[libsigrok.git] / src / scpi / scpi_usbtmc_libusb.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
 *
 * 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 <string.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "scpi.h"

#define LOG_PREFIX "scpi_usbtmc"

#define MAX_TRANSFER_LENGTH 2048
#define TRANSFER_TIMEOUT 1000

struct scpi_usbtmc_libusb {
	struct sr_context *ctx;
	struct sr_usb_dev_inst *usb;
	int detached_kernel_driver;
	uint8_t interface;
	uint8_t bulk_in_ep;
	uint8_t bulk_out_ep;
	uint8_t interrupt_ep;
	uint8_t usbtmc_int_cap;
	uint8_t usbtmc_dev_cap;
	uint8_t usb488_dev_cap;
	uint8_t bTag;
	uint8_t bulkin_attributes;
	uint8_t buffer[MAX_TRANSFER_LENGTH];
	int response_length;
	int response_bytes_read;
	int remaining_length;
};

/* Some USBTMC-specific enums, as defined in the USBTMC standard. */
#define SUBCLASS_USBTMC 0x03
#define USBTMC_USB488   0x01

enum {
	/* USBTMC control requests */
	INITIATE_ABORT_BULK_OUT     =   1,
	CHECK_ABORT_BULK_OUT_STATUS =   2,
	INITIATE_ABORT_BULK_IN      =   3,
	CHECK_ABORT_BULK_IN_STATUS  =   4,
	INITIATE_CLEAR              =   5,
	CHECK_CLEAR_STATUS          =   6,
	GET_CAPABILITIES            =   7,
	INDICATOR_PULSE             =  64,

	/* USB488 control requests */
	READ_STATUS_BYTE            = 128,
	REN_CONTROL                 = 160,
	GO_TO_LOCAL                 = 161,
	LOCAL_LOCKOUT               = 162,
};

/* USBTMC status codes */
#define USBTMC_STATUS_SUCCESS      0x01

/* USBTMC capabilities */
#define USBTMC_INT_CAP_LISTEN_ONLY 0x01
#define USBTMC_INT_CAP_TALK_ONLY   0x02
#define USBTMC_INT_CAP_INDICATOR   0x04

#define USBTMC_DEV_CAP_TERMCHAR    0x01

#define USB488_DEV_CAP_DT1         0x01
#define USB488_DEV_CAP_RL1         0x02
#define USB488_DEV_CAP_SR1         0x04
#define USB488_DEV_CAP_SCPI        0x08

/* Bulk messages constants */
#define USBTMC_BULK_HEADER_SIZE 12

/* Bulk MsgID values */
#define DEV_DEP_MSG_OUT        1
#define REQUEST_DEV_DEP_MSG_IN 2
#define DEV_DEP_MSG_IN         2

/* bmTransferAttributes */
#define EOM               0x01
#define TERM_CHAR_ENABLED 0x02

struct usbtmc_blacklist {
	uint16_t vid;
	uint16_t pid;
};

/* Devices that publish RL1 support, but don't support it. */
static struct usbtmc_blacklist blacklist_remote[] = {
	{ 0x1ab1, 0x0588 }, /* Rigol DS1000 series */
	{ 0x1ab1, 0x04b0 }, /* Rigol DS2000 series */
	{ 0x0957, 0x0588 }, /* Agilent DSO1000 series (rebadged Rigol DS1000) */
	{ 0x0b21, 0xffff }, /* All Yokogawa devices */
	{ 0xf4ec, 0xffff }, /* All Siglent SDS devices */
	ALL_ZERO
};

/* Devices that shall get reset during open(). */
static struct usbtmc_blacklist whitelist_usb_reset[] = {
	{ 0xf4ec, 0xffff }, /* All Siglent SDS devices */
	ALL_ZERO
};

static GSList *scpi_usbtmc_libusb_scan(struct drv_context *drvc)
{
	struct libusb_device **devlist;
	struct libusb_device_descriptor des;
	struct libusb_config_descriptor *confdes;
	const struct libusb_interface_descriptor *intfdes;
	GSList *resources = NULL;
	int confidx, intfidx, ret, i;
	char *res;

	ret = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	if (ret < 0) {
		sr_err("Failed to get device list: %s.",
		       libusb_error_name(ret));
		return NULL;
	}
	for (i = 0; devlist[i]; i++) {
		libusb_get_device_descriptor(devlist[i], &des);

		for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
			if ((ret = libusb_get_config_descriptor(devlist[i], confidx, &confdes)) < 0) {
				sr_dbg("Failed to get configuration descriptor: %s, "
				       "ignoring device.", libusb_error_name(ret));
				break;
			}
			for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
				intfdes = confdes->interface[intfidx].altsetting;
				if (intfdes->bInterfaceClass    != LIBUSB_CLASS_APPLICATION ||
				    intfdes->bInterfaceSubClass != SUBCLASS_USBTMC          ||
				    intfdes->bInterfaceProtocol != USBTMC_USB488)
					continue;
				sr_dbg("Found USBTMC device (VID:PID = %04x:%04x, "
				       "bus.address = %d.%d).", des.idVendor, des.idProduct,
				       libusb_get_bus_number(devlist[i]),
				       libusb_get_device_address(devlist[i]));
				res = g_strdup_printf("usbtmc/%d.%d",
				                      libusb_get_bus_number(devlist[i]),
				                      libusb_get_device_address(devlist[i]));
				resources = g_slist_append(resources, res);
			}
			libusb_free_config_descriptor(confdes);
		}
	}
	libusb_free_device_list(devlist, 1);

	/* No log message for #devices found (caller will log that). */

	return resources;
}

static int scpi_usbtmc_libusb_dev_inst_new(void *priv, struct drv_context *drvc,
		const char *resource, char **params, const char *serialcomm)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	GSList *devices;

	(void)resource;
	(void)serialcomm;

	if (!params || !params[1]) {
		sr_err("Invalid parameters.");
		return SR_ERR;
	}

	uscpi->ctx = drvc->sr_ctx;
	devices = sr_usb_find(uscpi->ctx->libusb_ctx, params[1]);
	if (g_slist_length(devices) != 1) {
		sr_err("Failed to find USB device '%s'.", params[1]);
		g_slist_free_full(devices, (GDestroyNotify)sr_usb_dev_inst_free);
		return SR_ERR;
	}
	uscpi->usb = devices->data;
	g_slist_free(devices);

	return SR_OK;
}

static int check_usbtmc_blacklist(struct usbtmc_blacklist *blacklist,
		uint16_t vid, uint16_t pid)
{
	int i;

	for (i = 0; blacklist[i].vid; i++) {
		if ((blacklist[i].vid == vid && blacklist[i].pid == 0xFFFF) ||
			(blacklist[i].vid == vid && blacklist[i].pid == pid))
			return TRUE;
	}

	return FALSE;
}

static int scpi_usbtmc_remote(struct scpi_usbtmc_libusb *uscpi)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	struct libusb_device *dev;
	struct libusb_device_descriptor des;
	int ret;
	uint8_t status;

	if (!(uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1))
		return SR_OK;

	dev = libusb_get_device(usb->devhdl);
	libusb_get_device_descriptor(dev, &des);
	if (check_usbtmc_blacklist(blacklist_remote, des.idVendor, des.idProduct))
		return SR_OK;

	sr_dbg("Locking out local control.");
	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN |
		LIBUSB_REQUEST_TYPE_CLASS | LIBUSB_RECIPIENT_INTERFACE,
		REN_CONTROL, 1, uscpi->interface, &status, 1, TRANSFER_TIMEOUT);
	if (ret < 0 || status != USBTMC_STATUS_SUCCESS) {
		if (ret < 0)
			sr_dbg("Failed to enter REN state: %s.", libusb_error_name(ret));
		else
			sr_dbg("Failed to enter REN state: USBTMC status %d.", status);
		return SR_ERR;
	}

	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN |
		LIBUSB_REQUEST_TYPE_CLASS | LIBUSB_RECIPIENT_INTERFACE,
		LOCAL_LOCKOUT, 0, uscpi->interface, &status, 1,
		TRANSFER_TIMEOUT);
	if (ret < 0 || status != USBTMC_STATUS_SUCCESS) {
		if (ret < 0)
			sr_dbg("Failed to enter local lockout state: %s.",
					libusb_error_name(ret));
		else
			sr_dbg("Failed to enter local lockout state: USBTMC "
					"status %d.", status);
		return SR_ERR;
	}

	return SR_OK;
}

static void scpi_usbtmc_local(struct scpi_usbtmc_libusb *uscpi)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	struct libusb_device *dev;
	struct libusb_device_descriptor des;
	int ret;
	uint8_t status;

	if (!(uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1))
		return;

	dev = libusb_get_device(usb->devhdl);
	libusb_get_device_descriptor(dev, &des);
	if (check_usbtmc_blacklist(blacklist_remote, des.idVendor, des.idProduct))
		return;

	sr_dbg("Returning local control.");
	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN |
		LIBUSB_REQUEST_TYPE_CLASS | LIBUSB_RECIPIENT_INTERFACE,
		GO_TO_LOCAL, 0, uscpi->interface, &status, 1, TRANSFER_TIMEOUT);
	if (ret < 0 || status != USBTMC_STATUS_SUCCESS) {
		if (ret < 0)
			sr_dbg("Failed to clear local lockout state: %s.",
					libusb_error_name(ret));
		else
			sr_dbg("Failed to clear local lockout state: USBTMC "
					"status %d.", status);
	}

	return;
}

static int scpi_usbtmc_libusb_open(struct sr_scpi_dev_inst *scpi)
{
	struct scpi_usbtmc_libusb *uscpi = scpi->priv;
	struct sr_usb_dev_inst *usb = uscpi->usb;
	struct libusb_device *dev;
	struct libusb_device_descriptor des;
	struct libusb_config_descriptor *confdes;
	const struct libusb_interface_descriptor *intfdes;
	const struct libusb_endpoint_descriptor *ep;
	int confidx, intfidx, epidx, config = 0, current_config;
	uint8_t capabilities[24];
	int ret, found = 0;
	int do_reset;

	if (usb->devhdl)
		return SR_OK;

	if (sr_usb_open(uscpi->ctx->libusb_ctx, usb) != SR_OK)
		return SR_ERR;

	dev = libusb_get_device(usb->devhdl);
	libusb_get_device_descriptor(dev, &des);

	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
		if ((ret = libusb_get_config_descriptor(dev, confidx, &confdes)) < 0) {
			sr_dbg("Failed to get configuration descriptor: %s, "
			       "ignoring device.", libusb_error_name(ret));
			continue;
		}
		for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
			intfdes = confdes->interface[intfidx].altsetting;
			if (intfdes->bInterfaceClass    != LIBUSB_CLASS_APPLICATION ||
			    intfdes->bInterfaceSubClass != SUBCLASS_USBTMC ||
			    intfdes->bInterfaceProtocol != USBTMC_USB488)
				continue;
			uscpi->interface = intfdes->bInterfaceNumber;
			config = confdes->bConfigurationValue;
			sr_dbg("Interface %d configuration %d.", uscpi->interface, config);
			for (epidx = 0; epidx < intfdes->bNumEndpoints; epidx++) {
				ep = &intfdes->endpoint[epidx];
				if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
				    !(ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK))) {
					uscpi->bulk_out_ep = ep->bEndpointAddress;
					sr_dbg("Bulk OUT EP %d", uscpi->bulk_out_ep);
				}
				if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
				    ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
					uscpi->bulk_in_ep = ep->bEndpointAddress;
					sr_dbg("Bulk IN EP %d", uscpi->bulk_in_ep & 0x7f);
				}
				if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_INTERRUPT &&
				    ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
					uscpi->interrupt_ep = ep->bEndpointAddress;
					sr_dbg("Interrupt EP %d", uscpi->interrupt_ep & 0x7f);
				}
			}
			found = 1;
		}
		libusb_free_config_descriptor(confdes);
		if (found)
			break;
	}

	if (!found) {
		sr_err("Failed to find USBTMC interface.");
		return SR_ERR;
	}

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

	if (libusb_get_configuration(usb->devhdl, &current_config) == 0
	    && current_config != config) {
		if ((ret = libusb_set_configuration(usb->devhdl, config)) < 0) {
			sr_err("Failed to set configuration: %s.",
			       libusb_error_name(ret));
			return SR_ERR;
		}
	}

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

	/* Optionally reset the USB device. */
	do_reset = check_usbtmc_blacklist(whitelist_usb_reset,
		des.idVendor, des.idProduct);
	if (do_reset)
		libusb_reset_device(usb->devhdl);

	/* Get capabilities. */
	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN |
		LIBUSB_REQUEST_TYPE_CLASS | LIBUSB_RECIPIENT_INTERFACE,
		GET_CAPABILITIES, 0, uscpi->interface, capabilities,
		sizeof(capabilities), TRANSFER_TIMEOUT);
	if (ret == sizeof(capabilities)) {
		uscpi->usbtmc_int_cap = capabilities[ 4];
		uscpi->usbtmc_dev_cap = capabilities[ 5];
		uscpi->usb488_dev_cap = capabilities[15];
	}
	sr_dbg("Device capabilities: %s%s%s%s%s, %s, %s",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_SCPI        ? "SCPI, "    : "",
	       uscpi->usbtmc_dev_cap & USBTMC_DEV_CAP_TERMCHAR    ? "TermChar, ": "",
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY ? "L3, " :
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY   ? ""     : "L4, ",
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY   ? "T5, " :
	       uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY ? ""     : "T6, ",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_SR1         ? "SR1"  : "SR0",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1         ? "RL1"  : "RL0",
	       uscpi->usb488_dev_cap & USB488_DEV_CAP_DT1         ? "DT1"  : "DT0");

	scpi_usbtmc_remote(uscpi);

	return SR_OK;
}

static int scpi_usbtmc_libusb_source_add(struct sr_session *session,
		void *priv, int events, int timeout, sr_receive_data_callback cb,
		void *cb_data)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	(void)events;
	return usb_source_add(session, uscpi->ctx, timeout, cb, cb_data);
}

static int scpi_usbtmc_libusb_source_remove(struct sr_session *session,
		void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	return usb_source_remove(session, uscpi->ctx);
}

static void usbtmc_bulk_out_header_write(void *header, uint8_t MsgID,
                                         uint8_t bTag,
                                         uint32_t TransferSize,
                                         uint8_t bmTransferAttributes,
                                         char TermChar)
{
	  W8(header +  0, MsgID);
	  W8(header +  1, bTag);
	  W8(header +  2, ~bTag);
	  W8(header +  3, 0);
	WL32(header +  4, TransferSize);
	  W8(header +  8, bmTransferAttributes);
	  W8(header +  9, TermChar);
	WL16(header + 10, 0);
}

static int usbtmc_bulk_in_header_read(void *header, uint8_t MsgID,
                                      unsigned char bTag,
                                      int32_t *TransferSize,
                                      uint8_t *bmTransferAttributes)
{
	if (R8(header + 0) != MsgID ||
	    R8(header + 1) != bTag  ||
	    R8(header + 2) != (unsigned char)~bTag)
		return SR_ERR;
	if (TransferSize)
		*TransferSize = RL32(header + 4);
	if (bmTransferAttributes)
		*bmTransferAttributes = R8(header + 8);

	return SR_OK;
}

static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
                               uint8_t msg_id, const void *data, int32_t size,
                               uint8_t transfer_attributes)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int padded_size, ret, transferred;

	if (data && (size + USBTMC_BULK_HEADER_SIZE + 3) > (int)sizeof(uscpi->buffer)) {
		sr_err("USBTMC bulk out transfer is too big.");
		return SR_ERR;
	}

	uscpi->bTag++;
	uscpi->bTag += !uscpi->bTag; /* bTag == 0 is invalid so avoid it. */

	usbtmc_bulk_out_header_write(uscpi->buffer, msg_id, uscpi->bTag,
	                             size, transfer_attributes, 0);
	if (data)
		memcpy(uscpi->buffer + USBTMC_BULK_HEADER_SIZE, data, size);
	else
		size = 0;
	size += USBTMC_BULK_HEADER_SIZE;
	padded_size = (size + 3) & ~0x3;
	memset(uscpi->buffer + size, 0, padded_size - size);

	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_out_ep,
	                           uscpi->buffer, padded_size, &transferred,
	                           TRANSFER_TIMEOUT);
	if (ret < 0) {
		sr_err("USBTMC bulk out transfer error: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	if (transferred < padded_size) {
		sr_dbg("USBTMC bulk out partial transfer (%d/%d bytes).",
		       transferred, padded_size);
		return SR_ERR;
	}

	return transferred - USBTMC_BULK_HEADER_SIZE;
}

static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
                                    uint8_t msg_id, void *data, int32_t size,
                                    uint8_t *transfer_attributes)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int ret, transferred, message_size;

	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	                           &transferred, TRANSFER_TIMEOUT);
	if (ret < 0) {
		sr_err("USBTMC bulk in transfer error: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
	                               transfer_attributes) != SR_OK) {
		sr_err("USBTMC invalid bulk in header.");
		return SR_ERR;
	}

	message_size += USBTMC_BULK_HEADER_SIZE;
	uscpi->response_length = MIN(transferred, message_size);
	uscpi->response_bytes_read = USBTMC_BULK_HEADER_SIZE;
	uscpi->remaining_length = message_size - uscpi->response_length;

	return transferred - USBTMC_BULK_HEADER_SIZE;
}

static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
                                       void *data, int size)
{
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int ret, transferred;

	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	                           &transferred, TRANSFER_TIMEOUT);
	if (ret < 0) {
		sr_err("USBTMC bulk in transfer error: %s.",
		       libusb_error_name(ret));
		return SR_ERR;
	}

	uscpi->response_length = MIN(transferred, uscpi->remaining_length);
	uscpi->response_bytes_read = 0;
	uscpi->remaining_length -= uscpi->response_length;

	return transferred;
}

static int scpi_usbtmc_libusb_send(void *priv, const char *command)
{
	struct scpi_usbtmc_libusb *uscpi = priv;

	if (scpi_usbtmc_bulkout(uscpi, DEV_DEP_MSG_OUT,
	                        command, strlen(command), EOM) <= 0)
		return SR_ERR;

	sr_spew("Successfully sent SCPI command: '%s'.", command);

	return SR_OK;
}

static int scpi_usbtmc_libusb_read_begin(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;

	uscpi->remaining_length = 0;

	if (scpi_usbtmc_bulkout(uscpi, REQUEST_DEV_DEP_MSG_IN,
	    NULL, INT32_MAX, 0) < 0)
		return SR_ERR;
	if (scpi_usbtmc_bulkin_start(uscpi, DEV_DEP_MSG_IN,
	                             uscpi->buffer, sizeof(uscpi->buffer),
	                             &uscpi->bulkin_attributes) < 0)
		return SR_ERR;

	return SR_OK;
}

static int scpi_usbtmc_libusb_read_data(void *priv, char *buf, int maxlen)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	int read_length;

	if (uscpi->response_bytes_read >= uscpi->response_length) {
		if (uscpi->remaining_length > 0) {
			if (scpi_usbtmc_bulkin_continue(uscpi, uscpi->buffer,
			                                sizeof(uscpi->buffer)) <= 0)
				return SR_ERR;
		} else {
			if (uscpi->bulkin_attributes & EOM)
				return SR_ERR;
			if (scpi_usbtmc_libusb_read_begin(uscpi) < 0)
				return SR_ERR;
		}
	}

	read_length = MIN(uscpi->response_length - uscpi->response_bytes_read, maxlen);

	memcpy(buf, uscpi->buffer + uscpi->response_bytes_read, read_length);

	uscpi->response_bytes_read += read_length;

	return read_length;
}

static int scpi_usbtmc_libusb_read_complete(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	return uscpi->response_bytes_read >= uscpi->response_length &&
	       uscpi->remaining_length <= 0 &&
	       uscpi->bulkin_attributes & EOM;
}

static int scpi_usbtmc_libusb_close(struct sr_scpi_dev_inst *scpi)
{
	struct scpi_usbtmc_libusb *uscpi = scpi->priv;
	struct sr_usb_dev_inst *usb = uscpi->usb;
	int ret;

	if (!usb->devhdl)
		return SR_ERR;

	scpi_usbtmc_local(uscpi);

	if ((ret = libusb_release_interface(usb->devhdl, uscpi->interface)) < 0)
		sr_err("Failed to release interface: %s.",
		       libusb_error_name(ret));

	if (uscpi->detached_kernel_driver) {
		if ((ret = libusb_attach_kernel_driver(usb->devhdl,
						uscpi->interface)) < 0)
			sr_err("Failed to re-attach kernel driver: %s.",
			       libusb_error_name(ret));

		uscpi->detached_kernel_driver = 0;
	}
	sr_usb_close(usb);

	return SR_OK;
}

static void scpi_usbtmc_libusb_free(void *priv)
{
	struct scpi_usbtmc_libusb *uscpi = priv;
	sr_usb_dev_inst_free(uscpi->usb);
}

SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
	.name          = "USBTMC",
	.prefix        = "usbtmc",
	.priv_size     = sizeof(struct scpi_usbtmc_libusb),
	.scan          = scpi_usbtmc_libusb_scan,
	.dev_inst_new  = scpi_usbtmc_libusb_dev_inst_new,
	.open          = scpi_usbtmc_libusb_open,
	.source_add    = scpi_usbtmc_libusb_source_add,
	.source_remove = scpi_usbtmc_libusb_source_remove,
	.send          = scpi_usbtmc_libusb_send,
	.read_begin    = scpi_usbtmc_libusb_read_begin,
	.read_data     = scpi_usbtmc_libusb_read_data,
	.read_complete = scpi_usbtmc_libusb_read_complete,
	.close         = scpi_usbtmc_libusb_close,
	.free          = scpi_usbtmc_libusb_free,
};
Commit	Line	Data
	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
	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>
	21	#include <string.h>
	22	#include <libsigrok/libsigrok.h>
	23	#include "libsigrok-internal.h"
	24	#include "scpi.h"
	25
	26	#define LOG_PREFIX "scpi_usbtmc"
	27
	28	#define MAX_TRANSFER_LENGTH 2048
	29	#define TRANSFER_TIMEOUT 1000
	30
	31	struct scpi_usbtmc_libusb {
	32	struct sr_context *ctx;
	33	struct sr_usb_dev_inst *usb;
	34	int detached_kernel_driver;
	35	uint8_t interface;
	36	uint8_t bulk_in_ep;
	37	uint8_t bulk_out_ep;
	38	uint8_t interrupt_ep;
	39	uint8_t usbtmc_int_cap;
	40	uint8_t usbtmc_dev_cap;
	41	uint8_t usb488_dev_cap;
	42	uint8_t bTag;
	43	uint8_t bulkin_attributes;
	44	uint8_t buffer[MAX_TRANSFER_LENGTH];
	45	int response_length;
	46	int response_bytes_read;
	47	int remaining_length;
	48	};
	49
	50	/* Some USBTMC-specific enums, as defined in the USBTMC standard. */
	51	#define SUBCLASS_USBTMC 0x03
	52	#define USBTMC_USB488 0x01
	53
	54	enum {
	55	/* USBTMC control requests */
	56	INITIATE_ABORT_BULK_OUT = 1,
	57	CHECK_ABORT_BULK_OUT_STATUS = 2,
	58	INITIATE_ABORT_BULK_IN = 3,
	59	CHECK_ABORT_BULK_IN_STATUS = 4,
	60	INITIATE_CLEAR = 5,
	61	CHECK_CLEAR_STATUS = 6,
	62	GET_CAPABILITIES = 7,
	63	INDICATOR_PULSE = 64,
	64
	65	/* USB488 control requests */
	66	READ_STATUS_BYTE = 128,
	67	REN_CONTROL = 160,
	68	GO_TO_LOCAL = 161,
	69	LOCAL_LOCKOUT = 162,
	70	};
	71
	72	/* USBTMC status codes */
	73	#define USBTMC_STATUS_SUCCESS 0x01
	74
	75	/* USBTMC capabilities */
	76	#define USBTMC_INT_CAP_LISTEN_ONLY 0x01
	77	#define USBTMC_INT_CAP_TALK_ONLY 0x02
	78	#define USBTMC_INT_CAP_INDICATOR 0x04
	79
	80	#define USBTMC_DEV_CAP_TERMCHAR 0x01
	81
	82	#define USB488_DEV_CAP_DT1 0x01
	83	#define USB488_DEV_CAP_RL1 0x02
	84	#define USB488_DEV_CAP_SR1 0x04
	85	#define USB488_DEV_CAP_SCPI 0x08
	86
	87	/* Bulk messages constants */
	88	#define USBTMC_BULK_HEADER_SIZE 12
	89
	90	/* Bulk MsgID values */
	91	#define DEV_DEP_MSG_OUT 1
	92	#define REQUEST_DEV_DEP_MSG_IN 2
	93	#define DEV_DEP_MSG_IN 2
	94
	95	/* bmTransferAttributes */
	96	#define EOM 0x01
	97	#define TERM_CHAR_ENABLED 0x02
	98
	99	struct usbtmc_blacklist {
	100	uint16_t vid;
	101	uint16_t pid;
	102	};
	103
	104	/* Devices that publish RL1 support, but don't support it. */
	105	static struct usbtmc_blacklist blacklist_remote[] = {
	106	{ 0x1ab1, 0x0588 }, /* Rigol DS1000 series */
	107	{ 0x1ab1, 0x04b0 }, /* Rigol DS2000 series */
	108	{ 0x0957, 0x0588 }, /* Agilent DSO1000 series (rebadged Rigol DS1000) */
	109	{ 0x0b21, 0xffff }, /* All Yokogawa devices */
	110	{ 0xf4ec, 0xffff }, /* All Siglent SDS devices */
	111	ALL_ZERO
	112	};
	113
	114	/* Devices that shall get reset during open(). */
	115	static struct usbtmc_blacklist whitelist_usb_reset[] = {
	116	{ 0xf4ec, 0xffff }, /* All Siglent SDS devices */
	117	ALL_ZERO
	118	};
	119
	120	static GSList scpi_usbtmc_libusb_scan(struct drv_context drvc)
	121	{
	122	struct libusb_device **devlist;
	123	struct libusb_device_descriptor des;
	124	struct libusb_config_descriptor *confdes;
	125	const struct libusb_interface_descriptor *intfdes;
	126	GSList *resources = NULL;
	127	int confidx, intfidx, ret, i;
	128	char *res;
	129
	130	ret = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
	131	if (ret < 0) {
	132	sr_err("Failed to get device list: %s.",
	133	libusb_error_name(ret));
	134	return NULL;
	135	}
	136	for (i = 0; devlist[i]; i++) {
	137	libusb_get_device_descriptor(devlist[i], &des);
	138
	139	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
	140	if ((ret = libusb_get_config_descriptor(devlist[i], confidx, &confdes)) < 0) {
	141	sr_dbg("Failed to get configuration descriptor: %s, "
	142	"ignoring device.", libusb_error_name(ret));
	143	break;
	144	}
	145	for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
	146	intfdes = confdes->interface[intfidx].altsetting;
	147	if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION \|\|
	148	intfdes->bInterfaceSubClass != SUBCLASS_USBTMC \|\|
	149	intfdes->bInterfaceProtocol != USBTMC_USB488)
	150	continue;
	151	sr_dbg("Found USBTMC device (VID:PID = %04x:%04x, "
	152	"bus.address = %d.%d).", des.idVendor, des.idProduct,
	153	libusb_get_bus_number(devlist[i]),
	154	libusb_get_device_address(devlist[i]));
	155	res = g_strdup_printf("usbtmc/%d.%d",
	156	libusb_get_bus_number(devlist[i]),
	157	libusb_get_device_address(devlist[i]));
	158	resources = g_slist_append(resources, res);
	159	}
	160	libusb_free_config_descriptor(confdes);
	161	}
	162	}
	163	libusb_free_device_list(devlist, 1);
	164
	165	/* No log message for #devices found (caller will log that). */
	166
	167	return resources;
	168	}
	169
	170	static int scpi_usbtmc_libusb_dev_inst_new(void priv, struct drv_context drvc,
	171	const char resource, char params, const char serialcomm)
	172	{
	173	struct scpi_usbtmc_libusb *uscpi = priv;
	174	GSList *devices;
	175
	176	(void)resource;
	177	(void)serialcomm;
	178
	179	if (!params \|\| !params[1]) {
	180	sr_err("Invalid parameters.");
	181	return SR_ERR;
	182	}
	183
	184	uscpi->ctx = drvc->sr_ctx;
	185	devices = sr_usb_find(uscpi->ctx->libusb_ctx, params[1]);
	186	if (g_slist_length(devices) != 1) {
	187	sr_err("Failed to find USB device '%s'.", params[1]);
	188	g_slist_free_full(devices, (GDestroyNotify)sr_usb_dev_inst_free);
	189	return SR_ERR;
	190	}
	191	uscpi->usb = devices->data;
	192	g_slist_free(devices);
	193
	194	return SR_OK;
	195	}
	196
	197	static int check_usbtmc_blacklist(struct usbtmc_blacklist *blacklist,
	198	uint16_t vid, uint16_t pid)
	199	{
	200	int i;
	201
	202	for (i = 0; blacklist[i].vid; i++) {
	203	if ((blacklist[i].vid == vid && blacklist[i].pid == 0xFFFF) \|\|
	204	(blacklist[i].vid == vid && blacklist[i].pid == pid))
	205	return TRUE;
	206	}
	207
	208	return FALSE;
	209	}
	210
	211	static int scpi_usbtmc_remote(struct scpi_usbtmc_libusb *uscpi)
	212	{
	213	struct sr_usb_dev_inst *usb = uscpi->usb;
	214	struct libusb_device *dev;
	215	struct libusb_device_descriptor des;
	216	int ret;
	217	uint8_t status;
	218
	219	if (!(uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1))
	220	return SR_OK;
	221
	222	dev = libusb_get_device(usb->devhdl);
	223	libusb_get_device_descriptor(dev, &des);
	224	if (check_usbtmc_blacklist(blacklist_remote, des.idVendor, des.idProduct))
	225	return SR_OK;
	226
	227	sr_dbg("Locking out local control.");
	228	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN \|
	229	LIBUSB_REQUEST_TYPE_CLASS \| LIBUSB_RECIPIENT_INTERFACE,
	230	REN_CONTROL, 1, uscpi->interface, &status, 1, TRANSFER_TIMEOUT);
	231	if (ret < 0 \|\| status != USBTMC_STATUS_SUCCESS) {
	232	if (ret < 0)
	233	sr_dbg("Failed to enter REN state: %s.", libusb_error_name(ret));
	234	else
	235	sr_dbg("Failed to enter REN state: USBTMC status %d.", status);
	236	return SR_ERR;
	237	}
	238
	239	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN \|
	240	LIBUSB_REQUEST_TYPE_CLASS \| LIBUSB_RECIPIENT_INTERFACE,
	241	LOCAL_LOCKOUT, 0, uscpi->interface, &status, 1,
	242	TRANSFER_TIMEOUT);
	243	if (ret < 0 \|\| status != USBTMC_STATUS_SUCCESS) {
	244	if (ret < 0)
	245	sr_dbg("Failed to enter local lockout state: %s.",
	246	libusb_error_name(ret));
	247	else
	248	sr_dbg("Failed to enter local lockout state: USBTMC "
	249	"status %d.", status);
	250	return SR_ERR;
	251	}
	252
	253	return SR_OK;
	254	}
	255
	256	static void scpi_usbtmc_local(struct scpi_usbtmc_libusb *uscpi)
	257	{
	258	struct sr_usb_dev_inst *usb = uscpi->usb;
	259	struct libusb_device *dev;
	260	struct libusb_device_descriptor des;
	261	int ret;
	262	uint8_t status;
	263
	264	if (!(uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1))
	265	return;
	266
	267	dev = libusb_get_device(usb->devhdl);
	268	libusb_get_device_descriptor(dev, &des);
	269	if (check_usbtmc_blacklist(blacklist_remote, des.idVendor, des.idProduct))
	270	return;
	271
	272	sr_dbg("Returning local control.");
	273	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN \|
	274	LIBUSB_REQUEST_TYPE_CLASS \| LIBUSB_RECIPIENT_INTERFACE,
	275	GO_TO_LOCAL, 0, uscpi->interface, &status, 1, TRANSFER_TIMEOUT);
	276	if (ret < 0 \|\| status != USBTMC_STATUS_SUCCESS) {
	277	if (ret < 0)
	278	sr_dbg("Failed to clear local lockout state: %s.",
	279	libusb_error_name(ret));
	280	else
	281	sr_dbg("Failed to clear local lockout state: USBTMC "
	282	"status %d.", status);
	283	}
	284
	285	return;
	286	}
	287
	288	static int scpi_usbtmc_libusb_open(struct sr_scpi_dev_inst *scpi)
	289	{
	290	struct scpi_usbtmc_libusb *uscpi = scpi->priv;
	291	struct sr_usb_dev_inst *usb = uscpi->usb;
	292	struct libusb_device *dev;
	293	struct libusb_device_descriptor des;
	294	struct libusb_config_descriptor *confdes;
	295	const struct libusb_interface_descriptor *intfdes;
	296	const struct libusb_endpoint_descriptor *ep;
	297	int confidx, intfidx, epidx, config = 0, current_config;
	298	uint8_t capabilities[24];
	299	int ret, found = 0;
	300	int do_reset;
	301
	302	if (usb->devhdl)
	303	return SR_OK;
	304
	305	if (sr_usb_open(uscpi->ctx->libusb_ctx, usb) != SR_OK)
	306	return SR_ERR;
	307
	308	dev = libusb_get_device(usb->devhdl);
	309	libusb_get_device_descriptor(dev, &des);
	310
	311	for (confidx = 0; confidx < des.bNumConfigurations; confidx++) {
	312	if ((ret = libusb_get_config_descriptor(dev, confidx, &confdes)) < 0) {
	313	sr_dbg("Failed to get configuration descriptor: %s, "
	314	"ignoring device.", libusb_error_name(ret));
	315	continue;
	316	}
	317	for (intfidx = 0; intfidx < confdes->bNumInterfaces; intfidx++) {
	318	intfdes = confdes->interface[intfidx].altsetting;
	319	if (intfdes->bInterfaceClass != LIBUSB_CLASS_APPLICATION \|\|
	320	intfdes->bInterfaceSubClass != SUBCLASS_USBTMC \|\|
	321	intfdes->bInterfaceProtocol != USBTMC_USB488)
	322	continue;
	323	uscpi->interface = intfdes->bInterfaceNumber;
	324	config = confdes->bConfigurationValue;
	325	sr_dbg("Interface %d configuration %d.", uscpi->interface, config);
	326	for (epidx = 0; epidx < intfdes->bNumEndpoints; epidx++) {
	327	ep = &intfdes->endpoint[epidx];
	328	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
	329	!(ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK))) {
	330	uscpi->bulk_out_ep = ep->bEndpointAddress;
	331	sr_dbg("Bulk OUT EP %d", uscpi->bulk_out_ep);
	332	}
	333	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_BULK &&
	334	ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
	335	uscpi->bulk_in_ep = ep->bEndpointAddress;
	336	sr_dbg("Bulk IN EP %d", uscpi->bulk_in_ep & 0x7f);
	337	}
	338	if (ep->bmAttributes == LIBUSB_TRANSFER_TYPE_INTERRUPT &&
	339	ep->bEndpointAddress & (LIBUSB_ENDPOINT_DIR_MASK)) {
	340	uscpi->interrupt_ep = ep->bEndpointAddress;
	341	sr_dbg("Interrupt EP %d", uscpi->interrupt_ep & 0x7f);
	342	}
	343	}
	344	found = 1;
	345	}
	346	libusb_free_config_descriptor(confdes);
	347	if (found)
	348	break;
	349	}
	350
	351	if (!found) {
	352	sr_err("Failed to find USBTMC interface.");
	353	return SR_ERR;
	354	}
	355
	356	if (libusb_kernel_driver_active(usb->devhdl, uscpi->interface) == 1) {
	357	if ((ret = libusb_detach_kernel_driver(usb->devhdl,
	358	uscpi->interface)) < 0) {
	359	sr_err("Failed to detach kernel driver: %s.",
	360	libusb_error_name(ret));
	361	return SR_ERR;
	362	}
	363	uscpi->detached_kernel_driver = 1;
	364	}
	365
	366	if (libusb_get_configuration(usb->devhdl, &current_config) == 0
	367	&& current_config != config) {
	368	if ((ret = libusb_set_configuration(usb->devhdl, config)) < 0) {
	369	sr_err("Failed to set configuration: %s.",
	370	libusb_error_name(ret));
	371	return SR_ERR;
	372	}
	373	}
	374
	375	if ((ret = libusb_claim_interface(usb->devhdl, uscpi->interface)) < 0) {
	376	sr_err("Failed to claim interface: %s.",
	377	libusb_error_name(ret));
	378	return SR_ERR;
	379	}
	380
	381	/* Optionally reset the USB device. */
	382	do_reset = check_usbtmc_blacklist(whitelist_usb_reset,
	383	des.idVendor, des.idProduct);
	384	if (do_reset)
	385	libusb_reset_device(usb->devhdl);
	386
	387	/* Get capabilities. */
	388	ret = libusb_control_transfer(usb->devhdl, LIBUSB_ENDPOINT_IN \|
	389	LIBUSB_REQUEST_TYPE_CLASS \| LIBUSB_RECIPIENT_INTERFACE,
	390	GET_CAPABILITIES, 0, uscpi->interface, capabilities,
	391	sizeof(capabilities), TRANSFER_TIMEOUT);
	392	if (ret == sizeof(capabilities)) {
	393	uscpi->usbtmc_int_cap = capabilities[ 4];
	394	uscpi->usbtmc_dev_cap = capabilities[ 5];
	395	uscpi->usb488_dev_cap = capabilities[15];
	396	}
	397	sr_dbg("Device capabilities: %s%s%s%s%s, %s, %s",
	398	uscpi->usb488_dev_cap & USB488_DEV_CAP_SCPI ? "SCPI, " : "",
	399	uscpi->usbtmc_dev_cap & USBTMC_DEV_CAP_TERMCHAR ? "TermChar, ": "",
	400	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY ? "L3, " :
	401	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY ? "" : "L4, ",
	402	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_TALK_ONLY ? "T5, " :
	403	uscpi->usbtmc_int_cap & USBTMC_INT_CAP_LISTEN_ONLY ? "" : "T6, ",
	404	uscpi->usb488_dev_cap & USB488_DEV_CAP_SR1 ? "SR1" : "SR0",
	405	uscpi->usb488_dev_cap & USB488_DEV_CAP_RL1 ? "RL1" : "RL0",
	406	uscpi->usb488_dev_cap & USB488_DEV_CAP_DT1 ? "DT1" : "DT0");
	407
	408	scpi_usbtmc_remote(uscpi);
	409
	410	return SR_OK;
	411	}
	412
	413	static int scpi_usbtmc_libusb_source_add(struct sr_session *session,
	414	void *priv, int events, int timeout, sr_receive_data_callback cb,
	415	void *cb_data)
	416	{
	417	struct scpi_usbtmc_libusb *uscpi = priv;
	418	(void)events;
	419	return usb_source_add(session, uscpi->ctx, timeout, cb, cb_data);
	420	}
	421
	422	static int scpi_usbtmc_libusb_source_remove(struct sr_session *session,
	423	void *priv)
	424	{
	425	struct scpi_usbtmc_libusb *uscpi = priv;
	426	return usb_source_remove(session, uscpi->ctx);
	427	}
	428
	429	static void usbtmc_bulk_out_header_write(void *header, uint8_t MsgID,
	430	uint8_t bTag,
	431	uint32_t TransferSize,
	432	uint8_t bmTransferAttributes,
	433	char TermChar)
	434	{
	435	W8(header + 0, MsgID);
	436	W8(header + 1, bTag);
	437	W8(header + 2, ~bTag);
	438	W8(header + 3, 0);
	439	WL32(header + 4, TransferSize);
	440	W8(header + 8, bmTransferAttributes);
	441	W8(header + 9, TermChar);
	442	WL16(header + 10, 0);
	443	}
	444
	445	static int usbtmc_bulk_in_header_read(void *header, uint8_t MsgID,
	446	unsigned char bTag,
	447	int32_t *TransferSize,
	448	uint8_t *bmTransferAttributes)
	449	{
	450	if (R8(header + 0) != MsgID \|\|
	451	R8(header + 1) != bTag \|\|
	452	R8(header + 2) != (unsigned char)~bTag)
	453	return SR_ERR;
	454	if (TransferSize)
	455	*TransferSize = RL32(header + 4);
	456	if (bmTransferAttributes)
	457	*bmTransferAttributes = R8(header + 8);
	458
	459	return SR_OK;
	460	}
	461
	462	static int scpi_usbtmc_bulkout(struct scpi_usbtmc_libusb *uscpi,
	463	uint8_t msg_id, const void *data, int32_t size,
	464	uint8_t transfer_attributes)
	465	{
	466	struct sr_usb_dev_inst *usb = uscpi->usb;
	467	int padded_size, ret, transferred;
	468
	469	if (data && (size + USBTMC_BULK_HEADER_SIZE + 3) > (int)sizeof(uscpi->buffer)) {
	470	sr_err("USBTMC bulk out transfer is too big.");
	471	return SR_ERR;
	472	}
	473
	474	uscpi->bTag++;
	475	uscpi->bTag += !uscpi->bTag; /* bTag == 0 is invalid so avoid it. */
	476
	477	usbtmc_bulk_out_header_write(uscpi->buffer, msg_id, uscpi->bTag,
	478	size, transfer_attributes, 0);
	479	if (data)
	480	memcpy(uscpi->buffer + USBTMC_BULK_HEADER_SIZE, data, size);
	481	else
	482	size = 0;
	483	size += USBTMC_BULK_HEADER_SIZE;
	484	padded_size = (size + 3) & ~0x3;
	485	memset(uscpi->buffer + size, 0, padded_size - size);
	486
	487	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_out_ep,
	488	uscpi->buffer, padded_size, &transferred,
	489	TRANSFER_TIMEOUT);
	490	if (ret < 0) {
	491	sr_err("USBTMC bulk out transfer error: %s.",
	492	libusb_error_name(ret));
	493	return SR_ERR;
	494	}
	495
	496	if (transferred < padded_size) {
	497	sr_dbg("USBTMC bulk out partial transfer (%d/%d bytes).",
	498	transferred, padded_size);
	499	return SR_ERR;
	500	}
	501
	502	return transferred - USBTMC_BULK_HEADER_SIZE;
	503	}
	504
	505	static int scpi_usbtmc_bulkin_start(struct scpi_usbtmc_libusb *uscpi,
	506	uint8_t msg_id, void *data, int32_t size,
	507	uint8_t *transfer_attributes)
	508	{
	509	struct sr_usb_dev_inst *usb = uscpi->usb;
	510	int ret, transferred, message_size;
	511
	512	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	513	&transferred, TRANSFER_TIMEOUT);
	514	if (ret < 0) {
	515	sr_err("USBTMC bulk in transfer error: %s.",
	516	libusb_error_name(ret));
	517	return SR_ERR;
	518	}
	519
	520	if (usbtmc_bulk_in_header_read(data, msg_id, uscpi->bTag, &message_size,
	521	transfer_attributes) != SR_OK) {
	522	sr_err("USBTMC invalid bulk in header.");
	523	return SR_ERR;
	524	}
	525
	526	message_size += USBTMC_BULK_HEADER_SIZE;
	527	uscpi->response_length = MIN(transferred, message_size);
	528	uscpi->response_bytes_read = USBTMC_BULK_HEADER_SIZE;
	529	uscpi->remaining_length = message_size - uscpi->response_length;
	530
	531	return transferred - USBTMC_BULK_HEADER_SIZE;
	532	}
	533
	534	static int scpi_usbtmc_bulkin_continue(struct scpi_usbtmc_libusb *uscpi,
	535	void *data, int size)
	536	{
	537	struct sr_usb_dev_inst *usb = uscpi->usb;
	538	int ret, transferred;
	539
	540	ret = libusb_bulk_transfer(usb->devhdl, uscpi->bulk_in_ep, data, size,
	541	&transferred, TRANSFER_TIMEOUT);
	542	if (ret < 0) {
	543	sr_err("USBTMC bulk in transfer error: %s.",
	544	libusb_error_name(ret));
	545	return SR_ERR;
	546	}
	547
	548	uscpi->response_length = MIN(transferred, uscpi->remaining_length);
	549	uscpi->response_bytes_read = 0;
	550	uscpi->remaining_length -= uscpi->response_length;
	551
	552	return transferred;
	553	}
	554
	555	static int scpi_usbtmc_libusb_send(void priv, const char command)
	556	{
	557	struct scpi_usbtmc_libusb *uscpi = priv;
	558
	559	if (scpi_usbtmc_bulkout(uscpi, DEV_DEP_MSG_OUT,
	560	command, strlen(command), EOM) <= 0)
	561	return SR_ERR;
	562
	563	sr_spew("Successfully sent SCPI command: '%s'.", command);
	564
	565	return SR_OK;
	566	}
	567
	568	static int scpi_usbtmc_libusb_read_begin(void *priv)
	569	{
	570	struct scpi_usbtmc_libusb *uscpi = priv;
	571
	572	uscpi->remaining_length = 0;
	573
	574	if (scpi_usbtmc_bulkout(uscpi, REQUEST_DEV_DEP_MSG_IN,
	575	NULL, INT32_MAX, 0) < 0)
	576	return SR_ERR;
	577	if (scpi_usbtmc_bulkin_start(uscpi, DEV_DEP_MSG_IN,
	578	uscpi->buffer, sizeof(uscpi->buffer),
	579	&uscpi->bulkin_attributes) < 0)
	580	return SR_ERR;
	581
	582	return SR_OK;
	583	}
	584
	585	static int scpi_usbtmc_libusb_read_data(void priv, char buf, int maxlen)
	586	{
	587	struct scpi_usbtmc_libusb *uscpi = priv;
	588	int read_length;
	589
	590	if (uscpi->response_bytes_read >= uscpi->response_length) {
	591	if (uscpi->remaining_length > 0) {
	592	if (scpi_usbtmc_bulkin_continue(uscpi, uscpi->buffer,
	593	sizeof(uscpi->buffer)) <= 0)
	594	return SR_ERR;
	595	} else {
	596	if (uscpi->bulkin_attributes & EOM)
	597	return SR_ERR;
	598	if (scpi_usbtmc_libusb_read_begin(uscpi) < 0)
	599	return SR_ERR;
	600	}
	601	}
	602
	603	read_length = MIN(uscpi->response_length - uscpi->response_bytes_read, maxlen);
	604
	605	memcpy(buf, uscpi->buffer + uscpi->response_bytes_read, read_length);
	606
	607	uscpi->response_bytes_read += read_length;
	608
	609	return read_length;
	610	}
	611
	612	static int scpi_usbtmc_libusb_read_complete(void *priv)
	613	{
	614	struct scpi_usbtmc_libusb *uscpi = priv;
	615	return uscpi->response_bytes_read >= uscpi->response_length &&
	616	uscpi->remaining_length <= 0 &&
	617	uscpi->bulkin_attributes & EOM;
	618	}
	619
	620	static int scpi_usbtmc_libusb_close(struct sr_scpi_dev_inst *scpi)
	621	{
	622	struct scpi_usbtmc_libusb *uscpi = scpi->priv;
	623	struct sr_usb_dev_inst *usb = uscpi->usb;
	624	int ret;
	625
	626	if (!usb->devhdl)
	627	return SR_ERR;
	628
	629	scpi_usbtmc_local(uscpi);
	630
	631	if ((ret = libusb_release_interface(usb->devhdl, uscpi->interface)) < 0)
	632	sr_err("Failed to release interface: %s.",
	633	libusb_error_name(ret));
	634
	635	if (uscpi->detached_kernel_driver) {
	636	if ((ret = libusb_attach_kernel_driver(usb->devhdl,
	637	uscpi->interface)) < 0)
	638	sr_err("Failed to re-attach kernel driver: %s.",
	639	libusb_error_name(ret));
	640
	641	uscpi->detached_kernel_driver = 0;
	642	}
	643	sr_usb_close(usb);
	644
	645	return SR_OK;
	646	}
	647
	648	static void scpi_usbtmc_libusb_free(void *priv)
	649	{
	650	struct scpi_usbtmc_libusb *uscpi = priv;
	651	sr_usb_dev_inst_free(uscpi->usb);
	652	}
	653
	654	SR_PRIV const struct sr_scpi_dev_inst scpi_usbtmc_libusb_dev = {
	655	.name = "USBTMC",
	656	.prefix = "usbtmc",
	657	.priv_size = sizeof(struct scpi_usbtmc_libusb),
	658	.scan = scpi_usbtmc_libusb_scan,
	659	.dev_inst_new = scpi_usbtmc_libusb_dev_inst_new,
	660	.open = scpi_usbtmc_libusb_open,
	661	.source_add = scpi_usbtmc_libusb_source_add,
	662	.source_remove = scpi_usbtmc_libusb_source_remove,
	663	.send = scpi_usbtmc_libusb_send,
	664	.read_begin = scpi_usbtmc_libusb_read_begin,
	665	.read_data = scpi_usbtmc_libusb_read_data,
	666	.read_complete = scpi_usbtmc_libusb_read_complete,
	667	.close = scpi_usbtmc_libusb_close,
	668	.free = scpi_usbtmc_libusb_free,
	669	};