/* Copyright 2023 Dual Tachyon
 * https://github.com/DualTachyon
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *     Unless required by applicable law or agreed to in writing, software
 *     distributed under the License is distributed on an "AS IS" BASIS,
 *     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *     See the License for the specific language governing permissions and
 *     limitations under the License.
 */

#include "ARMCM0.h"
#include "bsp/dp32g030/pmu.h"
#include "bsp/dp32g030/saradc.h"
#include "bsp/dp32g030/syscon.h"
#include "sram-overlay.h"

static volatile uint32_t *pFlash = 0;
uint32_t                  overlay_FLASH_MainClock;
uint32_t                  overlay_FLASH_ClockMultiplier;
uint32_t                  overlay_0x20000478;         // Nothing is using this???

void overlay_FLASH_RebootToBootloader(void)
{
	overlay_FLASH_MaskUnlock();
	overlay_FLASH_SetMaskSel(FLASH_MASK_SELECTION_NONE);
	overlay_FLASH_MaskLock();
	overlay_SystemReset();
}

bool overlay_FLASH_IsBusy(void)
{
	return (FLASH_ST & FLASH_ST_BUSY_MASK) != FLASH_ST_BUSY_BITS_READY;
}

bool overlay_FLASH_IsInitComplete(void)
{
	return (FLASH_ST & FLASH_ST_INIT_BUSY_MASK) == FLASH_ST_INIT_BUSY_BITS_COMPLETE;
}

void overlay_FLASH_Start(void)
{
	overlay_FLASH_Unlock();
	FLASH_START |= FLASH_START_START_BITS_START;
}

void overlay_FLASH_Init(FLASH_READ_MODE ReadMode)
{
	overlay_FLASH_WakeFromDeepSleep();
	overlay_FLASH_SetMode(FLASH_MODE_READ_AHB);
	overlay_FLASH_SetReadMode(ReadMode);
	overlay_FLASH_SetEraseTime();
	overlay_FLASH_SetProgramTime();
	overlay_FLASH_Lock();
}

void overlay_FLASH_MaskLock(void)
{
	FLASH_MASK = (FLASH_MASK & ~FLASH_MASK_LOCK_MASK) | FLASH_MASK_LOCK_BITS_SET;
}

void overlay_FLASH_SetMaskSel(FLASH_MASK_SELECTION Mask)
{
	FLASH_MASK = (FLASH_MASK & ~FLASH_MASK_SEL_MASK) | ((Mask << FLASH_MASK_SEL_SHIFT) & FLASH_MASK_SEL_MASK);
}

void overlay_FLASH_MaskUnlock(void)
{
	FLASH_MASK = (FLASH_MASK & ~FLASH_MASK_LOCK_MASK) | FLASH_MASK_LOCK_BITS_NOT_SET;
}

void overlay_FLASH_Lock(void)
{
	FLASH_LOCK = FLASH_LOCK_LOCK_BITS_LOCK;
}

void overlay_FLASH_Unlock(void)
{
	FLASH_UNLOCK = FLASH_UNLOCK_UNLOCK_BITS_UNLOCK;
}

uint32_t overlay_FLASH_ReadByAHB(uint32_t Offset)
{

	return pFlash[(Offset & ~3U) / 4];
}

uint32_t overlay_FLASH_ReadByAPB(uint32_t Offset)
{
	uint32_t Data;

	while (overlay_FLASH_IsBusy()) {}

	overlay_FLASH_SetMode(FLASH_MODE_READ_APB);
	FLASH_ADDR = Offset >> 2;

	overlay_FLASH_Start();

	while (overlay_FLASH_IsBusy()) {}

	Data = FLASH_RDATA;

	overlay_FLASH_SetMode(FLASH_MODE_READ_AHB);
	overlay_FLASH_Lock();

	return Data;
}

void overlay_FLASH_SetArea(FLASH_AREA Area)
{
	FLASH_CFG = (FLASH_CFG & ~FLASH_CFG_NVR_SEL_MASK) | ((Area << FLASH_CFG_NVR_SEL_SHIFT) & FLASH_CFG_NVR_SEL_MASK);
}

void overlay_FLASH_SetReadMode(FLASH_READ_MODE Mode)
{
	if (Mode == FLASH_READ_MODE_1_CYCLE)
		FLASH_CFG = (FLASH_CFG & ~FLASH_CFG_READ_MD_MASK) | FLASH_CFG_READ_MD_BITS_1_CYCLE;
	else
	if (Mode == FLASH_READ_MODE_2_CYCLE)
		FLASH_CFG = (FLASH_CFG & ~FLASH_CFG_READ_MD_MASK) | FLASH_CFG_READ_MD_BITS_2_CYCLE;
}

void overlay_FLASH_SetEraseTime(void)
{
	FLASH_ERASETIME = ((overlay_FLASH_ClockMultiplier & 0xFFFFU) * 0x1A00000U) + (overlay_FLASH_ClockMultiplier * 3600U);
}

void overlay_FLASH_WakeFromDeepSleep(void)
{
	FLASH_CFG = (FLASH_CFG & ~FLASH_CFG_DEEP_PD_MASK) | FLASH_CFG_DEEP_PD_BITS_NORMAL;
	while (!overlay_FLASH_IsInitComplete()) {}
}

void overlay_FLASH_SetMode(FLASH_MODE Mode)
{
	FLASH_CFG = (FLASH_CFG & ~FLASH_CFG_MODE_MASK) | ((Mode << FLASH_CFG_MODE_SHIFT) & FLASH_CFG_MODE_MASK);
}

void overlay_FLASH_SetProgramTime(void)
{
	FLASH_PROGTIME = overlay_FLASH_ClockMultiplier * 45074;
}

void overlay_SystemReset(void)
{
	// Lifted from core_cm0.h to preserve function order in the object file.

	__DSB();     // Ensure all outstanding memory accesses included buffered write are completed before reset
	SCB->AIRCR = (0x5FAUL << SCB_AIRCR_VECTKEY_Pos) | SCB_AIRCR_SYSRESETREQ_Msk;
	__DSB();     // Ensure completion of memory access

	for (;;)     // wait until reset
		__NOP();
}

uint32_t overlay_FLASH_ReadNvrWord(uint32_t Offset)
{
	uint32_t Data;
	overlay_FLASH_SetArea(FLASH_AREA_NVR);
	Data = overlay_FLASH_ReadByAHB(Offset);
	overlay_FLASH_SetArea(FLASH_AREA_MAIN);
	return Data;
}

void overlay_FLASH_ConfigureTrimValues(void)
{
	uint32_t Data;

	overlay_FLASH_SetArea(FLASH_AREA_NVR);

	SYSCON_CHIP_ID0 = overlay_FLASH_ReadByAPB(0xF018);
	SYSCON_CHIP_ID1 = overlay_FLASH_ReadByAPB(0xF01C);
	SYSCON_CHIP_ID2 = overlay_FLASH_ReadByAPB(0xF020);
	SYSCON_CHIP_ID3 = overlay_FLASH_ReadByAPB(0xF024);

	SYSCON_RC_FREQ_DELTA   = overlay_FLASH_ReadByAHB(0x07C8);
	SYSCON_VREF_VOLT_DELTA = overlay_FLASH_ReadByAHB(0x07C4);

	PMU_TRIM_POW0 = overlay_FLASH_ReadByAHB(0x07E4);
	PMU_TRIM_POW1 = overlay_FLASH_ReadByAHB(0x07E0);
	PMU_TRIM_RCHF = overlay_FLASH_ReadByAHB(0x07D8);
	PMU_TRIM_RCLF = overlay_FLASH_ReadByAHB(0x07D4);
	PMU_TRIM_OPA  = overlay_FLASH_ReadByAHB(0x07D0);
	PMU_TRIM_PLL  = overlay_FLASH_ReadByAHB(0x07CC);

	overlay_0x20000478 = overlay_FLASH_ReadByAHB(0x07B8);

	Data                = overlay_FLASH_ReadByAHB(0x07BC);
	SYSCON_DEV_CLK_GATE = (SYSCON_DEV_CLK_GATE & ~SYSCON_DEV_CLK_GATE_SARADC_MASK) | SYSCON_DEV_CLK_GATE_SARADC_BITS_ENABLE;
	SARADC_CALIB_OFFSET = ((Data & 0xFFFF) << SARADC_CALIB_OFFSET_OFFSET_SHIFT) & SARADC_CALIB_OFFSET_OFFSET_MASK;
	SARADC_CALIB_KD     = (((Data >> 16) & 0xFFFF) << SARADC_CALIB_KD_KD_SHIFT) & SARADC_CALIB_KD_KD_MASK;
	overlay_FLASH_SetArea(FLASH_AREA_MAIN);
}