[libsigrok.git] / src / std.c

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

/**
 * @file
 *
 * Standard API helper functions.
 *
 * @internal
 */

#include <config.h>
#include <glib.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "scpi.h"

#define LOG_PREFIX "std"

/**
 * Standard sr_driver_init() API helper.
 *
 * This function can be used to simplify most driver's init() API callback.
 *
 * It creates a new 'struct drv_context' (drvc), assigns sr_ctx to it, and
 * then 'drvc' is assigned to the 'struct sr_dev_driver' (di) that is passed.
 *
 * @param di The driver instance to use.
 * @param sr_ctx The libsigrok context to assign.
 *
 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
 */
SR_PRIV int std_init(struct sr_dev_driver *di, struct sr_context *sr_ctx)
{
	struct drv_context *drvc;

	drvc = g_malloc0(sizeof(struct drv_context));
	drvc->sr_ctx = sr_ctx;
	drvc->instances = NULL;
	di->context = drvc;

	return SR_OK;
}

/**
 * Standard driver cleanup() callback API helper
 *
 * @param di The driver instance to use.
 *
 * Frees all device instances by calling sr_dev_clear() and then releases any
 * resources allocated by std_init().
 *
 * @retval SR_OK Success
 * @retval SR_ERR_ARG Invalid driver
 *
*/
SR_PRIV int std_cleanup(const struct sr_dev_driver *di)
{
	int ret;

	ret = sr_dev_clear(di);
	g_free(di->context);

	return ret;
}

/**
 * Standard API helper for sending an SR_DF_HEADER packet.
 *
 * This function can be used to simplify most driver's
 * dev_acquisition_start() API callback.
 *
 * @param sdi The device instance to use.
 *
 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
 *         SR_ERR upon other errors.
 */
SR_PRIV int std_session_send_df_header(const struct sr_dev_inst *sdi)
{
	const char *prefix = (sdi->driver) ? sdi->driver->name : "unknown";
	int ret;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_header header;

	/* Send header packet to the session bus. */
	sr_dbg("%s: Sending SR_DF_HEADER packet.", prefix);
	packet.type = SR_DF_HEADER;
	packet.payload = (uint8_t *)&header;
	header.feed_version = 1;
	gettimeofday(&header.starttime, NULL);

	if ((ret = sr_session_send(sdi, &packet)) < 0) {
		sr_err("%s: Failed to send header packet: %d.", prefix, ret);
		return ret;
	}

	return SR_OK;
}

/**
 * Standard API helper for sending an SR_DF_END packet.
 *
 * @param sdi The device instance to use. Must not be NULL.
 *
 * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
 *         SR_ERR upon other errors.
 */
SR_PRIV int std_session_send_df_end(const struct sr_dev_inst *sdi)
{
	const char *prefix = (sdi->driver) ? sdi->driver->name : "unknown";
	int ret;
	struct sr_datafeed_packet packet;

	if (!sdi)
		return SR_ERR_ARG;

	sr_dbg("%s: Sending SR_DF_END packet.", prefix);

	packet.type = SR_DF_END;
	packet.payload = NULL;

	if ((ret = sr_session_send(sdi, &packet)) < 0) {
		sr_err("%s: Failed to send SR_DF_END packet: %d.", prefix, ret);
		return ret;
	}

	return SR_OK;
}

#ifdef HAVE_LIBSERIALPORT

/**
 * Standard serial driver dev_open() helper.
 *
 * This function can be used to implement the dev_open() driver API
 * callback in drivers that use a serial port. The port is opened
 * with the SERIAL_RDWR flag.
 *
 * If the open succeeded, the status field of the given sdi is set
 * to SR_ST_ACTIVE.
 *
 * @retval SR_OK Success.
 * @retval SR_ERR Serial port open failed.
 */
SR_PRIV int std_serial_dev_open(struct sr_dev_inst *sdi)
{
	struct sr_serial_dev_inst *serial;

	serial = sdi->conn;
	if (serial_open(serial, SERIAL_RDWR) != SR_OK)
		return SR_ERR;

	sdi->status = SR_ST_ACTIVE;

	return SR_OK;
}

/**
 * Standard serial driver dev_close() helper.
 *
 * This function can be used to implement the dev_close() driver API
 * callback in drivers that use a serial port.
 *
 * After closing the port, the status field of the given sdi is set
 * to SR_ST_INACTIVE.
 *
 * @retval SR_OK Success.
 */
SR_PRIV int std_serial_dev_close(struct sr_dev_inst *sdi)
{
	struct sr_serial_dev_inst *serial;

	serial = sdi->conn;
	if (serial && sdi->status == SR_ST_ACTIVE) {
		serial_close(serial);
		sdi->status = SR_ST_INACTIVE;
	}

	return SR_OK;
}

/**
 * Standard sr_session_stop() API helper.
 *
 * This function can be used to simplify most (serial port based) driver's
 * dev_acquisition_stop() API callback.
 *
 * @param sdi The device instance for which acquisition should stop.
 *            Must not be NULL.
 *
 * @retval SR_OK Success.
 * @retval SR_ERR_ARG Invalid arguments.
 * @retval SR_ERR_DEV_CLOSED Device is closed.
 * @retval SR_ERR Other errors.
 */
SR_PRIV int std_serial_dev_acquisition_stop(struct sr_dev_inst *sdi)
{
	struct sr_serial_dev_inst *serial = sdi->conn;
	const char *prefix = sdi->driver->name;
	int ret;

	if ((ret = serial_source_remove(sdi->session, serial)) < 0) {
		sr_err("%s: Failed to remove source: %d.", prefix, ret);
		return ret;
	}

	if ((ret = sdi->driver->dev_close(sdi)) < 0) {
		sr_err("%s: Failed to close device: %d.", prefix, ret);
		return ret;
	}

	std_session_send_df_end(sdi);

	return SR_OK;
}

#endif

/**
 * Standard driver dev_clear() helper.
 *
 * Clear driver, this means, close all instances.
 *
 * This function can be used to implement the dev_clear() driver API
 * callback. dev_close() is called before every sr_dev_inst is cleared.
 *
 * The only limitation is driver-specific device contexts (sdi->priv).
 * These are freed, but any dynamic allocation within structs stored
 * there cannot be freed.
 *
 * @param driver The driver which will have its instances released.
 * @param clear_private If not NULL, this points to a function called
 * with sdi->priv as argument. The function can then clear any device
 * instance-specific resources kept there. It must also clear the struct
 * pointed to by sdi->priv.
 *
 * @return SR_OK on success.
 */
SR_PRIV int std_dev_clear(const struct sr_dev_driver *driver,
		std_dev_clear_callback clear_private)
{
	struct drv_context *drvc;
	struct sr_dev_inst *sdi;
	GSList *l;
	int ret;

	if (!(drvc = driver->context))
		/* Driver was never initialized, nothing to do. */
		return SR_OK;

	ret = SR_OK;
	for (l = drvc->instances; l; l = l->next) {
		if (!(sdi = l->data)) {
			ret = SR_ERR_BUG;
			continue;
		}
		if (driver->dev_close)
			driver->dev_close(sdi);

		if (sdi->conn) {
#ifdef HAVE_LIBSERIALPORT
			if (sdi->inst_type == SR_INST_SERIAL)
				sr_serial_dev_inst_free(sdi->conn);
#endif
#ifdef HAVE_LIBUSB_1_0
			if (sdi->inst_type == SR_INST_USB)
				sr_usb_dev_inst_free(sdi->conn);
#endif
			if (sdi->inst_type == SR_INST_SCPI)
				sr_scpi_free(sdi->conn);
			if (sdi->inst_type == SR_INST_MODBUS)
				sr_modbus_free(sdi->conn);
		}
		if (clear_private)
			/* The helper function is responsible for freeing
			 * its own sdi->priv! */
			clear_private(sdi->priv);
		else
			g_free(sdi->priv);

		sr_dev_inst_free(sdi);
	}

	g_slist_free(drvc->instances);
	drvc->instances = NULL;

	return ret;
}

/**
 * Standard implementation for the driver dev_list() callback
 *
 * This function can be used as the dev_list callback by most drivers that use
 * the standard helper functions. It returns the devices contained in the driver
 * context instances list.
 *
 * @param di The driver instance to use.
 *
 * @return The list of devices/instances of this driver, or NULL upon errors
 *         or if the list is empty.
 */
SR_PRIV GSList *std_dev_list(const struct sr_dev_driver *di)
{
	struct drv_context *drvc = di->context;

	return drvc->instances;
}

/**
 * Standard scan() callback API helper.
 *
 * This function can be used to perform common tasks required by a driver's
 * scan() callback. It will initialize the driver for each device on the list
 * and add the devices on the list to the driver's device instance list.
 * Usually it should be used as the last step in the scan() callback, right
 * before returning.
 *
 * Note: This function can only be used if std_init() has been called
 * previously by the driver.
 *
 * Example:
 * @code{c}
 * static GSList *scan(struct sr_dev_driver *di, GSList *options)
 * {
 *     struct GSList *device;
 *     struct sr_dev_inst *sdi;
 *
 *     sdi = g_new0(sr_dev_inst, 1);
 *     sdi->vendor = ...;
 *     ...
 *     devices = g_slist_append(devices, sdi);
 *     ...
 *     return std_scan_complete(di, devices);
 * }
 * @endcode
 *
 * @param di The driver instance to use. Must not be NULL.
 * @param devices List of newly discovered devices (struct sr_dev_inst).
 *
 * @return The @p devices list.
 */
SR_PRIV GSList *std_scan_complete(struct sr_dev_driver *di, GSList *devices)
{
	struct drv_context *drvc;
	GSList *l;

	if (!di) {
		sr_err("Invalid driver instance (di), cannot complete scan.");
		return NULL;
	}

	drvc = di->context;

	for (l = devices; l; l = l->next) {
		struct sr_dev_inst *sdi = l->data;
		if (!sdi) {
			sr_err("Invalid driver instance, cannot complete scan.");
			return NULL;
		}
		sdi->driver = di;
	}

	drvc->instances = g_slist_concat(drvc->instances, g_slist_copy(devices));

	return devices;
}
Commit	Line	Data
063e7aef	1	/*
50985c20	2	* This file is part of the libsigrok project.
063e7aef UH	3	*
	4	* Copyright (C) 2013 Uwe Hermann <uwe@hermann-uwe.de>
	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/>.
063e7aef UH	18	*/
063e7aef UH	19
d9251a2c UH	20	/**
	21	* @file
	22	*
	23	* Standard API helper functions.
	24	*
	25	* @internal
	26	*/
04cb9157	27
6ec6c43b	28	#include <config.h>
063e7aef	29	#include <glib.h>
c1aae900	30	#include <libsigrok/libsigrok.h>
063e7aef	31	#include "libsigrok-internal.h"
5a1afc09	32	#include "scpi.h"
063e7aef	33
3544f848 ML	34	#define LOG_PREFIX "std"
3544f848 ML	35
063e7aef UH	36	/**
	37	* Standard sr_driver_init() API helper.
	38	*
6078d2c9	39	* This function can be used to simplify most driver's init() API callback.
063e7aef UH	40	*
	41	* It creates a new 'struct drv_context' (drvc), assigns sr_ctx to it, and
	42	* then 'drvc' is assigned to the 'struct sr_dev_driver' (di) that is passed.
	43	*
063e7aef	44	* @param di The driver instance to use.
1f8f5bc0	45	* @param sr_ctx The libsigrok context to assign.
063e7aef	46	*
91219afc	47	* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments.
063e7aef	48	*/
c45c32ce	49	SR_PRIV int std_init(struct sr_dev_driver di, struct sr_context sr_ctx)
063e7aef UH	50	{
	51	struct drv_context *drvc;
	52
91219afc	53	drvc = g_malloc0(sizeof(struct drv_context));
063e7aef	54	drvc->sr_ctx = sr_ctx;
c2523f22	55	drvc->instances = NULL;
41812aca	56	di->context = drvc;
063e7aef UH	57
	58	return SR_OK;
	59	}
4afdfd46	60
700d6b64 LPC	61	/**
	62	* Standard driver cleanup() callback API helper
	63	*
	64	* @param di The driver instance to use.
	65	*
	66	* Frees all device instances by calling sr_dev_clear() and then releases any
	67	* resources allocated by std_init().
	68	*
	69	* @retval SR_OK Success
	70	* @retval SR_ERR_ARG Invalid driver
	71	*
	72	*/
	73	SR_PRIV int std_cleanup(const struct sr_dev_driver *di)
	74	{
	75	int ret;
	76
	77	ret = sr_dev_clear(di);
	78	g_free(di->context);
	79
	80	return ret;
	81	}
	82
4afdfd46 UH	83	/**
	84	* Standard API helper for sending an SR_DF_HEADER packet.
	85	*
	86	* This function can be used to simplify most driver's
6078d2c9	87	* dev_acquisition_start() API callback.
4afdfd46 UH	88	*
4afdfd46 UH	89	* @param sdi The device instance to use.
4afdfd46 UH	90	*
	91	* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
	92	* SR_ERR upon other errors.
	93	*/
bee2b016	94	SR_PRIV int std_session_send_df_header(const struct sr_dev_inst *sdi)
4afdfd46	95	{
23630316	96	const char *prefix = (sdi->driver) ? sdi->driver->name : "unknown";
4afdfd46 UH	97	int ret;
	98	struct sr_datafeed_packet packet;
	99	struct sr_datafeed_header header;
	100
4afdfd46	101	/* Send header packet to the session bus. */
ac2926b3	102	sr_dbg("%s: Sending SR_DF_HEADER packet.", prefix);
4afdfd46 UH	103	packet.type = SR_DF_HEADER;
	104	packet.payload = (uint8_t *)&header;
	105	header.feed_version = 1;
	106	gettimeofday(&header.starttime, NULL);
	107
	108	if ((ret = sr_session_send(sdi, &packet)) < 0) {
ac2926b3	109	sr_err("%s: Failed to send header packet: %d.", prefix, ret);
4afdfd46 UH	110	return ret;
	111	}
	112
	113	return SR_OK;
	114	}
cd2f0fe2	115
3be42bc2 UH	116	/**
	117	* Standard API helper for sending an SR_DF_END packet.
	118	*
	119	* @param sdi The device instance to use. Must not be NULL.
3be42bc2 UH	120	*
	121	* @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
	122	* SR_ERR upon other errors.
	123	*/
bee2b016	124	SR_PRIV int std_session_send_df_end(const struct sr_dev_inst *sdi)
3be42bc2	125	{
23630316	126	const char *prefix = (sdi->driver) ? sdi->driver->name : "unknown";
3be42bc2 UH	127	int ret;
	128	struct sr_datafeed_packet packet;
	129
bee2b016	130	if (!sdi)
3be42bc2 UH	131	return SR_ERR_ARG;
	132
	133	sr_dbg("%s: Sending SR_DF_END packet.", prefix);
	134
	135	packet.type = SR_DF_END;
	136	packet.payload = NULL;
	137
	138	if ((ret = sr_session_send(sdi, &packet)) < 0) {
	139	sr_err("%s: Failed to send SR_DF_END packet: %d.", prefix, ret);
	140	return ret;
	141	}
	142
	143	return SR_OK;
	144	}
	145
c4f2dfd0 UH	146	#ifdef HAVE_LIBSERIALPORT
c4f2dfd0 UH	147
813aab69	148	/**
23dc6661 BV	149	* Standard serial driver dev_open() helper.
	150	*
	151	* This function can be used to implement the dev_open() driver API
	152	* callback in drivers that use a serial port. The port is opened
6c592ece	153	* with the SERIAL_RDWR flag.
23dc6661 BV	154	*
	155	* If the open succeeded, the status field of the given sdi is set
	156	* to SR_ST_ACTIVE.
	157	*
	158	* @retval SR_OK Success.
	159	* @retval SR_ERR Serial port open failed.
	160	*/
	161	SR_PRIV int std_serial_dev_open(struct sr_dev_inst *sdi)
	162	{
	163	struct sr_serial_dev_inst *serial;
	164
	165	serial = sdi->conn;
6c592ece	166	if (serial_open(serial, SERIAL_RDWR) != SR_OK)
23dc6661 BV	167	return SR_ERR;
	168
	169	sdi->status = SR_ST_ACTIVE;
	170
	171	return SR_OK;
	172	}
	173
813aab69	174	/**
1e7134dc BV	175	* Standard serial driver dev_close() helper.
	176	*
	177	* This function can be used to implement the dev_close() driver API
	178	* callback in drivers that use a serial port.
	179	*
	180	* After closing the port, the status field of the given sdi is set
	181	* to SR_ST_INACTIVE.
	182	*
	183	* @retval SR_OK Success.
	184	*/
	185	SR_PRIV int std_serial_dev_close(struct sr_dev_inst *sdi)
	186	{
	187	struct sr_serial_dev_inst *serial;
	188
	189	serial = sdi->conn;
	190	if (serial && sdi->status == SR_ST_ACTIVE) {
	191	serial_close(serial);
	192	sdi->status = SR_ST_INACTIVE;
	193	}
	194
	195	return SR_OK;
	196	}
	197
813aab69	198	/**
cd2f0fe2 UH	199	* Standard sr_session_stop() API helper.
	200	*
	201	* This function can be used to simplify most (serial port based) driver's
6078d2c9	202	* dev_acquisition_stop() API callback.
cd2f0fe2 UH	203	*
	204	* @param sdi The device instance for which acquisition should stop.
	205	* Must not be NULL.
cd2f0fe2	206	*
1477a9a6 MH	207	* @retval SR_OK Success.
	208	* @retval SR_ERR_ARG Invalid arguments.
	209	* @retval SR_ERR_DEV_CLOSED Device is closed.
	210	* @retval SR_ERR Other errors.
cd2f0fe2	211	*/
1b38775b	212	SR_PRIV int std_serial_dev_acquisition_stop(struct sr_dev_inst *sdi)
cd2f0fe2	213	{
15f96409	214	struct sr_serial_dev_inst *serial = sdi->conn;
bee2b016	215	const char *prefix = sdi->driver->name;
cd2f0fe2	216	int ret;
cd2f0fe2	217
102f1239	218	if ((ret = serial_source_remove(sdi->session, serial)) < 0) {
ac2926b3	219	sr_err("%s: Failed to remove source: %d.", prefix, ret);
cd2f0fe2 UH	220	return ret;
	221	}
	222
1b38775b	223	if ((ret = sdi->driver->dev_close(sdi)) < 0) {
ac2926b3	224	sr_err("%s: Failed to close device: %d.", prefix, ret);
cd2f0fe2 UH	225	return ret;
	226	}
	227
bee2b016	228	std_session_send_df_end(sdi);
cd2f0fe2 UH	229
	230	return SR_OK;
	231	}
49f00e13	232
c4f2dfd0 UH	233	#endif
c4f2dfd0 UH	234
813aab69	235	/**
49f00e13 BV	236	* Standard driver dev_clear() helper.
49f00e13 BV	237	*
813aab69 MH	238	* Clear driver, this means, close all instances.
813aab69 MH	239	*
49f00e13 BV	240	* This function can be used to implement the dev_clear() driver API
	241	* callback. dev_close() is called before every sr_dev_inst is cleared.
	242	*
	243	* The only limitation is driver-specific device contexts (sdi->priv).
	244	* These are freed, but any dynamic allocation within structs stored
	245	* there cannot be freed.
	246	*
	247	* @param driver The driver which will have its instances released.
12a33563 BV	248	* @param clear_private If not NULL, this points to a function called
	249	* with sdi->priv as argument. The function can then clear any device
	250	* instance-specific resources kept there. It must also clear the struct
	251	* pointed to by sdi->priv.
49f00e13 BV	252	*
	253	* @return SR_OK on success.
	254	*/
ae5859ff	255	SR_PRIV int std_dev_clear(const struct sr_dev_driver *driver,
144f6660	256	std_dev_clear_callback clear_private)
49f00e13	257	{
49f00e13	258	struct drv_context *drvc;
12a33563	259	struct sr_dev_inst *sdi;
7aebe22d	260	GSList *l;
49f00e13 BV	261	int ret;
49f00e13 BV	262
41812aca	263	if (!(drvc = driver->context))
3a277f3b BV	264	/* Driver was never initialized, nothing to do. */
	265	return SR_OK;
	266
49f00e13 BV	267	ret = SR_OK;
49f00e13 BV	268	for (l = drvc->instances; l; l = l->next) {
49f00e13 BV	269	if (!(sdi = l->data)) {
	270	ret = SR_ERR_BUG;
	271	continue;
	272	}
49f00e13 BV	273	if (driver->dev_close)
	274	driver->dev_close(sdi);
	275
	276	if (sdi->conn) {
45357ce6	277	#ifdef HAVE_LIBSERIALPORT
c4f2dfd0	278	if (sdi->inst_type == SR_INST_SERIAL)
12a33563	279	sr_serial_dev_inst_free(sdi->conn);
c4f2dfd0	280	#endif
45357ce6	281	#ifdef HAVE_LIBUSB_1_0
c4f2dfd0	282	if (sdi->inst_type == SR_INST_USB)
49f00e13	283	sr_usb_dev_inst_free(sdi->conn);
a0c7e23a	284	#endif
23f43dff ML	285	if (sdi->inst_type == SR_INST_SCPI)
23f43dff ML	286	sr_scpi_free(sdi->conn);
daa39012 AJ	287	if (sdi->inst_type == SR_INST_MODBUS)
daa39012 AJ	288	sr_modbus_free(sdi->conn);
49f00e13	289	}
ae5859ff	290	if (clear_private)
886413b6 BV	291	/* The helper function is responsible for freeing
886413b6 BV	292	* its own sdi->priv! */
ae5859ff	293	clear_private(sdi->priv);
12a33563 BV	294	else
12a33563 BV	295	g_free(sdi->priv);
886413b6	296
49f00e13 BV	297	sr_dev_inst_free(sdi);
	298	}
	299
	300	g_slist_free(drvc->instances);
	301	drvc->instances = NULL;
	302
	303	return ret;
	304	}
c01bf34c LPC	305
	306	/**
	307	* Standard implementation for the driver dev_list() callback
	308	*
	309	* This function can be used as the dev_list callback by most drivers that use
	310	* the standard helper functions. It returns the devices contained in the driver
	311	* context instances list.
	312	*
	313	* @param di The driver instance to use.
	314	*
	315	* @return The list of devices/instances of this driver, or NULL upon errors
	316	* or if the list is empty.
	317	*/
	318	SR_PRIV GSList std_dev_list(const struct sr_dev_driver di)
	319	{
	320	struct drv_context *drvc = di->context;
	321
	322	return drvc->instances;
	323	}
15a5bfe4 LPC	324
	325	/**
	326	* Standard scan() callback API helper.
	327	*
	328	* This function can be used to perform common tasks required by a driver's
	329	* scan() callback. It will initialize the driver for each device on the list
	330	* and add the devices on the list to the driver's device instance list.
	331	* Usually it should be used as the last step in the scan() callback, right
	332	* before returning.
	333	*
	334	* Note: This function can only be used if std_init() has been called
	335	* previously by the driver.
	336	*
	337	* Example:
	338	* @code{c}
	339	* static GSList scan(struct sr_dev_driver di, GSList *options)
	340	* {
	341	* struct GSList *device;
	342	* struct sr_dev_inst *sdi;
	343	*
	344	* sdi = g_new0(sr_dev_inst, 1);
	345	* sdi->vendor = ...;
	346	* ...
	347	* devices = g_slist_append(devices, sdi);
	348	* ...
	349	* return std_scan_complete(di, devices);
	350	* }
	351	* @endcode
	352	*
39fcfdc9	353	* @param di The driver instance to use. Must not be NULL.
15a5bfe4 LPC	354	* @param devices List of newly discovered devices (struct sr_dev_inst).
	355	*
	356	* @return The @p devices list.
	357	*/
	358	SR_PRIV GSList std_scan_complete(struct sr_dev_driver di, GSList *devices)
	359	{
39fcfdc9	360	struct drv_context *drvc;
15a5bfe4 LPC	361	GSList *l;
15a5bfe4 LPC	362
39fcfdc9 UH	363	if (!di) {
	364	sr_err("Invalid driver instance (di), cannot complete scan.");
	365	return NULL;
	366	}
	367
	368	drvc = di->context;
	369
15a5bfe4 LPC	370	for (l = devices; l; l = l->next) {
15a5bfe4 LPC	371	struct sr_dev_inst *sdi = l->data;
39fcfdc9 UH	372	if (!sdi) {
	373	sr_err("Invalid driver instance, cannot complete scan.");
	374	return NULL;
	375	}
15a5bfe4 LPC	376	sdi->driver = di;
	377	}
	378
	379	drvc->instances = g_slist_concat(drvc->instances, g_slist_copy(devices));
	380
	381	return devices;
	382	}