_device(&indio_dev->dev)) : NULL;
}

/**
 * iio_device_set_parent() - assign parent device to the IIO device object
 * @indio_dev: 		IIO device structure
 * @parent:		reference to parent device object
 *
 * This utility must be called between IIO device allocation
 * (via devm_iio_device_alloc()) & IIO device registration
 * (via iio_device_register() and devm_iio_device_register())).
 * By default, the device allocation will also assign a parent device to
 * the IIO device object. In cases where devm_iio_device_alloc() is used,
 * sometimes the parent device must be different than the device used to
 * manage the allocation.
 * In that case, this helper should be used to change the parent, hence the
 * requirement to call this between allocation & registration.
 **/
static inline void iio_device_set_parent(struct iio_dev *indio_dev,
					 struct device *parent)
{
	indio_dev->dev.parent = parent;
}

/**
 * iio_device_set_drvdata() - Set device driver data
 * @indio_dev: IIO device structure
 * @data: Driver specific data
 *
 * Allows to attach an arbitrary pointer to an IIO device, which can later be
 * retrieved by iio_device_get_drvdata().
 */
static inline void iio_device_set_drvdata(struct iio_dev *indio_dev, void *data)
{
	dev_set_drvdata(&indio_dev->dev, data);
}

/**
 * iio_device_get_drvdata() - Get device driver data
 * @indio_dev: IIO device structure
 *
 * Returns the data previously set with iio_device_set_drvdata()
 */
static inline void *iio_device_get_drvdata(const struct iio_dev *indio_dev)
{
	return dev_get_drvdata(&indio_dev->dev);
}

/*
 * Used to ensure the iio_priv() structure is aligned to allow that structure
 * to in turn include IIO_DMA_MINALIGN'd elements such as buffers which
 * must not share  cachelines with the rest of the structure, thus making
 * them safe for use with non-coherent DMA.
 */
#define IIO_DMA_MINALIGN ARCH_DMA_MINALIGN
struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv);

/* The information at the returned address is guaranteed to be cacheline aligned */
static inline void *iio_priv(const struct iio_dev *indio_dev)
{
	return indio_dev->priv;
}

void iio_device_free(struct iio_dev *indio_dev);
struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv);

#define devm_iio_trigger_alloc(parent, fmt, ...) \
	__devm_iio_trigger_alloc((parent), THIS_MODULE, (fmt), ##__VA_ARGS__)
__printf(3, 4)
struct iio_trigger *__devm_iio_trigger_alloc(struct device *parent,
					     struct module *this_mod,
					     const char *fmt, ...);
/**
 * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
 * @indio_dev:		IIO device structure for device
 **/
#if defined(CONFIG_DEBUG_FS)
struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev);
#else
static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
{
	return NULL;
}
#endif

/**
 * iio_device_suspend_triggering() - suspend trigger attached to an iio_dev
 * @indio_dev: iio_dev associated with the device that will have triggers suspended
 *
 * Return 0 if successful, negative otherwise
 **/
int iio_device_suspend_triggering(struct iio_dev *indio_dev);

/**
 * iio_device_resume_triggering() - resume trigger attached to an iio_dev
 *	that was previously suspended with iio_device_suspend_triggering()
 * @indio_dev: iio_dev associated with the device that will have triggers resumed
 *
 * Return 0 if successful, negative otherwise
 **/
int iio_device_resume_triggering(struct iio_dev *indio_dev);

#ifdef CONFIG_ACPI
bool iio_read_acpi_mount_matrix(struct device *dev,
				struct iio_mount_matrix *orientation,
				char *acpi_method);
#else
static inline bool iio_read_acpi_mount_matrix(struct device *dev,
					      struct iio_mount_matrix *orientation,
					      char *acpi_method)
{
	return false;
}
#endif

/**
 * iio_get_current_scan_type - Get the current scan type for a channel
 * @indio_dev:	the IIO device to get the scan type for
 * @chan:	the channel to get the scan type for
 *
 * Most devices only have one scan type per channel and can just access it
 * directly without calling this function. Core IIO code and drivers that
 * implement ext_scan_type in the channel spec should use this function to
 * get the current scan type for a channel.
 *
 * Returns: the current scan type for the channel or error.
 */
static inline const struct iio_scan_type
*iio_get_current_scan_type(const struct iio_dev *indio_dev,
			   const struct iio_chan_spec *chan)
{
	int ret;

	if (chan->has_ext_scan_type) {
		ret = indio_dev->info->get_current_scan_type(indio_dev, chan);
		if (ret < 0)
			return ERR_PTR(ret);

		if (ret >= chan->num_ext_scan_type)
			return ERR_PTR(-EINVAL);

		return &chan->ext_scan_type[ret];
	}

	return &chan->scan_type;
}

/**
 * iio_get_masklength - Get length of the channels mask
 * @indio_dev: the IIO device to get the masklength for
 */
static inline unsigned int iio_get_masklength(const struct iio_dev *indio_dev)
{
	return ACCESS_PRIVATE(indio_dev, masklength);
}

int iio_active_scan_mask_index(struct iio_dev *indio_dev);

/**
 * iio_for_each_active_channel - Iterated over active channels
 * @indio_dev: the IIO device
 * @chan: Holds the index of the enabled channel
 */
#define iio_for_each_active_channel(indio_dev, chan) \
	for_each_set_bit((chan), (indio_dev)->active_scan_mask, \
			 iio_get_masklength(indio_dev))

ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals);

int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer,
	int *fract);

/**
 * IIO_DEGREE_TO_RAD() - Convert degree to rad
 * @deg: A value in degree
 *
 * Returns the given value converted from degree to rad
 */
#define IIO_DEGREE_TO_RAD(deg) (((deg) * 314159ULL + 9000000ULL) / 18000000ULL)

/**
 * IIO_RAD_TO_DEGREE() - Convert rad to degree
 * @rad: A value in rad
 *
 * Returns the given value converted from rad to degree
 */
#define IIO_RAD_TO_DEGREE(rad) \
	(((rad) * 18000000ULL + 314159ULL / 2) / 314159ULL)

/**
 * IIO_G_TO_M_S_2() - Convert g to meter / second**2
 * @g: A value in g
 *
 * Returns the given value converted from g to meter / second**2
 */
#define IIO_G_TO_M_S_2(g) ((g) * 980665ULL / 100000ULL)

/**
 * IIO_M_S_2_TO_G() - Convert meter / second**2 to g
 * @ms2: A value in meter / second**2
 *
 * Returns the given value converted from meter / second**2 to g
 */
#define IIO_M_S_2_TO_G(ms2) (((ms2) * 100000ULL + 980665ULL / 2) / 980665ULL)

#endif /* _INDUSTRIAL_IO_H_ */