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Diffstat (limited to 'include/linux/iio/iio.h')
| -rw-r--r-- | include/linux/iio/iio.h | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h new file mode 100644 index 000000000..d86b753e9 --- /dev/null +++ b/include/linux/iio/iio.h @@ -0,0 +1,652 @@ + +/* 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> +#include <linux/of.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, + IIO_CHAN_INFO_ENABLE, + IIO_CHAN_INFO_CALIBHEIGHT, + IIO_CHAN_INFO_CALIBWEIGHT, + IIO_CHAN_INFO_DEBOUNCE_COUNT, + IIO_CHAN_INFO_DEBOUNCE_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 + * 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. + * @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; + u8 repeat; + 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) +{ + return ktime_get_real_ns(); +} + +/* 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_ALL_BUFFER_MODES \ + (INDIO_BUFFER_TRIGGERED | INDIO_BUFFER_HARDWARE | INDIO_BUFFER_SOFTWARE) + +#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 + * @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 { + 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); + 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 + * @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 | + 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) +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_ */ |