libsigrok.h

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/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef LIBSIGROK_LIBSIGROK_H
#define LIBSIGROK_LIBSIGROK_H

#include <stdio.h>
#include <sys/time.h>
#include <stdint.h>
#include <inttypes.h>
#include <glib.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @file
 *
 * The public libsigrok header file to be used by frontends.
 *
 * This is the only file that libsigrok users (frontends) are supposed to
 * use and \#include. There are other header files which get installed with
 * libsigrok, but those are not meant to be used directly by frontends.
 *
 * The correct way to get/use the libsigrok API functions is:
 *
 * @code{.c}
 *   #include <libsigrok/libsigrok.h>
 * @endcode
 */

/*
 * All possible return codes of libsigrok functions must be listed here.
 * Functions should never return hardcoded numbers as status, but rather
 * use these enum values. All error codes are negative numbers.
 *
 * The error codes are globally unique in libsigrok, i.e. if one of the
 * libsigrok functions returns a "malloc error" it must be exactly the same
 * return value as used by all other functions to indicate "malloc error".
 * There must be no functions which indicate two different errors via the
 * same return code.
 *
 * Also, for compatibility reasons, no defined return codes are ever removed
 * or reused for different errors later. You can only add new entries and
 * return codes, but never remove or redefine existing ones.
 */

/** Status/error codes returned by libsigrok functions. */
enum sr_error_code {
        SR_OK                =  0, /**< No error. */
        SR_ERR               = -1, /**< Generic/unspecified error. */
        SR_ERR_MALLOC        = -2, /**< Malloc/calloc/realloc error. */
        SR_ERR_ARG           = -3, /**< Function argument error. */
        SR_ERR_BUG           = -4, /**< Errors hinting at internal bugs. */
        SR_ERR_SAMPLERATE    = -5, /**< Incorrect samplerate. */
        SR_ERR_NA            = -6, /**< Not applicable. */
        SR_ERR_DEV_CLOSED    = -7, /**< Device is closed, but must be open. */
        SR_ERR_TIMEOUT       = -8, /**< A timeout occurred. */
        SR_ERR_CHANNEL_GROUP = -9, /**< A channel group must be specified. */
        SR_ERR_DATA          =-10, /**< Data is invalid.  */
        SR_ERR_IO            =-11, /**< Input/output error. */

        /* Update sr_strerror()/sr_strerror_name() (error.c) upon changes! */
};

/** Ternary return type for DMM/LCR/etc packet parser validity checks. */
enum sr_valid_code {
        SR_PACKET_INVALID = -1, /**< Certainly invalid. */
        SR_PACKET_VALID = 0,    /**< Certainly valid. */
        SR_PACKET_NEED_RX = +1, /**< Need more RX data. */
};

#define SR_MAX_CHANNELNAME_LEN 32

/* Handy little macros */
#define SR_HZ(n)  (n)
#define SR_KHZ(n) ((n) * UINT64_C(1000))
#define SR_MHZ(n) ((n) * UINT64_C(1000000))
#define SR_GHZ(n) ((n) * UINT64_C(1000000000))

#define SR_HZ_TO_NS(n) (UINT64_C(1000000000) / (n))

/** libsigrok loglevels. */
enum sr_loglevel {
        SR_LOG_NONE = 0, /**< Output no messages at all. */
        SR_LOG_ERR  = 1, /**< Output error messages. */
        SR_LOG_WARN = 2, /**< Output warnings. */
        SR_LOG_INFO = 3, /**< Output informational messages. */
        SR_LOG_DBG  = 4, /**< Output debug messages. */
        SR_LOG_SPEW = 5, /**< Output very noisy debug messages. */
};

/*
 * Use SR_API to mark public API symbols, and SR_PRIV for private symbols.
 *
 * Variables and functions marked 'static' are private already and don't
 * need SR_PRIV. However, functions which are not static (because they need
 * to be used in other libsigrok-internal files) but are also not meant to
 * be part of the public libsigrok API, must use SR_PRIV.
 *
 * This uses the 'visibility' feature of gcc (requires gcc >= 4.0).
 *
 * This feature is not available on MinGW/Windows, as it is a feature of
 * ELF files and MinGW/Windows uses PE files.
 *
 * Details: http://gcc.gnu.org/wiki/Visibility
 */

/* Marks public libsigrok API symbols. */
#ifndef _WIN32
#define SR_API __attribute__((visibility("default")))
#else
#define SR_API
#endif

/* Marks private, non-public libsigrok symbols (not part of the API). */
#ifndef _WIN32
#define SR_PRIV __attribute__((visibility("hidden")))
#else
#define SR_PRIV
#endif

/** Type definition for callback function for data reception. */
typedef int (*sr_receive_data_callback)(int fd, int revents, void *cb_data);

/** Data types used by sr_config_info(). */
enum sr_datatype {
        SR_T_UINT64 = 10000,
        SR_T_STRING,
        SR_T_BOOL,
        SR_T_FLOAT,
        SR_T_RATIONAL_PERIOD,
        SR_T_RATIONAL_VOLT,
        SR_T_KEYVALUE,
        SR_T_UINT64_RANGE,
        SR_T_DOUBLE_RANGE,
        SR_T_INT32,
        SR_T_MQ,
        SR_T_UINT32,

        /* Update sr_variant_type_get() (hwdriver.c) upon changes! */
};

/** Value for sr_datafeed_packet.type. */
enum sr_packettype {
        /** Payload is sr_datafeed_header. */
        SR_DF_HEADER = 10000,
        /** End of stream (no further data). */
        SR_DF_END,
        /** Payload is struct sr_datafeed_meta */
        SR_DF_META,
        /** The trigger matched at this point in the data feed. No payload. */
        SR_DF_TRIGGER,
        /** Payload is struct sr_datafeed_logic. */
        SR_DF_LOGIC,
        /** Beginning of frame. No payload. */
        SR_DF_FRAME_BEGIN,
        /** End of frame. No payload. */
        SR_DF_FRAME_END,
        /** Payload is struct sr_datafeed_analog. */
        SR_DF_ANALOG,

        /* Update datafeed_dump() (session.c) upon changes! */
};

/** Measured quantity, sr_analog_meaning.mq. */
enum sr_mq {
        SR_MQ_VOLTAGE = 10000,
        SR_MQ_CURRENT,
        SR_MQ_RESISTANCE,
        SR_MQ_CAPACITANCE,
        SR_MQ_TEMPERATURE,
        SR_MQ_FREQUENCY,
        /** Duty cycle, e.g. on/off ratio. */
        SR_MQ_DUTY_CYCLE,
        /** Continuity test. */
        SR_MQ_CONTINUITY,
        SR_MQ_PULSE_WIDTH,
        SR_MQ_CONDUCTANCE,
        /** Electrical power, usually in W, or dBm. */
        SR_MQ_POWER,
        /** Gain (a transistor's gain, or hFE, for example). */
        SR_MQ_GAIN,
        /** Logarithmic representation of sound pressure relative to a
         * reference value. */
        SR_MQ_SOUND_PRESSURE_LEVEL,
        /** Carbon monoxide level */
        SR_MQ_CARBON_MONOXIDE,
        /** Humidity */
        SR_MQ_RELATIVE_HUMIDITY,
        /** Time */
        SR_MQ_TIME,
        /** Wind speed */
        SR_MQ_WIND_SPEED,
        /** Pressure */
        SR_MQ_PRESSURE,
        /** Parallel inductance (LCR meter model). */
        SR_MQ_PARALLEL_INDUCTANCE,
        /** Parallel capacitance (LCR meter model). */
        SR_MQ_PARALLEL_CAPACITANCE,
        /** Parallel resistance (LCR meter model). */
        SR_MQ_PARALLEL_RESISTANCE,
        /** Series inductance (LCR meter model). */
        SR_MQ_SERIES_INDUCTANCE,
        /** Series capacitance (LCR meter model). */
        SR_MQ_SERIES_CAPACITANCE,
        /** Series resistance (LCR meter model). */
        SR_MQ_SERIES_RESISTANCE,
        /** Dissipation factor. */
        SR_MQ_DISSIPATION_FACTOR,
        /** Quality factor. */
        SR_MQ_QUALITY_FACTOR,
        /** Phase angle. */
        SR_MQ_PHASE_ANGLE,
        /** Difference from reference value. */
        SR_MQ_DIFFERENCE,
        /** Count. */
        SR_MQ_COUNT,
        /** Power factor. */
        SR_MQ_POWER_FACTOR,
        /** Apparent power */
        SR_MQ_APPARENT_POWER,
        /** Mass */
        SR_MQ_MASS,
        /** Harmonic ratio */
        SR_MQ_HARMONIC_RATIO,
        /** Energy. */
        SR_MQ_ENERGY,
        /** Electric charge. */
        SR_MQ_ELECTRIC_CHARGE,

        /* Update sr_key_info_mq[] (hwdriver.c) upon changes! */
};

/** Unit of measured quantity, sr_analog_meaning.unit. */
enum sr_unit {
        /** Volt */
        SR_UNIT_VOLT = 10000,
        /** Ampere (current). */
        SR_UNIT_AMPERE,
        /** Ohm (resistance). */
        SR_UNIT_OHM,
        /** Farad (capacity). */
        SR_UNIT_FARAD,
        /** Kelvin (temperature). */
        SR_UNIT_KELVIN,
        /** Degrees Celsius (temperature). */
        SR_UNIT_CELSIUS,
        /** Degrees Fahrenheit (temperature). */
        SR_UNIT_FAHRENHEIT,
        /** Hertz (frequency, 1/s, [Hz]). */
        SR_UNIT_HERTZ,
        /** Percent value. */
        SR_UNIT_PERCENTAGE,
        /** Boolean value. */
        SR_UNIT_BOOLEAN,
        /** Time in seconds. */
        SR_UNIT_SECOND,
        /** Unit of conductance, the inverse of resistance. */
        SR_UNIT_SIEMENS,
        /**
         * An absolute measurement of power, in decibels, referenced to
         * 1 milliwatt (dBm).
         */
        SR_UNIT_DECIBEL_MW,
        /** Voltage in decibel, referenced to 1 volt (dBV). */
        SR_UNIT_DECIBEL_VOLT,
        /**
         * Measurements that intrinsically do not have units attached, such
         * as ratios, gains, etc. Specifically, a transistor's gain (hFE) is
         * a unitless quantity, for example.
         */
        SR_UNIT_UNITLESS,
        /** Sound pressure level, in decibels, relative to 20 micropascals. */
        SR_UNIT_DECIBEL_SPL,
        /**
         * Normalized (0 to 1) concentration of a substance or compound with 0
         * representing a concentration of 0%, and 1 being 100%. This is
         * represented as the fraction of number of particles of the substance.
         */
        SR_UNIT_CONCENTRATION,
        /** Revolutions per minute. */
        SR_UNIT_REVOLUTIONS_PER_MINUTE,
        /** Apparent power [VA]. */
        SR_UNIT_VOLT_AMPERE,
        /** Real power [W]. */
        SR_UNIT_WATT,
        /** Energy (consumption) in watt hour [Wh]. */
        SR_UNIT_WATT_HOUR,
        /** Wind speed in meters per second. */
        SR_UNIT_METER_SECOND,
        /** Pressure in hectopascal */
        SR_UNIT_HECTOPASCAL,
        /** Relative humidity assuming air temperature of 293 Kelvin (%rF). */
        SR_UNIT_HUMIDITY_293K,
        /** Plane angle in 1/360th of a full circle. */
        SR_UNIT_DEGREE,
        /** Henry (inductance). */
        SR_UNIT_HENRY,
        /** Mass in gram [g]. */
        SR_UNIT_GRAM,
        /** Mass in carat [ct]. */
        SR_UNIT_CARAT,
        /** Mass in ounce [oz]. */
        SR_UNIT_OUNCE,
        /** Mass in troy ounce [oz t]. */
        SR_UNIT_TROY_OUNCE,
        /** Mass in pound [lb]. */
        SR_UNIT_POUND,
        /** Mass in pennyweight [dwt]. */
        SR_UNIT_PENNYWEIGHT,
        /** Mass in grain [gr]. */
        SR_UNIT_GRAIN,
        /** Mass in tael (variants: Hong Kong, Singapore/Malaysia, Taiwan) */
        SR_UNIT_TAEL,
        /** Mass in momme. */
        SR_UNIT_MOMME,
        /** Mass in tola. */
        SR_UNIT_TOLA,
        /** Pieces (number of items). */
        SR_UNIT_PIECE,
        /** Energy in joule. */
        SR_UNIT_JOULE,
        /** Electric charge in coulomb. */
        SR_UNIT_COULOMB,
        /** Electric charge in ampere hour [Ah]. */
        SR_UNIT_AMPERE_HOUR,

        /*
         * Update unit_strings[] (analog.c) and fancyprint() (output/analog.c)
         * upon changes!
         */
};

/** Values for sr_analog_meaning.mqflags. */
enum sr_mqflag {
        /** Voltage measurement is alternating current (AC). */
        SR_MQFLAG_AC = 0x01,
        /** Voltage measurement is direct current (DC). */
        SR_MQFLAG_DC = 0x02,
        /** This is a true RMS measurement. */
        SR_MQFLAG_RMS = 0x04,
        /** Value is voltage drop across a diode, or NAN. */
        SR_MQFLAG_DIODE = 0x08,
        /** Device is in "hold" mode (repeating the last measurement). */
        SR_MQFLAG_HOLD = 0x10,
        /** Device is in "max" mode, only updating upon a new max value. */
        SR_MQFLAG_MAX = 0x20,
        /** Device is in "min" mode, only updating upon a new min value. */
        SR_MQFLAG_MIN = 0x40,
        /** Device is in autoranging mode. */
        SR_MQFLAG_AUTORANGE = 0x80,
        /** Device is in relative mode. */
        SR_MQFLAG_RELATIVE = 0x100,
        /** Sound pressure level is A-weighted in the frequency domain,
         * according to IEC 61672:2003. */
        SR_MQFLAG_SPL_FREQ_WEIGHT_A = 0x200,
        /** Sound pressure level is C-weighted in the frequency domain,
         * according to IEC 61672:2003. */
        SR_MQFLAG_SPL_FREQ_WEIGHT_C = 0x400,
        /** Sound pressure level is Z-weighted (i.e. not at all) in the
         * frequency domain, according to IEC 61672:2003. */
        SR_MQFLAG_SPL_FREQ_WEIGHT_Z = 0x800,
        /** Sound pressure level is not weighted in the frequency domain,
         * albeit without standards-defined low and high frequency limits. */
        SR_MQFLAG_SPL_FREQ_WEIGHT_FLAT = 0x1000,
        /** Sound pressure level measurement is S-weighted (1s) in the
         * time domain. */
        SR_MQFLAG_SPL_TIME_WEIGHT_S = 0x2000,
        /** Sound pressure level measurement is F-weighted (125ms) in the
         * time domain. */
        SR_MQFLAG_SPL_TIME_WEIGHT_F = 0x4000,
        /** Sound pressure level is time-averaged (LAT), also known as
         * Equivalent Continuous A-weighted Sound Level (LEQ). */
        SR_MQFLAG_SPL_LAT = 0x8000,
        /** Sound pressure level represented as a percentage of measurements
         * that were over a preset alarm level. */
        SR_MQFLAG_SPL_PCT_OVER_ALARM = 0x10000,
        /** Time is duration (as opposed to epoch, ...). */
        SR_MQFLAG_DURATION = 0x20000,
        /** Device is in "avg" mode, averaging upon each new value. */
        SR_MQFLAG_AVG = 0x40000,
        /** Reference value shown. */
        SR_MQFLAG_REFERENCE = 0x80000,
        /** Unstable value (hasn't settled yet). */
        SR_MQFLAG_UNSTABLE = 0x100000,
        /** Measurement is four wire (e.g. Kelvin connection). */
        SR_MQFLAG_FOUR_WIRE = 0x200000,

        /*
         * Update mq_strings[] (analog.c) and fancyprint() (output/analog.c)
         * upon changes!
         */
};

enum sr_trigger_matches {
        SR_TRIGGER_ZERO = 1,
        SR_TRIGGER_ONE,
        SR_TRIGGER_RISING,
        SR_TRIGGER_FALLING,
        SR_TRIGGER_EDGE,
        SR_TRIGGER_OVER,
        SR_TRIGGER_UNDER,
};

/** The representation of a trigger, consisting of one or more stages
 * containing one or more matches on a channel.
 */
struct sr_trigger {
        /** A name for this trigger. This may be NULL if none is needed. */
        char *name;
        /** List of pointers to struct sr_trigger_stage. */
        GSList *stages;
};

/** A trigger stage. */
struct sr_trigger_stage {
        /** Starts at 0. */
        int stage;
        /** List of pointers to struct sr_trigger_match. */
        GSList *matches;
};

/** A channel to match and what to match it on. */
struct sr_trigger_match {
        /** The channel to trigger on. */
        struct sr_channel *channel;
        /** The trigger match to use.
         * For logic channels, only the following matches may be used:
         * SR_TRIGGER_ZERO
         * SR_TRIGGER_ONE
         * SR_TRIGGER_RISING
         * SR_TRIGGER_FALLING
         * SR_TRIGGER_EDGE
         *
         * For analog channels, only these matches may be used:
         * SR_TRIGGER_RISING
         * SR_TRIGGER_FALLING
         * SR_TRIGGER_OVER
         * SR_TRIGGER_UNDER
         *
         */
        int match;
        /** If the trigger match is one of SR_TRIGGER_OVER or SR_TRIGGER_UNDER,
         * this contains the value to compare against. */
        float value;
};

/**
 * @struct sr_context
 * Opaque structure representing a libsigrok context.
 *
 * None of the fields of this structure are meant to be accessed directly.
 *
 * @see sr_init(), sr_exit().
 */
struct sr_context;

/**
 * @struct sr_session
 * Opaque structure representing a libsigrok session.
 *
 * None of the fields of this structure are meant to be accessed directly.
 *
 * @see sr_session_new(), sr_session_destroy().
 */
struct sr_session;

struct sr_rational {
        /** Numerator of the rational number. */
        int64_t p;
        /** Denominator of the rational number. */
        uint64_t q;
};

/** Packet in a sigrok data feed. */
struct sr_datafeed_packet {
        uint16_t type;
        const void *payload;
};

/** Header of a sigrok data feed. */
struct sr_datafeed_header {
        int feed_version;
        struct timeval starttime;
};

/** Datafeed payload for type SR_DF_META. */
struct sr_datafeed_meta {
        GSList *config;
};

/** Logic datafeed payload for type SR_DF_LOGIC. */
struct sr_datafeed_logic {
        uint64_t length;
        uint16_t unitsize;
        void *data;
};

/** Analog datafeed payload for type SR_DF_ANALOG. */
struct sr_datafeed_analog {
        void *data;
        uint32_t num_samples;
        struct sr_analog_encoding *encoding;
        struct sr_analog_meaning *meaning;
        struct sr_analog_spec *spec;
};

struct sr_analog_encoding {
        uint8_t unitsize;
        gboolean is_signed;
        gboolean is_float;
        gboolean is_bigendian;
        /**
         * Number of significant digits after the decimal point, if positive.
         * When negative, exponent with reversed polarity that is necessary to
         * express the value with all digits without a decimal point.
         * Refers to the value we actually read on the wire.
         *
         * Examples:
         *
         * | Disp. value | Exp. notation       | Exp. not. normalized | digits |
         * |-------------|---------------------|----------------------|--------|
         * |  12.34 MOhm |  1.234 * 10^7   Ohm |    1234 * 10^4   Ohm |     -4 |
         * | 1.2345 MOhm | 1.2345 * 10^6   Ohm |   12345 * 10^2   Ohm |     -2 |
         * |  123.4 kOhm |  1.234 * 10^5   Ohm |    1234 * 10^2   Ohm |     -2 |
         * |   1234  Ohm |  1.234 * 10^3   Ohm |    1234 * 10^0   Ohm |      0 |
         * |  12.34  Ohm |  1.234 * 10^1   Ohm |    1234 * 10^-2  Ohm |      2 |
         * | 0.0123  Ohm |   1.23 * 10^-2  Ohm |     123 * 10^-4  Ohm |      4 |
         * |  1.234 pF   |  1.234 * 10^-12 F   |    1234 * 10^-15 F   |     15 |
         */
        int8_t digits;
        gboolean is_digits_decimal;
        struct sr_rational scale;
        struct sr_rational offset;
};

struct sr_analog_meaning {
        enum sr_mq mq;
        enum sr_unit unit;
        enum sr_mqflag mqflags;
        GSList *channels;
};

struct sr_analog_spec {
        /**
         * Number of significant digits after the decimal point, if positive.
         * When negative, exponent with reversed polarity that is necessary to
         * express the value with all digits without a decimal point.
         * Refers to vendor specifications/datasheet or actual device display.
         *
         * Examples:
         *
         * | On the wire | Exp. notation       | Exp. not. normalized | spec_digits |
         * |-------------|---------------------|----------------------|-------------|
         * |  12.34 MOhm |  1.234 * 10^7   Ohm |    1234 * 10^4   Ohm |          -4 |
         * | 1.2345 MOhm | 1.2345 * 10^6   Ohm |   12345 * 10^2   Ohm |          -2 |
         * |  123.4 kOhm |  1.234 * 10^5   Ohm |    1234 * 10^2   Ohm |          -2 |
         * |   1234  Ohm |  1.234 * 10^3   Ohm |    1234 * 10^0   Ohm |           0 |
         * |  12.34  Ohm |  1.234 * 10^1   Ohm |    1234 * 10^-2  Ohm |           2 |
         * | 0.0123  Ohm |   1.23 * 10^-2  Ohm |     123 * 10^-4  Ohm |           4 |
         * |  1.234 pF   |  1.234 * 10^-12 F   |    1234 * 10^-15 F   |          15 |
         */
        int8_t spec_digits;
};

/** Generic option struct used by various subsystems. */
struct sr_option {
        /* Short name suitable for commandline usage, [a-z0-9-]. */
        const char *id;
        /* Short name suitable for GUI usage, can contain UTF-8. */
        const char *name;
        /* Description of the option, in a sentence. */
        const char *desc;
        /* Default value for this option. */
        GVariant *def;
        /* List of possible values, if this is an option with few values. */
        GSList *values;
};

/** Resource type.
 * @since 0.4.0
 */
enum sr_resource_type {
        SR_RESOURCE_FIRMWARE = 1,
};

/** Resource descriptor.
 * @since 0.4.0
 */
struct sr_resource {
        /** Size of resource in bytes; set by resource open callback. */
        uint64_t size;
        /** File handle or equivalent; set by resource open callback. */
        void *handle;
        /** Resource type (SR_RESOURCE_FIRMWARE, ...) */
        int type;
};

/** Output module flags. */
enum sr_output_flag {
        /** If set, this output module writes the output itself. */
        SR_OUTPUT_INTERNAL_IO_HANDLING = 0x01,
};

struct sr_input;
struct sr_input_module;
struct sr_output;
struct sr_output_module;
struct sr_transform;
struct sr_transform_module;

/** Constants for channel type. */
enum sr_channeltype {
        /** Channel type is logic channel. */
        SR_CHANNEL_LOGIC = 10000,
        /** Channel type is analog channel. */
        SR_CHANNEL_ANALOG,
};

/** Information on single channel. */
struct sr_channel {
        /** The device this channel is attached to. */
        struct sr_dev_inst *sdi;
        /** The index of this channel, starting at 0. Logic channels will
         * be encoded according to this index in SR_DF_LOGIC packets. */
        int index;
        /** Channel type (SR_CHANNEL_LOGIC, ...) */
        int type;
        /** Is this channel enabled? */
        gboolean enabled;
        /** Name of channel. */
        char *name;
        /** Private data for driver use. */
        void *priv;
};

/** Structure for groups of channels that have common properties. */
struct sr_channel_group {
        /** Name of the channel group. */
        char *name;
        /** List of sr_channel structs of the channels belonging to this group. */
        GSList *channels;
        /** Private data for driver use. */
        void *priv;
};

/** Used for setting or getting value of a config item. */
struct sr_config {
        /** Config key like SR_CONF_CONN, etc. */
        uint32_t key;
        /** Key-specific data. */
        GVariant *data;
};

enum sr_keytype {
        SR_KEY_CONFIG,
        SR_KEY_MQ,
        SR_KEY_MQFLAGS,
};

/** Information about a key. */
struct sr_key_info {
        /** Config key like SR_CONF_CONN, MQ value like SR_MQ_VOLTAGE, etc. */
        uint32_t key;
        /** Data type like SR_T_STRING, etc if applicable. */
        int datatype;
        /** Short, lowercase ID string, e.g. "serialcomm", "voltage". */
        const char *id;
        /** Full capitalized name, e.g. "Serial communication". */
        const char *name;
        /** Verbose description (unused currently). */
        const char *description;
};

/** Configuration capabilities. */
enum sr_configcap {
        /** Value can be read. */
        SR_CONF_GET = (1UL << 31),
        /** Value can be written. */
        SR_CONF_SET = (1UL << 30),
        /** Possible values can be enumerated. */
        SR_CONF_LIST = (1UL << 29),
};

/** Configuration keys */
enum sr_configkey {
        /*--- Device classes ------------------------------------------------*/

        /** The device can act as logic analyzer. */
        SR_CONF_LOGIC_ANALYZER = 10000,

        /** The device can act as an oscilloscope. */
        SR_CONF_OSCILLOSCOPE,

        /** The device can act as a multimeter. */
        SR_CONF_MULTIMETER,

        /** The device is a demo device. */
        SR_CONF_DEMO_DEV,

        /** The device can act as a sound level meter. */
        SR_CONF_SOUNDLEVELMETER,

        /** The device can measure temperature. */
        SR_CONF_THERMOMETER,

        /** The device can measure humidity. */
        SR_CONF_HYGROMETER,

        /** The device can measure energy consumption. */
        SR_CONF_ENERGYMETER,

        /** The device can act as a signal demodulator. */
        SR_CONF_DEMODULATOR,

        /** The device can act as a programmable power supply. */
        SR_CONF_POWER_SUPPLY,

        /** The device can act as an LCR meter. */
        SR_CONF_LCRMETER,

        /** The device can act as an electronic load. */
        SR_CONF_ELECTRONIC_LOAD,

        /** The device can act as a scale. */
        SR_CONF_SCALE,

        /** The device can act as a function generator. */
        SR_CONF_SIGNAL_GENERATOR,

        /** The device can measure power. */
        SR_CONF_POWERMETER,

        /**
         * The device can switch between multiple sources, e.g. a relay actuator
         * or multiplexer.
         */
        SR_CONF_MULTIPLEXER,

        /* Update sr_key_info_config[] (hwdriver.c) upon changes! */

        /*--- Driver scan options -------------------------------------------*/

        /**
         * Specification on how to connect to a device.
         *
         * In combination with SR_CONF_SERIALCOMM, this is a serial port in
         * the form which makes sense to the OS (e.g., /dev/ttyS0).
         * Otherwise this specifies a USB device, either in the form of
         * @verbatim <bus>.<address> @endverbatim (decimal, e.g. 1.65) or
         * @verbatim <vendorid>.<productid> @endverbatim
         * (hexadecimal, e.g. 1d6b.0001).
         */
        SR_CONF_CONN = 20000,

        /**
         * Serial communication specification, in the form:
         *
         *   @verbatim <baudrate>/<databits><parity><stopbits> @endverbatim
         *
         * Example: 9600/8n1
         *
         * The string may also be followed by one or more special settings,
         * in the form "/key=value". Supported keys and their values are:
         *
         * rts    0,1    set the port's RTS pin to low or high
         * dtr    0,1    set the port's DTR pin to low or high
         * flow   0      no flow control
         *        1      hardware-based (RTS/CTS) flow control
         *        2      software-based (XON/XOFF) flow control
         *
         * This is always an optional parameter, since a driver typically
         * knows the speed at which the device wants to communicate.
         */
        SR_CONF_SERIALCOMM,

        /**
         * Modbus slave address specification.
         *
         * This is always an optional parameter, since a driver typically
         * knows the default slave address of the device.
         */
        SR_CONF_MODBUSADDR,

        /**
         * User specified forced driver attachment to unknown devices.
         *
         * By design the interpretation of the string depends on the
         * specific driver. It typically would be either a replacement
         * '*IDN?' response value, or a sub-driver name. But could also
         * be anything else and totally arbitrary.
         */
        SR_CONF_FORCE_DETECT,

        /**
         * Override builtin probe names from user specs.
         *
         * Users may want to override the names which are assigned to
         * probes during scan (these usually match the vendor's labels
         * on the device). This avoids the interactive tedium of
         * changing channel names after device creation and before
         * protocol decoder attachment. Think of IEEE488 recorders or
         * parallel computer bus loggers. The scan option eliminates
         * the issue of looking up previously assigned names before
         * renaming a channel (see sigrok-cli -C), which depends on
         * the device as well as the application, and is undesirable.
         * The scan option is limited to those drivers which implement
         * support for it, but works identically across those drivers.
         *
         * The value is a string, either a comma separated list of
         * probe names, or an alias for a typical set of names.
         */
        SR_CONF_PROBE_NAMES,

        /* Update sr_key_info_config[] (hwdriver.c) upon changes! */

        /*--- Device (or channel group) configuration -----------------------*/

        /** The device supports setting its samplerate, in Hz. */
        SR_CONF_SAMPLERATE = 30000,

        /** The device supports setting a pre/post-trigger capture ratio. */
        SR_CONF_CAPTURE_RATIO,

        /** The device supports setting a pattern (pattern generator mode). */
        SR_CONF_PATTERN_MODE,

        /** The device supports run-length encoding (RLE). */
        SR_CONF_RLE,

        /** The device supports setting trigger slope. */
        SR_CONF_TRIGGER_SLOPE,

        /** The device supports averaging. */
        SR_CONF_AVERAGING,

        /**
         * The device supports setting number of samples to be
         * averaged over.
         */
        SR_CONF_AVG_SAMPLES,

        /** Trigger source. */
        SR_CONF_TRIGGER_SOURCE,

        /** Horizontal trigger position. */
        SR_CONF_HORIZ_TRIGGERPOS,

        /** Buffer size. */
        SR_CONF_BUFFERSIZE,

        /** Time base. */
        SR_CONF_TIMEBASE,

        /** Filter. */
        SR_CONF_FILTER,

        /** Volts/div. */
        SR_CONF_VDIV,

        /** Coupling. */
        SR_CONF_COUPLING,

        /** Trigger matches. */
        SR_CONF_TRIGGER_MATCH,

        /** The device supports setting its sample interval, in ms. */
        SR_CONF_SAMPLE_INTERVAL,

        /** Number of horizontal divisions, as related to SR_CONF_TIMEBASE. */
        SR_CONF_NUM_HDIV,

        /** Number of vertical divisions, as related to SR_CONF_VDIV. */
        SR_CONF_NUM_VDIV,

        /** Sound pressure level frequency weighting. */
        SR_CONF_SPL_WEIGHT_FREQ,

        /** Sound pressure level time weighting. */
        SR_CONF_SPL_WEIGHT_TIME,

        /** Sound pressure level measurement range. */
        SR_CONF_SPL_MEASUREMENT_RANGE,

        /** Max hold mode. */
        SR_CONF_HOLD_MAX,

        /** Min hold mode. */
        SR_CONF_HOLD_MIN,

        /** Logic low-high threshold range. */
        SR_CONF_VOLTAGE_THRESHOLD,

        /** The device supports using an external clock. */
        SR_CONF_EXTERNAL_CLOCK,

        /**
         * The device supports swapping channels. Typical this is between
         * buffered and unbuffered channels.
         */
        SR_CONF_SWAP,

        /** Center frequency.
         * The input signal is downmixed by this frequency before the ADC
         * anti-aliasing filter.
         */
        SR_CONF_CENTER_FREQUENCY,

        /** The device supports setting the number of logic channels. */
        SR_CONF_NUM_LOGIC_CHANNELS,

        /** The device supports setting the number of analog channels. */
        SR_CONF_NUM_ANALOG_CHANNELS,

        /**
         * Current voltage.
         * @arg type: double
         * @arg get: get measured voltage
         */
        SR_CONF_VOLTAGE,

        /**
         * Maximum target voltage.
         * @arg type: double
         * @arg get: get target voltage
         * @arg set: change target voltage
         */
        SR_CONF_VOLTAGE_TARGET,

        /**
         * Current current.
         * @arg type: double
         * @arg get: get measured current
         */
        SR_CONF_CURRENT,

        /**
         * Current limit.
         * @arg type: double
         * @arg get: get current limit
         * @arg set: change current limit
         */
        SR_CONF_CURRENT_LIMIT,

        /**
         * Enabling/disabling channel.
         * @arg type: boolean
         * @arg get: @b true if currently enabled
         * @arg set: enable/disable
         */
        SR_CONF_ENABLED,

        /**
         * Channel configuration.
         * @arg type: string
         * @arg get: get current setting
         * @arg set: change current setting
         * @arg list: array of possible values
         */
        SR_CONF_CHANNEL_CONFIG,

        /**
         * Over-voltage protection (OVP) feature
         * @arg type: boolean
         * @arg get: @b true if currently enabled
         * @arg set: enable/disable
         */
        SR_CONF_OVER_VOLTAGE_PROTECTION_ENABLED,

        /**
         * Over-voltage protection (OVP) active
         * @arg type: boolean
         * @arg get: @b true if device has activated OVP, i.e. the output voltage
         *      exceeds the over-voltage protection threshold.
         */
        SR_CONF_OVER_VOLTAGE_PROTECTION_ACTIVE,

        /**
         * Over-voltage protection (OVP) threshold
         * @arg type: double (voltage)
         * @arg get: get current threshold
         * @arg set: set new threshold
         */
        SR_CONF_OVER_VOLTAGE_PROTECTION_THRESHOLD,

        /**
         * Over-current protection (OCP) feature
         * @arg type: boolean
         * @arg get: @b true if currently enabled
         * @arg set: enable/disable
         */
        SR_CONF_OVER_CURRENT_PROTECTION_ENABLED,

        /**
         * Over-current protection (OCP) active
         * @arg type: boolean
         * @arg get: @b true if device has activated OCP, i.e. the current current
         *      exceeds the over-current protection threshold.
         */
        SR_CONF_OVER_CURRENT_PROTECTION_ACTIVE,

        /**
         * Over-current protection (OCP) threshold
         * @arg type: double (current)
         * @arg get: get current threshold
         * @arg set: set new threshold
         */
        SR_CONF_OVER_CURRENT_PROTECTION_THRESHOLD,

        /** Choice of clock edge for external clock ("r" or "f"). */
        SR_CONF_CLOCK_EDGE,

        /** Amplitude of a source without strictly-defined MQ. */
        SR_CONF_AMPLITUDE,

        /**
         * Channel regulation
         * get: "CV", "CC" or "UR", denoting constant voltage, constant current
         *      or unregulated.
         *      "CC-" denotes a power supply in current sink mode (e.g. HP 66xxB).
         *      "" is used when there is no regulation, e.g. the output is disabled.
         */
        SR_CONF_REGULATION,

        /** Over-temperature protection (OTP) */
        SR_CONF_OVER_TEMPERATURE_PROTECTION,

        /** Output frequency in Hz. */
        SR_CONF_OUTPUT_FREQUENCY,

        /** Output frequency target in Hz. */
        SR_CONF_OUTPUT_FREQUENCY_TARGET,

        /** Measured quantity. */
        SR_CONF_MEASURED_QUANTITY,

        /** Equivalent circuit model. */
        SR_CONF_EQUIV_CIRCUIT_MODEL,

        /** Over-temperature protection (OTP) active. */
        SR_CONF_OVER_TEMPERATURE_PROTECTION_ACTIVE,

        /** Under-voltage condition. */
        SR_CONF_UNDER_VOLTAGE_CONDITION,

        /** Under-voltage condition active. */
        SR_CONF_UNDER_VOLTAGE_CONDITION_ACTIVE,

        /** Trigger level. */
        SR_CONF_TRIGGER_LEVEL,

        /** Under-voltage condition threshold. */
        SR_CONF_UNDER_VOLTAGE_CONDITION_THRESHOLD,

        /**
         * Which external clock source to use if the device supports
         * multiple external clock channels.
         */
        SR_CONF_EXTERNAL_CLOCK_SOURCE,

        /** Offset of a source without strictly-defined MQ. */
        SR_CONF_OFFSET,

        /** The device supports setting a pattern for the logic trigger. */
        SR_CONF_TRIGGER_PATTERN,

        /** High resolution mode. */
        SR_CONF_HIGH_RESOLUTION,

        /** Peak detection. */
        SR_CONF_PEAK_DETECTION,

        /** Logic threshold: predefined levels (TTL, ECL, CMOS, etc). */
        SR_CONF_LOGIC_THRESHOLD,

        /** Logic threshold: custom numerical value. */
        SR_CONF_LOGIC_THRESHOLD_CUSTOM,

        /** The measurement range of a DMM or the output range of a power supply. */
        SR_CONF_RANGE,

        /** The number of digits (e.g. for a DMM). */
        SR_CONF_DIGITS,

        /** Phase of a source signal. */
        SR_CONF_PHASE,

        /** Duty cycle of a source signal. */
        SR_CONF_DUTY_CYCLE,

        /**
         * Current power.
         * @arg type: double
         * @arg get: get measured power
         */
        SR_CONF_POWER,

        /**
         * Power target.
         * @arg type: double
         * @arg get: get power target
         * @arg set: change power target
         */
        SR_CONF_POWER_TARGET,

        /**
         * Resistance target.
         * @arg type: double
         * @arg get: get resistance target
         * @arg set: change resistance target
         */
        SR_CONF_RESISTANCE_TARGET,

        /**
         * Over-current protection (OCP) delay
         * @arg type: double (time)
         * @arg get: get current delay
         * @arg set: set new delay
         */
        SR_CONF_OVER_CURRENT_PROTECTION_DELAY,

        /* Update sr_key_info_config[] (hwdriver.c) upon changes! */

        /*--- Special stuff -------------------------------------------------*/

        /** Session filename. */
        SR_CONF_SESSIONFILE = 40000,

        /** The device supports specifying a capturefile to inject. */
        SR_CONF_CAPTUREFILE,

        /** The device supports specifying the capturefile unit size. */
        SR_CONF_CAPTURE_UNITSIZE,

        /** Power off the device. */
        SR_CONF_POWER_OFF,

        /**
         * Data source for acquisition. If not present, acquisition from
         * the device is always "live", i.e. acquisition starts when the
         * frontend asks and the results are sent out as soon as possible.
         *
         * If present, it indicates that either the device has no live
         * acquisition capability (for example a pure data logger), or
         * there is a choice. sr_config_list() returns those choices.
         *
         * In any case if a device has live acquisition capabilities, it
         * is always the default.
         */
        SR_CONF_DATA_SOURCE,

        /** The device supports setting a probe factor. */
        SR_CONF_PROBE_FACTOR,

        /** Number of powerline cycles for ADC integration time. */
        SR_CONF_ADC_POWERLINE_CYCLES,

        /* Update sr_key_info_config[] (hwdriver.c) upon changes! */

        /*--- Acquisition modes, sample limiting ----------------------------*/

        /**
         * The device supports setting a sample time limit (how long
         * the sample acquisition should run, in ms).
         */
        SR_CONF_LIMIT_MSEC = 50000,

        /**
         * The device supports setting a sample number limit (how many
         * samples should be acquired).
         */
        SR_CONF_LIMIT_SAMPLES,

        /**
         * The device supports setting a frame limit (how many
         * frames should be acquired).
         */
        SR_CONF_LIMIT_FRAMES,

        /**
         * The device supports continuous sampling. Neither a time limit
         * nor a sample number limit has to be supplied, it will just acquire
         * samples continuously, until explicitly stopped by a certain command.
         */
        SR_CONF_CONTINUOUS,

        /** The device has internal storage, into which data is logged. This
         * starts or stops the internal logging. */
        SR_CONF_DATALOG,

        /** Device mode for multi-function devices. */
        SR_CONF_DEVICE_MODE,

        /** Self test mode. */
        SR_CONF_TEST_MODE,

        /* Update sr_key_info_config[] (hwdriver.c) upon changes! */
};

/**
 * Opaque structure representing a libsigrok device instance.
 *
 * None of the fields of this structure are meant to be accessed directly.
 */
struct sr_dev_inst;

/** Types of device instance, struct sr_dev_inst.type */
enum sr_dev_inst_type {
        /** Device instance type for USB devices. */
        SR_INST_USB = 10000,
        /** Device instance type for serial port devices. */
        SR_INST_SERIAL,
        /** Device instance type for SCPI devices. */
        SR_INST_SCPI,
        /** Device-instance type for user-created "devices". */
        SR_INST_USER,
        /** Device instance type for Modbus devices. */
        SR_INST_MODBUS,
};

/** Device instance status, struct sr_dev_inst.status */
enum sr_dev_inst_status {
        /** The device instance was not found. */
        SR_ST_NOT_FOUND = 10000,
        /** The device instance was found, but is still booting. */
        SR_ST_INITIALIZING,
        /** The device instance is live, but not in use. */
        SR_ST_INACTIVE,
        /** The device instance is actively in use in a session. */
        SR_ST_ACTIVE,
        /** The device is winding down its session. */
        SR_ST_STOPPING,
};

/** Device driver data. See also http://sigrok.org/wiki/Hardware_driver_API . */
struct sr_dev_driver {
        /* Driver-specific */
        /** Driver name. Lowercase a-z, 0-9 and dashes (-) only. */
        const char *name;
        /** Long name. Verbose driver name shown to user. */
        const char *longname;
        /** API version (currently 1).  */
        int api_version;
        /** Called when driver is loaded, e.g. program startup. */
        int (*init) (struct sr_dev_driver *driver, struct sr_context *sr_ctx);
        /** Called before driver is unloaded.
         *  Driver must free all resources held by it. */
        int (*cleanup) (const struct sr_dev_driver *driver);
        /** Scan for devices. Driver should do all initialisation required.
         *  Can be called several times, e.g. with different port options.
         *  @retval NULL Error or no devices found.
         *  @retval other GSList of a struct sr_dev_inst for each device.
         *                Must be freed by caller!
         */
        GSList *(*scan) (struct sr_dev_driver *driver, GSList *options);
        /** Get list of device instances the driver knows about.
         *  @returns NULL or GSList of a struct sr_dev_inst for each device.
         *           Must not be freed by caller!
         */
        GSList *(*dev_list) (const struct sr_dev_driver *driver);
        /** Clear list of devices the driver knows about. */
        int (*dev_clear) (const struct sr_dev_driver *driver);
        /** Query value of a configuration key in driver or given device instance.
         *  @see sr_config_get().
         */
        int (*config_get) (uint32_t key, GVariant **data,
                        const struct sr_dev_inst *sdi,
                        const struct sr_channel_group *cg);
        /** Set value of a configuration key in driver or a given device instance.
         *  @see sr_config_set(). */
        int (*config_set) (uint32_t key, GVariant *data,
                        const struct sr_dev_inst *sdi,
                        const struct sr_channel_group *cg);
        /** Channel status change.
         *  @see sr_dev_channel_enable(). */
        int (*config_channel_set) (const struct sr_dev_inst *sdi,
                        struct sr_channel *ch, unsigned int changes);
        /** Apply configuration settings to the device hardware.
         *  @see sr_config_commit().*/
        int (*config_commit) (const struct sr_dev_inst *sdi);
        /** List all possible values for a configuration key in a device instance.
         *  @see sr_config_list().
         */
        int (*config_list) (uint32_t key, GVariant **data,
                        const struct sr_dev_inst *sdi,
                        const struct sr_channel_group *cg);

        /* Device-specific */
        /** Open device */
        int (*dev_open) (struct sr_dev_inst *sdi);
        /** Close device */
        int (*dev_close) (struct sr_dev_inst *sdi);
        /** Begin data acquisition on the specified device. */
        int (*dev_acquisition_start) (const struct sr_dev_inst *sdi);
        /** End data acquisition on the specified device. */
        int (*dev_acquisition_stop) (struct sr_dev_inst *sdi);

        /* Dynamic */
        /** Device driver context, considered private. Initialized by init(). */
        void *context;
};

/** Serial port descriptor. */
struct sr_serial_port {
        /** The OS dependent name of the serial port. */
        char *name;
        /** An end user friendly description for the serial port. */
        char *description;
};

#include <libsigrok/proto.h>
#include <libsigrok/version.h>

#ifdef __cplusplus
}
#endif

#endif