hameg-hmo: Support BE format for SCPI sample downloads

[libsigrok.git] / src / hardware / hameg-hmo / protocol.c

diff --git a/src/hardware/hameg-hmo/protocol.c b/src/hardware/hameg-hmo/protocol.c
index 528d7b04295dac4eda31220d537c71ac614e35af..99a30acd75dd8ec21af14235be879732d87ea87b 100644 (file)
--- a/src/hardware/hameg-hmo/protocol.c
+++ b/src/hardware/hameg-hmo/protocol.c
@@ -48,6 +48,7 @@ static const char *hameg_scpi_dialect[] = {
        [SCPI_CMD_GET_ANALOG_CHAN_STATE]    = ":CHAN%d:STAT?",
        [SCPI_CMD_SET_ANALOG_CHAN_STATE]    = ":CHAN%d:STAT %d",
        [SCPI_CMD_GET_PROBE_UNIT]           = ":PROB%d:SET:ATT:UNIT?",
+       [SCPI_CMD_GET_BYTE_ORDER]           = ":FORM:BORD?",
 };
 
 static const uint32_t hmo_devopts[] = {
@@ -495,6 +496,22 @@ static int analog_channel_state_get(struct sr_scpi_dev_inst *scpi,
                g_free(tmp_str);
        }
 
+       /*
+        * Determine the byte order which will be used for data blocks.
+        * A ":FORM:BORD?" request will yield either an "MSBF" or "LSBF"
+        * response.
+        */
+       state->byteorder = '?';
+       if (sr_scpi_get_string(scpi,
+                              (*config->scpi_dialect)[SCPI_CMD_GET_BYTE_ORDER],
+                              &tmp_str) != SR_OK)
+               return SR_ERR;
+       if (tmp_str[0] == 'M')
+               state->byteorder = 'b';
+       else if (tmp_str[0] == 'L')
+               state->byteorder = 'l';
+       g_free(tmp_str);
+
        return SR_OK;
 }
 
@@ -821,7 +838,8 @@ SR_PRIV int hmo_receive_data(int fd, int revents, void *cb_data)
                encoding.unitsize = sizeof(float);
                encoding.is_signed = TRUE;
                encoding.is_float = TRUE;
-               encoding.is_bigendian = FALSE;
+               /* Assume LE format when unknown for backwards compat. */
+               encoding.is_bigendian = (state->byteorder == 'b') ? TRUE : FALSE;
                /* TODO: Use proper 'digits' value for this device (and its modes). */
                encoding.digits = 2;
                encoding.is_digits_decimal = FALSE;