[libsigrok.git] / src / hardware / victor-dmm / api.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2012 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/>.
 */

#include <glib.h>
#include <libusb.h>
#include <stdlib.h>
#include <string.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "protocol.h"

#define VICTOR_VID 0x1244
#define VICTOR_PID 0xd237
#define VICTOR_VENDOR "Victor"
#define VICTOR_INTERFACE 0
#define VICTOR_ENDPOINT (LIBUSB_ENDPOINT_IN | 1)

SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data);

static const uint32_t drvopts[] = {
	SR_CONF_MULTIMETER,
};

static const uint32_t scanopts[] = {
	SR_CONF_CONN,
};

static const uint32_t devopts[] = {
	SR_CONF_CONTINUOUS,
	SR_CONF_LIMIT_SAMPLES | SR_CONF_SET,
	SR_CONF_LIMIT_MSEC | SR_CONF_SET,
	SR_CONF_CONN | SR_CONF_GET,
};

static int init(struct sr_dev_driver *di, struct sr_context *sr_ctx)
{
	return std_init(sr_ctx, di, LOG_PREFIX);
}

static GSList *scan(struct sr_dev_driver *di, GSList *options)
{
	struct drv_context *drvc;
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	struct libusb_device_descriptor des;
	libusb_device **devlist;
	GSList *devices;
	int ret, i;
	char connection_id[64];

	(void)options;

	drvc = di->context;

	devices = NULL;
	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	for (i = 0; devlist[i]; i++) {
		if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
			sr_warn("Failed to get device descriptor: %s",
					libusb_error_name(ret));
			continue;
		}

		if (des.idVendor != VICTOR_VID || des.idProduct != VICTOR_PID)
			continue;

		usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));

		sdi = g_malloc0(sizeof(struct sr_dev_inst));
		sdi->status = SR_ST_INACTIVE;
		sdi->vendor = g_strdup(VICTOR_VENDOR);
		sdi->driver = di;
		sdi->connection_id = g_strdup(connection_id);
		devc = g_malloc0(sizeof(struct dev_context));
		sdi->priv = devc;

		sr_channel_new(sdi, 0, SR_CHANNEL_ANALOG, TRUE, "P1");

		sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
				libusb_get_device_address(devlist[i]), NULL);
		sdi->inst_type = SR_INST_USB;

		drvc->instances = g_slist_append(drvc->instances, sdi);
		devices = g_slist_append(devices, sdi);
	}
	libusb_free_device_list(devlist, 1);

	return devices;
}

static GSList *dev_list(const struct sr_dev_driver *di)
{
	return ((struct drv_context *)(di->context))->instances;
}

static int dev_open(struct sr_dev_inst *sdi)
{
	struct sr_dev_driver *di = sdi->driver;
	struct drv_context *drvc = di->context;
	struct sr_usb_dev_inst *usb;
	libusb_device **devlist;
	int ret, i;
	char connection_id[64];

	if (!di->context) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	usb = sdi->conn;

	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	for (i = 0; devlist[i]; i++) {
		usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
		if (strcmp(sdi->connection_id, connection_id))
			continue;
		if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
			sr_err("Failed to open device: %s.", libusb_error_name(ret));
			return SR_ERR;
		}
		break;
	}
	libusb_free_device_list(devlist, 1);
	if (!devlist[i]) {
		sr_err("Device not found.");
		return SR_ERR;
	}

	/* The device reports as HID class, so the kernel would have
	 * claimed it. */
	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
		if ((ret = libusb_detach_kernel_driver(usb->devhdl, 0)) < 0) {
			sr_err("Failed to detach kernel driver: %s.",
			       libusb_error_name(ret));
			return SR_ERR;
		}
	}

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

	return SR_OK;
}

static int dev_close(struct sr_dev_inst *sdi)
{
	struct sr_dev_driver *di = sdi->driver;
	struct sr_usb_dev_inst *usb;

	if (!di->context) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	usb = sdi->conn;

	if (!usb->devhdl)
		/*  Nothing to do. */
		return SR_OK;

	libusb_release_interface(usb->devhdl, VICTOR_INTERFACE);
	libusb_close(usb->devhdl);
	usb->devhdl = NULL;
	sdi->status = SR_ST_INACTIVE;

	return SR_OK;
}

static int cleanup(const struct sr_dev_driver *di)
{
	int ret;
	struct drv_context *drvc;

	if (!(drvc = di->context))
		/* Can get called on an unused driver, doesn't matter. */
		return SR_OK;

	ret = std_dev_clear(di, NULL);
	g_free(drvc);

	return ret;
}

static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
		const struct sr_channel_group *cg)
{
	struct sr_usb_dev_inst *usb;
	char str[128];

	(void)cg;

	switch (key) {
	case SR_CONF_CONN:
		if (!sdi || !sdi->conn)
			return SR_ERR_ARG;
		usb = sdi->conn;
		snprintf(str, 128, "%d.%d", usb->bus, usb->address);
		*data = g_variant_new_string(str);
		break;
	default:
		return SR_ERR_NA;
	}

	return SR_OK;
}

static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sdi,
		const struct sr_channel_group *cg)
{
	struct sr_dev_driver *di = sdi->driver;
	struct dev_context *devc;
	gint64 now;

	(void)cg;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR_DEV_CLOSED;

	if (!di->context) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	devc = sdi->priv;

	switch (key) {
	case SR_CONF_LIMIT_MSEC:
		devc->limit_msec = g_variant_get_uint64(data);
		now = g_get_monotonic_time() / 1000;
		devc->end_time = now + devc->limit_msec;
		break;
	case SR_CONF_LIMIT_SAMPLES:
		devc->limit_samples = g_variant_get_uint64(data);
		break;
	default:
		return SR_ERR_NA;
	}

	return SR_OK;
}

static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
		const struct sr_channel_group *cg)
{
	(void)sdi;
	(void)cg;

	switch (key) {
	case SR_CONF_SCAN_OPTIONS:
		*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
				scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
		break;
	case SR_CONF_DEVICE_OPTIONS:
		if (!sdi)
			*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
					drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
		else
			*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
					devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
		break;
	default:
		return SR_ERR_NA;
	}

	return SR_OK;
}

static void LIBUSB_CALL receive_transfer(struct libusb_transfer *transfer)
{
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	int ret;

	sdi = transfer->user_data;
	devc = sdi->priv;
	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
		/* USB device was unplugged. */
		dev_acquisition_stop(sdi, sdi);
	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
		sr_dbg("Got %d-byte packet.", transfer->actual_length);
		if (transfer->actual_length == DMM_DATA_SIZE) {
			victor_dmm_receive_data(sdi, transfer->buffer);
			if (devc->limit_samples) {
				if (devc->num_samples >= devc->limit_samples)
					dev_acquisition_stop(sdi, sdi);
			}
		}
	}
	/* Anything else is either an error or a timeout, which is fine:
	 * we were just going to send another transfer request anyway. */

	if (sdi->status == SR_ST_ACTIVE) {
		/* Send the same request again. */
		if ((ret = libusb_submit_transfer(transfer) != 0)) {
			sr_err("Unable to resubmit transfer: %s.",
			       libusb_error_name(ret));
			g_free(transfer->buffer);
			libusb_free_transfer(transfer);
			dev_acquisition_stop(sdi, sdi);
		}
	} else {
		/* This was the last transfer we're going to receive, so
		 * clean up now. */
		g_free(transfer->buffer);
		libusb_free_transfer(transfer);
	}
}

static int handle_events(int fd, int revents, void *cb_data)
{
	struct dev_context *devc;
	struct drv_context *drvc;
	struct sr_datafeed_packet packet;
	struct sr_dev_inst *sdi;
	struct sr_dev_driver *di;
	struct timeval tv;
	gint64 now;

	(void)fd;
	(void)revents;

	sdi = cb_data;
	devc = sdi->priv;
	di = sdi->driver;
	drvc = di->context;

	if (devc->limit_msec) {
		now = g_get_monotonic_time() / 1000;
		if (now > devc->end_time)
			dev_acquisition_stop(sdi, sdi);
	}

	if (sdi->status == SR_ST_STOPPING) {
		usb_source_remove(sdi->session, drvc->sr_ctx);

		dev_close(sdi);

		packet.type = SR_DF_END;
		sr_session_send(cb_data, &packet);
	}

	memset(&tv, 0, sizeof(struct timeval));
	libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
					       NULL);

	return TRUE;
}

static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
{
	struct sr_dev_driver *di = sdi->driver;
	struct dev_context *devc;
	struct drv_context *drvc = di->context;
	struct sr_usb_dev_inst *usb;
	struct libusb_transfer *transfer;
	int ret;
	unsigned char *buf;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR_DEV_CLOSED;

	if (!di->context) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	devc = sdi->priv;
	usb = sdi->conn;
	devc->cb_data = cb_data;

	/* Send header packet to the session bus. */
	std_session_send_df_header(cb_data, LOG_PREFIX);

	usb_source_add(sdi->session, drvc->sr_ctx, 100,
			handle_events, (void *)sdi);

	buf = g_malloc(DMM_DATA_SIZE);
	transfer = libusb_alloc_transfer(0);
	/* Each transfer request gets 100ms to arrive before it's restarted.
	 * The device only sends 1 transfer/second no matter how many
	 * times you ask, but we want to keep step with the USB events
	 * handling above. */
	libusb_fill_interrupt_transfer(transfer, usb->devhdl,
			VICTOR_ENDPOINT, buf, DMM_DATA_SIZE, receive_transfer,
			cb_data, 100);
	if ((ret = libusb_submit_transfer(transfer) != 0)) {
		sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
		libusb_free_transfer(transfer);
		g_free(buf);
		return SR_ERR;
	}

	return SR_OK;
}

static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
{
	struct sr_dev_driver *di = sdi->driver;
	(void)cb_data;

	if (!di->context) {
		sr_err("Driver was not initialized.");
		return SR_ERR;
	}

	if (sdi->status != SR_ST_ACTIVE) {
		sr_err("Device not active, can't stop acquisition.");
		return SR_ERR;
	}

	sdi->status = SR_ST_STOPPING;

	return SR_OK;
}

SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
	.name = "victor-dmm",
	.longname = "Victor DMMs",
	.api_version = 1,
	.init = init,
	.cleanup = cleanup,
	.scan = scan,
	.dev_list = dev_list,
	.dev_clear = NULL,
	.config_get = config_get,
	.config_set = config_set,
	.config_list = config_list,
	.dev_open = dev_open,
	.dev_close = dev_close,
	.dev_acquisition_start = dev_acquisition_start,
	.dev_acquisition_stop = dev_acquisition_stop,
	.context = NULL,
};
Commit	Line	Data
	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
	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 <glib.h>
	21	#include <libusb.h>
	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <libsigrok/libsigrok.h>
	25	#include "libsigrok-internal.h"
	26	#include "protocol.h"
	27
	28	#define VICTOR_VID 0x1244
	29	#define VICTOR_PID 0xd237
	30	#define VICTOR_VENDOR "Victor"
	31	#define VICTOR_INTERFACE 0
	32	#define VICTOR_ENDPOINT (LIBUSB_ENDPOINT_IN \| 1)
	33
	34	SR_PRIV struct sr_dev_driver victor_dmm_driver_info;
	35	static int dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data);
	36
	37	static const uint32_t drvopts[] = {
	38	SR_CONF_MULTIMETER,
	39	};
	40
	41	static const uint32_t scanopts[] = {
	42	SR_CONF_CONN,
	43	};
	44
	45	static const uint32_t devopts[] = {
	46	SR_CONF_CONTINUOUS,
	47	SR_CONF_LIMIT_SAMPLES \| SR_CONF_SET,
	48	SR_CONF_LIMIT_MSEC \| SR_CONF_SET,
	49	SR_CONF_CONN \| SR_CONF_GET,
	50	};
	51
	52	static int init(struct sr_dev_driver di, struct sr_context sr_ctx)
	53	{
	54	return std_init(sr_ctx, di, LOG_PREFIX);
	55	}
	56
	57	static GSList scan(struct sr_dev_driver di, GSList *options)
	58	{
	59	struct drv_context *drvc;
	60	struct dev_context *devc;
	61	struct sr_dev_inst *sdi;
	62	struct libusb_device_descriptor des;
	63	libusb_device **devlist;
	64	GSList *devices;
	65	int ret, i;
	66	char connection_id[64];
	67
	68	(void)options;
	69
	70	drvc = di->context;
	71
	72	devices = NULL;
	73	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	74	for (i = 0; devlist[i]; i++) {
	75	if ((ret = libusb_get_device_descriptor(devlist[i], &des)) != 0) {
	76	sr_warn("Failed to get device descriptor: %s",
	77	libusb_error_name(ret));
	78	continue;
	79	}
	80
	81	if (des.idVendor != VICTOR_VID \|\| des.idProduct != VICTOR_PID)
	82	continue;
	83
	84	usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
	85
	86	sdi = g_malloc0(sizeof(struct sr_dev_inst));
	87	sdi->status = SR_ST_INACTIVE;
	88	sdi->vendor = g_strdup(VICTOR_VENDOR);
	89	sdi->driver = di;
	90	sdi->connection_id = g_strdup(connection_id);
	91	devc = g_malloc0(sizeof(struct dev_context));
	92	sdi->priv = devc;
	93
	94	sr_channel_new(sdi, 0, SR_CHANNEL_ANALOG, TRUE, "P1");
	95
	96	sdi->conn = sr_usb_dev_inst_new(libusb_get_bus_number(devlist[i]),
	97	libusb_get_device_address(devlist[i]), NULL);
	98	sdi->inst_type = SR_INST_USB;
	99
	100	drvc->instances = g_slist_append(drvc->instances, sdi);
	101	devices = g_slist_append(devices, sdi);
	102	}
	103	libusb_free_device_list(devlist, 1);
	104
	105	return devices;
	106	}
	107
	108	static GSList dev_list(const struct sr_dev_driver di)
	109	{
	110	return ((struct drv_context *)(di->context))->instances;
	111	}
	112
	113	static int dev_open(struct sr_dev_inst *sdi)
	114	{
	115	struct sr_dev_driver *di = sdi->driver;
	116	struct drv_context *drvc = di->context;
	117	struct sr_usb_dev_inst *usb;
	118	libusb_device **devlist;
	119	int ret, i;
	120	char connection_id[64];
	121
	122	if (!di->context) {
	123	sr_err("Driver was not initialized.");
	124	return SR_ERR;
	125	}
	126
	127	usb = sdi->conn;
	128
	129	libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	130	for (i = 0; devlist[i]; i++) {
	131	usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
	132	if (strcmp(sdi->connection_id, connection_id))
	133	continue;
	134	if ((ret = libusb_open(devlist[i], &usb->devhdl))) {
	135	sr_err("Failed to open device: %s.", libusb_error_name(ret));
	136	return SR_ERR;
	137	}
	138	break;
	139	}
	140	libusb_free_device_list(devlist, 1);
	141	if (!devlist[i]) {
	142	sr_err("Device not found.");
	143	return SR_ERR;
	144	}
	145
	146	/* The device reports as HID class, so the kernel would have
	147	* claimed it. */
	148	if (libusb_kernel_driver_active(usb->devhdl, 0) == 1) {
	149	if ((ret = libusb_detach_kernel_driver(usb->devhdl, 0)) < 0) {
	150	sr_err("Failed to detach kernel driver: %s.",
	151	libusb_error_name(ret));
	152	return SR_ERR;
	153	}
	154	}
	155
	156	if ((ret = libusb_claim_interface(usb->devhdl,
	157	VICTOR_INTERFACE))) {
	158	sr_err("Failed to claim interface: %s.", libusb_error_name(ret));
	159	return SR_ERR;
	160	}
	161	sdi->status = SR_ST_ACTIVE;
	162
	163	return SR_OK;
	164	}
	165
	166	static int dev_close(struct sr_dev_inst *sdi)
	167	{
	168	struct sr_dev_driver *di = sdi->driver;
	169	struct sr_usb_dev_inst *usb;
	170
	171	if (!di->context) {
	172	sr_err("Driver was not initialized.");
	173	return SR_ERR;
	174	}
	175
	176	usb = sdi->conn;
	177
	178	if (!usb->devhdl)
	179	/* Nothing to do. */
	180	return SR_OK;
	181
	182	libusb_release_interface(usb->devhdl, VICTOR_INTERFACE);
	183	libusb_close(usb->devhdl);
	184	usb->devhdl = NULL;
	185	sdi->status = SR_ST_INACTIVE;
	186
	187	return SR_OK;
	188	}
	189
	190	static int cleanup(const struct sr_dev_driver *di)
	191	{
	192	int ret;
	193	struct drv_context *drvc;
	194
	195	if (!(drvc = di->context))
	196	/* Can get called on an unused driver, doesn't matter. */
	197	return SR_OK;
	198
	199	ret = std_dev_clear(di, NULL);
	200	g_free(drvc);
	201
	202	return ret;
	203	}
	204
	205	static int config_get(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	206	const struct sr_channel_group *cg)
	207	{
	208	struct sr_usb_dev_inst *usb;
	209	char str[128];
	210
	211	(void)cg;
	212
	213	switch (key) {
	214	case SR_CONF_CONN:
	215	if (!sdi \|\| !sdi->conn)
	216	return SR_ERR_ARG;
	217	usb = sdi->conn;
	218	snprintf(str, 128, "%d.%d", usb->bus, usb->address);
	219	*data = g_variant_new_string(str);
	220	break;
	221	default:
	222	return SR_ERR_NA;
	223	}
	224
	225	return SR_OK;
	226	}
	227
	228	static int config_set(uint32_t key, GVariant data, const struct sr_dev_inst sdi,
	229	const struct sr_channel_group *cg)
	230	{
	231	struct sr_dev_driver *di = sdi->driver;
	232	struct dev_context *devc;
	233	gint64 now;
	234
	235	(void)cg;
	236
	237	if (sdi->status != SR_ST_ACTIVE)
	238	return SR_ERR_DEV_CLOSED;
	239
	240	if (!di->context) {
	241	sr_err("Driver was not initialized.");
	242	return SR_ERR;
	243	}
	244
	245	devc = sdi->priv;
	246
	247	switch (key) {
	248	case SR_CONF_LIMIT_MSEC:
	249	devc->limit_msec = g_variant_get_uint64(data);
	250	now = g_get_monotonic_time() / 1000;
	251	devc->end_time = now + devc->limit_msec;
	252	break;
	253	case SR_CONF_LIMIT_SAMPLES:
	254	devc->limit_samples = g_variant_get_uint64(data);
	255	break;
	256	default:
	257	return SR_ERR_NA;
	258	}
	259
	260	return SR_OK;
	261	}
	262
	263	static int config_list(uint32_t key, GVariant *data, const struct sr_dev_inst sdi,
	264	const struct sr_channel_group *cg)
	265	{
	266	(void)sdi;
	267	(void)cg;
	268
	269	switch (key) {
	270	case SR_CONF_SCAN_OPTIONS:
	271	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	272	scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
	273	break;
	274	case SR_CONF_DEVICE_OPTIONS:
	275	if (!sdi)
	276	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	277	drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
	278	else
	279	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	280	devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
	281	break;
	282	default:
	283	return SR_ERR_NA;
	284	}
	285
	286	return SR_OK;
	287	}
	288
	289	static void LIBUSB_CALL receive_transfer(struct libusb_transfer *transfer)
	290	{
	291	struct dev_context *devc;
	292	struct sr_dev_inst *sdi;
	293	int ret;
	294
	295	sdi = transfer->user_data;
	296	devc = sdi->priv;
	297	if (transfer->status == LIBUSB_TRANSFER_NO_DEVICE) {
	298	/* USB device was unplugged. */
	299	dev_acquisition_stop(sdi, sdi);
	300	} else if (transfer->status == LIBUSB_TRANSFER_COMPLETED) {
	301	sr_dbg("Got %d-byte packet.", transfer->actual_length);
	302	if (transfer->actual_length == DMM_DATA_SIZE) {
	303	victor_dmm_receive_data(sdi, transfer->buffer);
	304	if (devc->limit_samples) {
	305	if (devc->num_samples >= devc->limit_samples)
	306	dev_acquisition_stop(sdi, sdi);
	307	}
	308	}
	309	}
	310	/* Anything else is either an error or a timeout, which is fine:
	311	* we were just going to send another transfer request anyway. */
	312
	313	if (sdi->status == SR_ST_ACTIVE) {
	314	/* Send the same request again. */
	315	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	316	sr_err("Unable to resubmit transfer: %s.",
	317	libusb_error_name(ret));
	318	g_free(transfer->buffer);
	319	libusb_free_transfer(transfer);
	320	dev_acquisition_stop(sdi, sdi);
	321	}
	322	} else {
	323	/* This was the last transfer we're going to receive, so
	324	* clean up now. */
	325	g_free(transfer->buffer);
	326	libusb_free_transfer(transfer);
	327	}
	328	}
	329
	330	static int handle_events(int fd, int revents, void *cb_data)
	331	{
	332	struct dev_context *devc;
	333	struct drv_context *drvc;
	334	struct sr_datafeed_packet packet;
	335	struct sr_dev_inst *sdi;
	336	struct sr_dev_driver *di;
	337	struct timeval tv;
	338	gint64 now;
	339
	340	(void)fd;
	341	(void)revents;
	342
	343	sdi = cb_data;
	344	devc = sdi->priv;
	345	di = sdi->driver;
	346	drvc = di->context;
	347
	348	if (devc->limit_msec) {
	349	now = g_get_monotonic_time() / 1000;
	350	if (now > devc->end_time)
	351	dev_acquisition_stop(sdi, sdi);
	352	}
	353
	354	if (sdi->status == SR_ST_STOPPING) {
	355	usb_source_remove(sdi->session, drvc->sr_ctx);
	356
	357	dev_close(sdi);
	358
	359	packet.type = SR_DF_END;
	360	sr_session_send(cb_data, &packet);
	361	}
	362
	363	memset(&tv, 0, sizeof(struct timeval));
	364	libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
	365	NULL);
	366
	367	return TRUE;
	368	}
	369
	370	static int dev_acquisition_start(const struct sr_dev_inst sdi, void cb_data)
	371	{
	372	struct sr_dev_driver *di = sdi->driver;
	373	struct dev_context *devc;
	374	struct drv_context *drvc = di->context;
	375	struct sr_usb_dev_inst *usb;
	376	struct libusb_transfer *transfer;
	377	int ret;
	378	unsigned char *buf;
	379
	380	if (sdi->status != SR_ST_ACTIVE)
	381	return SR_ERR_DEV_CLOSED;
	382
	383	if (!di->context) {
	384	sr_err("Driver was not initialized.");
	385	return SR_ERR;
	386	}
	387
	388	devc = sdi->priv;
	389	usb = sdi->conn;
	390	devc->cb_data = cb_data;
	391
	392	/* Send header packet to the session bus. */
	393	std_session_send_df_header(cb_data, LOG_PREFIX);
	394
	395	usb_source_add(sdi->session, drvc->sr_ctx, 100,
	396	handle_events, (void *)sdi);
	397
	398	buf = g_malloc(DMM_DATA_SIZE);
	399	transfer = libusb_alloc_transfer(0);
	400	/* Each transfer request gets 100ms to arrive before it's restarted.
	401	* The device only sends 1 transfer/second no matter how many
	402	* times you ask, but we want to keep step with the USB events
	403	* handling above. */
	404	libusb_fill_interrupt_transfer(transfer, usb->devhdl,
	405	VICTOR_ENDPOINT, buf, DMM_DATA_SIZE, receive_transfer,
	406	cb_data, 100);
	407	if ((ret = libusb_submit_transfer(transfer) != 0)) {
	408	sr_err("Unable to submit transfer: %s.", libusb_error_name(ret));
	409	libusb_free_transfer(transfer);
	410	g_free(buf);
	411	return SR_ERR;
	412	}
	413
	414	return SR_OK;
	415	}
	416
	417	static int dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data)
	418	{
	419	struct sr_dev_driver *di = sdi->driver;
	420	(void)cb_data;
	421
	422	if (!di->context) {
	423	sr_err("Driver was not initialized.");
	424	return SR_ERR;
	425	}
	426
	427	if (sdi->status != SR_ST_ACTIVE) {
	428	sr_err("Device not active, can't stop acquisition.");
	429	return SR_ERR;
	430	}
	431
	432	sdi->status = SR_ST_STOPPING;
	433
	434	return SR_OK;
	435	}
	436
	437	SR_PRIV struct sr_dev_driver victor_dmm_driver_info = {
	438	.name = "victor-dmm",
	439	.longname = "Victor DMMs",
	440	.api_version = 1,
	441	.init = init,
	442	.cleanup = cleanup,
	443	.scan = scan,
	444	.dev_list = dev_list,
	445	.dev_clear = NULL,
	446	.config_get = config_get,
	447	.config_set = config_set,
	448	.config_list = config_list,
	449	.dev_open = dev_open,
	450	.dev_close = dev_close,
	451	.dev_acquisition_start = dev_acquisition_start,
	452	.dev_acquisition_stop = dev_acquisition_stop,
	453	.context = NULL,
	454	};