]> sigrok.org Git - libsigrok.git/blobdiff - src/hardware/hameg-hmo/api.c
drivers: Factor out std_*_idx*().
[libsigrok.git] / src / hardware / hameg-hmo / api.c
index 77feac8637d54c00d039fd761cf5a39794bba0d3..f7ec7149b93cc14cbadc2de303ad797bffe0195c 100644 (file)
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <config.h>
 #include <stdlib.h>
+#include "scpi.h"
 #include "protocol.h"
 
 #define SERIALCOMM "115200/8n1/flow=1"
 
-SR_PRIV struct sr_dev_driver hameg_hmo_driver_info;
-static struct sr_dev_driver *di = &hameg_hmo_driver_info;
+static struct sr_dev_driver hameg_hmo_driver_info;
 
 static const char *manufacturers[] = {
        "HAMEG",
-};
-
-static const uint32_t drvopts[] = {
-       SR_CONF_OSCILLOSCOPE,
+       "Rohde&Schwarz",
 };
 
 static const uint32_t scanopts[] = {
@@ -38,6 +36,10 @@ static const uint32_t scanopts[] = {
        SR_CONF_SERIALCOMM,
 };
 
+static const uint32_t drvopts[] = {
+       SR_CONF_OSCILLOSCOPE,
+};
+
 enum {
        CG_INVALID = -1,
        CG_NONE,
@@ -45,22 +47,6 @@ enum {
        CG_DIGITAL,
 };
 
-static int init(struct sr_context *sr_ctx)
-{
-       return std_init(sr_ctx, di, LOG_PREFIX);
-}
-
-static int check_manufacturer(const char *manufacturer)
-{
-       unsigned int i;
-
-       for (i = 0; i < ARRAY_SIZE(manufacturers); ++i)
-               if (!strcmp(manufacturer, manufacturers[i]))
-                       return SR_OK;
-
-       return SR_ERR;
-}
-
 static struct sr_dev_inst *hmo_probe_serial_device(struct sr_scpi_dev_inst *scpi)
 {
        struct sr_dev_inst *sdi;
@@ -76,16 +62,15 @@ static struct sr_dev_inst *hmo_probe_serial_device(struct sr_scpi_dev_inst *scpi
                goto fail;
        }
 
-       if (check_manufacturer(hw_info->manufacturer) != SR_OK)
+       if (std_str_idx_s(hw_info->manufacturer, ARRAY_AND_SIZE(manufacturers)) < 0)
                goto fail;
 
        sdi = g_malloc0(sizeof(struct sr_dev_inst));
-       sdi->status = SR_ST_ACTIVE;
        sdi->vendor = g_strdup(hw_info->manufacturer);
        sdi->model = g_strdup(hw_info->model);
        sdi->version = g_strdup(hw_info->firmware_version);
        sdi->serial_num = g_strdup(hw_info->serial_number);
-       sdi->driver = di;
+       sdi->driver = &hameg_hmo_driver_info;
        sdi->inst_type = SR_INST_SCPI;
        sdi->conn = scpi;
 
@@ -99,100 +84,65 @@ static struct sr_dev_inst *hmo_probe_serial_device(struct sr_scpi_dev_inst *scpi
        if (hmo_init_device(sdi) != SR_OK)
                goto fail;
 
-       sr_scpi_close(sdi->conn);
-
-       sdi->status = SR_ST_INACTIVE;
-
        return sdi;
 
 fail:
-       if (hw_info)
-               sr_scpi_hw_info_free(hw_info);
-       if (sdi)
-               sr_dev_inst_free(sdi);
-       if (devc)
-               g_free(devc);
+       sr_scpi_hw_info_free(hw_info);
+       sr_dev_inst_free(sdi);
+       g_free(devc);
 
        return NULL;
 }
 
-static GSList *scan(GSList *options)
+static GSList *scan(struct sr_dev_driver *di, GSList *options)
 {
-       return sr_scpi_scan(di->priv, options, hmo_probe_serial_device);
+       return sr_scpi_scan(di->context, options, hmo_probe_serial_device);
 }
 
-static GSList *dev_list(void)
+static void clear_helper(struct dev_context *devc)
 {
-       return ((struct drv_context *)(di->priv))->instances;
-}
-
-static void clear_helper(void *priv)
-{
-       struct dev_context *devc;
-
-       devc = priv;
-
        hmo_scope_state_free(devc->model_state);
-
        g_free(devc->analog_groups);
        g_free(devc->digital_groups);
-
-       g_free(devc);
 }
 
-static int dev_clear(void)
+static int dev_clear(const struct sr_dev_driver *di)
 {
-       return std_dev_clear(di, clear_helper);
+       return std_dev_clear_with_callback(di, (std_dev_clear_callback)clear_helper);
 }
 
 static int dev_open(struct sr_dev_inst *sdi)
 {
-       if (sdi->status != SR_ST_ACTIVE && sr_scpi_open(sdi->conn) != SR_OK)
+       if (sr_scpi_open(sdi->conn) != SR_OK)
                return SR_ERR;
 
        if (hmo_scope_state_get(sdi) != SR_OK)
                return SR_ERR;
 
-       sdi->status = SR_ST_ACTIVE;
-
        return SR_OK;
 }
 
 static int dev_close(struct sr_dev_inst *sdi)
 {
-       if (sdi->status == SR_ST_INACTIVE)
-               return SR_OK;
-
-       sr_scpi_close(sdi->conn);
-
-       sdi->status = SR_ST_INACTIVE;
-
-       return SR_OK;
-}
-
-static int cleanup(void)
-{
-       dev_clear();
-
-       return SR_OK;
+       return sr_scpi_close(sdi->conn);
 }
 
 static int check_channel_group(struct dev_context *devc,
                             const struct sr_channel_group *cg)
 {
        unsigned int i;
-       struct scope_config *model;
+       const struct scope_config *model;
 
        model = devc->model_config;
 
        if (!cg)
                return CG_NONE;
 
-       for (i = 0; i < model->analog_channels; ++i)
+       for (i = 0; i < model->analog_channels; i++)
                if (cg == devc->analog_groups[i])
                        return CG_ANALOG;
 
-       for (i = 0; i < model->digital_pods; ++i)
+       for (i = 0; i < model->digital_pods; i++)
                if (cg == devc->digital_groups[i])
                        return CG_DIGITAL;
 
@@ -201,18 +151,20 @@ static int check_channel_group(struct dev_context *devc,
        return CG_INVALID;
 }
 
-static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
-                     const struct sr_channel_group *cg)
+static int config_get(uint32_t key, GVariant **data,
+       const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 {
        int ret, cg_type;
        unsigned int i;
        struct dev_context *devc;
-       struct scope_config *model;
+       const struct scope_config *model;
        struct scope_state *state;
 
-       if (!sdi || !(devc = sdi->priv))
+       if (!sdi)
                return SR_ERR_ARG;
 
+       devc = sdi->priv;
+
        if ((cg_type = check_channel_group(devc, cg)) == CG_INVALID)
                return SR_ERR;
 
@@ -232,10 +184,9 @@ static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *s
                break;
        case SR_CONF_NUM_VDIV:
                if (cg_type == CG_NONE) {
-                       sr_err("No channel group specified.");
                        return SR_ERR_CHANNEL_GROUP;
                } else if (cg_type == CG_ANALOG) {
-                       for (i = 0; i < model->analog_channels; ++i) {
+                       for (i = 0; i < model->analog_channels; i++) {
                                if (cg != devc->analog_groups[i])
                                        continue;
                                *data = g_variant_new_int32(model->num_ydivs);
@@ -249,10 +200,9 @@ static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *s
                break;
        case SR_CONF_VDIV:
                if (cg_type == CG_NONE) {
-                       sr_err("No channel group specified.");
                        return SR_ERR_CHANNEL_GROUP;
                } else if (cg_type == CG_ANALOG) {
-                       for (i = 0; i < model->analog_channels; ++i) {
+                       for (i = 0; i < model->analog_channels; i++) {
                                if (cg != devc->analog_groups[i])
                                        continue;
                                *data = g_variant_new("(tt)",
@@ -280,10 +230,9 @@ static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *s
                break;
        case SR_CONF_COUPLING:
                if (cg_type == CG_NONE) {
-                       sr_err("No channel group specified.");
                        return SR_ERR_CHANNEL_GROUP;
                } else if (cg_type == CG_ANALOG) {
-                       for (i = 0; i < model->analog_channels; ++i) {
+                       for (i = 0; i < model->analog_channels; i++) {
                                if (cg != devc->analog_groups[i])
                                        continue;
                                *data = g_variant_new_string((*model->coupling_options)[state->analog_channels[i].coupling]);
@@ -306,42 +255,24 @@ static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *s
        return ret;
 }
 
-static GVariant *build_tuples(const uint64_t (*array)[][2], unsigned int n)
+static int config_set(uint32_t key, GVariant *data,
+       const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 {
-       unsigned int i;
-       GVariant *rational[2];
-       GVariantBuilder gvb;
-
-       g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
-
-       for (i = 0; i < n; i++) {
-               rational[0] = g_variant_new_uint64((*array)[i][0]);
-               rational[1] = g_variant_new_uint64((*array)[i][1]);
-
-               /* FIXME: Valgrind reports a memory leak here. */
-               g_variant_builder_add_value(&gvb, g_variant_new_tuple(rational, 2));
-       }
-
-       return g_variant_builder_end(&gvb);
-}
-
-static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sdi,
-                     const struct sr_channel_group *cg)
-{
-       int ret, cg_type;
+       int ret, cg_type, idx;
        unsigned int i, j;
        char command[MAX_COMMAND_SIZE], float_str[30];
        struct dev_context *devc;
-       struct scope_config *model;
+       const struct scope_config *model;
        struct scope_state *state;
        const char *tmp;
-       uint64_t p, q;
        double tmp_d;
        gboolean update_sample_rate;
 
-       if (!sdi || !(devc = sdi->priv))
+       if (!sdi)
                return SR_ERR_ARG;
 
+       devc = sdi->priv;
+
        if ((cg_type = check_channel_group(devc, cg)) == CG_INVALID)
                return SR_ERR;
 
@@ -371,54 +302,37 @@ static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sd
                }
                break;
        case SR_CONF_VDIV:
-               if (cg_type == CG_NONE) {
-                       sr_err("No channel group specified.");
+               if (cg_type == CG_NONE)
                        return SR_ERR_CHANNEL_GROUP;
-               }
-
-               g_variant_get(data, "(tt)", &p, &q);
-
-               for (i = 0; i < model->num_vdivs; i++) {
-                       if (p != (*model->vdivs)[i][0] ||
-                           q != (*model->vdivs)[i][1])
+               if ((idx = std_u64_tuple_idx(data, *model->vdivs, model->num_vdivs)) < 0)
+                       return SR_ERR_ARG;
+               for (j = 1; j <= model->analog_channels; j++) {
+                       if (cg != devc->analog_groups[j - 1])
                                continue;
-                       for (j = 1; j <= model->analog_channels; ++j) {
-                               if (cg != devc->analog_groups[j - 1])
-                                       continue;
-                               state->analog_channels[j - 1].vdiv = i;
-                               g_ascii_formatd(float_str, sizeof(float_str), "%E", (float) p / q);
-                               g_snprintf(command, sizeof(command),
-                                          (*model->scpi_dialect)[SCPI_CMD_SET_VERTICAL_DIV],
-                                          j, float_str);
-
-                               if (sr_scpi_send(sdi->conn, command) != SR_OK ||
-                                   sr_scpi_get_opc(sdi->conn) != SR_OK)
-                                       return SR_ERR;
-
-                               break;
-                       }
-
-                       ret = SR_OK;
+                       state->analog_channels[j - 1].vdiv = idx;
+                       g_ascii_formatd(float_str, sizeof(float_str), "%E",
+                               (float) (*model->vdivs)[idx][0] / (*model->vdivs)[idx][1]);
+                       g_snprintf(command, sizeof(command),
+                                  (*model->scpi_dialect)[SCPI_CMD_SET_VERTICAL_DIV],
+                                  j, float_str);
+                       if (sr_scpi_send(sdi->conn, command) != SR_OK ||
+                           sr_scpi_get_opc(sdi->conn) != SR_OK)
+                               return SR_ERR;
                        break;
                }
+               ret = SR_OK;
                break;
        case SR_CONF_TIMEBASE:
-               g_variant_get(data, "(tt)", &p, &q);
-
-               for (i = 0; i < model->num_timebases; i++) {
-                       if (p != (*model->timebases)[i][0] ||
-                           q != (*model->timebases)[i][1])
-                               continue;
-                       state->timebase = i;
-                       g_ascii_formatd(float_str, sizeof(float_str), "%E", (float) p / q);
-                       g_snprintf(command, sizeof(command),
-                                  (*model->scpi_dialect)[SCPI_CMD_SET_TIMEBASE],
-                                  float_str);
-
-                       ret = sr_scpi_send(sdi->conn, command);
-                       update_sample_rate = TRUE;
-                       break;
-               }
+               if ((idx = std_u64_tuple_idx(data, *model->timebases, model->num_timebases)) < 0)
+                       return SR_ERR_ARG;
+               state->timebase = idx;
+               g_ascii_formatd(float_str, sizeof(float_str), "%E",
+                       (float) (*model->timebases)[idx][0] / (*model->timebases)[idx][1]);
+               g_snprintf(command, sizeof(command),
+                          (*model->scpi_dialect)[SCPI_CMD_SET_TIMEBASE],
+                          float_str);
+               ret = sr_scpi_send(sdi->conn, command);
+               update_sample_rate = TRUE;
                break;
        case SR_CONF_HORIZ_TRIGGERPOS:
                tmp_d = g_variant_get_double(data);
@@ -441,30 +355,28 @@ static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sd
                break;
        case SR_CONF_TRIGGER_SLOPE:
                tmp = g_variant_get_string(data, NULL);
+               for (i = 0; (*model->trigger_slopes)[i]; i++) {
+                       if (g_strcmp0(tmp, (*model->trigger_slopes)[i]) != 0)
+                               continue;
+                       state->trigger_slope = i;
+                       g_snprintf(command, sizeof(command),
+                                  (*model->scpi_dialect)[SCPI_CMD_SET_TRIGGER_SLOPE],
+                                  (*model->trigger_slopes)[i]);
 
-               if (!tmp || !(tmp[0] == 'f' || tmp[0] == 'r'))
-                       return SR_ERR_ARG;
-
-               state->trigger_slope = (tmp[0] == 'r') ? 0 : 1;
-
-               g_snprintf(command, sizeof(command),
-                          (*model->scpi_dialect)[SCPI_CMD_SET_TRIGGER_SLOPE],
-                          (state->trigger_slope == 0) ? "POS" : "NEG");
-
-               ret = sr_scpi_send(sdi->conn, command);
+                       ret = sr_scpi_send(sdi->conn, command);
+                       break;
+               }
                break;
        case SR_CONF_COUPLING:
-               if (cg_type == CG_NONE) {
-                       sr_err("No channel group specified.");
+               if (cg_type == CG_NONE)
                        return SR_ERR_CHANNEL_GROUP;
-               }
 
                tmp = g_variant_get_string(data, NULL);
 
                for (i = 0; (*model->coupling_options)[i]; i++) {
                        if (strcmp(tmp, (*model->coupling_options)[i]) != 0)
                                continue;
-                       for (j = 1; j <= model->analog_channels; ++j) {
+                       for (j = 1; j <= model->analog_channels; j++) {
                                if (cg != devc->analog_groups[j - 1])
                                        continue;
                                state->analog_channels[j-1].coupling = i;
@@ -497,14 +409,15 @@ static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sd
        return ret;
 }
 
-static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
-                      const struct sr_channel_group *cg)
+static int config_list(uint32_t key, GVariant **data,
+       const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 {
        int cg_type = CG_NONE;
        struct dev_context *devc = NULL;
-       struct scope_config *model = NULL;
+       const struct scope_config *model = NULL;
 
-       if (sdi && (devc = sdi->priv)) {
+       if (sdi) {
+               devc = sdi->priv;
                if ((cg_type = check_channel_group(devc, cg)) == CG_INVALID)
                        return SR_ERR;
 
@@ -513,24 +426,18 @@ static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *
 
        switch (key) {
        case SR_CONF_SCAN_OPTIONS:
-               *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
-                               scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
+               *data = std_gvar_array_u32(ARRAY_AND_SIZE(scanopts));
                break;
        case SR_CONF_DEVICE_OPTIONS:
                if (cg_type == CG_NONE) {
                        if (model)
-                               *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
-                                       model->devopts, model->num_devopts, sizeof(uint32_t));
+                               *data = std_gvar_array_u32((const uint32_t *)model->devopts, model->num_devopts);
                        else
-                               *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
-                                       drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
+                               *data = std_gvar_array_u32(ARRAY_AND_SIZE(drvopts));
                } else if (cg_type == CG_ANALOG) {
-                       *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
-                               model->analog_devopts, model->num_analog_devopts,
-                               sizeof(uint32_t));
+                       *data = std_gvar_array_u32((const uint32_t *)model->devopts_cg_analog, model->num_devopts_cg_analog);
                } else {
-                       *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
-                               NULL, 0, sizeof(uint32_t));
+                       *data = std_gvar_array_u32(NULL, 0);
                }
                break;
        case SR_CONF_COUPLING:
@@ -554,12 +461,12 @@ static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *
        case SR_CONF_TIMEBASE:
                if (!model)
                        return SR_ERR_ARG;
-               *data = build_tuples(model->timebases, model->num_timebases);
+               *data = std_gvar_tuple_array(*model->timebases, model->num_timebases);
                break;
        case SR_CONF_VDIV:
                if (cg_type == CG_NONE)
                        return SR_ERR_CHANNEL_GROUP;
-               *data = build_tuples(model->vdivs, model->num_vdivs);
+               *data = std_gvar_tuple_array(*model->vdivs, model->num_vdivs);
                break;
        default:
                return SR_ERR_NA;
@@ -573,7 +480,7 @@ SR_PRIV int hmo_request_data(const struct sr_dev_inst *sdi)
        char command[MAX_COMMAND_SIZE];
        struct sr_channel *ch;
        struct dev_context *devc;
-       struct scope_config *model;
+       const struct scope_config *model;
 
        devc = sdi->priv;
        model = devc->model_config;
@@ -584,6 +491,11 @@ SR_PRIV int hmo_request_data(const struct sr_dev_inst *sdi)
        case SR_CHANNEL_ANALOG:
                g_snprintf(command, sizeof(command),
                           (*model->scpi_dialect)[SCPI_CMD_GET_ANALOG_DATA],
+#ifdef WORDS_BIGENDIAN
+                          "MSBF",
+#else
+                          "LSBF",
+#endif
                           ch->index + 1);
                break;
        case SR_CHANNEL_LOGIC:
@@ -603,34 +515,50 @@ static int hmo_check_channels(GSList *channels)
 {
        GSList *l;
        struct sr_channel *ch;
-       gboolean enabled_pod1, enabled_pod2, enabled_chan3, enabled_chan4;
-
-       enabled_pod1 = enabled_pod2 = enabled_chan3 = enabled_chan4 = FALSE;
-
+       gboolean enabled_chan[MAX_ANALOG_CHANNEL_COUNT];
+       gboolean enabled_pod[MAX_DIGITAL_GROUP_COUNT];
+       size_t idx;
+
+       /* Preset "not enabled" for all channels / pods. */
+       for (idx = 0; idx < ARRAY_SIZE(enabled_chan); idx++)
+               enabled_chan[idx] = FALSE;
+       for (idx = 0; idx < ARRAY_SIZE(enabled_pod); idx++)
+               enabled_pod[idx] = FALSE;
+
+       /*
+        * Determine which channels / pods are required for the caller's
+        * specified configuration.
+        */
        for (l = channels; l; l = l->next) {
                ch = l->data;
                switch (ch->type) {
                case SR_CHANNEL_ANALOG:
-                       if (ch->index == 2)
-                               enabled_chan3 = TRUE;
-                       else if (ch->index == 3)
-                               enabled_chan4 = TRUE;
+                       idx = ch->index;
+                       if (idx < ARRAY_SIZE(enabled_chan))
+                               enabled_chan[idx] = TRUE;
                        break;
                case SR_CHANNEL_LOGIC:
-                       if (ch->index < 8)
-                               enabled_pod1 = TRUE;
-                       else
-                               enabled_pod2 = TRUE;
+                       idx = ch->index / 8;
+                       if (idx < ARRAY_SIZE(enabled_pod))
+                               enabled_pod[idx] = TRUE;
                        break;
                default:
                        return SR_ERR;
                }
        }
 
-       if ((enabled_pod1 && enabled_chan3) ||
-           (enabled_pod2 && enabled_chan4))
+       /*
+        * Check for resource conflicts. Some channels can be either
+        * analog or digital, but never both at the same time.
+        *
+        * Note that the constraints might depend on the specific model.
+        * These tests might need some adjustment when support for more
+        * models gets added to the driver.
+        */
+       if (enabled_pod[0] && enabled_chan[2])
+               return SR_ERR;
+       if (enabled_pod[1] && enabled_chan[3])
                return SR_ERR;
-
        return SR_OK;
 }
 
@@ -641,7 +569,7 @@ static int hmo_setup_channels(const struct sr_dev_inst *sdi)
        gboolean *pod_enabled, setup_changed;
        char command[MAX_COMMAND_SIZE];
        struct scope_state *state;
-       struct scope_config *model;
+       const struct scope_config *model;
        struct sr_channel *ch;
        struct dev_context *devc;
        struct sr_scpi_dev_inst *scpi;
@@ -694,7 +622,7 @@ static int hmo_setup_channels(const struct sr_dev_inst *sdi)
                }
        }
 
-       for (i = 1; i <= model->digital_pods; ++i) {
+       for (i = 1; i <= model->digital_pods; i++) {
                if (state->digital_pods[i - 1] == pod_enabled[i - 1])
                        continue;
                g_snprintf(command, sizeof(command),
@@ -714,75 +642,96 @@ static int hmo_setup_channels(const struct sr_dev_inst *sdi)
        return SR_OK;
 }
 
-static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
+static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 {
        GSList *l;
-       gboolean digital_added;
+       gboolean digital_added[MAX_DIGITAL_GROUP_COUNT];
+       size_t group, pod_count;
        struct sr_channel *ch;
        struct dev_context *devc;
        struct sr_scpi_dev_inst *scpi;
-
-       if (sdi->status != SR_ST_ACTIVE)
-               return SR_ERR_DEV_CLOSED;
+       int ret;
 
        scpi = sdi->conn;
        devc = sdi->priv;
-       digital_added = FALSE;
 
+       /* Preset empty results. */
+       for (group = 0; group < ARRAY_SIZE(digital_added); group++)
+               digital_added[group] = FALSE;
        g_slist_free(devc->enabled_channels);
        devc->enabled_channels = NULL;
 
+       /*
+        * Contruct the list of enabled channels. Determine the highest
+        * number of digital pods involved in the acquisition.
+        */
+       pod_count = 0;
        for (l = sdi->channels; l; l = l->next) {
                ch = l->data;
                if (!ch->enabled)
                        continue;
-               /* Only add a single digital channel. */
-               if (ch->type != SR_CHANNEL_LOGIC || !digital_added) {
+               /* Only add a single digital channel per group (pod). */
+               group = ch->index / 8;
+               if (ch->type != SR_CHANNEL_LOGIC || !digital_added[group]) {
                        devc->enabled_channels = g_slist_append(
                                        devc->enabled_channels, ch);
-                       if (ch->type == SR_CHANNEL_LOGIC)
-                               digital_added = TRUE;
+                       if (ch->type == SR_CHANNEL_LOGIC) {
+                               digital_added[group] = TRUE;
+                               if (pod_count < group + 1)
+                                       pod_count = group + 1;
+                       }
                }
        }
-
        if (!devc->enabled_channels)
                return SR_ERR;
+       devc->pod_count = pod_count;
+       devc->logic_data = NULL;
 
+       /*
+        * Check constraints. Some channels can be either analog or
+        * digital, but not both at the same time.
+        */
        if (hmo_check_channels(devc->enabled_channels) != SR_OK) {
                sr_err("Invalid channel configuration specified!");
-               return SR_ERR_NA;
+               ret = SR_ERR_NA;
+               goto free_enabled;
        }
 
+       /*
+        * Configure the analog and digital channels and the
+        * corresponding digital pods.
+        */
        if (hmo_setup_channels(sdi) != SR_OK) {
                sr_err("Failed to setup channel configuration!");
-               return SR_ERR;
+               ret = SR_ERR;
+               goto free_enabled;
        }
 
+       /*
+        * Start acquisition on the first enabled channel. The
+        * receive routine will continue driving the acquisition.
+        */
        sr_scpi_source_add(sdi->session, scpi, G_IO_IN, 50,
                        hmo_receive_data, (void *)sdi);
 
-       /* Send header packet to the session bus. */
-       std_session_send_df_header(cb_data, LOG_PREFIX);
+       std_session_send_df_header(sdi);
 
        devc->current_channel = devc->enabled_channels;
 
        return hmo_request_data(sdi);
+
+free_enabled:
+       g_slist_free(devc->enabled_channels);
+       devc->enabled_channels = NULL;
+       return ret;
 }
 
-static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
+static int dev_acquisition_stop(struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
        struct sr_scpi_dev_inst *scpi;
-       struct sr_datafeed_packet packet;
-
-       (void)cb_data;
-
-       packet.type = SR_DF_END;
-       packet.payload = NULL;
-       sr_session_send(sdi, &packet);
 
-       if (sdi->status != SR_ST_ACTIVE)
-               return SR_ERR_DEV_CLOSED;
+       std_session_send_df_end(sdi);
 
        devc = sdi->priv;
 
@@ -795,14 +744,14 @@ static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
        return SR_OK;
 }
 
-SR_PRIV struct sr_dev_driver hameg_hmo_driver_info = {
+static struct sr_dev_driver hameg_hmo_driver_info = {
        .name = "hameg-hmo",
        .longname = "Hameg HMO",
        .api_version = 1,
-       .init = init,
-       .cleanup = cleanup,
+       .init = std_init,
+       .cleanup = std_cleanup,
        .scan = scan,
-       .dev_list = dev_list,
+       .dev_list = std_dev_list,
        .dev_clear = dev_clear,
        .config_get = config_get,
        .config_set = config_set,
@@ -811,5 +760,6 @@ SR_PRIV struct sr_dev_driver hameg_hmo_driver_info = {
        .dev_close = dev_close,
        .dev_acquisition_start = dev_acquisition_start,
        .dev_acquisition_stop = dev_acquisition_stop,
-       .priv = NULL,
+       .context = NULL,
 };
+SR_REGISTER_DEV_DRIVER(hameg_hmo_driver_info);