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 63f3f15..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
@@ -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;