Add barebones SCPI handling

board/board.mk

 # List of all the board related files.
-BOARDSRC = $(ROOT)/board/board.c
+BOARDSRC = ./board/board.c
 # Required include directories
-BOARDINC = $(ROOT)/board
+BOARDINC = ./board
 
 # Shared variables
 ALLCSRC += $(BOARDSRC)

lib/libscpi/LICENSE

+BSD 2-Clause License
+
+Copyright (c) 2012-2018, Jan Breuer
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

lib/libscpi/error.c

+/*-
+ * BSD 2-Clause License
+ *
+ * Copyright (c) 2012-2018, Jan Breuer
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+/**
+ * @file   scpi_error.c
+ * @date   Thu Nov 15 10:58:45 UTC 2012
+ *
+ * @brief  Error handling and storing routines
+ *
+ *
+ */
+
+#include <stdint.h>
+
+#include "scpi/parser.h"
+#include "scpi/ieee488.h"
+#include "scpi/error.h"
+#include "fifo_private.h"
+#include "scpi/constants.h"
+
+#if USE_DEVICE_DEPENDENT_ERROR_INFORMATION
+#define SCPI_ERROR_SETVAL(e, c, i) do { (e)->error_code = (c); (e)->device_dependent_info = (i); } while(0)
+#else
+#define SCPI_ERROR_SETVAL(e, c, i) do { (e)->error_code = (c); (void)(i);} while(0)
+#endif
+
+/**
+ * Initialize error queue
+ * @param context - scpi context
+ */
+void SCPI_ErrorInit(scpi_t * context, scpi_error_t * data, int16_t size) {
+    fifo_init(&context->error_queue, data, size);
+}
+
+/**
+ * Emit no error
+ * @param context scpi context
+ */
+static void SCPI_ErrorEmitEmpty(scpi_t * context) {
+    if ((SCPI_ErrorCount(context) == 0) && (SCPI_RegGet(context, SCPI_REG_STB) & STB_QMA)) {
+        SCPI_RegClearBits(context, SCPI_REG_STB, STB_QMA);
+
+        if (context->interface && context->interface->error) {
+            context->interface->error(context, 0);
+        }
+    }
+}
+
+/**
+ * Emit error
+ * @param context scpi context
+ * @param err Error to emit
+ */
+static void SCPI_ErrorEmit(scpi_t * context, int16_t err) {
+    SCPI_RegSetBits(context, SCPI_REG_STB, STB_QMA);
+
+    if (context->interface && context->interface->error) {
+        context->interface->error(context, err);
+    }
+}
+
+/**
+ * Clear error queue
+ * @param context - scpi context
+ */
+void SCPI_ErrorClear(scpi_t * context) {
+#if USE_DEVICE_DEPENDENT_ERROR_INFORMATION
+    scpi_error_t error;
+    while (fifo_remove(&context->error_queue, &error)) {
+        SCPIDEFINE_free(&context->error_info_heap, error.device_dependent_info, false);
+    }
+#endif
+    fifo_clear(&context->error_queue);
+
+    SCPI_ErrorEmitEmpty(context);
+}
+
+/**
+ * Pop error from queue
+ * @param context - scpi context
+ * @param error
+ * @return
+ */
+scpi_bool_t SCPI_ErrorPop(scpi_t * context, scpi_error_t * error) {
+    if (!error || !context) return FALSE;
+    SCPI_ERROR_SETVAL(error, 0, NULL);
+    fifo_remove(&context->error_queue, error);
+
+    SCPI_ErrorEmitEmpty(context);
+
+    return TRUE;
+}
+
+/**
+ * Return number of errors/events in the queue
+ * @param context
+ * @return
+ */
+int32_t SCPI_ErrorCount(scpi_t * context) {
+    int16_t result = 0;
+
+    fifo_count(&context->error_queue, &result);
+
+    return result;
+}
+
+static scpi_bool_t SCPI_ErrorAddInternal(scpi_t * context, int16_t err, char * info, size_t info_len) {
+    scpi_error_t error_value;
+    /* SCPIDEFINE_strndup is sometimes a dumy that does not reference it's arguments. 
+       Since info_len is not referenced elsewhere caoing to void prevents unusd argument warnings */
+    (void) info_len;
+    char * info_ptr = info ? SCPIDEFINE_strndup(&context->error_info_heap, info, info_len) : NULL;
+    SCPI_ERROR_SETVAL(&error_value, err, info_ptr);
+    if (!fifo_add(&context->error_queue, &error_value)) {
+        SCPIDEFINE_free(&context->error_info_heap, error_value.device_dependent_info, true);
+        fifo_remove_last(&context->error_queue, &error_value);
+        SCPIDEFINE_free(&context->error_info_heap, error_value.device_dependent_info, true);
+        SCPI_ERROR_SETVAL(&error_value, SCPI_ERROR_QUEUE_OVERFLOW, NULL);
+        fifo_add(&context->error_queue, &error_value);
+        return FALSE;
+    }
+    return TRUE;
+}
+
+struct error_reg {
+    int16_t from;
+    int16_t to;
+    scpi_reg_val_t esrBit;
+};
+
+#define ERROR_DEFS_N 9
+
+static const struct error_reg errs[ERROR_DEFS_N] = {
+    {-100, -199, ESR_CER}, /* Command error (e.g. syntax error) ch 21.8.9    */
+    {-200, -299, ESR_EER}, /* Execution Error (e.g. range error) ch 21.8.10  */
+    {-300, -399, ESR_DER}, /* Device specific error -300, -399 ch 21.8.11    */
+    { 1, 32767, ESR_DER}, /* Device designer provided specific error 1, 32767 ch 21.8.11    */
+    {-400, -499, ESR_QER}, /* Query error -400, -499 ch 21.8.12              */
+    {-500, -599, ESR_PON}, /* Power on event -500, -599 ch 21.8.13           */
+    {-600, -699, ESR_URQ}, /* User Request Event -600, -699 ch 21.8.14       */
+    {-700, -799, ESR_REQ}, /* Request Control Event -700, -799 ch 21.8.15    */
+    {-800, -899, ESR_OPC}, /* Operation Complete Event -800, -899 ch 21.8.16 */
+};
+
+/**
+ * Push error to queue
+ * @param context
+ * @param err - error number
+ * @param info - additional text information or NULL for no text
+ * @param info_len - length of text or 0 for automatic length
+ */
+void SCPI_ErrorPushEx(scpi_t * context, int16_t err, char * info, size_t info_len) {
+    int i;
+    /* automatic calculation of length */
+    if (info && info_len == 0) {
+        info_len = SCPIDEFINE_strnlen(info, SCPI_STD_ERROR_DESC_MAX_STRING_LENGTH);
+    }
+    scpi_bool_t queue_overflow = !SCPI_ErrorAddInternal(context, err, info, info_len);
+
+    for (i = 0; i < ERROR_DEFS_N; i++) {
+        if ((err <= errs[i].from) && (err >= errs[i].to)) {
+            SCPI_RegSetBits(context, SCPI_REG_ESR, errs[i].esrBit);
+        }
+    }
+
+    SCPI_ErrorEmit(context, err);
+    if (queue_overflow) {
+        SCPI_ErrorEmit(context, SCPI_ERROR_QUEUE_OVERFLOW);
+    }
+
+    if (context) {
+        context->cmd_error = TRUE;
+    }
+}
+
+/**
+ * Push error to queue
+ * @param context - scpi context
+ * @param err - error number
+ */
+void SCPI_ErrorPush(scpi_t * context, int16_t err) {
+    SCPI_ErrorPushEx(context, err, NULL, 0);
+    return;
+}
+
+/**
+ * Translate error number to string
+ * @param err - error number
+ * @return Error string representation
+ */
+const char * SCPI_ErrorTranslate(int16_t err) {
+    switch (err) {
+#define X(def, val, str) case def: return str;
+#if USE_FULL_ERROR_LIST
+#define XE X
+#else
+#define XE(def, val, str)
+#endif
+        LIST_OF_ERRORS
+
+#if USE_USER_ERROR_LIST
+        LIST_OF_USER_ERRORS
+#endif
+#undef X
+#undef XE
+        default: return "Unknown error";
+    }
+}
+
+

lib/libscpi/expression.c

+/*-
+ * BSD 2-Clause License
+ *
+ * Copyright (c) 2012-2018, Jan Breuer
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file   expression.c
+ *
+ * @brief  Expressions handling
+ *
+ *
+ */
+
+#include "scpi/expression.h"
+#include "scpi/error.h"
+#include "scpi/parser.h"
+
+#include "lexer_private.h"
+
+/**
+ * Parse one range or single value
+ * @param state lexer state
+ * @param isRange return true if parsed expression is range
+ * @param valueFrom return parsed value from
+ * @param valueTo return parsed value to
+ * @return SCPI_EXPR_OK - parsing was succesful
+ *         SCPI_EXPR_ERROR - parser error
+ *         SCPI_EXPR_NO_MORE - no more data
+ */
+static scpi_expr_result_t numericRange(lex_state_t * state, scpi_bool_t * isRange, scpi_token_t * valueFrom, scpi_token_t * valueTo) {
+    if (scpiLex_DecimalNumericProgramData(state, valueFrom)) {
+        if (scpiLex_Colon(state, valueTo)) {
+            *isRange = TRUE;
+            if (scpiLex_DecimalNumericProgramData(state, valueTo)) {
+                return SCPI_EXPR_OK;
+            } else {
+                return SCPI_EXPR_ERROR;
+            }
+        } else {
+            *isRange = FALSE;
+            return SCPI_EXPR_OK;
+        }
+    }
+
+    return SCPI_EXPR_NO_MORE;
+}
+
+/**
+ * Parse entry on specified position
+ * @param context scpi context
+ * @param param input parameter
+ * @param index index of position (start from 0)
+ * @param isRange return true if expression at index was range
+ * @param valueFrom return value from
+ * @param valueTo return value to
+ * @return SCPI_EXPR_OK - parsing was succesful
+ *         SCPI_EXPR_ERROR - parser error
+ *         SCPI_EXPR_NO_MORE - no more data
+ * @see SCPI_ExprNumericListEntryInt, SCPI_ExprNumericListEntryDouble
+ */
+scpi_expr_result_t SCPI_ExprNumericListEntry(scpi_t * context, scpi_parameter_t * param, int index, scpi_bool_t * isRange, scpi_parameter_t * valueFrom, scpi_parameter_t * valueTo) {
+    lex_state_t lex;
+    int i;
+    scpi_expr_result_t res = SCPI_EXPR_OK;
+
+    if (!isRange || !valueFrom || !valueTo || !param) {
+        SCPI_ErrorPush(context, SCPI_ERROR_SYSTEM_ERROR);
+        return SCPI_EXPR_ERROR;
+    }
+
+    if (param->type != SCPI_TOKEN_PROGRAM_EXPRESSION) {
+        SCPI_ErrorPush(context, SCPI_ERROR_DATA_TYPE_ERROR);
+        return SCPI_EXPR_ERROR;
+    }
+
+    lex.buffer = param->ptr + 1;
+    lex.pos = lex.buffer;
+    lex.len = param->len - 2;
+
+    for (i = 0; i <= index; i++) {
+        res = numericRange(&lex, isRange, valueFrom, valueTo);
+        if (res != SCPI_EXPR_OK) {
+            break;
+        }
+        if (i != index) {
+            if (!scpiLex_Comma(&lex, valueFrom)) {
+                res = scpiLex_IsEos(&lex) ? SCPI_EXPR_NO_MORE : SCPI_EXPR_ERROR;
+                break;
+            }
+        }
+    }
+
+    if (res == SCPI_EXPR_ERROR) {
+        SCPI_ErrorPush(context, SCPI_ERROR_EXPRESSION_PARSING_ERROR);
+    }
+    return res;
+}
+
+/**
+ * Parse entry on specified position and convert result to int32_t
+ * @param context scpi context
+ * @param param input parameter
+ * @param index index of position (start from 0)
+ * @param isRange return true if expression at index was range
+ * @param valueFrom return value from
+ * @param valueTo return value to
+ * @return SCPI_EXPR_OK - parsing was succesful
+ *         SCPI_EXPR_ERROR - parser error
+ *         SCPI_EXPR_NO_MORE - no more data
+ * @see SCPI_ExprNumericListEntry, SCPI_ExprNumericListEntryDouble
+ */
+scpi_expr_result_t SCPI_ExprNumericListEntryInt(scpi_t * context, scpi_parameter_t * param, int index, scpi_bool_t * isRange, int32_t * valueFrom, int32_t * valueTo) {
+    scpi_expr_result_t res;
+    scpi_bool_t range = FALSE;
+    scpi_parameter_t paramFrom;
+    scpi_parameter_t paramTo;
+
+    res = SCPI_ExprNumericListEntry(context, param, index, &range, &paramFrom, &paramTo);
+    if (res == SCPI_EXPR_OK) {
+        *isRange = range;
+        SCPI_ParamToInt32(context, &paramFrom, valueFrom);
+        if (range) {
+            SCPI_ParamToInt32(context, &paramTo, valueTo);
+        }
+    }
+
+    return res;
+}
+
+/**
+ * Parse entry on specified position and convert result to double
+ * @param context scpi context
+ * @param param input parameter
+ * @param index index of position (start from 0)
+ * @param isRange return true if expression at index was range
+ * @param valueFrom return value from
+ * @param valueTo return value to
+ * @return SCPI_EXPR_OK - parsing was succesful
+ *         SCPI_EXPR_ERROR - parser error
+ *         SCPI_EXPR_NO_MORE - no more data
+ * @see SCPI_ExprNumericListEntry, SCPI_ExprNumericListEntryInt
+ */
+scpi_expr_result_t SCPI_ExprNumericListEntryDouble(scpi_t * context, scpi_parameter_t * param, int index, scpi_bool_t * isRange, double * valueFrom, double * valueTo) {
+    scpi_expr_result_t res;
+    scpi_bool_t range = FALSE;
+    scpi_parameter_t paramFrom;
+    scpi_parameter_t paramTo;
+
+    res = SCPI_ExprNumericListEntry(context, param, index, &range, &paramFrom, &paramTo);
+    if (res == SCPI_EXPR_OK) {
+        *isRange = range;
+        SCPI_ParamToDouble(context, &paramFrom, valueFrom);
+        if (range) {
+            SCPI_ParamToDouble(context, &paramTo, valueTo);
+        }
+    }
+
+    return res;
+}
+
+/**
+ * Parse one channel_spec e.g. "1!5!8"
+ * @param context
+ * @param state lexer state
+ * @param values range values
+ * @param length length of values array
+ * @param dimensions real number of dimensions
+ */
+static scpi_expr_result_t channelSpec(scpi_t * context, lex_state_t * state, int32_t * values, size_t length, size_t * dimensions) {
+    scpi_parameter_t param;
+    size_t i = 0;
+    while (scpiLex_DecimalNumericProgramData(state, &param)) {
+        if (i < length) {
+            SCPI_ParamToInt32(context, &param, &values[i]);
+        }
+
+        if (scpiLex_SpecificCharacter(state, &param, '!')) {
+            i++;
+        } else {
+            *dimensions = i + 1;
+            return SCPI_EXPR_OK;
+        }
+    }
+
+    if (i == 0) {
+        return SCPI_EXPR_NO_MORE;
+    } else {
+        /* there was at least one number followed by !, but after ! was not another number */
+        return SCPI_EXPR_ERROR;
+    }
+}
+
+/**
+ * Parse channel_range e.g. "1!2:5!6"
+ * @param context
+ * @param state lexer state
+ * @param isRange return true if it is range
+ * @param valuesFrom return array of values from
+ * @param valuesTo return array of values to
+ * @param length length of values arrays
+ * @param dimensions real number of dimensions
+ */
+static scpi_expr_result_t channelRange(scpi_t * context, lex_state_t * state, scpi_bool_t * isRange, int32_t * valuesFrom, int32_t * valuesTo, size_t length, size_t * dimensions) {
+    scpi_token_t token;
+    scpi_expr_result_t err;
+    size_t fromDimensions;
+    size_t toDimensions;
+
+    err = channelSpec(context, state, valuesFrom, length, &fromDimensions);
+    if (err == SCPI_EXPR_OK) {
+        if (scpiLex_Colon(state, &token)) {
+            *isRange = TRUE;
+            err = channelSpec(context, state, valuesTo, length, &toDimensions);
+            if (err != SCPI_EXPR_OK) {
+                return SCPI_EXPR_ERROR;
+            }
+            if (fromDimensions != toDimensions) {
+                return SCPI_EXPR_ERROR;
+            }
+            *dimensions = fromDimensions;
+        } else {
+            *isRange = FALSE;
+            *dimensions = fromDimensions;
+            return SCPI_EXPR_OK;
+        }
+    } else if (err == SCPI_EXPR_NO_MORE) {
+        err = SCPI_EXPR_ERROR;
+    }
+
+    return err;
+}
+
+/**
+ * Parse one list entry at specific position e.g. "1!2:5!6"
+ * @param context
+ * @param param
+ * @param index
+ * @param isRange return true if it is range
+ * @param valuesFrom return array of values from
+ * @param valuesTo return array of values to
+ * @param length length of values arrays
+ * @param dimensions real number of dimensions
+ */
+scpi_expr_result_t SCPI_ExprChannelListEntry(scpi_t * context, scpi_parameter_t * param, int index, scpi_bool_t * isRange, int32_t * valuesFrom, int32_t * valuesTo, size_t length, size_t * dimensions) {
+    lex_state_t lex;
+    int i;
+    scpi_expr_result_t res = SCPI_EXPR_OK;
+    scpi_token_t token;
+
+    if (!isRange || !param || !dimensions || (length && (!valuesFrom || !valuesTo))) {
+        SCPI_ErrorPush(context, SCPI_ERROR_SYSTEM_ERROR);
+        return SCPI_EXPR_ERROR;
+    }
+
+    if (param->type != SCPI_TOKEN_PROGRAM_EXPRESSION) {
+        SCPI_ErrorPush(context, SCPI_ERROR_DATA_TYPE_ERROR);
+        return SCPI_EXPR_ERROR;
+    }
+
+    lex.buffer = param->ptr + 1;
+    lex.pos = lex.buffer;
+    lex.len = param->len - 2;
+
+    /* detect channel list expression */
+    if (!scpiLex_SpecificCharacter(&lex, &token, '@')) {
+        SCPI_ErrorPush(context, SCPI_ERROR_EXPRESSION_PARSING_ERROR);
+        return SCPI_EXPR_ERROR;
+    }
+
+    for (i = 0; i <= index; i++) {
+        res = channelRange(context, &lex, isRange, valuesFrom, valuesTo, (i == index) ? length : 0, dimensions);
+        if (res != SCPI_EXPR_OK) {
+            break;
+        }
+        if (i != index) {
+            if (!scpiLex_Comma(&lex, &token)) {
+                res = scpiLex_IsEos(&lex) ? SCPI_EXPR_NO_MORE : SCPI_EXPR_ERROR;
+                break;
+            }
+        }
+    }
+
+    if (res == SCPI_EXPR_ERROR) {
+        SCPI_ErrorPush(context, SCPI_ERROR_EXPRESSION_PARSING_ERROR);
+    }
+    if (res == SCPI_EXPR_NO_MORE) {
+        if (!scpiLex_IsEos(&lex)) {
+            res = SCPI_EXPR_ERROR;
+            SCPI_ErrorPush(context, SCPI_ERROR_EXPRESSION_PARSING_ERROR);
+        }
+    }
+    return res;
+}

lib/libscpi/fifo.c

+/*-
+ * BSD 2-Clause License
+ *
+ * Copyright (c) 2012-2018, Jan Breuer
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fifo_private.h"
+
+/**
+ * Initialize fifo
+ * @param fifo
+ */
+void fifo_init(scpi_fifo_t * fifo, scpi_error_t * data, int16_t size) {
+    fifo->wr = 0;