/*
             LUFA Library
     Copyright (C) Dean Camera, 2021.

  dean [at] fourwalledcubicle [dot] com
           www.lufa-lib.org
*/

/*
  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
  without fee, provided that the above copyright notice appear in
  all copies and that both that the copyright notice and this
  permission notice and warranty disclaimer appear in supporting
  documentation, and that the name of the author not be used in
  advertising or publicity pertaining to distribution of the
  software without specific, written prior permission.

  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
  whatsoever resulting from loss of use, data or profits, whether
  in an action of contract, negligence or other tortious action,
  arising out of or in connection with the use or performance of
  this software.
*/

/** \file
 *
 *  V2Protocol parameter handler, to process V2 Protocol device parameters.
 */

#define  INCLUDE_FROM_V2PROTOCOL_PARAMS_C
#include "V2ProtocolParams.h"

/* 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[] =
	{
		{ .ParamID          = PARAM_BUILD_NUMBER_LOW,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = 0                                  },

		{ .ParamID          = PARAM_BUILD_NUMBER_HIGH,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = 0                                  },

		{ .ParamID          = PARAM_HW_VER,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = 0x00                               },

		{ .ParamID          = PARAM_SW_MAJOR,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = 0x01                               },

		{ .ParamID          = PARAM_SW_MINOR,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = FIRMWARE_VERSION_MINOR             },

		{ .ParamID          = PARAM_VTARGET,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = (uint8_t)(3.3 * 10)                },

		{ .ParamID          = PARAM_SCK_DURATION,
		  .ParamPrivileges  = PARAM_PRIV_READ | PARAM_PRIV_WRITE,
		  .ParamValue       = 6                                  },

		{ .ParamID          = PARAM_RESET_POLARITY,
		  .ParamPrivileges  = PARAM_PRIV_READ | PARAM_PRIV_WRITE,
		  .ParamValue       = 0x01                               },

		{ .ParamID          = PARAM_STATUS_TGT_CONN,
		  .ParamPrivileges  = PARAM_PRIV_READ,
		  .ParamValue       = STATUS_ISP_READY                   },

		{ .ParamID          = PARAM_DISCHARGEDELAY,
		  .ParamPrivileges  = PARAM_PRIV_READ | PARAM_PRIV_WRITE,
		  .ParamValue       = 0x00                               },
	};


/** 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)
{
	/* 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
 *  VTARGET levels from the ADC on supported AVR models.
 */
void V2Params_UpdateParamValues(void)
{
	#if (defined(ADC) && !defined(NO_VTARGET_DETECT))
	/* Update VTARGET parameter with the latest ADC conversion of VTARGET on supported AVR models */
	V2Params_GetParamFromTable(PARAM_VTARGET)->ParamValue = (((uint16_t)(VTARGET_REF_VOLTS * 10 * VTARGET_SCALE_FACTOR) * ADC_GetResult()) / 1024);
	#endif
}

/** Retrieves the host PC read/write privileges for a given parameter in the parameter table. This should
 *  be called before calls to \ref V2Params_GetParameterValue() or \ref V2Params_SetParameterValue() when
 *  getting or setting parameter values in response to requests from the host.
 *
 *  \param[in] ParamID  Parameter ID whose privileges are to be retrieved from the table
 *
 *  \return Privileges for the requested parameter, as a mask of \c PARAM_PRIV_* masks
 */
uint8_t V2Params_GetParameterPrivileges(const uint8_t ParamID)
{
	ParameterItem_t* const ParamInfo = V2Params_GetParamFromTable(ParamID);

	if (ParamInfo == NULL)
	  return 0;

	return ParamInfo->ParamPrivileges;
}

/** Retrieves the current value for a given parameter in the parameter table.
 *
 *  \note This function does not first check for read privileges - if the value is being sent to the host via a
 *        GET PARAM command, \ref V2Params_GetParameterPrivileges() should be called first to ensure that the
 *        parameter is host-readable.
 *
 *  \param[in] ParamID  Parameter ID whose value is to be retrieved from the table
 *
 *  \return Current value of the parameter in the table, or 0 if not found
 */
uint8_t V2Params_GetParameterValue(const uint8_t ParamID)
{
	ParameterItem_t* const ParamInfo = V2Params_GetParamFromTable(ParamID);

	if (ParamInfo == NULL)
	  return 0;

	return ParamInfo->ParamValue;
}

/** Sets the value for a given parameter in the parameter table.
 *
 *  \note This function does not first check for write privileges - if the value is being sourced from the host
 *        via a SET PARAM command, \ref V2Params_GetParameterPrivileges() should be called first to ensure that the
 *        parameter is host-writable.
 *
 *  \param[in] ParamID  Parameter ID whose value is to be set in the table
 *  \param[in] Value    New value to set the parameter to
 */
void V2Params_SetParameterValue(const uint8_t ParamID,
                                const uint8_t Value)
{
	ParameterItem_t* const ParamInfo = V2Params_GetParamFromTable(ParamID);

	if (ParamInfo == NULL)
	  return;

	ParamInfo->ParamValue = Value;

	/* 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
 *  parameter ID.
 *
 *  \param[in] ParamID  Parameter ID to find in the table
 *
 *  \return Pointer to the associated parameter information from the parameter table if found, NULL otherwise
 */
static ParameterItem_t* const V2Params_GetParamFromTable(const uint8_t ParamID)
{
	ParameterItem_t* CurrTableItem = ParameterTable;

	/* Find the parameter in the parameter table if present */
	for (uint8_t TableIndex = 0; TableIndex < TABLE_PARAM_COUNT; TableIndex++)
	{
		if (ParamID == CurrTableItem->ParamID)
		  return CurrTableItem;

		CurrTableItem++;
	}

	return NULL;
}

