[mirror_ubuntu-artful-kernel.git] / include / linux / iio / iio.h

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

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

enum iio_chan_info_enum {
        IIO_CHAN_INFO_RAW = 0,
        IIO_CHAN_INFO_PROCESSED,
        IIO_CHAN_INFO_SCALE,
        IIO_CHAN_INFO_OFFSET,
        IIO_CHAN_INFO_CALIBSCALE,
        IIO_CHAN_INFO_CALIBBIAS,
        IIO_CHAN_INFO_PEAK,
        IIO_CHAN_INFO_PEAK_SCALE,
        IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
        IIO_CHAN_INFO_AVERAGE_RAW,
        IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
        IIO_CHAN_INFO_SAMP_FREQ,
        IIO_CHAN_INFO_FREQUENCY,
        IIO_CHAN_INFO_PHASE,
        IIO_CHAN_INFO_HARDWAREGAIN,
        IIO_CHAN_INFO_HYSTERESIS,
        IIO_CHAN_INFO_INT_TIME,
};

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_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:          Sign:           's' or 'u' to specify signed or unsigned
 *                      realbits:       Number of valid bits of data
 *                      storage_bits:   Realbits + padding
 *                      shift:          Shift right by this before masking out
 *                                      realbits.
 *                      endianness:     little or big endian
 * @info_mask_separate: What 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_dir: What 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.
 * @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;
                enum iio_endian endianness;
        } scan_type;
        long                    info_mask_separate;
        long                    info_mask_shared_by_type;
        long                    info_mask_shared_by_dir;
        long                    info_mask_shared_by_all;
        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));
}

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

/**
 * iio_get_time_ns() - utility function to get a time stamp for events etc
 **/
static inline s64 iio_get_time_ns(void)
{
        struct timespec ts;
        /*
         * calls getnstimeofday.
         * If hrtimers then up to ns accurate, if not microsecond.
         */
        ktime_get_real_ts(&ts);

        return timespec_to_ns(&ts);
}

/* Device operating modes */
#define INDIO_DIRECT_MODE               0x01
#define INDIO_BUFFER_TRIGGERED          0x02
#define INDIO_BUFFER_HARDWARE           0x08

#define INDIO_ALL_BUFFER_MODES                                  \
        (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE)

#define INDIO_MAX_RAW_ELEMENTS          4

struct iio_trigger; /* forward declaration */
struct iio_dev;

/**
 * struct iio_info - constant information about device
 * @driver_module:      module structure used to ensure correct
 *                      ownership of chrdevs etc
 * @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.
 * @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
 **/
struct iio_info {
        struct module                   *driver_module;
        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 (*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);
};

/**
 * 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
 * @modes:              [DRIVER] operating modes supported by device
 * @currentmode:        [DRIVER] current operating mode
 * @dev:                [DRIVER] device structure, should be assigned a parent
 *                      and owner
 * @event_interface:    [INTERN] event chrdevs associated with interrupt lines
 * @buffer:             [DRIVER] any buffer present
 * @buffer_list:        [INTERN] list of all buffers currently attached
 * @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)
 * @pollfunc:           [DRIVER] function run on trigger being received
 * @channels:           [DRIVER] channel specification structure table
 * @num_channels:       [DRIVER] number of channels specified in @channels.
 * @channel_attr_list:  [INTERN] keep track of automatically created channel
 *                      attributes
 * @chan_attr_group:    [INTERN] group for all attrs in base directory
 * @name:               [DRIVER] name of the device.
 * @info:               [DRIVER] callbacks and constant info from driver
 * @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.
 * @debugfs_dentry:     [INTERN] device specific debugfs dentry.
 * @cached_reg_addr:    [INTERN] cached register address for debugfs reads.
 */
struct iio_dev {
        int                             id;

        int                             modes;
        int                             currentmode;
        struct device                   dev;

        struct iio_event_interface      *event_interface;

        struct iio_buffer               *buffer;
        struct list_head                buffer_list;
        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;
        struct iio_poll_func            *pollfunc;

        struct iio_chan_spec const      *channels;
        int                             num_channels;

        struct list_head                channel_attr_list;
        struct attribute_group          chan_attr_group;
        const char                      *name;
        const struct iio_info           *info;
        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;
#if defined(CONFIG_DEBUG_FS)
        struct dentry                   *debugfs_dentry;
        unsigned                        cached_reg_addr;
#endif
};

const struct iio_chan_spec
*iio_find_channel_from_si(struct iio_dev *indio_dev, int si);
int iio_device_register(struct iio_dev *indio_dev);
void iio_device_unregister(struct iio_dev *indio_dev);
int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev);
void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev);
int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);

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);
}

/**
 * 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_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(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(int sizeof_priv);

static inline void *iio_priv(const struct iio_dev *indio_dev)
{
        return (char *)indio_dev + ALIGN(sizeof(struct iio_dev), IIO_ALIGN);
}

static inline struct iio_dev *iio_priv_to_dev(void *priv)
{
        return (struct iio_dev *)((char *)priv -
                                  ALIGN(sizeof(struct iio_dev), IIO_ALIGN));
}

void iio_device_free(struct iio_dev *indio_dev);
struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
void devm_iio_device_free(struct device *dev, struct iio_dev *indio_dev);
struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
                                                const char *fmt, ...);
void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig);

/**
 * 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);
}

/**
 * iio_get_debugfs_dentry() - helper function to get the debugfs_dentry
 * @indio_dev:          IIO device structure for device
 **/
#if defined(CONFIG_DEBUG_FS)
static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
{
        return indio_dev->debugfs_dentry;
}
#else
static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
{
        return NULL;
}
#endif

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_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)

#endif /* _INDUSTRIAL_IO_H_ */