X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fscpi%2Fscpi.c;h=f6865c37dc846d809a016b0627cb4fb44630813d;hb=9ea4018f2f7c3bac99f738334ebd57b1e6ae0a2c;hp=576aa76e39aaac472763e17f4f423bc4c44fec11;hpb=04229f7bfc750f2b67e8dd54ac82ae6bb7eae1e4;p=libsigrok.git diff --git a/src/scpi/scpi.c b/src/scpi/scpi.c index 576aa76e..f6865c37 100644 --- a/src/scpi/scpi.c +++ b/src/scpi/scpi.c @@ -90,7 +90,7 @@ static const struct sr_scpi_dev_inst *scpi_devs[] = { &scpi_libgpib_dev, #endif #ifdef HAVE_LIBSERIALPORT - &scpi_serial_dev, /* must be last as it matches any resource */ + &scpi_serial_dev, /* Must be last as it matches any resource. */ #endif }; @@ -110,12 +110,16 @@ static struct sr_dev_inst *sr_scpi_scan_resource(struct drv_context *drvc, return NULL; }; - if ((sdi = probe_device(scpi))) - return sdi; + sdi = probe_device(scpi); sr_scpi_close(scpi); - sr_scpi_free(scpi); - return NULL; + + if (sdi) + sdi->status = SR_ST_INACTIVE; + else + sr_scpi_free(scpi); + + return sdi; } SR_PRIV GSList *sr_scpi_scan(struct drv_context *drvc, GSList *options, @@ -186,7 +190,7 @@ SR_PRIV struct sr_scpi_dev_inst *scpi_dev_inst_new(struct drv_context *drvc, scpi = g_malloc(sizeof(*scpi)); *scpi = *scpi_dev; scpi->priv = g_malloc0(scpi->priv_size); - scpi->read_timeout_ms = 1000; + scpi->read_timeout_us = 1000 * 1000; params = g_strsplit(resource, "/", 0); if (scpi->dev_inst_new(scpi->priv, drvc, resource, params, serialcomm) != SR_OK) { @@ -292,8 +296,10 @@ SR_PRIV int sr_scpi_send_variadic(struct sr_scpi_dev_inst *scpi, va_end(args_copy); /* Allocate buffer and write out command. */ - buf = g_malloc(len + 1); + buf = g_malloc0(len + 2); vsprintf(buf, format, args); + if (buf[len - 1] != '\n') + buf[len] = '\n'; /* Send command. */ ret = scpi->send(scpi->priv, buf); @@ -381,56 +387,84 @@ SR_PRIV void sr_scpi_free(struct sr_scpi_dev_inst *scpi) SR_PRIV int sr_scpi_get_string(struct sr_scpi_dev_inst *scpi, const char *command, char **scpi_response) { - char buf[256]; + GString *response; + response = g_string_sized_new(1024); + + if (sr_scpi_get_data(scpi, command, &response) != SR_OK) { + if (response) + g_string_free(response, TRUE); + return SR_ERR; + } + + /* Get rid of trailing linefeed if present */ + if (response->len >= 1 && response->str[response->len - 1] == '\n') + g_string_truncate(response, response->len - 1); + + /* Get rid of trailing carriage return if present */ + if (response->len >= 1 && response->str[response->len - 1] == '\r') + g_string_truncate(response, response->len - 1); + + sr_spew("Got response: '%.70s', length %" G_GSIZE_FORMAT ".", + response->str, response->len); + + *scpi_response = g_string_free(response, FALSE); + + return SR_OK; +} + +SR_PRIV int sr_scpi_get_data(struct sr_scpi_dev_inst *scpi, + const char *command, GString **scpi_response) +{ int len; GString *response; - gint64 laststart; - unsigned int elapsed_ms; + gint64 laststart, now; + unsigned int offset; + int space; - if (command) + /* Optionally send caller provided command. */ + if (command) { if (sr_scpi_send(scpi, command) != SR_OK) return SR_ERR; + } + /* Initiate SCPI read operation. */ if (sr_scpi_read_begin(scpi) != SR_OK) return SR_ERR; + /* Keep reading until completion or until timeout. */ laststart = g_get_monotonic_time(); - response = g_string_new(""); - - *scpi_response = NULL; + response = *scpi_response; + offset = response->len; while (!sr_scpi_read_complete(scpi)) { - len = sr_scpi_read_data(scpi, buf, sizeof(buf)); + /* Resize the buffer when free space drops below a threshold. */ + space = response->allocated_len - response->len; + if (space < 128) { + g_string_set_size(response, response->len + 1024); + g_string_set_size(response, offset); + space = response->allocated_len - response->len; + } + /* Read another chunk of the response. */ + len = sr_scpi_read_data(scpi, &response->str[offset], space); if (len < 0) { sr_err("Incompletely read SCPI response."); - g_string_free(response, TRUE); return SR_ERR; - } else if (len > 0) { - laststart = g_get_monotonic_time(); } - g_string_append_len(response, buf, len); - elapsed_ms = (g_get_monotonic_time() - laststart) / 1000; - if (elapsed_ms >= scpi->read_timeout_ms) { + + now = g_get_monotonic_time(); + + if (len > 0) { + laststart = now; + offset += len; + g_string_set_size(response, offset); + } else if ((now - laststart) >= scpi->read_timeout_us) { + /* Quit reading after a period of time without receiving data. */ sr_err("Timed out waiting for SCPI response."); - g_string_free(response, TRUE); - return SR_ERR; + return SR_ERR_TIMEOUT; } } - /* Get rid of trailing linefeed if present */ - if (response->len >= 1 && response->str[response->len - 1] == '\n') - g_string_truncate(response, response->len - 1); - - /* Get rid of trailing carriage return if present */ - if (response->len >= 1 && response->str[response->len - 1] == '\r') - g_string_truncate(response, response->len - 1); - - sr_spew("Got response: '%.70s', length %" G_GSIZE_FORMAT ".", - response->str, response->len); - - *scpi_response = g_string_free(response, FALSE); - return SR_OK; } @@ -575,7 +609,7 @@ 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) { + for (i = 0; i < SCPI_READ_RETRIES; i++) { sr_scpi_get_bool(scpi, SCPI_CMD_OPC, &opc); if (opc) return SR_OK; @@ -607,7 +641,6 @@ SR_PRIV int sr_scpi_get_floatv(struct sr_scpi_dev_inst *scpi, gchar **ptr, **tokens; GArray *response_array; - ret = SR_OK; response = NULL; tokens = NULL; @@ -664,7 +697,6 @@ SR_PRIV int sr_scpi_get_uint8v(struct sr_scpi_dev_inst *scpi, gchar **ptr, **tokens; GArray *response_array; - ret = SR_OK; response = NULL; tokens = NULL; @@ -700,6 +732,98 @@ SR_PRIV int sr_scpi_get_uint8v(struct sr_scpi_dev_inst *scpi, return ret; } +/** + * Send a SCPI command, read the reply, parse it as binary data with a + * "definite length block" header 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_block(struct sr_scpi_dev_inst *scpi, + const char *command, GByteArray **scpi_response) +{ + int ret; + GString* response; + char buf[10]; + long llen; + long datalen; + + /* + * Assume an initial maximum length, optionally gets adjusted below. + * Prepare a NULL return value for when error paths will be taken. + */ + response = g_string_sized_new(1024); + *scpi_response = NULL; + + /* Get (the first chunk of) the response. */ + ret = sr_scpi_get_data(scpi, command, &response); + if (ret != SR_OK) { + g_string_free(response, TRUE); + return ret; + } + + /* + * SCPI protocol data blocks are preceeded with a length spec. + * The length spec consists of a '#' marker, one digit which + * specifies the character count of the length spec, and the + * respective number of characters which specify the data block's + * length. Raw data bytes follow (thus one must no longer assume + * that the received input stream would be an ASCIIZ string). + * + * Get the data block length, and strip off the length spec from + * the input buffer, leaving just the data bytes. + */ + if (response->str[0] != '#') { + g_string_free(response, TRUE); + return SR_ERR_DATA; + } + buf[0] = response->str[1]; + buf[1] = '\0'; + ret = sr_atol(buf, &llen); + if ((ret != SR_OK) || (llen == 0)) { + g_string_free(response, TRUE); + return ret; + } + memcpy(buf, &response->str[2], llen); + buf[llen] = '\0'; + ret = sr_atol(buf, &datalen); + if ((ret != SR_OK) || (datalen == 0)) { + g_string_free(response, TRUE); + return ret; + } + g_string_erase(response, 0, 2 + llen); + + /* + * If the initially assumed length does not cover the data block + * length, then re-allocate the buffer size to the now known + * length, and keep reading more chunks of response data. + */ + if (response->len < (unsigned long)(datalen)) { + int oldlen = response->len; + g_string_set_size(response, datalen); + g_string_set_size(response, oldlen); + } + while (response->len < (unsigned long)(datalen)) { + ret = sr_scpi_get_data(scpi, NULL, &response); + if (ret != SR_OK) { + g_string_free(response, TRUE); + return ret; + } + } + + /* Convert received data to byte array. */ + *scpi_response = g_byte_array_new_take( + (guint8*)g_string_free(response, FALSE), datalen); + + 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.