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

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)
 * @_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, _e) \
{ \
        .name = (_name "_available"), \
        .shared = IIO_SHARED_BY_TYPE, \
        .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, const char *propname,
                          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_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
 * @scan_type.sign:             's' or 'u' to specify signed or unsigned
 * @scan_type.realbits:         Number of valid bits of data
 * @scan_type.storagebits:      Realbits + padding
 * @scan_type.shift:            Shift right by this before masking out
 *                              realbits.
 * @scan_type.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.
 * @scan_type.endianness:       little or big endian
 * @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.
 * @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.
 */
struct iio_chan_spec {
        enum iio_chan_type      type;
        int                     channel;
        int                     channel2;
        unsigned long           address;
        int                     scan_index;
        struct {
                char    sign;
                u8      realbits;
                u8      storagebits;
                u8      shift;
                u8      repeat;
                enum iio_endian endianness;
        } 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;
};


/**
 * 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);
unsigned int iio_get_time_res(const struct iio_dev *indio_dev);

/* Device operating modes */
#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_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.
 * @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.
 * @validate_trigger:   function to validate the trigger when the
 *                      current trigger gets changed.
 * @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
 * @of_xlate:           function pointer to obtain channel specifier index.
 *                      When #iio-cells is greater than '0', the driver could
 *                      provide a custom of_xlate function that reads the
 *                      *args* and returns the appropriate index in registered
 *                      IIO channels array.
 * @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 (*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 (*validate_trigger)(struct iio_dev *indio_dev,
                                struct iio_trigger *trig);
        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 (*of_xlate)(struct iio_dev *indio_dev,
                        const struct of_phandle_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
 * @id:                 [INTERN] used to identify device internally
 * @driver_module:      [INTERN] used to make it harder to undercut users
 * @modes:              [DRIVER] operating modes supported by device
 * @currentmode:        [DRIVER] current operating mode
 * @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
 * @mlock:              [INTERN] lock used to prevent simultaneous device state
 *                      changes
 * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
 * @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
 * @scan_index_timestamp:[INTERN] cache of the index to the timestamp
 * @trig:               [INTERN] current device trigger (buffer modes)
 * @trig_readonly:      [INTERN] mark the current trigger immutable
 * @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
 * @clock_id:           [INTERN] timestamping clock posix identifier
 * @info_exist_lock:    [INTERN] lock to prevent use during removal
 * @setup_ops:          [DRIVER] callbacks to call before and after buffer
 *                      enable/disable
 * @chrdev:             [INTERN] associated character device
 * @groups:             [INTERN] attribute groups
 * @groupcounter:       [INTERN] index of next attribute group
 * @flags:              [INTERN] file ops related flags including busy flag.
 * @priv:               [DRIVER] reference to driver's private information
 *                      **MUST** be accessed **ONLY** via iio_priv() helper
 */
struct iio_dev {
        int                             id;
        struct module                   *driver_module;

        int                             modes;
        int                             currentmode;
        struct device                   dev;

        struct iio_buffer               *buffer;
        int                             scan_bytes;
        struct mutex                    mlock;

        const unsigned long             *available_scan_masks;
        unsigned                        masklength;
        const unsigned long             *active_scan_mask;
        bool                            scan_timestamp;
        unsigned                        scan_index_timestamp;
        struct iio_trigger              *trig;
        bool                            trig_readonly;
        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;
        clockid_t                       clock_id;
        struct mutex                    info_exist_lock;
        const struct iio_buffer_setup_ops       *setup_ops;
        struct cdev                     chrdev;
#define IIO_MAX_GROUPS 6
        const struct attribute_group    *groups[IIO_MAX_GROUPS + 1];
        int                             groupcounter;

        unsigned long                   flags;
        void                            *priv;
};

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);

extern 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);
}

/**
 * iio_device_get_clock() - Retrieve current timestamping clock for the device
 * @indio_dev: IIO device structure containing the device
 */
static inline clockid_t iio_device_get_clock(const struct iio_dev *indio_dev)
{
        return indio_dev->clock_id;
}

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);
}

/* Can we make this smaller? */
#define IIO_ALIGN L1_CACHE_BYTES
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);
__printf(2, 3)
struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
                                           const char *fmt, ...);
/**
 * iio_buffer_enabled() - helper function to test if the buffer is enabled
 * @indio_dev:          IIO device structure for device
 **/
static inline bool iio_buffer_enabled(struct iio_dev *indio_dev)
{
        return indio_dev->currentmode
                & (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE |
                   INDIO_BUFFER_SOFTWARE);
}

/**
 * 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

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_ */