[libsigrok.git] / src / hardware / uni-t-dmm / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * 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 2 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 <string.h>
#include <glib.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "protocol.h"

/*
 * Driver for various UNI-T multimeters (and rebranded ones).
 *
 * Most UNI-T DMMs can be used with two (three) different PC interface cables:
 *  - The UT-D04 USB/HID cable, old version with Hoitek HE2325U chip.
 *  - The UT-D04 USB/HID cable, new version with WCH CH9325 chip.
 *  - The UT-D02 RS232 cable.
 *
 * This driver is meant to support all USB/HID cables, and various DMMs that
 * can be attached to a PC via these cables. Currently only the UT-D04 cable
 * (new version) is supported/tested.
 * The UT-D02 RS232 cable is handled by the 'serial-dmm' driver.
 *
 * The data for one DMM packet (e.g. 14 bytes if the respective DMM uses a
 * Fortune Semiconductor FS9922-DMM4 chip) is spread across multiple
 * 8-byte chunks.
 *
 * An 8-byte chunk looks like this:
 *  - Byte 0: 0xfz, where z is the number of actual data bytes in this chunk.
 *  - Bytes 1-7: z data bytes, the rest of the bytes should be ignored.
 *
 * Example:
 *  f0 00 00 00 00 00 00 00 (no data bytes)
 *  f2 55 77 00 00 00 00 00 (2 data bytes, 0x55 and 0x77)
 *  f1 d1 00 00 00 00 00 00 (1 data byte, 0xd1)
 */

static void decode_packet(struct sr_dev_inst *sdi, const uint8_t *buf)
{
	struct dev_context *devc;
	struct dmm_info *dmm;
	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;
	float floatval;
	void *info;
	int ret;

	devc = sdi->priv;
	dmm = (struct dmm_info *)sdi->driver;
	/* Note: digits/spec_digits will be overridden by the DMM parsers. */
	sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
	info = g_malloc(dmm->info_size);

	/* Parse the protocol packet. */
	ret = dmm->packet_parse(buf, &floatval, &analog, info);
	if (ret != SR_OK) {
		sr_dbg("Invalid DMM packet, ignoring.");
		g_free(info);
		return;
	}

	/* If this DMM needs additional handling, call the resp. function. */
	if (dmm->dmm_details)
		dmm->dmm_details(&analog, info);

	g_free(info);

	/* Send a sample packet with one analog value. */
	analog.meaning->channels = sdi->channels;
	analog.num_samples = 1;
	analog.data = &floatval;
	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;
	sr_session_send(sdi, &packet);

	sr_sw_limits_update_samples_read(&devc->limits, 1);
}

static int hid_chip_init(struct sr_dev_inst *sdi, uint16_t baudrate)
{
	int ret;
	uint8_t buf[5];
	struct sr_usb_dev_inst *usb;

	usb = sdi->conn;

	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
		ret = libusb_detach_kernel_driver(usb->devhdl, 0);
		if (ret < 0) {
			sr_err("Failed to detach kernel driver: %s.",
			       libusb_error_name(ret));
			return SR_ERR;
		}
	}

	if ((ret = libusb_claim_interface(usb->devhdl, 0)) < 0) {
		sr_err("Failed to claim interface 0: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	/* Set data for the HID feature report (e.g. baudrate). */
	buf[0] = baudrate & 0xff;        /* Baudrate, LSB */
	buf[1] = (baudrate >> 8) & 0xff; /* Baudrate, MSB */
	buf[2] = 0x00;                   /* Unknown/unused (?) */
	buf[3] = 0x00;                   /* Unknown/unused (?) */
	buf[4] = 0x03;                   /* Unknown, always 0x03. */

	/* Send HID feature report to setup the baudrate/chip. */
	sr_dbg("Sending initial HID feature report.");
	sr_spew("HID init = 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x (%d baud)",
		buf[0], buf[1], buf[2], buf[3], buf[4], baudrate);
	ret = libusb_control_transfer(
		usb->devhdl, /* libusb device handle */
		LIBUSB_REQUEST_TYPE_CLASS |
		LIBUSB_RECIPIENT_INTERFACE |
		LIBUSB_ENDPOINT_OUT,
		9, /* bRequest: HID set_report */
		0x300, /* wValue: HID feature, report number 0 */
		0, /* wIndex: interface 0 */
		(unsigned char *)&buf, /* payload buffer */
		5, /* wLength: 5 bytes payload */
		1000 /* timeout (ms) */);

	if (ret < 0) {
		sr_err("HID feature report error: %s.", libusb_error_name(ret));
		return SR_ERR;
	}

	if (ret != 5) {
		/* TODO: Handle better by also sending the remaining bytes. */
		sr_err("Short packet: sent %d/5 bytes.", ret);
		return SR_ERR;
	}

	return SR_OK;
}

static void log_8byte_chunk(const uint8_t *buf)
{
	sr_spew("8-byte chunk: %02x %02x %02x %02x %02x %02x %02x %02x "
		"(%d data bytes)", buf[0], buf[1], buf[2], buf[3],
		buf[4], buf[5], buf[6], buf[7], (buf[0] & 0x0f));
}

static void log_dmm_packet(const uint8_t *buf)
{
	sr_dbg("DMM packet:   %02x %02x %02x %02x %02x %02x %02x"
	       " %02x %02x %02x %02x %02x %02x %02x",
	       buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
	       buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13]);
}

static int get_and_handle_data(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	struct dmm_info *dmm;
	uint8_t buf[CHUNK_SIZE], *pbuf;
	int i, ret, len, num_databytes_in_chunk;
	struct sr_usb_dev_inst *usb;

	devc = sdi->priv;
	dmm = (struct dmm_info *)sdi->driver;
	usb = sdi->conn;
	pbuf = devc->protocol_buf;

	/* On the first run, we need to init the HID chip. */
	if (devc->first_run) {
		if ((ret = hid_chip_init(sdi, dmm->baudrate)) != SR_OK) {
			sr_err("HID chip init failed: %d.", ret);
			return SR_ERR;
		}
		memset(pbuf, 0x00, DMM_BUFSIZE);
		devc->first_run = FALSE;
	}

	memset(&buf, 0x00, CHUNK_SIZE);

	/* Get data from EP2 using an interrupt transfer. */
	ret = libusb_interrupt_transfer(
		usb->devhdl, /* libusb device handle */
		LIBUSB_ENDPOINT_IN | 2, /* EP2, IN */
		(unsigned char *)&buf, /* receive buffer */
		CHUNK_SIZE, /* wLength */
		&len, /* actually received byte count */
		1000 /* timeout (ms) */);

	if (ret < 0) {
		sr_err("USB receive error: %s.", libusb_error_name(ret));
		return SR_ERR;
	}

	if (len != CHUNK_SIZE) {
		sr_err("Short packet: received %d/%d bytes.", len, CHUNK_SIZE);
		/* TODO: Print the bytes? */
		return SR_ERR;
	}

	log_8byte_chunk((const uint8_t *)&buf);

	/* If there are no data bytes just return (without error). */
	if (buf[0] == 0xf0)
		return SR_OK;

	devc->bufoffset = 0;

	/*
	 * Append the 1-7 data bytes of this chunk to pbuf.
	 *
	 * Special case:
	 * DMMs with Cyrustek ES51922 chip and UT71x DMMs need serial settings
	 * of 7o1. The WCH CH9325 UART to USB/HID chip used in (some
	 * versions of) the UNI-T UT-D04 cable however, will also send
	 * the parity bit to the host in the 8-byte data chunks. This bit
	 * is encoded in bit 7 of each of the 1-7 data bytes and must thus
	 * be removed in order for the actual protocol parser to work properly.
	 */
	num_databytes_in_chunk = buf[0] & 0x0f;
	for (i = 0; i < num_databytes_in_chunk; i++, devc->buflen++) {
		pbuf[devc->buflen] = buf[1 + i];
		if ((dmm->packet_parse == sr_es519xx_19200_14b_parse) ||
		    (dmm->packet_parse == sr_es519xx_19200_11b_parse) ||
		    (dmm->packet_parse == sr_es519xx_2400_11b_parse) ||
		    (dmm->packet_parse == sr_ut71x_parse)) {
			/* Mask off the parity bit. */
			pbuf[devc->buflen] &= ~(1 << 7);
		}
	}

	/* Now look for packets in that data. */
	while ((devc->buflen - devc->bufoffset) >= dmm->packet_size) {
		if (dmm->packet_valid(pbuf + devc->bufoffset)) {
			log_dmm_packet(pbuf + devc->bufoffset);
			decode_packet(sdi, pbuf + devc->bufoffset);
			devc->bufoffset += dmm->packet_size;
		} else {
			devc->bufoffset++;
		}
	}

	/* Move remaining bytes to beginning of buffer. */
	if (devc->bufoffset < devc->buflen)
		memmove(pbuf, pbuf + devc->bufoffset, devc->buflen - devc->bufoffset);
	devc->buflen -= devc->bufoffset;

	return SR_OK;
}

SR_PRIV int uni_t_dmm_receive_data(int fd, int revents, void *cb_data)
{
	int ret;
	struct sr_dev_inst *sdi;
	struct dev_context *devc;

	(void)fd;
	(void)revents;

	sdi = cb_data;
	devc = sdi->priv;

	if ((ret = get_and_handle_data(sdi)) != SR_OK)
		return FALSE;

	/* Abort acquisition if we acquired enough samples. */
	if (sr_sw_limits_check(&devc->limits))
		sr_dev_acquisition_stop(sdi);

	return TRUE;
}
Commit	Line	Data
79081ec8	1	/*
50985c20	2	* This file is part of the libsigrok project.
79081ec8	3	*
bc653a56	4	* Copyright (C) 2012-2013 Uwe Hermann <uwe@hermann-uwe.de>
79081ec8 UH	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 2 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
2ea1fdf1	17	* along with this program; if not, see <http://www.gnu.org/licenses/>.
79081ec8 UH	18	*/
79081ec8 UH	19
6ec6c43b	20	#include <config.h>
79081ec8 UH	21	#include <string.h>
79081ec8 UH	22	#include <glib.h>
c1aae900	23	#include <libsigrok/libsigrok.h>
79081ec8 UH	24	#include "libsigrok-internal.h"
	25	#include "protocol.h"
	26
	27	/*
	28	* Driver for various UNI-T multimeters (and rebranded ones).
	29	*
	30	* Most UNI-T DMMs can be used with two (three) different PC interface cables:
	31	* - The UT-D04 USB/HID cable, old version with Hoitek HE2325U chip.
	32	* - The UT-D04 USB/HID cable, new version with WCH CH9325 chip.
c8852687	33	* - The UT-D02 RS232 cable.
79081ec8	34	*
c8852687	35	* This driver is meant to support all USB/HID cables, and various DMMs that
79081ec8	36	* can be attached to a PC via these cables. Currently only the UT-D04 cable
c8852687 UH	37	* (new version) is supported/tested.
c8852687 UH	38	* The UT-D02 RS232 cable is handled by the 'serial-dmm' driver.
79081ec8 UH	39	*
	40	* The data for one DMM packet (e.g. 14 bytes if the respective DMM uses a
	41	* Fortune Semiconductor FS9922-DMM4 chip) is spread across multiple
	42	* 8-byte chunks.
	43	*
	44	* An 8-byte chunk looks like this:
	45	* - Byte 0: 0xfz, where z is the number of actual data bytes in this chunk.
	46	* - Bytes 1-7: z data bytes, the rest of the bytes should be ignored.
	47	*
	48	* Example:
	49	* f0 00 00 00 00 00 00 00 (no data bytes)
	50	* f2 55 77 00 00 00 00 00 (2 data bytes, 0x55 and 0x77)
	51	* f1 d1 00 00 00 00 00 00 (1 data byte, 0xd1)
79081ec8 UH	52	*/
79081ec8 UH	53
f0540611	54	static void decode_packet(struct sr_dev_inst sdi, const uint8_t buf)
79081ec8	55	{
bc653a56	56	struct dev_context *devc;
f0540611	57	struct dmm_info *dmm;
79081ec8	58	struct sr_datafeed_packet packet;
dff60e3c UH	59	struct sr_datafeed_analog analog;
	60	struct sr_analog_encoding encoding;
	61	struct sr_analog_meaning meaning;
	62	struct sr_analog_spec spec;
79081ec8	63	float floatval;
f0540611	64	void *info;
79081ec8 UH	65	int ret;
79081ec8 UH	66
69e19dd7	67	devc = sdi->priv;
f0540611	68	dmm = (struct dmm_info *)sdi->driver;
869c8375	69	/* Note: digits/spec_digits will be overridden by the DMM parsers. */
dff60e3c	70	sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
f0540611	71	info = g_malloc(dmm->info_size);
79081ec8 UH	72
79081ec8 UH	73	/* Parse the protocol packet. */
f0540611	74	ret = dmm->packet_parse(buf, &floatval, &analog, info);
fdbcb86d	75	if (ret != SR_OK) {
bc653a56	76	sr_dbg("Invalid DMM packet, ignoring.");
f0540611	77	g_free(info);
79081ec8 UH	78	return;
	79	}
	80
c8852687	81	/* If this DMM needs additional handling, call the resp. function. */
f0540611 ML	82	if (dmm->dmm_details)
	83	dmm->dmm_details(&analog, info);
	84
	85	g_free(info);
c8852687	86
79081ec8	87	/* Send a sample packet with one analog value. */
dff60e3c	88	analog.meaning->channels = sdi->channels;
79081ec8 UH	89	analog.num_samples = 1;
79081ec8 UH	90	analog.data = &floatval;
dff60e3c	91	packet.type = SR_DF_ANALOG;
79081ec8	92	packet.payload = &analog;
695dc859	93	sr_session_send(sdi, &packet);
79081ec8	94
8a63a406	95	sr_sw_limits_update_samples_read(&devc->limits, 1);
79081ec8 UH	96	}
79081ec8 UH	97
3ece1dff	98	static int hid_chip_init(struct sr_dev_inst *sdi, uint16_t baudrate)
79081ec8 UH	99	{
	100	int ret;
	101	uint8_t buf[5];
3ece1dff	102	struct sr_usb_dev_inst *usb;
79081ec8	103
3ece1dff	104	usb = sdi->conn;
176d785d	105
3ece1dff UH	106	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
3ece1dff UH	107	ret = libusb_detach_kernel_driver(usb->devhdl, 0);
79081ec8	108	if (ret < 0) {
d4928d71 PS	109	sr_err("Failed to detach kernel driver: %s.",
d4928d71 PS	110	libusb_error_name(ret));
79081ec8 UH	111	return SR_ERR;
79081ec8 UH	112	}
79081ec8 UH	113	}
79081ec8 UH	114
3ece1dff	115	if ((ret = libusb_claim_interface(usb->devhdl, 0)) < 0) {
d4928d71 PS	116	sr_err("Failed to claim interface 0: %s.",
d4928d71 PS	117	libusb_error_name(ret));
79081ec8 UH	118	return SR_ERR;
79081ec8 UH	119	}
79081ec8	120
bc653a56	121	/* Set data for the HID feature report (e.g. baudrate). */
79081ec8 UH	122	buf[0] = baudrate & 0xff; /* Baudrate, LSB */
	123	buf[1] = (baudrate >> 8) & 0xff; /* Baudrate, MSB */
	124	buf[2] = 0x00; /* Unknown/unused (?) */
	125	buf[3] = 0x00; /* Unknown/unused (?) */
	126	buf[4] = 0x03; /* Unknown, always 0x03. */
	127
	128	/* Send HID feature report to setup the baudrate/chip. */
	129	sr_dbg("Sending initial HID feature report.");
	130	sr_spew("HID init = 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x (%d baud)",
	131	buf[0], buf[1], buf[2], buf[3], buf[4], baudrate);
	132	ret = libusb_control_transfer(
3ece1dff	133	usb->devhdl, /* libusb device handle */
79081ec8 UH	134	LIBUSB_REQUEST_TYPE_CLASS \|
	135	LIBUSB_RECIPIENT_INTERFACE \|
	136	LIBUSB_ENDPOINT_OUT,
	137	9, /* bRequest: HID set_report */
	138	0x300, /* wValue: HID feature, report number 0 */
	139	0, /* wIndex: interface 0 */
	140	(unsigned char )&buf, / payload buffer */
	141	5, /* wLength: 5 bytes payload */
	142	1000 /* timeout (ms) */);
	143
	144	if (ret < 0) {
d4928d71	145	sr_err("HID feature report error: %s.", libusb_error_name(ret));
79081ec8 UH	146	return SR_ERR;
	147	}
	148
	149	if (ret != 5) {
	150	/* TODO: Handle better by also sending the remaining bytes. */
	151	sr_err("Short packet: sent %d/5 bytes.", ret);
	152	return SR_ERR;
	153	}
	154
79081ec8 UH	155	return SR_OK;
	156	}
	157
	158	static void log_8byte_chunk(const uint8_t *buf)
	159	{
	160	sr_spew("8-byte chunk: %02x %02x %02x %02x %02x %02x %02x %02x "
	161	"(%d data bytes)", buf[0], buf[1], buf[2], buf[3],
	162	buf[4], buf[5], buf[6], buf[7], (buf[0] & 0x0f));
	163	}
	164
	165	static void log_dmm_packet(const uint8_t *buf)
	166	{
	167	sr_dbg("DMM packet: %02x %02x %02x %02x %02x %02x %02x"
	168	" %02x %02x %02x %02x %02x %02x %02x",
	169	buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6],
	170	buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13]);
	171	}
	172
f0540611	173	static int get_and_handle_data(struct sr_dev_inst *sdi)
79081ec8	174	{
79081ec8	175	struct dev_context *devc;
f0540611	176	struct dmm_info *dmm;
bc653a56	177	uint8_t buf[CHUNK_SIZE], *pbuf;
79081ec8	178	int i, ret, len, num_databytes_in_chunk;
3ece1dff	179	struct sr_usb_dev_inst *usb;
79081ec8	180
79081ec8	181	devc = sdi->priv;
f0540611	182	dmm = (struct dmm_info *)sdi->driver;
3ece1dff	183	usb = sdi->conn;
79081ec8 UH	184	pbuf = devc->protocol_buf;
	185
	186	/* On the first run, we need to init the HID chip. */
bc653a56	187	if (devc->first_run) {
f0540611	188	if ((ret = hid_chip_init(sdi, dmm->baudrate)) != SR_OK) {
79081ec8	189	sr_err("HID chip init failed: %d.", ret);
bc653a56	190	return SR_ERR;
79081ec8	191	}
bc653a56 UH	192	memset(pbuf, 0x00, DMM_BUFSIZE);
bc653a56 UH	193	devc->first_run = FALSE;
79081ec8 UH	194	}
	195
	196	memset(&buf, 0x00, CHUNK_SIZE);
	197
	198	/* Get data from EP2 using an interrupt transfer. */
	199	ret = libusb_interrupt_transfer(
3ece1dff	200	usb->devhdl, /* libusb device handle */
79081ec8 UH	201	LIBUSB_ENDPOINT_IN \| 2, /* EP2, IN */
	202	(unsigned char )&buf, / receive buffer */
	203	CHUNK_SIZE, /* wLength */
	204	&len, /* actually received byte count */
	205	1000 /* timeout (ms) */);
	206
	207	if (ret < 0) {
d4928d71	208	sr_err("USB receive error: %s.", libusb_error_name(ret));
bc653a56	209	return SR_ERR;
79081ec8 UH	210	}
	211
	212	if (len != CHUNK_SIZE) {
	213	sr_err("Short packet: received %d/%d bytes.", len, CHUNK_SIZE);
	214	/* TODO: Print the bytes? */
bc653a56	215	return SR_ERR;
79081ec8 UH	216	}
	217
	218	log_8byte_chunk((const uint8_t *)&buf);
	219
bc653a56 UH	220	/* If there are no data bytes just return (without error). */
	221	if (buf[0] == 0xf0)
	222	return SR_OK;
	223
	224	devc->bufoffset = 0;
	225
4d7ddff7 UH	226	/*
	227	* Append the 1-7 data bytes of this chunk to pbuf.
	228	*
	229	* Special case:
8769478c UH	230	* DMMs with Cyrustek ES51922 chip and UT71x DMMs need serial settings
8769478c UH	231	* of 7o1. The WCH CH9325 UART to USB/HID chip used in (some
4d7ddff7 UH	232	* versions of) the UNI-T UT-D04 cable however, will also send
	233	* the parity bit to the host in the 8-byte data chunks. This bit
	234	* is encoded in bit 7 of each of the 1-7 data bytes and must thus
8769478c	235	* be removed in order for the actual protocol parser to work properly.
4d7ddff7	236	*/
bc653a56	237	num_databytes_in_chunk = buf[0] & 0x0f;
4d7ddff7 UH	238	for (i = 0; i < num_databytes_in_chunk; i++, devc->buflen++) {
4d7ddff7 UH	239	pbuf[devc->buflen] = buf[1 + i];
f0540611	240	if ((dmm->packet_parse == sr_es519xx_19200_14b_parse) \|\|
06f0872e UH	241	(dmm->packet_parse == sr_es519xx_19200_11b_parse) \|\|
06f0872e UH	242	(dmm->packet_parse == sr_es519xx_2400_11b_parse) \|\|
f0540611	243	(dmm->packet_parse == sr_ut71x_parse)) {
8769478c	244	/* Mask off the parity bit. */
4d7ddff7	245	pbuf[devc->buflen] &= ~(1 << 7);
8769478c	246	}
4d7ddff7	247	}
bc653a56 UH	248
bc653a56 UH	249	/* Now look for packets in that data. */
f0540611 ML	250	while ((devc->buflen - devc->bufoffset) >= dmm->packet_size) {
f0540611 ML	251	if (dmm->packet_valid(pbuf + devc->bufoffset)) {
bc653a56	252	log_dmm_packet(pbuf + devc->bufoffset);
f0540611 ML	253	decode_packet(sdi, pbuf + devc->bufoffset);
f0540611 ML	254	devc->bufoffset += dmm->packet_size;
bc653a56 UH	255	} else {
bc653a56 UH	256	devc->bufoffset++;
79081ec8	257	}
bc653a56	258	}
79081ec8	259
bc653a56	260	/* Move remaining bytes to beginning of buffer. */
f7711ed5 GS	261	if (devc->bufoffset < devc->buflen)
f7711ed5 GS	262	memmove(pbuf, pbuf + devc->bufoffset, devc->buflen - devc->bufoffset);
bc653a56	263	devc->buflen -= devc->bufoffset;
79081ec8	264
bc653a56 UH	265	return SR_OK;
	266	}
	267
f0540611	268	SR_PRIV int uni_t_dmm_receive_data(int fd, int revents, void *cb_data)
bc653a56 UH	269	{
	270	int ret;
	271	struct sr_dev_inst *sdi;
	272	struct dev_context *devc;
c8852687	273
bc653a56 UH	274	(void)fd;
bc653a56 UH	275	(void)revents;
c8852687	276
bc653a56 UH	277	sdi = cb_data;
bc653a56 UH	278	devc = sdi->priv;
c8852687	279
f0540611	280	if ((ret = get_and_handle_data(sdi)) != SR_OK)
bc653a56	281	return FALSE;
79081ec8 UH	282
79081ec8 UH	283	/* Abort acquisition if we acquired enough samples. */
8a63a406	284	if (sr_sw_limits_check(&devc->limits))
d2f7c417	285	sr_dev_acquisition_stop(sdi);
c5ffac41	286
79081ec8 UH	287	return TRUE;
79081ec8 UH	288	}