scpi-pps: Add shadow driver for HPIB supplies (ID? instead of *IDN?)

HP instruments predating the 488.2 and SCPI standards do not
necessarily have a SCPI-compliant command set. The HP6630A series of
supplies is one such example.

While scpi-pps is flexible enough to accomodate almost any command
syntax given the right profile, it still assumes that "*IDN?" is the
correct question to ask the instrument. Since older HP gear instead
responds to "ID?", this assumption is no longer true.

Thus sr_scpi_get_hw_id() is not appropriate for these instruments, and
the shadow driver added here only replaces that function call, while
reusing the rest of the existing logic. The extra noise is necessary
in order to propagate this through the .scan member of the driver.

diff --git a/src/hardware/scpi-pps/api.c b/src/hardware/scpi-pps/api.c
index c3e5d5d4ad6a90607fcea56a9304ed94889cedba..ad3d0a379ea89a7e233d954181e645d8ed117151 100644 (file)
--- a/src/hardware/scpi-pps/api.c
+++ b/src/hardware/scpi-pps/api.c
@@ -24,6 +24,7 @@
 #include "protocol.h"
 
 static struct sr_dev_driver scpi_pps_driver_info;
+static struct sr_dev_driver hp_ib_pps_driver_info;
 
 static const uint32_t scanopts[] = {
        SR_CONF_CONN,
@@ -41,7 +42,10 @@ static const struct pps_channel_instance pci[] = {
        { SR_MQ_FREQUENCY, SCPI_CMD_GET_MEAS_FREQUENCY, "F" },
 };
 
-static struct sr_dev_inst *probe_device(struct sr_scpi_dev_inst *scpi)
+static struct sr_dev_inst *probe_device(struct sr_scpi_dev_inst *scpi,
+                                       int (*get_hw_id)(struct sr_scpi_dev_inst *scpi,
+                                                       struct sr_scpi_hw_info **scpi_response)
+                          )
 {
        struct dev_context *devc;
        struct sr_dev_inst *sdi;
@@ -62,7 +66,7 @@ static struct sr_dev_inst *probe_device(struct sr_scpi_dev_inst *scpi)
        const char *vendor;
        char ch_name[16];
 
-       if (sr_scpi_get_hw_id(scpi, &hw_info) != SR_OK) {
+       if (get_hw_id(scpi, &hw_info) != SR_OK) {
                sr_info("Couldn't get IDN response.");
                return NULL;
        }
@@ -166,9 +170,80 @@ static struct sr_dev_inst *probe_device(struct sr_scpi_dev_inst *scpi)
        return sdi;
 }
 
-static GSList *scan(struct sr_dev_driver *di, GSList *options)
+static gchar *hpib_get_revision(struct sr_scpi_dev_inst *scpi)
 {
-       return sr_scpi_scan(di->context, options, probe_device);
+       int ret;
+       gboolean matches;
+       char *response;
+       GRegex *version_regex;
+
+       ret = sr_scpi_get_string(scpi, "ROM?", &response);
+       if (ret != SR_OK && !response)
+               return NULL;
+
+       /* Example version string: "B01 B01" */
+       version_regex = g_regex_new("[A-Z][0-9]{2} [A-Z][0-9]{2}", 0, 0, NULL);
+       matches = g_regex_match(version_regex, response, 0, NULL);
+       g_regex_unref(version_regex);
+
+       if (!matches) {
+               /* Not a valid version string. Ignore it. */
+               g_free(response);
+               response = NULL;
+       } else {
+               /* Replace space with dot. */
+               response[3] = '.';
+       }
+
+       return response;
+}
+
+/*
+ * This function assumes the response is in the form "HP<model_number>"
+ *
+ * HP made many GPIB (then called HP-IB) instruments before the SCPI command
+ * set was introduced into the standard. We haven't seen any non-HP instruments
+ * which respond to the "ID?" query, so assume all are HP for now.
+ */
+static int hpib_get_hw_id(struct sr_scpi_dev_inst *scpi,
+                         struct sr_scpi_hw_info **scpi_response)
+{
+       int ret;
+       char *response;
+       struct sr_scpi_hw_info *hw_info;
+
+       ret = sr_scpi_get_string(scpi, "ID?", &response);
+       if ((ret != SR_OK) || !response)
+               return SR_ERR;
+
+       hw_info = g_malloc0(sizeof(struct sr_scpi_hw_info));
+
+       *scpi_response = hw_info;
+       hw_info->model = response;
+       hw_info->firmware_version = hpib_get_revision(scpi);
+       hw_info->manufacturer = g_strdup("HP");
+
+       return SR_OK;
+}
+
+static struct sr_dev_inst *probe_scpi_pps_device(struct sr_scpi_dev_inst *scpi)
+{
+       return probe_device(scpi, sr_scpi_get_hw_id);
+}
+
+static struct sr_dev_inst *probe_hpib_pps_device(struct sr_scpi_dev_inst *scpi)
+{
+       return probe_device(scpi, hpib_get_hw_id);
+}
+
+static GSList *scan_scpi_pps(struct sr_dev_driver *di, GSList *options)
+{
+       return sr_scpi_scan(di->context, options, probe_scpi_pps_device);
+}
+
+static GSList *scan_hpib_pps(struct sr_dev_driver *di, GSList *options)
+{
+       return sr_scpi_scan(di->context, options, probe_hpib_pps_device);
 }
 
 static int dev_open(struct sr_dev_inst *sdi)
@@ -628,7 +703,26 @@ static struct sr_dev_driver scpi_pps_driver_info = {
        .api_version = 1,
        .init = std_init,
        .cleanup = std_cleanup,
-       .scan = scan,
+       .scan = scan_scpi_pps,
+       .dev_list = std_dev_list,
+       .dev_clear = dev_clear,
+       .config_get = config_get,
+       .config_set = config_set,
+       .config_list = config_list,
+       .dev_open = dev_open,
+       .dev_close = dev_close,
+       .dev_acquisition_start = dev_acquisition_start,
+       .dev_acquisition_stop = dev_acquisition_stop,
+       .context = NULL,
+};
+
+static struct sr_dev_driver hp_ib_pps_driver_info = {
+       .name = "hpib-pps",
+       .longname = "HP-IB PPS",
+       .api_version = 1,
+       .init = std_init,
+       .cleanup = std_cleanup,
+       .scan = scan_hpib_pps,
        .dev_list = std_dev_list,
        .dev_clear = dev_clear,
        .config_get = config_get,
@@ -641,3 +735,4 @@ static struct sr_dev_driver scpi_pps_driver_info = {
        .context = NULL,
 };
 SR_REGISTER_DEV_DRIVER(scpi_pps_driver_info);
+SR_REGISTER_DEV_DRIVER(hp_ib_pps_driver_info);