rdtech-dps: rephrase how model specific ranges are handled

Commit 02a4f485de76 implemented ranges support such that _all_ models
including every RD as well as DPS device announced ranges, it's just
that most of them happen to support a single range.

Use this fact, accept any zero based index, and drop the "normalization"
to strict 0/1 values except for one RD specific code path when getting
the current state of multi-range supporting devices. Tell models with
"effectively no ranges" from devices which "support multile ranges".
This shall increase robustness and improve maintainability. Simplifies
future extensions when more ranges are involved.

diff --git a/src/hardware/rdtech-dps/protocol.c b/src/hardware/rdtech-dps/protocol.c
index da62b1b42cd20a76eb8a12167ec625d00d0f675a..dfcffbb16c2f8582924f77a37f49569f5ba66582 100644 (file)
--- a/src/hardware/rdtech-dps/protocol.c
+++ b/src/hardware/rdtech-dps/protocol.c
@@ -249,7 +249,7 @@ SR_PRIV int rdtech_dps_update_range(const struct sr_dev_inst *sdi)
         * Only update range if there are multiple ranges and data
         * acquisition hasn't started.
         */
-       if (devc->model->n_ranges == 1 || devc->acquisition_started)
+       if (devc->model->n_ranges <= 1 || devc->acquisition_started)
                return SR_OK;
        if (devc->model->model_type != MODEL_RD)
                return SR_ERR;
@@ -258,7 +258,8 @@ SR_PRIV int rdtech_dps_update_range(const struct sr_dev_inst *sdi)
                REG_RD_RANGE, 1, &range);
        if (ret != SR_OK)
                return ret;
-       devc->curr_range = range ? 1 : 0;
+       range = range ? 1 : 0;
+       devc->curr_range = range;
        rdtech_dps_update_multipliers(sdi);
 
        return SR_OK;
@@ -317,6 +318,7 @@ SR_PRIV int rdtech_dps_get_state(const struct sr_dev_inst *sdi,
        uint16_t reg_val, reg_state, out_state, ovpset_raw, ocpset_raw;
        gboolean is_lock, is_out_enabled, is_reg_cc;
        gboolean uses_ovp, uses_ocp;
+       gboolean have_range;
        uint16_t range;
        float volt_target, curr_limit;
        float ovp_threshold, ocp_threshold;
@@ -360,12 +362,9 @@ SR_PRIV int rdtech_dps_get_state(const struct sr_dev_inst *sdi,
        (void)get_init_state;
        (void)get_curr_meas;
 
-       /*
-        * The model RD6012P has two voltage/current ranges. We set a
-        * default value here such that the compiler doesn't generate
-        * an uninitialized variable warning.
-        */
-       range = 0;
+       have_range = devc->model->n_ranges > 1;
+       if (!have_range)
+               range = 0;
 
        switch (devc->model->model_type) {
        case MODEL_DPS:
@@ -460,7 +459,7 @@ SR_PRIV int rdtech_dps_get_state(const struct sr_dev_inst *sdi,
                is_reg_cc = reg_state == MODE_CC;
                out_state = read_u16be_inc(&rdptr); /* ENABLE */
                is_out_enabled = out_state != 0;
-               if (devc->model->n_ranges > 1) {
+               if (have_range) {
                        (void)read_u16be_inc(&rdptr); /* PRESET */
                        range = read_u16be_inc(&rdptr) ? 1 : 0; /* RANGE */
                }
@@ -524,7 +523,7 @@ SR_PRIV int rdtech_dps_get_state(const struct sr_dev_inst *sdi,
        state->mask |= STATE_CURRENT;
        state->power = curr_power;
        state->mask |= STATE_POWER;
-       if (devc->model->n_ranges > 1) {
+       if (have_range) {
                state->range = range;
                state->mask |= STATE_RANGE;
        }
@@ -657,10 +656,13 @@ SR_PRIV int rdtech_dps_set_state(const struct sr_dev_inst *sdi,
                        break;
                case MODEL_RD:
                        /*
+                        * Reject unsupported range indices.
                         * Need not set the range when the device only
                         * supports a single fixed range.
                         */
-                       if (devc->model->n_ranges == 1)
+                       if (reg_value >= devc->model->n_ranges)
+                               return SR_ERR_NA;
+                       if (devc->model->n_ranges <= 1)
                                return SR_OK;
                        ret = rdtech_rd_set_reg(sdi, REG_RD_RANGE, reg_value);
                        if (ret != SR_OK)
@@ -672,7 +674,7 @@ SR_PRIV int rdtech_dps_set_state(const struct sr_dev_inst *sdi,
                         * essential for meta package emission.
                         */
                        if (!devc->acquisition_started) {
-                               devc->curr_range = reg_value ? 1 : 0;
+                               devc->curr_range = reg_value;
                                rdtech_dps_update_multipliers(sdi);
                        }
                        break;