Add librevisa SCPI backend.

configure.ac

@@ -316,6 +316,22 @@ fi
 # Serial port helper code is only compiled in if libserialport was found.
 AM_CONDITIONAL(NEED_SERIAL, test "x$have_libserialport" != xno)
 
+PKG_CHECK_MODULES([librevisa], [librevisa >= 0.0.20130812],
+	[CFLAGS="$CFLAGS $librevisa_CFLAGS";
+	LIBS="$LIBS $librevisa_LIBS";
+	SR_PKGLIBS="$SR_PKGLIBS librevisa"], [])
+
+# VISA SCPI backend is only compiled in if librevisa was found.
+AM_CONDITIONAL(NEED_VISA, test "x$have_librevisa" != xno)
+
+# Define HAVE_LIBREVISA in config.h if we found librevisa.
+if test "x$have_librevisa" != "xno"; then
+	AC_DEFINE_UNQUOTED(HAVE_LIBREVISA, [1],
+		[Specifies whether we have librevisa.])
+fi
+
+AM_CONDITIONAL(NEED_VISA, test "x$have_librevisa" != xno)
+
 # libusb-1.0 is only needed for some hardware drivers. Disable the respective
 # drivers if it is not found.
 case "$host" in
@@ -635,7 +651,7 @@ echo "Detected libraries:"
 echo
 
 # Note: This only works for libs with pkg-config integration.
-for lib in "glib-2.0 >= 2.32.0" "libzip >= 0.10" "libserialport >= 0.1.0" "libusb-1.0 >= 1.0.16" "libftdi >= 0.16" "libudev >= 151" "alsa >= 1.0" "check >= 0.9.4"; do
+for lib in "glib-2.0 >= 2.32.0" "libzip >= 0.10" "libserialport >= 0.1.0" "librevisa >= 0.0.20130812" "libusb-1.0 >= 1.0.16" "libftdi >= 0.16" "libudev >= 151" "alsa >= 1.0" "check >= 0.9.4"; do
 	if `$PKG_CONFIG --exists $lib`; then
 		ver=`$PKG_CONFIG --modversion $lib`
 		answer="yes ($ver)"

hardware/common/Makefile.am

@@ -36,6 +36,10 @@ if NEED_USB
 libsigrok_hw_common_la_SOURCES += ezusb.c usb.c
 endif
 
+if NEED_VISA
+libsigrok_hw_common_la_SOURCES += scpi_visa.c
+endif
+
 libsigrok_hw_common_la_LIBADD = dmm/libsigrok_hw_common_dmm.la
 
 libsigrok_hw_common_la_CFLAGS = \

hardware/common/scpi.c

@@ -70,6 +70,7 @@ SR_PRIV extern const struct sr_scpi_dev_inst scpi_tcp_raw_dev;
 SR_PRIV extern const struct sr_scpi_dev_inst scpi_tcp_rigol_dev;
 SR_PRIV extern const struct sr_scpi_dev_inst scpi_usbtmc_dev;
 SR_PRIV extern const struct sr_scpi_dev_inst scpi_vxi_dev;
+SR_PRIV extern const struct sr_scpi_dev_inst scpi_visa_dev;
 
 static const struct sr_scpi_dev_inst *scpi_devs[] = {
 	&scpi_tcp_raw_dev,
@@ -78,6 +79,9 @@ static const struct sr_scpi_dev_inst *scpi_devs[] = {
 #if HAVE_RPC
 	&scpi_vxi_dev,
 #endif
+#ifdef HAVE_LIBREVISA
+	&scpi_visa_dev,
+#endif
 #ifdef HAVE_LIBSERIALPORT
 	&scpi_serial_dev,  /* must be last as it matches any resource */
 #endif

hardware/common/scpi_visa.c

@@ -0,0 +1,175 @@
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
+ *
+ * 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 "libsigrok.h"
+#include "libsigrok-internal.h"
+
+#include <visa.h>
+#include <string.h>
+
+#define LOG_PREFIX "scpi_visa"
+
+struct scpi_visa {
+	char *resource;
+	ViSession rmgr;
+	ViSession vi;
+};
+
+static int scpi_visa_dev_inst_new(void *priv, const char *resource,
+		char **params, const char *serialcomm)
+{
+	struct scpi_visa *vscpi = priv;
+
+	(void)resource;
+	(void)serialcomm;
+
+	if (!params || !params[1]) {
+		sr_err("Invalid parameters.");
+		return SR_ERR;
+	}
+
+	vscpi->resource = g_strdup(params[1]);
+
+	return SR_OK;
+}
+
+static int scpi_visa_open(void *priv)
+{
+	struct scpi_visa *vscpi = priv;
+
+	if (viOpenDefaultRM(&vscpi->rmgr) != VI_SUCCESS) {
+		sr_err("Cannot open default resource manager.");
+		return SR_ERR;
+	}
+
+	if (viOpen(vscpi->rmgr, vscpi->resource, VI_NO_LOCK, 0, &vscpi->vi) != VI_SUCCESS)
+	{
+		sr_err("Cannot open resource.");
+		return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
+static int scpi_visa_source_add(void *priv, int events, int timeout,
+			sr_receive_data_callback_t cb, void *cb_data)
+{
+	(void) priv;
+
+	/* Hook up a dummy handler to receive data from the device. */
+	return sr_source_add(-1, events, timeout, cb, cb_data);
+}
+
+static int scpi_visa_source_remove(void *priv)
+{
+	(void) priv;
+
+	return sr_source_remove(-1);;
+}
+
+static int scpi_visa_send(void *priv, const char *command)
+{
+	struct scpi_visa *vscpi = priv;
+	gchar *terminated_command;
+	ViUInt32 written;
+	int len;
+
+	terminated_command = g_strconcat(command, "\n", NULL);
+	len = strlen(terminated_command);
+	if (viWrite(vscpi->vi, (ViBuf) (terminated_command + written), len,
+			&written) != VI_SUCCESS) {
+		sr_err("Error while sending SCPI command: '%s'.", command);
+		g_free(terminated_command);
+		return SR_ERR;
+	}
+
+	g_free(terminated_command);
+
+	sr_spew("Successfully sent SCPI command: '%s'.", command);
+
+	return SR_OK;
+}
+
+static int scpi_visa_read_begin(void *priv)
+{
+	(void) priv;
+
+	return SR_OK;
+}
+
+static int scpi_visa_read_data(void *priv, char *buf, int maxlen)
+{
+	struct scpi_visa *vscpi = priv;
+	ViUInt32 count;
+
+	if (viRead(vscpi->vi, (ViBuf) buf, maxlen, &count) != VI_SUCCESS)
+	{
+		sr_err("Read failed");
+		return SR_ERR;
+	}
+
+	return count;
+}
+
+static int scpi_visa_read_complete(void *priv)
+{
+	struct scpi_visa *vscpi = priv;
+	ViUInt16 status;
+
+	if (viReadSTB(vscpi->vi, &status) != VI_SUCCESS) {
+		sr_err("Failed to read status");
+		return SR_ERR;
+	}
+
+	return !(status & 16);
+}
+
+static int scpi_visa_close(void *priv)
+{
+	struct scpi_visa *vscpi = priv;
+
+	viClose(vscpi->vi);
+	viClose(vscpi->rmgr);
+
+	return SR_OK;
+}
+
+static void scpi_visa_free(void *priv)
+{
+	struct scpi_visa *vscpi = priv;
+
+	g_free(vscpi->resource);
+	g_free(vscpi);
+}
+
+SR_PRIV const struct sr_scpi_dev_inst scpi_visa_dev = {
+	.name = "VISA",
+	.prefix = "visa",
+	.priv_size = sizeof(struct scpi_visa),
+	.dev_inst_new = scpi_visa_dev_inst_new,
+	.open = scpi_visa_open,
+	.source_add = scpi_visa_source_add,
+	.source_remove = scpi_visa_source_remove,
+	.send = scpi_visa_send,
+	.read_begin = scpi_visa_read_begin,
+	.read_data = scpi_visa_read_data,
+	.read_complete = scpi_visa_read_complete,
+	.close = scpi_visa_close,
+	.free = scpi_visa_free,
+};