Documentation: Update changelog.

[pub/lufa.git] / Projects / AVRISP-MKII / Lib / V2ProtocolParams.c

diff --git a/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c b/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c
index 2c5ac3f..c42c6c4 100644 (file)
--- a/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c
+++ b/Projects/AVRISP-MKII/Lib/V2ProtocolParams.c
@@ -1,13 +1,13 @@
 /*
              LUFA Library
-     Copyright (C) Dean Camera, 2012.
+     Copyright (C) Dean Camera, 2021.
 
   dean [at] fourwalledcubicle [dot] com
            www.lufa-lib.org
 */
 
 /*
-  Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+  Copyright 2021  Dean Camera (dean [at] fourwalledcubicle [dot] com)
 
   Permission to use, copy, modify, distribute, and sell this
   software and its documentation for any purpose is hereby granted
@@ -18,7 +18,7 @@
   advertising or publicity pertaining to distribution of the
   software without specific, written prior permission.
 
-  The author disclaim all warranties with regard to this
+  The author disclaims all warranties with regard to this
   software, including all implied warranties of merchantability
   and fitness.  In no event shall the author be liable for any
   special, indirect or consequential damages or any damages
@@ -39,6 +39,17 @@
 /* Non-Volatile Parameter Values for EEPROM storage */
 static uint8_t EEMEM EEPROM_Reset_Polarity = 0x01;
 
+/* Non-Volatile Parameter Values for EEPROM storage */
+static uint8_t EEMEM EEPROM_SCK_Duration   = 0x06;
+
+/* Randomly generated magic constant for EEPROM data validation */
+#define EEPROM_MAGIC 0xEB401412UL
+
+/* EEPROM location which should contain EEPROM_MAGIC.  If this value is not correct, all other EEPROM locations are
+ * assumed to contain invalid data, therefore all parameters will be reset to their default values.
+ */
+static uint32_t EEMEM EEPROM_Magic_Value = EEPROM_MAGIC;
+
 /* Volatile Parameter Values for RAM storage */
 static ParameterItem_t ParameterTable[] =
        {
@@ -84,11 +95,40 @@ static ParameterItem_t ParameterTable[] =
        };
 
 
+/** Check the non-volatile storage in the EEPROM for the proper magic value, and erase the parameter area if the magic
+ *  value was not correct.
+ */
+static void V2Params_CheckNonVolatileStorage(void)
+{
+       /* Read the magic value from the EEPROM */
+       uint32_t MagicValue = eeprom_read_dword(&EEPROM_Magic_Value);
+       if (MagicValue != EEPROM_MAGIC) {
+               /* If the magic value was not correct, erase the parameter values in the EEPROM */
+               eeprom_update_byte(&EEPROM_Reset_Polarity, 0xFF);
+               eeprom_update_byte(&EEPROM_SCK_Duration, 0xFF);
+
+               /* Write the correct magic value to confirm that the data stored in the EEPROM is now valid */
+               eeprom_update_dword(&EEPROM_Magic_Value, EEPROM_MAGIC);
+       }
+}
+
 /** Loads saved non-volatile parameter values from the EEPROM into the parameter table, as needed. */
 void V2Params_LoadNonVolatileParamValues(void)
 {
-       /* Target RESET line polarity is a non-volatile value, retrieve current parameter value from EEPROM */
-       V2Params_GetParamFromTable(PARAM_RESET_POLARITY)->ParamValue = eeprom_read_byte(&EEPROM_Reset_Polarity);
+       /* Check that the EEPROM contains valid data */
+       V2Params_CheckNonVolatileStorage();
+
+       /* Read parameter values that are stored in non-volatile EEPROM */
+       uint8_t ResetPolarity = eeprom_read_byte(&EEPROM_Reset_Polarity);
+       uint8_t SCKDuration   = eeprom_read_byte(&EEPROM_SCK_Duration);
+
+       /* Update current parameter table if the EEPROM contents was not blank */
+       if (ResetPolarity != 0xFF)
+         V2Params_GetParamFromTable(PARAM_RESET_POLARITY)->ParamValue = ResetPolarity;
+
+       /* Update current parameter table if the EEPROM contents was not blank */
+       if (SCKDuration != 0xFF)
+         V2Params_GetParamFromTable(PARAM_SCK_DURATION)->ParamValue   = SCKDuration;
 }
 
 /** Updates any parameter values that are sourced from hardware rather than explicitly set by the host, such as
@@ -112,7 +152,7 @@ void V2Params_UpdateParamValues(void)
  */
 uint8_t V2Params_GetParameterPrivileges(const uint8_t ParamID)
 {
-       ParameterItem_t* ParamInfo = V2Params_GetParamFromTable(ParamID);
+       ParameterItem_t* const ParamInfo = V2Params_GetParamFromTable(ParamID);
 
        if (ParamInfo == NULL)
          return 0;
@@ -132,7 +172,7 @@ uint8_t V2Params_GetParameterPrivileges(const uint8_t ParamID)
  */
 uint8_t V2Params_GetParameterValue(const uint8_t ParamID)
 {
-       ParameterItem_t* ParamInfo = V2Params_GetParamFromTable(ParamID);
+       ParameterItem_t* const ParamInfo = V2Params_GetParamFromTable(ParamID);
 
        if (ParamInfo == NULL)
          return 0;
@@ -154,7 +194,7 @@ uint8_t V2Params_GetParameterValue(const uint8_t ParamID)
 void V2Params_SetParameterValue(const uint8_t ParamID,
                                 const uint8_t Value)
 {
-       ParameterItem_t* ParamInfo = V2Params_GetParamFromTable(ParamID);
+       ParameterItem_t* const ParamInfo = V2Params_GetParamFromTable(ParamID);
 
        if (ParamInfo == NULL)
          return;
@@ -164,6 +204,10 @@ void V2Params_SetParameterValue(const uint8_t ParamID,
        /* The target RESET line polarity is a non-volatile parameter, save to EEPROM when changed */
        if (ParamID == PARAM_RESET_POLARITY)
          eeprom_update_byte(&EEPROM_Reset_Polarity, Value);
+
+       /* The target SCK line period is a non-volatile parameter, save to EEPROM when changed */
+       if (ParamID == PARAM_SCK_DURATION)
+         eeprom_update_byte(&EEPROM_SCK_Duration, Value);
 }
 
 /** Retrieves a parameter entry (including ID, value and privileges) from the parameter table that matches the given
@@ -173,7 +217,7 @@ void V2Params_SetParameterValue(const uint8_t ParamID,
  *
  *  \return Pointer to the associated parameter information from the parameter table if found, NULL otherwise
  */
-static ParameterItem_t* V2Params_GetParamFromTable(const uint8_t ParamID)
+static ParameterItem_t* const V2Params_GetParamFromTable(const uint8_t ParamID)
 {
        ParameterItem_t* CurrTableItem = ParameterTable;