[libsigrok.git] / src / hardware / dcttech-usbrelay / api.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2021 Gerhard Sittig <gerhard.sittig@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 <hidapi.h>
#include <string.h>

#include "protocol.h"

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

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

static const uint32_t devopts[] = {
	SR_CONF_CONN | SR_CONF_GET,
	SR_CONF_ENABLED | SR_CONF_SET, /* Enable/disable all relays at once. */
};

static const uint32_t devopts_cg[] = {
	SR_CONF_ENABLED | SR_CONF_GET | SR_CONF_SET,
};

static struct sr_dev_driver dcttech_usbrelay_driver_info;

static struct sr_dev_inst *probe_device(const char *path, size_t relay_count)
{
	hid_device *hid;
	int ret;
	char serno[SERNO_LENGTH + 1];
	uint8_t curr_state;
	uint8_t report[1 + REPORT_BYTECOUNT];
	GString *txt;
	size_t snr_pos;
	char c;
	struct sr_dev_inst *sdi;
	struct dev_context *devc;
	struct channel_group_context *cgc;
	size_t idx, nr;
	struct sr_channel_group *cg;

	/* Open device, need to communicate to identify. */
	hid = hid_open_path(path);
	if (!hid)
		return NULL;

	/* Get an HID report. */
	hid_set_nonblocking(hid, 0);
	memset(&report, 0, sizeof(report));
	report[0] = REPORT_NUMBER;
	ret = hid_get_feature_report(hid, report, sizeof(report));
	hid_close(hid);
	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
		txt = sr_hexdump_new(report, sizeof(report));
		sr_spew("raw report, rc %d, bytes %s", ret, txt->str);
		sr_hexdump_free(txt);
	}
	if (ret != sizeof(report))
		return NULL;

	/*
	 * Serial number must be all printable characters. Relay state
	 * is for information only, gets re-retrieved before configure
	 * API calls (get/set).
	 */
	memset(serno, 0, sizeof(serno));
	for (snr_pos = 0; snr_pos < SERNO_LENGTH; snr_pos++) {
		c = report[1 + snr_pos];
		serno[snr_pos] = c;
		if (c < 0x20 || c > 0x7e)
			return NULL;
	}
	curr_state = report[1 + STATE_INDEX];
	sr_spew("report data, serno[%s], relays 0x%02x.", serno, curr_state);

	/*
	 * Create a device instance, create channels (groups). The
	 * caller fills in vendor, model, conn from USB enum details.
	 */
	sdi = g_malloc0(sizeof(*sdi));
	sdi->serial_num = g_strdup(serno);
	sdi->connection_id = g_strdup(path);
	devc = g_malloc0(sizeof(*devc));
	sdi->priv = devc;
	devc->hid_path = g_strdup(path);
	devc->relay_count = relay_count;
	devc->relay_mask = (1U << relay_count) - 1;
	for (idx = 0; idx < devc->relay_count; idx++) {
		nr = idx + 1;
		cg = g_malloc0(sizeof(*cg));
		cg->name = g_strdup_printf("R%zu", nr);
		cgc = g_malloc0(sizeof(*cgc));
		cg->priv = cgc;
		cgc->number = nr;
		sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
	}

	return sdi;
}

static GSList *scan(struct sr_dev_driver *di, GSList *options)
{
	const char *conn;
	GSList *devices;
	struct drv_context *drvc;
	struct hid_device_info *devs, *curdev;
	int ret;
	wchar_t *ws;
	char nonws[32];
	char *s, *endp;
	unsigned long relay_count;
	struct sr_dev_inst *sdi;

	/* Get optional conn= spec when provided. */
	conn = NULL;
	(void)sr_serial_extract_options(options, &conn, NULL);
	if (conn && !*conn)
		conn = NULL;
	/*
	 * TODO Accept different types of conn= specs? Either paths that
	 * hidapi(3) can open. Or bus.addr specs that we can check for
	 * during USB enumeration. Derive want_path, want_bus, want_addr
	 * here from the optional conn= spec.
	 */

	devices = NULL;
	drvc = di->context;
	drvc->instances = NULL;

	/*
	 * The firmware is V-USB based. The USB VID:PID identification
	 * is shared across several projects. Need to inspect the vendor
	 * and product _strings_ to actually identify the device.
	 *
	 * The USB serial number need not be present nor reliable. The
	 * HID report contains a five character string which may serve
	 * as an identification for boards (is said to differ between
	 * boards). The last byte encodes the current relays state.
	 */
	devs = hid_enumerate(VENDOR_ID, PRODUCT_ID);
	for (curdev = devs; curdev; curdev = curdev->next) {
		if (!curdev->vendor_id || !curdev->product_id)
			continue;
		if (!curdev->manufacturer_string || !curdev->product_string)
			continue;
		if (!*curdev->manufacturer_string || !*curdev->product_string)
			continue;
		if (conn && strcmp(curdev->path, conn) != 0) {
			sr_dbg("skipping %s, conn= mismatch", curdev->path);
			continue;
		}
		sr_dbg("checking %04hx:%04hx, vendor %ls, product %ls.",
			curdev->vendor_id, curdev->product_id,
			curdev->manufacturer_string, curdev->product_string);

		/* Check USB details retrieved by enumeration. */
		ws = curdev->manufacturer_string;
		if (!ws || !wcslen(ws))
			continue;
		snprintf(nonws, sizeof(nonws), "%ls", ws);
		if (strcmp(nonws, VENDOR_STRING) != 0)
			continue;
		ws = curdev->product_string;
		if (!ws || !wcslen(ws))
			continue;
		snprintf(nonws, sizeof(nonws), "%ls", ws);
		s = nonws;
		if (!g_str_has_prefix(s, PRODUCT_STRING_PREFIX))
			continue;
		s += strlen(PRODUCT_STRING_PREFIX);
		ret = sr_atoul_base(s, &relay_count, &endp, 10);
		if (ret != SR_OK || !endp || *endp)
			continue;
		sr_info("Found: HID path %s, relay count %lu.",
			curdev->path, relay_count);

		/* Identify device by communicating to it. */
		sdi = probe_device(curdev->path, relay_count);
		if (!sdi) {
			sr_warn("Failed to communicate to %s.", curdev->path);
			continue;
		}

		/* Amend driver instance from USB enumeration details. */
		sdi->vendor = g_strdup_printf("%ls", curdev->manufacturer_string);
		sdi->model = g_strdup_printf("%ls", curdev->product_string);
		sdi->driver = &dcttech_usbrelay_driver_info;
		sdi->inst_type = SR_INST_USB;

		devices = g_slist_append(devices, sdi);
	}
	hid_free_enumeration(devs);

	return devices;
}

static int dev_open(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;

	devc = sdi->priv;

	if (devc->hid_dev) {
		hid_close(devc->hid_dev);
		devc->hid_dev = NULL;
	}

	devc->hid_dev = hid_open_path(devc->hid_path);
	if (!devc->hid_dev)
		return SR_ERR_IO;

	(void)dcttech_usbrelay_update_state(sdi);

	return SR_OK;
}

static int dev_close(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;

	devc = sdi->priv;

	if (devc->hid_dev) {
		hid_close(devc->hid_dev);
		devc->hid_dev = NULL;
	}

	return SR_OK;
}

static int config_get(uint32_t key, GVariant **data,
	const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
{
	gboolean on;
	int ret;

	if (!cg) {
		switch (key) {
		case SR_CONF_CONN:
			if (!sdi->connection_id)
				return SR_ERR_NA;
			*data = g_variant_new_string(sdi->connection_id);
			return SR_OK;
		default:
			return SR_ERR_NA;
		}
	}

	switch (key) {
	case SR_CONF_ENABLED:
		ret = dcttech_usbrelay_query_cg(sdi, cg, &on);
		if (ret != SR_OK)
			return ret;
		*data = g_variant_new_boolean(on);
		return SR_OK;
	default:
		return SR_ERR_NA;
	}
}

static int config_set(uint32_t key, GVariant *data,
	const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
{
	gboolean on;

	if (!cg) {
		switch (key) {
		case SR_CONF_ENABLED:
			/* Enable/disable all channels at the same time. */
			on = g_variant_get_boolean(data);
			return dcttech_usbrelay_switch_cg(sdi, cg, on);
		default:
			return SR_ERR_NA;
		}
	} else {
		switch (key) {
		case SR_CONF_ENABLED:
			on = g_variant_get_boolean(data);
			return dcttech_usbrelay_switch_cg(sdi, cg, on);
		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)
{

	if (!cg) {
		switch (key) {
		case SR_CONF_SCAN_OPTIONS:
		case SR_CONF_DEVICE_OPTIONS:
			return STD_CONFIG_LIST(key, data, sdi, cg,
				scanopts, drvopts, devopts);
		default:
			return SR_ERR_NA;
		}
	}

	switch (key) {
	case SR_CONF_DEVICE_OPTIONS:
		*data = std_gvar_array_u32(ARRAY_AND_SIZE(devopts_cg));
		return SR_OK;
	default:
		return SR_ERR_NA;
	}
}

static struct sr_dev_driver dcttech_usbrelay_driver_info = {
	.name = "dcttech-usbrelay",
	.longname = "dcttech usbrelay",
	.api_version = 1,
	.init = std_init,
	.cleanup = std_cleanup,
	.scan = scan,
	.dev_list = std_dev_list,
	.dev_clear = std_dev_clear,
	.config_get = config_get,
	.config_set = config_set,
	.config_list = config_list,
	.dev_open = dev_open,
	.dev_close = dev_close,
	.dev_acquisition_start = std_dummy_dev_acquisition_start,
	.dev_acquisition_stop = std_dummy_dev_acquisition_stop,
	.context = NULL,
};
SR_REGISTER_DEV_DRIVER(dcttech_usbrelay_driver_info);
Commit	Line	Data
64d54a71 GS	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2021 Gerhard Sittig <gerhard.sittig@gmx.net>
	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>
321f85fb GS	21
	22	#include <hidapi.h>
	23	#include <string.h>
	24
64d54a71 GS	25	#include "protocol.h"
64d54a71 GS	26
321f85fb GS	27	static const uint32_t scanopts[] = {
	28	SR_CONF_CONN,
	29	};
	30
	31	static const uint32_t drvopts[] = {
	32	SR_CONF_MULTIPLEXER,
	33	};
	34
	35	static const uint32_t devopts[] = {
	36	SR_CONF_CONN \| SR_CONF_GET,
	37	SR_CONF_ENABLED \| SR_CONF_SET, /* Enable/disable all relays at once. */
	38	};
	39
	40	static const uint32_t devopts_cg[] = {
	41	SR_CONF_ENABLED \| SR_CONF_GET \| SR_CONF_SET,
	42	};
	43
64d54a71 GS	44	static struct sr_dev_driver dcttech_usbrelay_driver_info;
64d54a71 GS	45
321f85fb GS	46	static struct sr_dev_inst probe_device(const char path, size_t relay_count)
	47	{
	48	hid_device *hid;
	49	int ret;
	50	char serno[SERNO_LENGTH + 1];
	51	uint8_t curr_state;
	52	uint8_t report[1 + REPORT_BYTECOUNT];
	53	GString *txt;
	54	size_t snr_pos;
	55	char c;
	56	struct sr_dev_inst *sdi;
	57	struct dev_context *devc;
	58	struct channel_group_context *cgc;
	59	size_t idx, nr;
	60	struct sr_channel_group *cg;
	61
	62	/* Open device, need to communicate to identify. */
	63	hid = hid_open_path(path);
	64	if (!hid)
	65	return NULL;
	66
	67	/* Get an HID report. */
	68	hid_set_nonblocking(hid, 0);
	69	memset(&report, 0, sizeof(report));
	70	report[0] = REPORT_NUMBER;
	71	ret = hid_get_feature_report(hid, report, sizeof(report));
	72	hid_close(hid);
	73	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
	74	txt = sr_hexdump_new(report, sizeof(report));
	75	sr_spew("raw report, rc %d, bytes %s", ret, txt->str);
	76	sr_hexdump_free(txt);
	77	}
	78	if (ret != sizeof(report))
	79	return NULL;
	80
	81	/*
	82	* Serial number must be all printable characters. Relay state
	83	* is for information only, gets re-retrieved before configure
	84	* API calls (get/set).
	85	*/
	86	memset(serno, 0, sizeof(serno));
	87	for (snr_pos = 0; snr_pos < SERNO_LENGTH; snr_pos++) {
	88	c = report[1 + snr_pos];
	89	serno[snr_pos] = c;
	90	if (c < 0x20 \|\| c > 0x7e)
	91	return NULL;
	92	}
	93	curr_state = report[1 + STATE_INDEX];
	94	sr_spew("report data, serno[%s], relays 0x%02x.", serno, curr_state);
	95
	96	/*
	97	* Create a device instance, create channels (groups). The
	98	* caller fills in vendor, model, conn from USB enum details.
	99	*/
	100	sdi = g_malloc0(sizeof(*sdi));
e333a40c GS	101	sdi->serial_num = g_strdup(serno);
e333a40c GS	102	sdi->connection_id = g_strdup(path);
321f85fb GS	103	devc = g_malloc0(sizeof(*devc));
	104	sdi->priv = devc;
	105	devc->hid_path = g_strdup(path);
	106	devc->relay_count = relay_count;
	107	devc->relay_mask = (1U << relay_count) - 1;
	108	for (idx = 0; idx < devc->relay_count; idx++) {
	109	nr = idx + 1;
	110	cg = g_malloc0(sizeof(*cg));
	111	cg->name = g_strdup_printf("R%zu", nr);
	112	cgc = g_malloc0(sizeof(*cgc));
	113	cg->priv = cgc;
	114	cgc->number = nr;
	115	sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
	116	}
	117
	118	return sdi;
	119	}
	120
64d54a71 GS	121	static GSList scan(struct sr_dev_driver di, GSList *options)
64d54a71 GS	122	{
321f85fb	123	const char *conn;
64d54a71	124	GSList *devices;
321f85fb GS	125	struct drv_context *drvc;
	126	struct hid_device_info devs, curdev;
	127	int ret;
	128	wchar_t *ws;
	129	char nonws[32];
	130	char s, endp;
	131	unsigned long relay_count;
	132	struct sr_dev_inst *sdi;
	133
	134	/* Get optional conn= spec when provided. */
	135	conn = NULL;
	136	(void)sr_serial_extract_options(options, &conn, NULL);
	137	if (conn && !*conn)
	138	conn = NULL;
	139	/*
	140	* TODO Accept different types of conn= specs? Either paths that
	141	* hidapi(3) can open. Or bus.addr specs that we can check for
	142	* during USB enumeration. Derive want_path, want_bus, want_addr
	143	* here from the optional conn= spec.
	144	*/
64d54a71 GS	145
	146	devices = NULL;
	147	drvc = di->context;
	148	drvc->instances = NULL;
	149
321f85fb GS	150	/*
	151	* The firmware is V-USB based. The USB VID:PID identification
	152	* is shared across several projects. Need to inspect the vendor
	153	* and product _strings_ to actually identify the device.
	154	*
	155	* The USB serial number need not be present nor reliable. The
	156	* HID report contains a five character string which may serve
	157	* as an identification for boards (is said to differ between
	158	* boards). The last byte encodes the current relays state.
	159	*/
	160	devs = hid_enumerate(VENDOR_ID, PRODUCT_ID);
	161	for (curdev = devs; curdev; curdev = curdev->next) {
	162	if (!curdev->vendor_id \|\| !curdev->product_id)
	163	continue;
	164	if (!curdev->manufacturer_string \|\| !curdev->product_string)
	165	continue;
	166	if (!curdev->manufacturer_string \|\| !curdev->product_string)
	167	continue;
	168	if (conn && strcmp(curdev->path, conn) != 0) {
	169	sr_dbg("skipping %s, conn= mismatch", curdev->path);
	170	continue;
	171	}
	172	sr_dbg("checking %04hx:%04hx, vendor %ls, product %ls.",
	173	curdev->vendor_id, curdev->product_id,
	174	curdev->manufacturer_string, curdev->product_string);
	175
	176	/* Check USB details retrieved by enumeration. */
	177	ws = curdev->manufacturer_string;
	178	if (!ws \|\| !wcslen(ws))
	179	continue;
	180	snprintf(nonws, sizeof(nonws), "%ls", ws);
	181	if (strcmp(nonws, VENDOR_STRING) != 0)
	182	continue;
	183	ws = curdev->product_string;
	184	if (!ws \|\| !wcslen(ws))
	185	continue;
	186	snprintf(nonws, sizeof(nonws), "%ls", ws);
	187	s = nonws;
	188	if (!g_str_has_prefix(s, PRODUCT_STRING_PREFIX))
	189	continue;
	190	s += strlen(PRODUCT_STRING_PREFIX);
	191	ret = sr_atoul_base(s, &relay_count, &endp, 10);
	192	if (ret != SR_OK \|\| !endp \|\| *endp)
	193	continue;
	194	sr_info("Found: HID path %s, relay count %lu.",
	195	curdev->path, relay_count);
	196
	197	/* Identify device by communicating to it. */
	198	sdi = probe_device(curdev->path, relay_count);
	199	if (!sdi) {
	200	sr_warn("Failed to communicate to %s.", curdev->path);
	201	continue;
	202	}
	203
	204	/* Amend driver instance from USB enumeration details. */
	205	sdi->vendor = g_strdup_printf("%ls", curdev->manufacturer_string);
	206	sdi->model = g_strdup_printf("%ls", curdev->product_string);
321f85fb GS	207	sdi->driver = &dcttech_usbrelay_driver_info;
	208	sdi->inst_type = SR_INST_USB;
	209
	210	devices = g_slist_append(devices, sdi);
	211	}
	212	hid_free_enumeration(devs);
64d54a71 GS	213
	214	return devices;
	215	}
	216
	217	static int dev_open(struct sr_dev_inst *sdi)
	218	{
321f85fb GS	219	struct dev_context *devc;
	220
	221	devc = sdi->priv;
	222
	223	if (devc->hid_dev) {
	224	hid_close(devc->hid_dev);
	225	devc->hid_dev = NULL;
	226	}
64d54a71	227
321f85fb GS	228	devc->hid_dev = hid_open_path(devc->hid_path);
	229	if (!devc->hid_dev)
	230	return SR_ERR_IO;
	231
	232	(void)dcttech_usbrelay_update_state(sdi);
64d54a71 GS	233
	234	return SR_OK;
	235	}
	236
	237	static int dev_close(struct sr_dev_inst *sdi)
	238	{
321f85fb GS	239	struct dev_context *devc;
	240
	241	devc = sdi->priv;
64d54a71	242
321f85fb GS	243	if (devc->hid_dev) {
	244	hid_close(devc->hid_dev);
	245	devc->hid_dev = NULL;
	246	}
64d54a71 GS	247
	248	return SR_OK;
	249	}
	250
	251	static int config_get(uint32_t key, GVariant **data,
	252	const struct sr_dev_inst sdi, const struct sr_channel_group cg)
	253	{
321f85fb	254	gboolean on;
64d54a71 GS	255	int ret;
64d54a71 GS	256
321f85fb GS	257	if (!cg) {
	258	switch (key) {
	259	case SR_CONF_CONN:
e333a40c	260	if (!sdi->connection_id)
321f85fb	261	return SR_ERR_NA;
e333a40c	262	*data = g_variant_new_string(sdi->connection_id);
321f85fb GS	263	return SR_OK;
	264	default:
	265	return SR_ERR_NA;
	266	}
	267	}
64d54a71	268
64d54a71	269	switch (key) {
321f85fb GS	270	case SR_CONF_ENABLED:
	271	ret = dcttech_usbrelay_query_cg(sdi, cg, &on);
	272	if (ret != SR_OK)
	273	return ret;
	274	*data = g_variant_new_boolean(on);
	275	return SR_OK;
64d54a71 GS	276	default:
	277	return SR_ERR_NA;
	278	}
64d54a71 GS	279	}
	280
	281	static int config_set(uint32_t key, GVariant *data,
	282	const struct sr_dev_inst sdi, const struct sr_channel_group cg)
	283	{
321f85fb GS	284	gboolean on;
	285
	286	if (!cg) {
	287	switch (key) {
	288	case SR_CONF_ENABLED:
	289	/* Enable/disable all channels at the same time. */
	290	on = g_variant_get_boolean(data);
	291	return dcttech_usbrelay_switch_cg(sdi, cg, on);
	292	default:
	293	return SR_ERR_NA;
	294	}
	295	} else {
	296	switch (key) {
	297	case SR_CONF_ENABLED:
	298	on = g_variant_get_boolean(data);
	299	return dcttech_usbrelay_switch_cg(sdi, cg, on);
	300	default:
	301	return SR_ERR_NA;
	302	}
64d54a71 GS	303	}
64d54a71 GS	304
321f85fb	305	return SR_OK;
64d54a71 GS	306	}
	307
	308	static int config_list(uint32_t key, GVariant **data,
	309	const struct sr_dev_inst sdi, const struct sr_channel_group cg)
	310	{
64d54a71	311
321f85fb GS	312	if (!cg) {
	313	switch (key) {
	314	case SR_CONF_SCAN_OPTIONS:
	315	case SR_CONF_DEVICE_OPTIONS:
	316	return STD_CONFIG_LIST(key, data, sdi, cg,
	317	scanopts, drvopts, devopts);
	318	default:
	319	return SR_ERR_NA;
	320	}
	321	}
64d54a71	322
64d54a71	323	switch (key) {
321f85fb GS	324	case SR_CONF_DEVICE_OPTIONS:
	325	*data = std_gvar_array_u32(ARRAY_AND_SIZE(devopts_cg));
	326	return SR_OK;
64d54a71 GS	327	default:
	328	return SR_ERR_NA;
	329	}
64d54a71 GS	330	}
	331
	332	static struct sr_dev_driver dcttech_usbrelay_driver_info = {
	333	.name = "dcttech-usbrelay",
	334	.longname = "dcttech usbrelay",
	335	.api_version = 1,
	336	.init = std_init,
	337	.cleanup = std_cleanup,
	338	.scan = scan,
	339	.dev_list = std_dev_list,
	340	.dev_clear = std_dev_clear,
	341	.config_get = config_get,
	342	.config_set = config_set,
	343	.config_list = config_list,
	344	.dev_open = dev_open,
	345	.dev_close = dev_close,
321f85fb GS	346	.dev_acquisition_start = std_dummy_dev_acquisition_start,
321f85fb GS	347	.dev_acquisition_stop = std_dummy_dev_acquisition_stop,
64d54a71 GS	348	.context = NULL,
	349	};
	350	SR_REGISTER_DEV_DRIVER(dcttech_usbrelay_driver_info);