[libsigrok.git] / src / hardware / hp-3478a / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2017-2021 Frank Stettner <frank-stettner@gmx.net>
 *
 * 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/>.
 */

#include <config.h>
#include <math.h>
#include <stdlib.h>
#include "scpi.h"
#include "protocol.h"

static int set_mq_volt(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
static int set_mq_amp(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
static int set_mq_ohm(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);

static const struct {
	enum sr_mq mq;
	int (*set_mode)(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
} sr_mq_to_cmd_map[] = {
	{ SR_MQ_VOLTAGE, set_mq_volt },
	{ SR_MQ_CURRENT, set_mq_amp },
	{ SR_MQ_RESISTANCE, set_mq_ohm },
};

static int set_mq_volt(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
{
	if ((flags & SR_MQFLAG_AC) != SR_MQFLAG_AC &&
		(flags & SR_MQFLAG_DC) != SR_MQFLAG_DC)
		return SR_ERR_NA;

	return sr_scpi_send(scpi, "%s",
		((flags & SR_MQFLAG_AC) == SR_MQFLAG_AC) ? "F2" : "F1");
}

static int set_mq_amp(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
{
	if ((flags & SR_MQFLAG_AC) != SR_MQFLAG_AC &&
		(flags & SR_MQFLAG_DC) != SR_MQFLAG_DC)
		return SR_ERR_NA;

	return sr_scpi_send(scpi, "%s", (flags & SR_MQFLAG_AC) ? "F6" : "F5");
}

static int set_mq_ohm(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
{
	return sr_scpi_send(scpi, "%s",
		(flags & SR_MQFLAG_FOUR_WIRE) ? "F4" : "F3");
}

SR_PRIV int hp_3478a_set_mq(const struct sr_dev_inst *sdi, enum sr_mq mq,
				enum sr_mqflag mq_flags)
{
	int ret;
	size_t i;
	struct sr_scpi_dev_inst *scpi = sdi->conn;
	struct dev_context *devc = sdi->priv;

	/* No need to send a command if we're not changing the measurement type. */
	if (devc->measurement_mq == mq && devc->measurement_mq_flag == mq_flags)
		return SR_OK;

	for (i = 0; i < ARRAY_SIZE(sr_mq_to_cmd_map); i++) {
		if (sr_mq_to_cmd_map[i].mq != mq)
			continue;

		ret = sr_mq_to_cmd_map[i].set_mode(scpi, mq_flags);
		if (ret != SR_OK)
			return ret;

		ret = hp_3478a_get_status_bytes(sdi);
		return ret;
	}

	return SR_ERR_NA;
}

SR_PRIV int hp_3478a_set_range(const struct sr_dev_inst *sdi, int range_exp)
{
	int ret;
	struct sr_scpi_dev_inst *scpi = sdi->conn;
	struct dev_context *devc = sdi->priv;

	/* No need to send command if we're not changing the range. */
	if (devc->range_exp == range_exp)
		return SR_OK;

	/* -99 is a dummy exponent for auto ranging. */
	if (range_exp == -99)
		ret = sr_scpi_send(scpi, "RA");
	else
		ret = sr_scpi_send(scpi, "R%i", range_exp);
	if (ret != SR_OK)
		return ret;

	return hp_3478a_get_status_bytes(sdi);
}

SR_PRIV int hp_3478a_set_digits(const struct sr_dev_inst *sdi, uint8_t digits)
{
	int ret;
	struct sr_scpi_dev_inst *scpi = sdi->conn;
	struct dev_context *devc = sdi->priv;

	/* No need to send command if we're not changing the resolution. */
	if (devc->digits == digits)
		return SR_OK;

	/* digits are the total number of digits, so we have to substract 1 */
	ret = sr_scpi_send(scpi, "N%i", digits-1);
	if (ret != SR_OK)
		return ret;

	return hp_3478a_get_status_bytes(sdi);
}

static int parse_range_vdc(struct dev_context *devc, uint8_t range_byte)
{
	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30MV) {
		devc->range_exp = -2;
		devc->sr_digits = devc->digits + 1;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300MV) {
		devc->range_exp = -1;
		devc->sr_digits = devc->digits;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_3V) {
		devc->range_exp = 0;
		devc->sr_digits = devc->digits - 1;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30V) {
		devc->range_exp = 1;
		devc->sr_digits = devc->digits - 2;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300V) {
		devc->range_exp = 2;
		devc->sr_digits = devc->digits - 3;
	} else
		return SR_ERR_DATA;

	return SR_OK;
}

static int parse_range_vac(struct dev_context *devc, uint8_t range_byte)
{
	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300MV) {
		devc->range_exp = -1;
		devc->sr_digits = devc->digits;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_3V) {
		devc->range_exp = 0;
		devc->sr_digits = devc->digits - 1;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_30V) {
		devc->range_exp = 1;
		devc->sr_digits = devc->digits - 2;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300V) {
		devc->range_exp = 2;
		devc->sr_digits = devc->digits - 3;
	} else
		return SR_ERR_DATA;

	return SR_OK;
}

static int parse_range_a(struct dev_context *devc, uint8_t range_byte)
{
	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_300MA) {
		devc->range_exp = -1;
		devc->sr_digits = devc->digits;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_3A) {
		devc->range_exp = 0;
		devc->sr_digits = devc->digits - 1;
	} else
		return SR_ERR_DATA;

	return SR_OK;
}

static int parse_range_ohm(struct dev_context *devc, uint8_t range_byte)
{
	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30R) {
		devc->range_exp = 1;
		devc->sr_digits = devc->digits - 2;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300R) {
		devc->range_exp = 2;
		devc->sr_digits = devc->digits - 3;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3KR) {
		devc->range_exp = 3;
		devc->sr_digits = devc->digits - 4;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30KR) {
		devc->range_exp = 4;
		devc->sr_digits = devc->digits - 5;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300KR) {
		devc->range_exp = 5;
		devc->sr_digits = devc->digits - 6;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3MR) {
		devc->range_exp = 6;
		devc->sr_digits = devc->digits - 7;
	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30MR) {
		devc->range_exp = 7;
		devc->sr_digits = devc->digits - 8;
	} else
		return SR_ERR_DATA;

	return SR_OK;
}

static int parse_function_byte(struct dev_context *devc, uint8_t function_byte)
{
	/* Digits / Resolution (digits must be set before range parsing) */
	if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_5_5)
		devc->digits = 6;
	else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_4_5)
		devc->digits = 5;
	else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_3_5)
		devc->digits = 4;
	else
		return SR_ERR_DATA;

	/* Function + Range */
	devc->measurement_mq_flag = 0;
	devc->acquisition_mq_flags = 0;
	if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VDC) {
		devc->measurement_mq = SR_MQ_VOLTAGE;
		devc->measurement_mq_flag = SR_MQFLAG_DC;
		devc->acquisition_mq_flags |= SR_MQFLAG_DC;
		devc->measurement_unit = SR_UNIT_VOLT;
		parse_range_vdc(devc, function_byte);
	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VAC) {
		devc->measurement_mq = SR_MQ_VOLTAGE;
		devc->measurement_mq_flag = SR_MQFLAG_AC;
		devc->acquisition_mq_flags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
		devc->measurement_unit = SR_UNIT_VOLT;
		parse_range_vac(devc, function_byte);
	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_2WR) {
		devc->measurement_mq = SR_MQ_RESISTANCE;
		devc->measurement_unit = SR_UNIT_OHM;
		parse_range_ohm(devc, function_byte);
	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_4WR) {
		devc->measurement_mq = SR_MQ_RESISTANCE;
		devc->measurement_mq_flag = SR_MQFLAG_FOUR_WIRE;
		devc->acquisition_mq_flags |= SR_MQFLAG_FOUR_WIRE;
		devc->measurement_unit = SR_UNIT_OHM;
		parse_range_ohm(devc, function_byte);
	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_ADC) {
		devc->measurement_mq = SR_MQ_CURRENT;
		devc->measurement_mq_flag = SR_MQFLAG_DC;
		devc->acquisition_mq_flags |= SR_MQFLAG_DC;
		devc->measurement_unit = SR_UNIT_AMPERE;
		parse_range_a(devc, function_byte);
	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_AAC) {
		devc->measurement_mq = SR_MQ_CURRENT;
		devc->measurement_mq_flag = SR_MQFLAG_AC;
		devc->acquisition_mq_flags |= SR_MQFLAG_AC | SR_MQFLAG_RMS;
		devc->measurement_unit = SR_UNIT_AMPERE;
		parse_range_a(devc, function_byte);
	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_EXR) {
		devc->measurement_mq = SR_MQ_RESISTANCE;
		devc->measurement_unit = SR_UNIT_OHM;
		parse_range_ohm(devc, function_byte);
	}

	return SR_OK;
}

static int parse_status_byte(struct dev_context *devc, uint8_t status_byte)
{
	devc->trigger = TRIGGER_UNDEFINED;

	/* External Trigger */
	if ((status_byte & STATUS_EXT_TRIGGER) == STATUS_EXT_TRIGGER)
		devc->trigger = TRIGGER_EXTERNAL;

	/* Cal RAM */
	if ((status_byte & STATUS_CAL_RAM) == STATUS_CAL_RAM)
		devc->calibration = TRUE;
	else
		devc->calibration = FALSE;

	/* Front/Rear terminals */
	if ((status_byte & STATUS_FRONT_TERMINAL) == STATUS_FRONT_TERMINAL)
		devc->terminal = TERMINAL_FRONT;
	else
		devc->terminal = TERMINAL_REAR;

	/* 50Hz / 60Hz */
	if ((status_byte & STATUS_50HZ) == STATUS_50HZ)
		devc->line = LINE_50HZ;
	else
		devc->line = LINE_60HZ;

	/* Auto-Zero */
	if ((status_byte & STATUS_AUTO_ZERO) == STATUS_AUTO_ZERO)
		devc->auto_zero = TRUE;
	else
		devc->auto_zero = FALSE;

	/* Auto-Range */
	if ((status_byte & STATUS_AUTO_RANGE) == STATUS_AUTO_RANGE) {
		devc->acquisition_mq_flags |= SR_MQFLAG_AUTORANGE;
		devc->range_exp = -99;
	} else
		devc->acquisition_mq_flags &= ~SR_MQFLAG_AUTORANGE;

	/* Internal trigger */
	if ((status_byte & STATUS_INT_TRIGGER) == STATUS_INT_TRIGGER)
		devc->trigger = TRIGGER_INTERNAL;

	return SR_OK;
}

static int parse_srq_byte(uint8_t sqr_byte)
{
	(void)sqr_byte;

#if 0
	/* The ServiceReQuest register isn't used at the moment. */

	/* PON SRQ */
	if ((sqr_byte & SRQ_POWER_ON) == SRQ_POWER_ON)
		sr_spew("Power On SRQ or clear msg received");

	/* Cal failed SRQ */
	if ((sqr_byte & SRQ_CAL_FAILED) == SRQ_CAL_FAILED)
		sr_spew("CAL failed SRQ");

	/* Keyboard SRQ */
	if ((sqr_byte & SRQ_KEYBORD) == SRQ_KEYBORD)
		sr_spew("Keyboard SRQ");

	/* Hardware error SRQ */
	if ((sqr_byte & SRQ_HARDWARE_ERR) == SRQ_HARDWARE_ERR)
		sr_spew("Hardware error SRQ");

	/* Syntax error SRQ */
	if ((sqr_byte & SRQ_SYNTAX_ERR) == SRQ_SYNTAX_ERR)
		sr_spew("Syntax error SRQ");

	/* Every reading is available to the bus SRQ */
	if ((sqr_byte & SRQ_BUS_AVAIL) == SRQ_BUS_AVAIL)
		sr_spew("Every reading is available to the bus SRQ");
#endif

	return SR_OK;
}

static int parse_error_byte(uint8_t error_byte)
{
	int ret;

	ret = SR_OK;

	/* A/D link */
	if ((error_byte & ERROR_AD_LINK) == ERROR_AD_LINK) {
		sr_err("Failure in the A/D link");
		ret = SR_ERR;
	}

	/* A/D Self Test */
	if ((error_byte & ERROR_AD_SELF_TEST) == ERROR_AD_SELF_TEST) {
		sr_err("A/D has failed its internal Self Test");
		ret = SR_ERR;
	}

	/* A/D slope error */
	if ((error_byte & ERROR_AD_SLOPE) == ERROR_AD_SLOPE) {
		sr_err("There has been an A/D slope error");
		ret = SR_ERR;
	}

	/* ROM Selt Test */
	if ((error_byte & ERROR_ROM_SELF_TEST) == ERROR_ROM_SELF_TEST) {
		sr_err("The ROM Self Test has failed");
		ret = SR_ERR;
	}

	/* RAM Selt Test */
	if ((error_byte & ERROR_RAM_SELF_TEST) == ERROR_RAM_SELF_TEST) {
		sr_err("The RAM Self Test has failed");
		ret = SR_ERR;
	}

	/* Selt Test */
	if ((error_byte & ERROR_SELF_TEST) == ERROR_SELF_TEST) {
		sr_err("Self Test: Any of the CAL RAM locations have bad "
		       "checksums, or a range with a bad checksum is selected");
		ret = SR_ERR;
	}

	return ret;
}

SR_PRIV int hp_3478a_get_status_bytes(const struct sr_dev_inst *sdi)
{
	int ret;
	char *response;
	uint8_t function_byte, status_byte, srq_byte, error_byte;
	struct sr_scpi_dev_inst *scpi = sdi->conn;
	struct dev_context *devc = sdi->priv;

	ret = sr_scpi_get_string(scpi, "B", &response);
	if (ret != SR_OK)
		return ret;

	if (!response)
		return SR_ERR;

	function_byte = (uint8_t)response[0];
	status_byte = (uint8_t)response[1];
	srq_byte = (uint8_t)response[2];
	error_byte = (uint8_t)response[3];

	g_free(response);

	parse_function_byte(devc, function_byte);
	parse_status_byte(devc, status_byte);
	parse_srq_byte(srq_byte);
	ret = parse_error_byte(error_byte);

	return ret;
}

static void acq_send_measurement(struct sr_dev_inst *sdi)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_analog analog;
	struct sr_analog_encoding encoding;
	struct sr_analog_meaning meaning;
	struct sr_analog_spec spec;
	struct dev_context *devc;
	float f;

	devc = sdi->priv;

	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;

	sr_analog_init(&analog, &encoding, &meaning, &spec, devc->sr_digits);

	/* TODO: Implement NAN, depending on counts, range and value. */
	f = devc->measurement;
	analog.num_samples = 1;
	analog.data = &f;

	encoding.unitsize = sizeof(float);
	encoding.is_float = TRUE;
	encoding.digits = devc->sr_digits;

	meaning.mq = devc->measurement_mq;
	meaning.mqflags = devc->acquisition_mq_flags;
	meaning.unit = devc->measurement_unit;
	meaning.channels = sdi->channels;

	spec.spec_digits = devc->sr_digits;

	sr_session_send(sdi, &packet);
}

SR_PRIV int hp_3478a_receive_data(int fd, int revents, void *cb_data)
{
	struct sr_scpi_dev_inst *scpi;
	struct sr_dev_inst *sdi;
	struct dev_context *devc;
	char status_register;

	(void)fd;
	(void)revents;

	if (!(sdi = cb_data) || !(devc = sdi->priv))
		return TRUE;

	scpi = sdi->conn;

	/*
	 * TODO: Wait for SRQ from the DMM when a new measurement is available.
	 *       For now, we don't wait for a SRQ, but just do a SPoll and
	 *       check the Data Ready bit (0x01).
	 *       This is necessary, because (1) reading a value will block the
	 *       bus until a measurement is available and (2) when switching
	 *       ranges, there could be a timeout.
	 */
	if (sr_scpi_gpib_spoll(scpi, &status_register) != SR_OK)
		return FALSE;
	if (!(((uint8_t)status_register) & SRQ_BUS_AVAIL))
		return TRUE;

	/* Get a reading from the DMM. */
	if (sr_scpi_get_double(scpi, NULL, &devc->measurement) != SR_OK)
		return FALSE;

	/* Check for overflow. */
	if (devc->measurement >= 9.998e+9)
		devc->measurement = INFINITY;

	/*
	 * This is necessary to get the actual range for the encoding digits.
	 * Must be called after reading the value, because it resets the
	 * status register!
	 */
	if (hp_3478a_get_status_bytes(sdi) != SR_OK)
		return FALSE;

	acq_send_measurement(sdi);
	sr_sw_limits_update_samples_read(&devc->limits, 1);

	if (sr_sw_limits_check(&devc->limits))
		sr_dev_acquisition_stop(sdi);

	return TRUE;
}
Commit	Line	Data
1d9eebf4 FS	1	/*
	2	* This file is part of the libsigrok project.
	3	*
569165c0	4	* Copyright (C) 2017-2021 Frank Stettner <frank-stettner@gmx.net>
1d9eebf4 FS	5	*
	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 3 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <config.h>
d2c1730a FS	21	#include <math.h>
	22	#include <stdlib.h>
	23	#include "scpi.h"
1d9eebf4 FS	24	#include "protocol.h"
1d9eebf4 FS	25
d2c1730a FS	26	static int set_mq_volt(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
	27	static int set_mq_amp(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
	28	static int set_mq_ohm(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags);
	29
	30	static const struct {
	31	enum sr_mq mq;
	32	int (set_mode)(struct sr_scpi_dev_inst scpi, enum sr_mqflag flags);
	33	} sr_mq_to_cmd_map[] = {
	34	{ SR_MQ_VOLTAGE, set_mq_volt },
	35	{ SR_MQ_CURRENT, set_mq_amp },
	36	{ SR_MQ_RESISTANCE, set_mq_ohm },
	37	};
	38
	39	static int set_mq_volt(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
	40	{
d2c1730a FS	41	if ((flags & SR_MQFLAG_AC) != SR_MQFLAG_AC &&
	42	(flags & SR_MQFLAG_DC) != SR_MQFLAG_DC)
	43	return SR_ERR_NA;
	44
04c4a677 UH	45	return sr_scpi_send(scpi, "%s",
04c4a677 UH	46	((flags & SR_MQFLAG_AC) == SR_MQFLAG_AC) ? "F2" : "F1");
d2c1730a FS	47	}
	48
	49	static int set_mq_amp(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
	50	{
d2c1730a FS	51	if ((flags & SR_MQFLAG_AC) != SR_MQFLAG_AC &&
	52	(flags & SR_MQFLAG_DC) != SR_MQFLAG_DC)
	53	return SR_ERR_NA;
	54
04c4a677	55	return sr_scpi_send(scpi, "%s", (flags & SR_MQFLAG_AC) ? "F6" : "F5");
d2c1730a FS	56	}
	57
	58	static int set_mq_ohm(struct sr_scpi_dev_inst *scpi, enum sr_mqflag flags)
	59	{
04c4a677 UH	60	return sr_scpi_send(scpi, "%s",
04c4a677 UH	61	(flags & SR_MQFLAG_FOUR_WIRE) ? "F4" : "F3");
d2c1730a FS	62	}
	63
	64	SR_PRIV int hp_3478a_set_mq(const struct sr_dev_inst *sdi, enum sr_mq mq,
	65	enum sr_mqflag mq_flags)
	66	{
	67	int ret;
	68	size_t i;
	69	struct sr_scpi_dev_inst *scpi = sdi->conn;
	70	struct dev_context *devc = sdi->priv;
	71
569165c0 FS	72	/* No need to send a command if we're not changing the measurement type. */
569165c0 FS	73	if (devc->measurement_mq == mq && devc->measurement_mq_flag == mq_flags)
d2c1730a FS	74	return SR_OK;
	75
	76	for (i = 0; i < ARRAY_SIZE(sr_mq_to_cmd_map); i++) {
	77	if (sr_mq_to_cmd_map[i].mq != mq)
	78	continue;
	79
	80	ret = sr_mq_to_cmd_map[i].set_mode(scpi, mq_flags);
	81	if (ret != SR_OK)
	82	return ret;
	83
	84	ret = hp_3478a_get_status_bytes(sdi);
	85	return ret;
	86	}
	87
	88	return SR_ERR_NA;
	89	}
	90
e5137b93 FS	91	SR_PRIV int hp_3478a_set_range(const struct sr_dev_inst *sdi, int range_exp)
	92	{
	93	int ret;
	94	struct sr_scpi_dev_inst *scpi = sdi->conn;
	95	struct dev_context *devc = sdi->priv;
	96
	97	/* No need to send command if we're not changing the range. */
	98	if (devc->range_exp == range_exp)
	99	return SR_OK;
	100
	101	/* -99 is a dummy exponent for auto ranging. */
	102	if (range_exp == -99)
	103	ret = sr_scpi_send(scpi, "RA");
	104	else
	105	ret = sr_scpi_send(scpi, "R%i", range_exp);
	106	if (ret != SR_OK)
	107	return ret;
	108
	109	return hp_3478a_get_status_bytes(sdi);
	110	}
	111
7812a5c8 FS	112	SR_PRIV int hp_3478a_set_digits(const struct sr_dev_inst *sdi, uint8_t digits)
	113	{
	114	int ret;
	115	struct sr_scpi_dev_inst *scpi = sdi->conn;
	116	struct dev_context *devc = sdi->priv;
	117
c8260fa8 FS	118	/* No need to send command if we're not changing the resolution. */
c8260fa8 FS	119	if (devc->digits == digits)
7812a5c8 FS	120	return SR_OK;
7812a5c8 FS	121
c8260fa8	122	/* digits are the total number of digits, so we have to substract 1 */
7812a5c8 FS	123	ret = sr_scpi_send(scpi, "N%i", digits-1);
	124	if (ret != SR_OK)
	125	return ret;
	126
	127	return hp_3478a_get_status_bytes(sdi);
	128	}
	129
d2c1730a FS	130	static int parse_range_vdc(struct dev_context *devc, uint8_t range_byte)
d2c1730a FS	131	{
e5137b93 FS	132	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30MV) {
e5137b93 FS	133	devc->range_exp = -2;
c8260fa8	134	devc->sr_digits = devc->digits + 1;
e5137b93 FS	135	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300MV) {
e5137b93 FS	136	devc->range_exp = -1;
c8260fa8	137	devc->sr_digits = devc->digits;
e5137b93 FS	138	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_3V) {
e5137b93 FS	139	devc->range_exp = 0;
c8260fa8	140	devc->sr_digits = devc->digits - 1;
e5137b93 FS	141	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_30V) {
e5137b93 FS	142	devc->range_exp = 1;
c8260fa8	143	devc->sr_digits = devc->digits - 2;
e5137b93 FS	144	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VDC_300V) {
e5137b93 FS	145	devc->range_exp = 2;
c8260fa8	146	devc->sr_digits = devc->digits - 3;
e5137b93	147	} else
d2c1730a	148	return SR_ERR_DATA;
d2c1730a FS	149
	150	return SR_OK;
	151	}
	152
	153	static int parse_range_vac(struct dev_context *devc, uint8_t range_byte)
	154	{
e5137b93 FS	155	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300MV) {
e5137b93 FS	156	devc->range_exp = -1;
c8260fa8	157	devc->sr_digits = devc->digits;
e5137b93 FS	158	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_3V) {
e5137b93 FS	159	devc->range_exp = 0;
c8260fa8	160	devc->sr_digits = devc->digits - 1;
e5137b93 FS	161	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_30V) {
e5137b93 FS	162	devc->range_exp = 1;
c8260fa8	163	devc->sr_digits = devc->digits - 2;
e5137b93 FS	164	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_VAC_300V) {
e5137b93 FS	165	devc->range_exp = 2;
c8260fa8	166	devc->sr_digits = devc->digits - 3;
e5137b93	167	} else
d2c1730a	168	return SR_ERR_DATA;
d2c1730a FS	169
	170	return SR_OK;
	171	}
	172
	173	static int parse_range_a(struct dev_context *devc, uint8_t range_byte)
	174	{
e5137b93 FS	175	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_300MA) {
e5137b93 FS	176	devc->range_exp = -1;
c8260fa8	177	devc->sr_digits = devc->digits;
e5137b93 FS	178	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_A_3A) {
e5137b93 FS	179	devc->range_exp = 0;
c8260fa8	180	devc->sr_digits = devc->digits - 1;
e5137b93	181	} else
d2c1730a	182	return SR_ERR_DATA;
d2c1730a FS	183
	184	return SR_OK;
	185	}
	186
	187	static int parse_range_ohm(struct dev_context *devc, uint8_t range_byte)
	188	{
e5137b93 FS	189	if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30R) {
e5137b93 FS	190	devc->range_exp = 1;
c8260fa8	191	devc->sr_digits = devc->digits - 2;
e5137b93 FS	192	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300R) {
e5137b93 FS	193	devc->range_exp = 2;
c8260fa8	194	devc->sr_digits = devc->digits - 3;
e5137b93 FS	195	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3KR) {
e5137b93 FS	196	devc->range_exp = 3;
c8260fa8	197	devc->sr_digits = devc->digits - 4;
e5137b93 FS	198	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30KR) {
e5137b93 FS	199	devc->range_exp = 4;
c8260fa8	200	devc->sr_digits = devc->digits - 5;
e5137b93 FS	201	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_300KR) {
e5137b93 FS	202	devc->range_exp = 5;
c8260fa8	203	devc->sr_digits = devc->digits - 6;
e5137b93 FS	204	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_3MR) {
e5137b93 FS	205	devc->range_exp = 6;
c8260fa8	206	devc->sr_digits = devc->digits - 7;
e5137b93 FS	207	} else if ((range_byte & SB1_RANGE_BLOCK) == RANGE_OHM_30MR) {
e5137b93 FS	208	devc->range_exp = 7;
c8260fa8	209	devc->sr_digits = devc->digits - 8;
e5137b93	210	} else
d2c1730a	211	return SR_ERR_DATA;
d2c1730a FS	212
	213	return SR_OK;
	214	}
	215
	216	static int parse_function_byte(struct dev_context *devc, uint8_t function_byte)
	217	{
c8260fa8	218	/* Digits / Resolution (digits must be set before range parsing) */
94cf02d0	219	if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_5_5)
c8260fa8	220	devc->digits = 6;
94cf02d0	221	else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_4_5)
c8260fa8	222	devc->digits = 5;
94cf02d0	223	else if ((function_byte & SB1_DIGITS_BLOCK) == DIGITS_3_5)
c8260fa8	224	devc->digits = 4;
94cf02d0 FS	225	else
94cf02d0 FS	226	return SR_ERR_DATA;
d2c1730a FS	227
d2c1730a FS	228	/* Function + Range */
569165c0	229	devc->measurement_mq_flag = 0;
e5137b93	230	devc->acquisition_mq_flags = 0;
d2c1730a FS	231	if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VDC) {
d2c1730a FS	232	devc->measurement_mq = SR_MQ_VOLTAGE;
569165c0	233	devc->measurement_mq_flag = SR_MQFLAG_DC;
e5137b93	234	devc->acquisition_mq_flags \|= SR_MQFLAG_DC;
d2c1730a FS	235	devc->measurement_unit = SR_UNIT_VOLT;
	236	parse_range_vdc(devc, function_byte);
	237	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_VAC) {
	238	devc->measurement_mq = SR_MQ_VOLTAGE;
569165c0	239	devc->measurement_mq_flag = SR_MQFLAG_AC;
e5137b93	240	devc->acquisition_mq_flags \|= SR_MQFLAG_AC \| SR_MQFLAG_RMS;
d2c1730a FS	241	devc->measurement_unit = SR_UNIT_VOLT;
	242	parse_range_vac(devc, function_byte);
	243	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_2WR) {
	244	devc->measurement_mq = SR_MQ_RESISTANCE;
	245	devc->measurement_unit = SR_UNIT_OHM;
	246	parse_range_ohm(devc, function_byte);
	247	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_4WR) {
	248	devc->measurement_mq = SR_MQ_RESISTANCE;
569165c0	249	devc->measurement_mq_flag = SR_MQFLAG_FOUR_WIRE;
e5137b93	250	devc->acquisition_mq_flags \|= SR_MQFLAG_FOUR_WIRE;
d2c1730a FS	251	devc->measurement_unit = SR_UNIT_OHM;
	252	parse_range_ohm(devc, function_byte);
	253	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_ADC) {
	254	devc->measurement_mq = SR_MQ_CURRENT;
569165c0	255	devc->measurement_mq_flag = SR_MQFLAG_DC;
e5137b93	256	devc->acquisition_mq_flags \|= SR_MQFLAG_DC;
d2c1730a FS	257	devc->measurement_unit = SR_UNIT_AMPERE;
	258	parse_range_a(devc, function_byte);
	259	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_AAC) {
	260	devc->measurement_mq = SR_MQ_CURRENT;
569165c0	261	devc->measurement_mq_flag = SR_MQFLAG_AC;
e5137b93	262	devc->acquisition_mq_flags \|= SR_MQFLAG_AC \| SR_MQFLAG_RMS;
d2c1730a FS	263	devc->measurement_unit = SR_UNIT_AMPERE;
	264	parse_range_a(devc, function_byte);
	265	} else if ((function_byte & SB1_FUNCTION_BLOCK) == FUNCTION_EXR) {
	266	devc->measurement_mq = SR_MQ_RESISTANCE;
	267	devc->measurement_unit = SR_UNIT_OHM;
	268	parse_range_ohm(devc, function_byte);
	269	}
	270
d2c1730a FS	271	return SR_OK;
	272	}
	273
	274	static int parse_status_byte(struct dev_context *devc, uint8_t status_byte)
	275	{
	276	devc->trigger = TRIGGER_UNDEFINED;
	277
	278	/* External Trigger */
	279	if ((status_byte & STATUS_EXT_TRIGGER) == STATUS_EXT_TRIGGER)
	280	devc->trigger = TRIGGER_EXTERNAL;
	281
	282	/* Cal RAM */
	283	if ((status_byte & STATUS_CAL_RAM) == STATUS_CAL_RAM)
	284	devc->calibration = TRUE;
	285	else
	286	devc->calibration = FALSE;
	287
	288	/* Front/Rear terminals */
	289	if ((status_byte & STATUS_FRONT_TERMINAL) == STATUS_FRONT_TERMINAL)
	290	devc->terminal = TERMINAL_FRONT;
	291	else
	292	devc->terminal = TERMINAL_REAR;
	293
	294	/* 50Hz / 60Hz */
	295	if ((status_byte & STATUS_50HZ) == STATUS_50HZ)
	296	devc->line = LINE_50HZ;
	297	else
	298	devc->line = LINE_60HZ;
	299
	300	/* Auto-Zero */
	301	if ((status_byte & STATUS_AUTO_ZERO) == STATUS_AUTO_ZERO)
	302	devc->auto_zero = TRUE;
	303	else
	304	devc->auto_zero = FALSE;
	305
	306	/* Auto-Range */
e5137b93 FS	307	if ((status_byte & STATUS_AUTO_RANGE) == STATUS_AUTO_RANGE) {
	308	devc->acquisition_mq_flags \|= SR_MQFLAG_AUTORANGE;
	309	devc->range_exp = -99;
	310	} else
	311	devc->acquisition_mq_flags &= ~SR_MQFLAG_AUTORANGE;
d2c1730a FS	312
	313	/* Internal trigger */
	314	if ((status_byte & STATUS_INT_TRIGGER) == STATUS_INT_TRIGGER)
	315	devc->trigger = TRIGGER_INTERNAL;
	316
	317	return SR_OK;
	318	}
	319
	320	static int parse_srq_byte(uint8_t sqr_byte)
	321	{
	322	(void)sqr_byte;
	323
	324	#if 0
	325	/* The ServiceReQuest register isn't used at the moment. */
	326
	327	/* PON SRQ */
	328	if ((sqr_byte & SRQ_POWER_ON) == SRQ_POWER_ON)
6ddedf5b	329	sr_spew("Power On SRQ or clear msg received");
d2c1730a FS	330
	331	/* Cal failed SRQ */
	332	if ((sqr_byte & SRQ_CAL_FAILED) == SRQ_CAL_FAILED)
6ddedf5b	333	sr_spew("CAL failed SRQ");
d2c1730a FS	334
	335	/* Keyboard SRQ */
	336	if ((sqr_byte & SRQ_KEYBORD) == SRQ_KEYBORD)
6ddedf5b	337	sr_spew("Keyboard SRQ");
d2c1730a FS	338
	339	/* Hardware error SRQ */
	340	if ((sqr_byte & SRQ_HARDWARE_ERR) == SRQ_HARDWARE_ERR)
6ddedf5b	341	sr_spew("Hardware error SRQ");
d2c1730a FS	342
	343	/* Syntax error SRQ */
	344	if ((sqr_byte & SRQ_SYNTAX_ERR) == SRQ_SYNTAX_ERR)
6ddedf5b	345	sr_spew("Syntax error SRQ");
d2c1730a FS	346
	347	/* Every reading is available to the bus SRQ */
	348	if ((sqr_byte & SRQ_BUS_AVAIL) == SRQ_BUS_AVAIL)
6ddedf5b	349	sr_spew("Every reading is available to the bus SRQ");
d2c1730a FS	350	#endif
	351
	352	return SR_OK;
	353	}
	354
	355	static int parse_error_byte(uint8_t error_byte)
	356	{
	357	int ret;
	358
	359	ret = SR_OK;
	360
	361	/* A/D link */
	362	if ((error_byte & ERROR_AD_LINK) == ERROR_AD_LINK) {
6ddedf5b	363	sr_err("Failure in the A/D link");
d2c1730a FS	364	ret = SR_ERR;
	365	}
	366
	367	/* A/D Self Test */
	368	if ((error_byte & ERROR_AD_SELF_TEST) == ERROR_AD_SELF_TEST) {
6ddedf5b	369	sr_err("A/D has failed its internal Self Test");
d2c1730a FS	370	ret = SR_ERR;
	371	}
	372
	373	/* A/D slope error */
	374	if ((error_byte & ERROR_AD_SLOPE) == ERROR_AD_SLOPE) {
6ddedf5b	375	sr_err("There has been an A/D slope error");
d2c1730a FS	376	ret = SR_ERR;
	377	}
	378
	379	/* ROM Selt Test */
	380	if ((error_byte & ERROR_ROM_SELF_TEST) == ERROR_ROM_SELF_TEST) {
6ddedf5b	381	sr_err("The ROM Self Test has failed");
d2c1730a FS	382	ret = SR_ERR;
	383	}
	384
	385	/* RAM Selt Test */
	386	if ((error_byte & ERROR_RAM_SELF_TEST) == ERROR_RAM_SELF_TEST) {
6ddedf5b	387	sr_err("The RAM Self Test has failed");
d2c1730a FS	388	ret = SR_ERR;
	389	}
	390
	391	/* Selt Test */
	392	if ((error_byte & ERROR_SELF_TEST) == ERROR_SELF_TEST) {
6ddedf5b UH	393	sr_err("Self Test: Any of the CAL RAM locations have bad "
6ddedf5b UH	394	"checksums, or a range with a bad checksum is selected");
d2c1730a FS	395	ret = SR_ERR;
	396	}
	397
	398	return ret;
	399	}
	400
	401	SR_PRIV int hp_3478a_get_status_bytes(const struct sr_dev_inst *sdi)
	402	{
	403	int ret;
	404	char *response;
	405	uint8_t function_byte, status_byte, srq_byte, error_byte;
	406	struct sr_scpi_dev_inst *scpi = sdi->conn;
	407	struct dev_context *devc = sdi->priv;
	408
	409	ret = sr_scpi_get_string(scpi, "B", &response);
	410	if (ret != SR_OK)
	411	return ret;
	412
	413	if (!response)
	414	return SR_ERR;
	415
	416	function_byte = (uint8_t)response[0];
	417	status_byte = (uint8_t)response[1];
	418	srq_byte = (uint8_t)response[2];
	419	error_byte = (uint8_t)response[3];
	420
	421	g_free(response);
	422
	423	parse_function_byte(devc, function_byte);
	424	parse_status_byte(devc, status_byte);
	425	parse_srq_byte(srq_byte);
	426	ret = parse_error_byte(error_byte);
	427
	428	return ret;
	429	}
	430
	431	static void acq_send_measurement(struct sr_dev_inst *sdi)
	432	{
	433	struct sr_datafeed_packet packet;
	434	struct sr_datafeed_analog analog;
	435	struct sr_analog_encoding encoding;
	436	struct sr_analog_meaning meaning;
	437	struct sr_analog_spec spec;
	438	struct dev_context *devc;
	439	float f;
	440
	441	devc = sdi->priv;
	442
	443	packet.type = SR_DF_ANALOG;
	444	packet.payload = &analog;
	445
c8260fa8	446	sr_analog_init(&analog, &encoding, &meaning, &spec, devc->sr_digits);
d2c1730a FS	447
	448	/* TODO: Implement NAN, depending on counts, range and value. */
	449	f = devc->measurement;
	450	analog.num_samples = 1;
	451	analog.data = &f;
	452
	453	encoding.unitsize = sizeof(float);
	454	encoding.is_float = TRUE;
c8260fa8	455	encoding.digits = devc->sr_digits;
d2c1730a FS	456
d2c1730a FS	457	meaning.mq = devc->measurement_mq;
e5137b93	458	meaning.mqflags = devc->acquisition_mq_flags;
d2c1730a FS	459	meaning.unit = devc->measurement_unit;
	460	meaning.channels = sdi->channels;
	461
c8260fa8	462	spec.spec_digits = devc->sr_digits;
d2c1730a FS	463
	464	sr_session_send(sdi, &packet);
	465	}
	466
1d9eebf4 FS	467	SR_PRIV int hp_3478a_receive_data(int fd, int revents, void *cb_data)
1d9eebf4 FS	468	{
d2c1730a FS	469	struct sr_scpi_dev_inst *scpi;
d2c1730a FS	470	struct sr_dev_inst *sdi;
1d9eebf4	471	struct dev_context *devc;
02d4db35	472	char status_register;
1d9eebf4 FS	473
1d9eebf4 FS	474	(void)fd;
d2c1730a	475	(void)revents;
1d9eebf4	476
d2c1730a	477	if (!(sdi = cb_data) \|\| !(devc = sdi->priv))
1d9eebf4 FS	478	return TRUE;
1d9eebf4 FS	479
d2c1730a	480	scpi = sdi->conn;
1d9eebf4	481
d2c1730a	482	/*
02d4db35 FS	483	* TODO: Wait for SRQ from the DMM when a new measurement is available.
	484	* For now, we don't wait for a SRQ, but just do a SPoll and
	485	* check the Data Ready bit (0x01).
	486	* This is necessary, because (1) reading a value will block the
	487	* bus until a measurement is available and (2) when switching
	488	* ranges, there could be a timeout.
d2c1730a	489	*/
02d4db35 FS	490	if (sr_scpi_gpib_spoll(scpi, &status_register) != SR_OK)
02d4db35 FS	491	return FALSE;
d07ef6f7	492	if (!(((uint8_t)status_register) & SRQ_BUS_AVAIL))
02d4db35 FS	493	return TRUE;
	494
	495	/* Get a reading from the DMM. */
	496	if (sr_scpi_get_double(scpi, NULL, &devc->measurement) != SR_OK)
d2c1730a FS	497	return FALSE;
d2c1730a FS	498
675cb86f FS	499	/* Check for overflow. */
	500	if (devc->measurement >= 9.998e+9)
	501	devc->measurement = INFINITY;
	502
d2c1730a	503	/*
02d4db35 FS	504	* This is necessary to get the actual range for the encoding digits.
	505	* Must be called after reading the value, because it resets the
	506	* status register!
d2c1730a	507	*/
02d4db35	508	if (hp_3478a_get_status_bytes(sdi) != SR_OK)
d2c1730a FS	509	return FALSE;
	510
	511	acq_send_measurement(sdi);
	512	sr_sw_limits_update_samples_read(&devc->limits, 1);
	513
	514	if (sr_sw_limits_check(&devc->limits))
	515	sr_dev_acquisition_stop(sdi);
1d9eebf4 FS	516
	517	return TRUE;
	518	}