]> sigrok.org Git - libsigrok.git/blobdiff - hardware/common/scpi.c
Don't define names ending with _t (POSIX reserved).
[libsigrok.git] / hardware / common / scpi.c
index 03eea3eea747a6b1c16a7c99c4e6b923b6e1399e..dbcd3f090bf2c7dee2a1629d0a5ee701c1f70248 100644 (file)
 #include <glib.h>
 #include <string.h>
 
-/* Message logging helpers with subsystem-specific prefix string. */
-#define LOG_PREFIX "scpi: "
-#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
-#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
-#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
-#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
-#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
+#define LOG_PREFIX "scpi"
 
 #define SCPI_READ_RETRIES 100
 #define SCPI_READ_RETRY_TIMEOUT 10000
@@ -45,7 +39,7 @@
  *
  * @return SR_OK on success, SR_ERR on failure.
  */
-static int sr_parse_strict_bool(const char *str, gboolean *ret)
+static int parse_strict_bool(const char *str, gboolean *ret)
 {
        if (!str)
                return SR_ERR_ARG;
@@ -56,17 +50,14 @@ static int sr_parse_strict_bool(const char *str, gboolean *ret)
            !g_ascii_strncasecmp(str, "yes", 3) ||
            !g_ascii_strncasecmp(str, "true", 4) ||
            !g_ascii_strncasecmp(str, "on", 2)) {
-
                *ret = TRUE;
                return SR_OK;
-
        } else if (!g_strcmp0(str, "0") ||
                   !g_ascii_strncasecmp(str, "n", 1) ||
                   !g_ascii_strncasecmp(str, "f", 1) ||
                   !g_ascii_strncasecmp(str, "no", 2) ||
                   !g_ascii_strncasecmp(str, "false", 5) ||
                   !g_ascii_strncasecmp(str, "off", 3)) {
-
                *ret = FALSE;
                return SR_OK;
        }
@@ -74,122 +65,356 @@ static int sr_parse_strict_bool(const char *str, gboolean *ret)
        return SR_ERR;
 }
 
+SR_PRIV extern const struct sr_scpi_dev_inst scpi_serial_dev;
+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_usbtmc_libusb_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,
+       &scpi_tcp_rigol_dev,
+       /* &scpi_usbtmc_dev, */
+#ifdef HAVE_LIBUSB_1_0
+       &scpi_usbtmc_libusb_dev,
+#endif
+#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
+};
+
+static GSList *sr_scpi_scan_resource(struct drv_context *drvc,
+               const char *resource, const char *serialcomm,
+               struct sr_dev_inst *(*probe_device)(struct sr_scpi_dev_inst *scpi))
+{
+       struct sr_scpi_dev_inst *scpi;
+       struct sr_dev_inst *sdi;
+
+       if (!(scpi = scpi_dev_inst_new(drvc, resource, serialcomm)))
+               return NULL;
+
+       if (sr_scpi_open(scpi) != SR_OK) {
+               sr_info("Couldn't open SCPI device.");
+               sr_scpi_free(scpi);
+               return NULL;
+       };
+
+       if ((sdi = probe_device(scpi)))
+               return g_slist_append(NULL, sdi);
+
+       sr_scpi_close(scpi);
+       sr_scpi_free(scpi);
+       return NULL;
+}
+
+SR_PRIV GSList *sr_scpi_scan(struct drv_context *drvc, GSList *options,
+               struct sr_dev_inst *(*probe_device)(struct sr_scpi_dev_inst *scpi))
+{
+       GSList *resources, *l, *d, *devices = NULL;
+       const char *resource = NULL;
+       const char *serialcomm = NULL;
+       gchar **res;
+       unsigned i;
+
+       for (l = options; l; l = l->next) {
+               struct sr_config *src = l->data;
+               switch (src->key) {
+               case SR_CONF_CONN:
+                       resource = g_variant_get_string(src->data, NULL);
+                       break;
+               case SR_CONF_SERIALCOMM:
+                       serialcomm = g_variant_get_string(src->data, NULL);
+                       break;
+               }
+       }
+
+       for (i = 0; i < ARRAY_SIZE(scpi_devs); i++) {
+               if ((resource && strcmp(resource, scpi_devs[i]->prefix))
+                   || !scpi_devs[i]->scan)
+                       continue;
+               resources = scpi_devs[i]->scan(drvc);
+               for (l = resources; l; l = l->next) {
+                       res = g_strsplit(l->data, ":", 2);
+                       if (res[0] && (d = sr_scpi_scan_resource(drvc, res[0],
+                                      serialcomm ? serialcomm : res[1], probe_device)))
+                               devices = g_slist_concat(devices, d);
+                       g_strfreev(res);
+               }
+               g_slist_free_full(resources, g_free);
+       }
+
+       if (!devices && resource)
+               devices = sr_scpi_scan_resource(drvc, resource, serialcomm,
+                                               probe_device);
+
+       /* Tack a copy of the newly found devices onto the driver list. */
+       if (devices)
+               drvc->instances = g_slist_concat(drvc->instances,
+                                                g_slist_copy(devices));
+
+       return devices;
+}
+
+SR_PRIV struct sr_scpi_dev_inst *scpi_dev_inst_new(struct drv_context *drvc,
+               const char *resource, const char *serialcomm)
+{
+       struct sr_scpi_dev_inst *scpi = NULL;
+       const struct sr_scpi_dev_inst *scpi_dev;
+       gchar **params;
+       unsigned i;
+
+       for (i = 0; i < ARRAY_SIZE(scpi_devs); i++) {
+               scpi_dev = scpi_devs[i];
+               if (!strncmp(resource, scpi_dev->prefix, strlen(scpi_dev->prefix))) {
+                       sr_dbg("Opening %s device %s.", scpi_dev->name, resource);
+                       scpi = g_malloc(sizeof(*scpi));
+                       *scpi = *scpi_dev;
+                       scpi->priv = g_malloc0(scpi->priv_size);
+                       params = g_strsplit(resource, "/", 0);
+                       if (scpi->dev_inst_new(scpi->priv, drvc, resource,
+                                              params, serialcomm) != SR_OK) {
+                               sr_scpi_free(scpi);
+                               scpi = NULL;
+                       }
+                       g_strfreev(params);
+                       break;
+               }
+       }
+
+       return scpi;
+}
+
+/**
+ * Open SCPI device.
+ *
+ * @param scpi Previously initialized SCPI device structure.
+ *
+ * @return SR_OK on success, SR_ERR on failure.
+ */
+SR_PRIV int sr_scpi_open(struct sr_scpi_dev_inst *scpi)
+{
+       return scpi->open(scpi->priv);
+}
+
+/**
+ * Add an event source for an SCPI device.
+ *
+ * @param scpi Previously initialized SCPI device structure.
+ * @param events Events to check for.
+ * @param timeout Max time to wait before the callback is called, ignored if 0.
+ * @param cb Callback function to add. Must not be NULL.
+ * @param cb_data Data for the callback function. Can be NULL.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors.
+ */
+SR_PRIV int sr_scpi_source_add(struct sr_scpi_dev_inst *scpi, int events,
+               int timeout, sr_receive_data_callback cb, void *cb_data)
+{
+       return scpi->source_add(scpi->priv, events, timeout, cb, cb_data);
+}
+
+/**
+ * Remove event source for an SCPI device.
+ *
+ * @param scpi Previously initialized SCPI device structure.
+ *
+ * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
+ *         SR_ERR_MALLOC upon memory allocation errors, SR_ERR_BUG upon
+ *         internal errors.
+ */
+SR_PRIV int sr_scpi_source_remove(struct sr_scpi_dev_inst *scpi)
+{
+       return scpi->source_remove(scpi->priv);
+}
+
 /**
  * Send a SCPI command.
  *
- * @param serial Previously initialized serial port structure.
- * @param command The SCPI command to send to the device.
+ * @param scpi Previously initialized SCPI device structure.
+ * @param format Format string, to be followed by any necessary arguments.
  *
  * @return SR_OK on success, SR_ERR on failure.
  */
-SR_PRIV int sr_scpi_send(struct sr_serial_dev_inst *serial,
-                        const char *command)
+SR_PRIV int sr_scpi_send(struct sr_scpi_dev_inst *scpi,
+                        const char *format, ...)
 {
-       int len;
-       int out;
-       gchar *terminated_command;
+       va_list args;
+       int ret;
 
-       terminated_command = g_strconcat(command, "\n", NULL);
-       len = strlen(terminated_command);
+       va_start(args, format);
+       ret = sr_scpi_send_variadic(scpi, format, args);
+       va_end(args);
 
-       out = serial_write(serial, terminated_command,
-                          strlen(terminated_command));
+       return ret;
+}
 
-       g_free(terminated_command);
+/**
+ * Send a SCPI command with a variadic argument list.
+ *
+ * @param scpi Previously initialized SCPI device structure.
+ * @param format Format string.
+ * @param args Argument list.
+ *
+ * @return SR_OK on success, SR_ERR on failure.
+ */
+SR_PRIV int sr_scpi_send_variadic(struct sr_scpi_dev_inst *scpi,
+                        const char *format, va_list args)
+{
+       va_list args_copy;
+       char *buf;
+       int len, ret;
 
-       if (out != len) {
-               sr_dbg("Only sent %d/%d bytes of SCPI command: '%s'.", out,
-                      len, command);
-               return SR_ERR;
-       }
+       /* Get length of buffer required. */
+       va_copy(args_copy, args);
+       len = vsnprintf(NULL, 0, format, args_copy);
+       va_end(args_copy);
 
-       sr_spew("Successfully sent SCPI command: '%s'.", command);
+       /* Allocate buffer and write out command. */
+       buf = g_malloc(len + 1);
+       vsprintf(buf, format, args);
 
-       return SR_OK;
+       /* Send command. */
+       ret = scpi->send(scpi->priv, buf);
+
+       /* Free command buffer. */
+       g_free(buf);
+
+       return ret;
+}
+
+/**
+ * Begin receiving an SCPI reply.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ *
+ * @return SR_OK on success, SR_ERR on failure.
+ */
+SR_PRIV int sr_scpi_read_begin(struct sr_scpi_dev_inst *scpi)
+{
+       return scpi->read_begin(scpi->priv);
+}
+
+/**
+ * Read part of a response from SCPI device.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ * @param buf Buffer to store result.
+ * @param maxlen Maximum number of bytes to read.
+ *
+ * @return Number of bytes read, or SR_ERR upon failure.
+ */
+SR_PRIV int sr_scpi_read_data(struct sr_scpi_dev_inst *scpi,
+                       char *buf, int maxlen)
+{
+       return scpi->read_data(scpi->priv, buf, maxlen);
+}
+
+/**
+ * Check whether a complete SCPI response has been received.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ *
+ * @return 1 if complete, 0 otherwise.
+ */
+SR_PRIV int sr_scpi_read_complete(struct sr_scpi_dev_inst *scpi)
+{
+       return scpi->read_complete(scpi->priv);
+}
+
+/**
+ * Close SCPI device.
+ *
+ * @param scpi Previously initialized SCPI device structure.
+ *
+ * @return SR_OK on success, SR_ERR on failure.
+ */
+SR_PRIV int sr_scpi_close(struct sr_scpi_dev_inst *scpi)
+{
+       return scpi->close(scpi->priv);
+}
+
+/**
+ * Free SCPI device.
+ *
+ * @param scpi Previously initialized SCPI device structure.
+ *
+ * @return SR_OK on success, SR_ERR on failure.
+ */
+SR_PRIV void sr_scpi_free(struct sr_scpi_dev_inst *scpi)
+{
+       scpi->free(scpi->priv);
+       g_free(scpi->priv);
+       g_free(scpi);
 }
 
 /**
  * Send a SCPI command, receive the reply and store the reply in scpi_response.
  *
- * @param serial Previously initialized serial port structure.
+ * @param scpi Previously initialised SCPI device structure.
  * @param command The SCPI command to send to the device (can be NULL).
- * @param scpi_response Pointer where to store the scpi response.
+ * @param scpi_response Pointer where to store the SCPI response.
  *
- * @return SR_OK upon fetching a full SCPI response, SR_ERR upon fetching a
- * incomplete or no response. The allocated response must be freed by the caller
- * in the case of a full response as well in the case of an incomplete.
+ * @return SR_OK on success, SR_ERR on failure.
  */
-SR_PRIV int sr_scpi_get_string(struct sr_serial_dev_inst *serial,
-                                const char *command, char **scpi_response)
+SR_PRIV int sr_scpi_get_string(struct sr_scpi_dev_inst *scpi,
+                              const char *command, char **scpi_response)
 {
-       int len;
-       int ret;
        char buf[256];
-       unsigned int i;
+       int len;
        GString *response;
 
        if (command)
-               if (sr_scpi_send(serial, command) != SR_OK)
+               if (sr_scpi_send(scpi, command) != SR_OK)
                        return SR_ERR;
 
-       response = g_string_sized_new(1024);
+       if (sr_scpi_read_begin(scpi) != SR_OK)
+               return SR_ERR;
 
-       for (i = 0; i <= SCPI_READ_RETRIES; i++) {
-               while ((len = serial_read(serial, buf, sizeof(buf))) > 0)
-                       response = g_string_append_len(response, buf, len);
+       response = g_string_new("");
 
-               if (response->len > 0 &&
-                   response->str[response->len-1] == '\n') {
-                       sr_spew("Fetched full SCPI response");
-                       break;
-               }
+       *scpi_response = NULL;
 
-               g_usleep(SCPI_READ_RETRY_TIMEOUT);
+       while (!sr_scpi_read_complete(scpi)) {
+               len = sr_scpi_read_data(scpi, buf, sizeof(buf));
+               if (len < 0) {
+                       g_string_free(response, TRUE);
+                       return SR_ERR;
+               }
+               g_string_append_len(response, buf, len);
        }
 
-       if (response->len == 0) {
-               sr_dbg("No SCPI response received");
-               g_string_free(response, TRUE);
-               *scpi_response = NULL;
-               return SR_ERR;
-
-       } else if (response->str[response->len-1] == '\n') {
-               /*
-                * The SCPI response contains a LF ('\n') at the end and we
-                * don't need this so replace it with a '\0' and decrement
-                * the length.
-                */
-               response->str[--response->len] = '\0';
-               ret = SR_OK;
+       /* Get rid of trailing linefeed if present */
+       if (response->len >= 1 && response->str[response->len - 1] == '\n')
+               g_string_truncate(response, response->len - 1);
 
-       } else {
-               sr_warn("Incomplete SCPI response received!");
-               ret = SR_ERR;
-       }
-
-       /* Minor optimization: steal the string instead of copying. */
        *scpi_response = response->str;
-
-       /* A SCPI response can be quite large, print at most 50 characters */
-       sr_dbg("SCPI response for command %s received (length %d): '%.50s'",
-              command, response->len, response->str);
-
        g_string_free(response, FALSE);
 
-       return ret;
+       sr_spew("Got response: '%.70s'.", *scpi_response);
+
+       return SR_OK;
 }
 
 /**
  * Send a SCPI command, read the reply, parse it as a bool value and store the
  * result in scpi_response.
  *
- * @param serial Previously initialized serial port structure.
+ * @param scpi Previously initialised SCPI device structure.
  * @param command The SCPI command to send to the device (can be NULL).
  * @param scpi_response Pointer where to store the parsed result.
  *
  * @return SR_OK on success, SR_ERR on failure.
  */
-SR_PRIV int sr_scpi_get_bool(struct sr_serial_dev_inst *serial,
+SR_PRIV int sr_scpi_get_bool(struct sr_scpi_dev_inst *scpi,
                             const char *command, gboolean *scpi_response)
 {
        int ret;
@@ -197,11 +422,11 @@ SR_PRIV int sr_scpi_get_bool(struct sr_serial_dev_inst *serial,
 
        response = NULL;
 
-       if (sr_scpi_get_string(serial, command, &response) != SR_OK)
+       if (sr_scpi_get_string(scpi, command, &response) != SR_OK)
                if (!response)
                        return SR_ERR;
 
-       if (sr_parse_strict_bool(response, scpi_response) == SR_OK)
+       if (parse_strict_bool(response, scpi_response) == SR_OK)
                ret = SR_OK;
        else
                ret = SR_ERR;
@@ -215,21 +440,21 @@ SR_PRIV int sr_scpi_get_bool(struct sr_serial_dev_inst *serial,
  * Send a SCPI command, read the reply, parse it as an integer and store the
  * result in scpi_response.
  *
- * @param serial Previously initialized serial port structure.
+ * @param scpi Previously initialised SCPI device structure.
  * @param command The SCPI command to send to the device (can be NULL).
  * @param scpi_response Pointer where to store the parsed result.
  *
  * @return SR_OK on success, SR_ERR on failure.
  */
-SR_PRIV int sr_scpi_get_int(struct sr_serial_dev_inst *serial,
-                                 const char *command, int *scpi_response)
+SR_PRIV int sr_scpi_get_int(struct sr_scpi_dev_inst *scpi,
+                           const char *command, int *scpi_response)
 {
        int ret;
        char *response;
 
        response = NULL;
 
-       if (sr_scpi_get_string(serial, command, &response) != SR_OK)
+       if (sr_scpi_get_string(scpi, command, &response) != SR_OK)
                if (!response)
                        return SR_ERR;
 
@@ -247,13 +472,13 @@ SR_PRIV int sr_scpi_get_int(struct sr_serial_dev_inst *serial,
  * Send a SCPI command, read the reply, parse it as a float and store the
  * result in scpi_response.
  *
- * @param serial Previously initialized serial port structure.
+ * @param scpi Previously initialised SCPI device structure.
  * @param command The SCPI command to send to the device (can be NULL).
  * @param scpi_response Pointer where to store the parsed result.
  *
  * @return SR_OK on success, SR_ERR on failure.
  */
-SR_PRIV int sr_scpi_get_float(struct sr_serial_dev_inst *serial,
+SR_PRIV int sr_scpi_get_float(struct sr_scpi_dev_inst *scpi,
                              const char *command, float *scpi_response)
 {
        int ret;
@@ -261,11 +486,11 @@ SR_PRIV int sr_scpi_get_float(struct sr_serial_dev_inst *serial,
 
        response = NULL;
 
-       if (sr_scpi_get_string(serial, command, &response) != SR_OK)
+       if (sr_scpi_get_string(scpi, command, &response) != SR_OK)
                if (!response)
                        return SR_ERR;
 
-       if (sr_atof(response, scpi_response) == SR_OK)
+       if (sr_atof_ascii(response, scpi_response) == SR_OK)
                ret = SR_OK;
        else
                ret = SR_ERR;
@@ -279,21 +504,21 @@ SR_PRIV int sr_scpi_get_float(struct sr_serial_dev_inst *serial,
  * Send a SCPI command, read the reply, parse it as a double and store the
  * result in scpi_response.
  *
- * @param serial Previously initialized serial port structure.
+ * @param scpi Previously initialised SCPI device structure.
  * @param command The SCPI command to send to the device (can be NULL).
  * @param scpi_response Pointer where to store the parsed result.
  *
  * @return SR_OK on success, SR_ERR on failure.
  */
-SR_PRIV int sr_scpi_get_double(struct sr_serial_dev_inst *serial,
-                             const char *command, double *scpi_response)
+SR_PRIV int sr_scpi_get_double(struct sr_scpi_dev_inst *scpi,
+                              const char *command, double *scpi_response)
 {
        int ret;
        char *response;
 
        response = NULL;
 
-       if (sr_scpi_get_string(serial, command, &response) != SR_OK)
+       if (sr_scpi_get_string(scpi, command, &response) != SR_OK)
                if (!response)
                        return SR_ERR;
 
@@ -307,32 +532,172 @@ SR_PRIV int sr_scpi_get_double(struct sr_serial_dev_inst *serial,
        return ret;
 }
 
+/**
+ * Send a SCPI *OPC? command, read the reply and return the result of the
+ * command.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ *
+ * @return SR_OK on success, SR_ERR on failure.
+ */
+SR_PRIV int sr_scpi_get_opc(struct sr_scpi_dev_inst *scpi)
+{
+       unsigned int i;
+       gboolean opc;
+
+       for (i = 0; i < SCPI_READ_RETRIES; ++i) {
+               sr_scpi_get_bool(scpi, SCPI_CMD_OPC, &opc);
+               if (opc)
+                       return SR_OK;
+               g_usleep(SCPI_READ_RETRY_TIMEOUT);
+       }
+
+       return SR_ERR;
+}
+
+/**
+ * Send a SCPI command, read the reply, parse it as comma separated list of
+ * floats and store the as an result in scpi_response.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ * @param command The SCPI command to send to the device (can be NULL).
+ * @param scpi_response Pointer where to store the parsed result.
+ *
+ * @return SR_OK upon successfully parsing all values, SR_ERR upon a parsing
+ *         error or upon no response. The allocated response must be freed by
+ *         the caller in the case of an SR_OK as well as in the case of
+ *         parsing error.
+ */
+SR_PRIV int sr_scpi_get_floatv(struct sr_scpi_dev_inst *scpi,
+                              const char *command, GArray **scpi_response)
+{
+       int ret;
+       float tmp;
+       char *response;
+       gchar **ptr, **tokens;
+       GArray *response_array;
+
+       ret = SR_OK;
+       response = NULL;
+       tokens = NULL;
+
+       if (sr_scpi_get_string(scpi, command, &response) != SR_OK)
+               if (!response)
+                       return SR_ERR;
+
+       tokens = g_strsplit(response, ",", 0);
+       ptr = tokens;
+
+       response_array = g_array_sized_new(TRUE, FALSE, sizeof(float), 256);
+
+       while (*ptr) {
+               if (sr_atof_ascii(*ptr, &tmp) == SR_OK)
+                       response_array = g_array_append_val(response_array,
+                                                           tmp);
+               else
+                       ret = SR_ERR;
+
+               ptr++;
+       }
+       g_strfreev(tokens);
+       g_free(response);
+
+       if (ret == SR_ERR && response_array->len == 0) {
+               g_array_free(response_array, TRUE);
+               *scpi_response = NULL;
+               return SR_ERR;
+       }
+
+       *scpi_response = response_array;
+
+       return ret;
+}
+
+/**
+ * Send a SCPI command, read the reply, parse it as comma separated list of
+ * unsigned 8 bit integers and store the as an result in scpi_response.
+ *
+ * @param scpi Previously initialised SCPI device structure.
+ * @param command The SCPI command to send to the device (can be NULL).
+ * @param scpi_response Pointer where to store the parsed result.
+ *
+ * @return SR_OK upon successfully parsing all values, SR_ERR upon a parsing
+ *         error or upon no response. The allocated response must be freed by
+ *         the caller in the case of an SR_OK as well as in the case of
+ *         parsing error.
+ */
+SR_PRIV int sr_scpi_get_uint8v(struct sr_scpi_dev_inst *scpi,
+                              const char *command, GArray **scpi_response)
+{
+       int tmp, ret;
+       char *response;
+       gchar **ptr, **tokens;
+       GArray *response_array;
+
+       ret = SR_OK;
+       response = NULL;
+       tokens = NULL;
+
+       if (sr_scpi_get_string(scpi, command, &response) != SR_OK)
+               if (!response)
+                       return SR_ERR;
+
+       tokens = g_strsplit(response, ",", 0);
+       ptr = tokens;
+
+       response_array = g_array_sized_new(TRUE, FALSE, sizeof(uint8_t), 256);
+
+       while (*ptr) {
+               if (sr_atoi(*ptr, &tmp) == SR_OK)
+                       response_array = g_array_append_val(response_array,
+                                                           tmp);
+               else
+                       ret = SR_ERR;
+
+               ptr++;
+       }
+       g_strfreev(tokens);
+       g_free(response);
+
+       if (response_array->len == 0) {
+               g_array_free(response_array, TRUE);
+               *scpi_response = NULL;
+               return SR_ERR;
+       }
+
+       *scpi_response = response_array;
+
+       return ret;
+}
+
 /**
  * Send the *IDN? SCPI command, receive the reply, parse it and store the
  * reply as a sr_scpi_hw_info structure in the supplied scpi_response pointer.
  *
- * @param serial Previously initialized serial port structure.
+ * The hw_info structure must be freed by the caller via sr_scpi_hw_info_free().
+ *
+ * @param scpi Previously initialised SCPI device structure.
  * @param scpi_response Pointer where to store the hw_info structure.
  *
  * @return SR_OK upon success, SR_ERR on failure.
- * The hw_info structure must be freed by the caller with sr_scpi_hw_info_free().
  */
-SR_PRIV int sr_scpi_get_hw_id(struct sr_serial_dev_inst *serial,
+SR_PRIV int sr_scpi_get_hw_id(struct sr_scpi_dev_inst *scpi,
                              struct sr_scpi_hw_info **scpi_response)
 {
        int num_tokens;
        char *response;
        gchar **tokens;
-
        struct sr_scpi_hw_info *hw_info;
 
        response = NULL;
        tokens = NULL;
 
-       if (sr_scpi_get_string(serial, SCPI_CMD_IDN, &response) != SR_OK)
+       if (sr_scpi_get_string(scpi, SCPI_CMD_IDN, &response) != SR_OK)
                if (!response)
                        return SR_ERR;
 
+       sr_info("Got IDN string: '%s'", response);
+
        /*
         * The response to a '*IDN?' is specified by the SCPI spec. It contains
         * a comma-separated list containing the manufacturer name, instrument
@@ -343,7 +708,7 @@ SR_PRIV int sr_scpi_get_hw_id(struct sr_serial_dev_inst *serial,
        for (num_tokens = 0; tokens[num_tokens] != NULL; num_tokens++);
 
        if (num_tokens != 4) {
-               sr_dbg("IDN response not according to spec: %80.s", response);
+               sr_dbg("IDN response not according to spec: %80.s.", response);
                g_strfreev(tokens);
                g_free(response);
                return SR_ERR;