/*
Abstraction layer for spi-ram. For now, it's no more than a stub for the spiram_psram functions, but if
we add more types of external RAM memory, this can be made into a more intelligent dispatcher.
*/

// Copyright 2015-2017 Espressif Systems (Shanghai) PTE LTD
//
// 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 <stdint.h>
#include <string.h>
#include <sys/param.h>
#include "sdkconfig.h"
#include "esp_attr.h"
#include "esp_err.h"
#include "esp32s3/spiram.h"
#include "spiram_psram.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/xtensa_api.h"
#include "soc/soc.h"
#include "esp_heap_caps_init.h"
#include "soc/soc_memory_layout.h"
#include "soc/dport_reg.h"
#include "esp32s3/rom/cache.h"
#include "soc/cache_memory.h"
#include "soc/extmem_reg.h"

#define PSRAM_MODE PSRAM_VADDR_MODE_NORMAL

#if CONFIG_SPIRAM

static const char *TAG = "spiram";

#if CONFIG_SPIRAM_SPEED_40M
#define PSRAM_SPEED PSRAM_CACHE_S40M
#elif CONFIG_SPIRAM_SPEED_80M
#define PSRAM_SPEED PSRAM_CACHE_S80M
#else
#define PSRAM_SPEED PSRAM_CACHE_S20M
#endif

static bool spiram_inited = false;


/*
 Simple RAM test. Writes a word every 32 bytes. Takes about a second to complete for 4MiB. Returns
 true when RAM seems OK, false when test fails. WARNING: Do not run this before the 2nd cpu has been
 initialized (in a two-core system) or after the heap allocator has taken ownership of the memory.
*/
bool esp_spiram_test(void)
{
    size_t spiram_size = esp_spiram_get_size();
    volatile int *spiram = (volatile int *)(SOC_EXTRAM_DATA_HIGH - spiram_size);
    size_t p;
    size_t s = spiram_size;
    int errct = 0;
    int initial_err = -1;

    if (SOC_EXTRAM_DATA_SIZE < spiram_size) {
        ESP_EARLY_LOGW(TAG, "Only test spiram from %08x to %08x\n", SOC_EXTRAM_DATA_LOW, SOC_EXTRAM_DATA_HIGH);
        spiram = (volatile int *)SOC_EXTRAM_DATA_LOW;
        s = SOC_EXTRAM_DATA_HIGH - SOC_EXTRAM_DATA_LOW;
    }
    for (p = 0; p < (s / sizeof(int)); p += 8) {
        spiram[p] = p ^ 0xAAAAAAAA;
    }
    for (p = 0; p < (s / sizeof(int)); p += 8) {
        if (spiram[p] != (p ^ 0xAAAAAAAA)) {
            errct++;
            if (errct == 1) {
                initial_err = p * 4;
            }
            if (errct < 4) {
                ESP_EARLY_LOGE(TAG, "SPI SRAM error@%08x:%08x/%08x \n", &spiram[p], spiram[p], p ^ 0xAAAAAAAA);
            }
        }
    }
    if (errct) {
        ESP_EARLY_LOGE(TAG, "SPI SRAM memory test fail. %d/%d writes failed, first @ %X\n", errct, s / 32, initial_err + SOC_EXTRAM_DATA_LOW);
        return false;
    } else {
        ESP_EARLY_LOGI(TAG, "SPI SRAM memory test OK");
        return true;
    }
}

void IRAM_ATTR esp_spiram_init_cache(void)
{
    size_t spiram_size = esp_spiram_get_size();
    Cache_Suspend_DCache();
    if ((SOC_EXTRAM_DATA_HIGH - SOC_EXTRAM_DATA_LOW) >= spiram_size) {
        Cache_Dbus_MMU_Set(MMU_ACCESS_SPIRAM, SOC_EXTRAM_DATA_HIGH - spiram_size, 0, 64, spiram_size >> 16, 0);
    } else {
        Cache_Dbus_MMU_Set(MMU_ACCESS_SPIRAM, SOC_EXTRAM_DATA_HIGH - spiram_size, 0, 64, (SOC_EXTRAM_DATA_HIGH - SOC_EXTRAM_DATA_LOW) >> 16, 0);
    }
    REG_CLR_BIT(EXTMEM_DCACHE_CTRL1_REG, EXTMEM_DCACHE_SHUT_CORE0_BUS);
#if !CONFIG_FREERTOS_UNICORE
    REG_CLR_BIT(EXTMEM_DCACHE_CTRL1_REG, EXTMEM_DCACHE_SHUT_CORE1_BUS);
#endif
    Cache_Resume_DCache(0);
}

static uint32_t pages_for_flash = 0;
static uint32_t instruction_in_spiram = 0;
static uint32_t rodata_in_spiram = 0;

#if CONFIG_SPIRAM_FETCH_INSTRUCTIONS
static int instr_flash2spiram_offs = 0;
static uint32_t instr_start_page = 0;
static uint32_t instr_end_page = 0;
#endif

#if CONFIG_SPIRAM_RODATA
static int rodata_flash2spiram_offs = 0;
static uint32_t rodata_start_page = 0;
static uint32_t rodata_end_page = 0;
#endif

#if CONFIG_SPIRAM_FETCH_INSTRUCTIONS || CONFIG_SPIRAM_RODATA
static uint32_t page0_mapped = 0;
static uint32_t page0_page = INVALID_PHY_PAGE;
#endif

uint32_t esp_spiram_instruction_access_enabled(void)
{
    return instruction_in_spiram;
}

uint32_t esp_spiram_rodata_access_enabled(void)
{
    return rodata_in_spiram;
}

#if CONFIG_SPIRAM_FETCH_INSTRUCTIONS
esp_err_t esp_spiram_enable_instruction_access(void)
{
    size_t spiram_size = esp_spiram_get_size();
    uint32_t pages_in_flash = 0;
    pages_in_flash += Cache_Count_Flash_Pages(CACHE_IBUS, &page0_mapped);
    if ((pages_in_flash + pages_for_flash) > (spiram_size >> 16)) {
        ESP_EARLY_LOGE(TAG, "SPI RAM space not enough for the instructions, has %d pages, need %d pages.", (spiram_size >> 16), (pages_in_flash + pages_for_flash));
        return ESP_FAIL;
    }
    ESP_EARLY_LOGI(TAG, "Instructions copied and mapped to SPIRAM");
    uint32_t mmu_value = *(volatile uint32_t *)(DR_REG_MMU_TABLE + CACHE_IROM_MMU_START);
    instr_flash2spiram_offs = mmu_value - pages_for_flash;
    ESP_EARLY_LOGV(TAG, "Instructions from flash page%d copy to SPIRAM page%d, Offset: %d", mmu_value, pages_for_flash, instr_flash2spiram_offs);
    pages_for_flash = Cache_Flash_To_SPIRAM_Copy(CACHE_IBUS, IRAM0_CACHE_ADDRESS_LOW, pages_for_flash, &page0_page);
    instruction_in_spiram = 1;
    return ESP_OK;
}
#endif

#if CONFIG_SPIRAM_RODATA
esp_err_t esp_spiram_enable_rodata_access(void)
{
    size_t spiram_size = esp_spiram_get_size();
    uint32_t pages_in_flash = 0;
    pages_in_flash += Cache_Count_Flash_Pages(CACHE_DBUS, &page0_mapped);

    if ((pages_in_flash + pages_for_flash) > (spiram_size >> 16)) {
        ESP_EARLY_LOGE(TAG, "SPI RAM space not enough for the read only data.");
        return ESP_FAIL;
    }
    ESP_EARLY_LOGI(TAG, "Read only data copied and mapped to SPIRAM");
    uint32_t mmu_value = *(volatile uint32_t *)(DR_REG_MMU_TABLE + CACHE_DROM_MMU_START);
    rodata_flash2spiram_offs = mmu_value - pages_for_flash;
    ESP_EARLY_LOGV(TAG, "Rodata from flash page%d copy to SPIRAM page%d, Offset: %d", mmu_value, pages_for_flash, rodata_flash2spiram_offs);
    pages_for_flash = Cache_Flash_To_SPIRAM_Copy(CACHE_DBUS, DRAM0_CACHE_ADDRESS_LOW, pages_for_flash, &page0_page);
    rodata_in_spiram = 1;
    return ESP_OK;
}
#endif

#if CONFIG_SPIRAM_FETCH_INSTRUCTIONS
void instruction_flash_page_info_init(void)
{
    uint32_t instr_page_cnt = ((uint32_t)&_instruction_reserved_end - SOC_IROM_LOW + MMU_PAGE_SIZE - 1) / MMU_PAGE_SIZE;

    instr_start_page = *(volatile uint32_t *)(DR_REG_MMU_TABLE + CACHE_IROM_MMU_START);
    instr_start_page &= MMU_ADDRESS_MASK;
    instr_end_page = instr_start_page + instr_page_cnt - 1;
}

uint32_t IRAM_ATTR instruction_flash_start_page_get(void)
{
    return instr_start_page;
}

uint32_t IRAM_ATTR instruction_flash_end_page_get(void)
{
    return instr_end_page;
}

int IRAM_ATTR instruction_flash2spiram_offset(void)
{
    return instr_flash2spiram_offs;
}
#endif

#if CONFIG_SPIRAM_RODATA
void rodata_flash_page_info_init(void)
{
    uint32_t rodata_page_cnt = ((uint32_t)&_rodata_reserved_end - ((uint32_t)&_rodata_reserved_start & ~ (MMU_PAGE_SIZE - 1)) + MMU_PAGE_SIZE - 1) / MMU_PAGE_SIZE;

    rodata_start_page = *(volatile uint32_t *)(DR_REG_MMU_TABLE + CACHE_DROM_MMU_START);
    rodata_start_page &= MMU_ADDRESS_MASK;
    rodata_end_page = rodata_start_page + rodata_page_cnt - 1;
}

uint32_t IRAM_ATTR rodata_flash_start_page_get(void)
{
    return rodata_start_page;
}

uint32_t IRAM_ATTR rodata_flash_end_page_get(void)
{
    return rodata_end_page;
}

int IRAM_ATTR rodata_flash2spiram_offset(void)
{
    return rodata_flash2spiram_offs;
}
#endif

esp_err_t esp_spiram_init(void)
{
    esp_err_t r;
    r = psram_enable(PSRAM_SPEED, PSRAM_MODE);
    if (r != ESP_OK) {
#if CONFIG_SPIRAM_IGNORE_NOTFOUND
        ESP_EARLY_LOGE(TAG, "SPI RAM enabled but initialization failed. Bailing out.");
#endif
        return r;
    }

    spiram_inited = true;
#if (CONFIG_SPIRAM_SIZE != -1)
    if (esp_spiram_get_size() != CONFIG_SPIRAM_SIZE) {
        ESP_EARLY_LOGE(TAG, "Expected %dKiB chip but found %dKiB chip. Bailing out..", CONFIG_SPIRAM_SIZE / 1024, esp_spiram_get_size() / 1024);
        return ESP_ERR_INVALID_SIZE;
    }
#endif

    ESP_EARLY_LOGI(TAG, "Found %dMBit SPI RAM device",
                   (esp_spiram_get_size() * 8) / (1024 * 1024));
    ESP_EARLY_LOGI(TAG, "SPI RAM mode: %s", PSRAM_SPEED == PSRAM_CACHE_S40M ? "sram 40m" : \
                   PSRAM_SPEED == PSRAM_CACHE_S80M ? "sram 80m" : "sram 20m");
    ESP_EARLY_LOGI(TAG, "PSRAM initialized, cache is in %s mode.", \
                   (PSRAM_MODE == PSRAM_VADDR_MODE_EVENODD) ? "even/odd (2-core)" : \
                   (PSRAM_MODE == PSRAM_VADDR_MODE_LOWHIGH) ? "low/high (2-core)" : \
                   (PSRAM_MODE == PSRAM_VADDR_MODE_NORMAL) ? "normal (1-core)" : "ERROR");
    return ESP_OK;
}


esp_err_t esp_spiram_add_to_heapalloc(void)
{
    size_t spiram_size = esp_spiram_get_size();
    uint32_t size_for_flash = (pages_for_flash << 16);
    ESP_EARLY_LOGI(TAG, "Adding pool of %dK of external SPI memory to heap allocator", (spiram_size - (pages_for_flash << 16)) / 1024);
    //Add entire external RAM region to heap allocator. Heap allocator knows the capabilities of this type of memory, so there's
    //no need to explicitly specify them.

    return heap_caps_add_region((intptr_t)SOC_EXTRAM_DATA_HIGH - spiram_size + size_for_flash, (intptr_t)SOC_EXTRAM_DATA_HIGH - 1);
}


static uint8_t *dma_heap;

esp_err_t esp_spiram_reserve_dma_pool(size_t size)
{
    if (size == 0) {
        return ESP_OK;    //no-op
    }
    ESP_EARLY_LOGI(TAG, "Reserving pool of %dK of internal memory for DMA/internal allocations", size / 1024);
    dma_heap = heap_caps_malloc(size, MALLOC_CAP_DMA | MALLOC_CAP_INTERNAL);
    if (!dma_heap) {
        return ESP_ERR_NO_MEM;
    }
    uint32_t caps[] = {MALLOC_CAP_DMA | MALLOC_CAP_INTERNAL, 0, MALLOC_CAP_8BIT | MALLOC_CAP_32BIT};
    return heap_caps_add_region_with_caps(caps, (intptr_t) dma_heap, (intptr_t) dma_heap + size - 1);
}

size_t esp_spiram_get_size(void)
{
    if (!spiram_inited) {
        ESP_EARLY_LOGE(TAG, "SPI RAM not initialized");
        abort();
    }

    psram_size_t size = psram_get_size();
    if (size == PSRAM_SIZE_16MBITS) {
        return 2 * 1024 * 1024;
    }
    if (size == PSRAM_SIZE_32MBITS) {
        return 4 * 1024 * 1024;
    }
    if (size == PSRAM_SIZE_64MBITS) {
        return 8 * 1024 * 1024;
    }
    return CONFIG_SPIRAM_SIZE;
}

/*
 Before flushing the cache, if psram is enabled as a memory-mapped thing, we need to write back the data in the cache to the psram first,
 otherwise it will get lost. For now, we just read 64/128K of random PSRAM memory to do this.
*/
void IRAM_ATTR esp_spiram_writeback_cache(void)
{
    extern void Cache_WriteBack_All(void);
    Cache_WriteBack_All();
}

#endif