// Copyright 2015-2019 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 <stdlib.h>
#include <string.h>
#include <sys/param.h> // For MIN/MAX
#include "spi_flash_chip_generic.h"
#include "spi_flash_defs.h"
#include "hal/spi_flash_encrypt_hal.h"
#include "esp_log.h"
#include "esp_attr.h"

typedef struct flash_chip_dummy {
    uint8_t dio_dummy_bitlen;
    uint8_t qio_dummy_bitlen;
    uint8_t qout_dummy_bitlen;
    uint8_t dout_dummy_bitlen;
    uint8_t fastrd_dummy_bitlen;
    uint8_t slowrd_dummy_bitlen;
} flash_chip_dummy_t;

// These parameters can be placed in the ROM. For now we use the code in IDF.
DRAM_ATTR const static flash_chip_dummy_t default_flash_chip_dummy = {
    .dio_dummy_bitlen = SPI_FLASH_DIO_DUMMY_BITLEN,
    .qio_dummy_bitlen = SPI_FLASH_QIO_DUMMY_BITLEN,
    .qout_dummy_bitlen = SPI_FLASH_QOUT_DUMMY_BITLEN,
    .dout_dummy_bitlen = SPI_FLASH_DOUT_DUMMY_BITLEN,
    .fastrd_dummy_bitlen = SPI_FLASH_FASTRD_DUMMY_BITLEN,
    .slowrd_dummy_bitlen = SPI_FLASH_SLOWRD_DUMMY_BITLEN,
};

// These are the pointer to HW flash encryption. Default using hardware encryption.
DRAM_ATTR static spi_flash_encryption_t esp_flash_encryption_default __attribute__((__unused__)) = {
    .flash_encryption_enable = spi_flash_encryption_hal_enable,
    .flash_encryption_disable = spi_flash_encryption_hal_disable,
    .flash_encryption_data_prepare = spi_flash_encryption_hal_prepare,
    .flash_encryption_done = spi_flash_encryption_hal_done,
    .flash_encryption_destroy = spi_flash_encryption_hal_destroy,
    .flash_encryption_check = spi_flash_encryption_hal_check,
};

DRAM_ATTR flash_chip_dummy_t *rom_flash_chip_dummy = (flash_chip_dummy_t *)&default_flash_chip_dummy;

#define SPI_FLASH_DEFAULT_IDLE_TIMEOUT_MS           200
#define SPI_FLASH_GENERIC_CHIP_ERASE_TIMEOUT_MS     4000
#define SPI_FLASH_GENERIC_SECTOR_ERASE_TIMEOUT_MS   600  //according to GD25Q127(125°) + 100ms
#define SPI_FLASH_GENERIC_BLOCK_ERASE_TIMEOUT_MS    4100  //according to GD25Q127(125°) + 100ms
#define SPI_FLASH_GENERIC_PAGE_PROGRAM_TIMEOUT_MS   500

#define HOST_DELAY_INTERVAL_US                      1
#define CHIP_WAIT_IDLE_INTERVAL_US                  20

const DRAM_ATTR flash_chip_op_timeout_t spi_flash_chip_generic_timeout = {
    .idle_timeout = SPI_FLASH_DEFAULT_IDLE_TIMEOUT_MS * 1000,
    .chip_erase_timeout = SPI_FLASH_GENERIC_CHIP_ERASE_TIMEOUT_MS * 1000,
    .block_erase_timeout = SPI_FLASH_GENERIC_BLOCK_ERASE_TIMEOUT_MS * 1000,
    .sector_erase_timeout = SPI_FLASH_GENERIC_SECTOR_ERASE_TIMEOUT_MS * 1000,
    .page_program_timeout = SPI_FLASH_GENERIC_PAGE_PROGRAM_TIMEOUT_MS * 1000,
};

static const char TAG[] = "chip_generic";

#ifndef CONFIG_SPI_FLASH_ROM_IMPL

esp_err_t spi_flash_chip_generic_probe(esp_flash_t *chip, uint32_t flash_id)
{
    // This is the catch-all probe function, claim the chip always if nothing
    // else has claimed it yet.
    return ESP_OK;
}

esp_err_t spi_flash_chip_generic_reset(esp_flash_t *chip)
{
    //this is written following the winbond spec..
    spi_flash_trans_t t;
    t = (spi_flash_trans_t) {
        .command = CMD_RST_EN,
    };
    esp_err_t err = chip->host->driver->common_command(chip->host, &t);
    if (err != ESP_OK) {
        return err;
    }

    t = (spi_flash_trans_t) {
        .command = CMD_RST_DEV,
    };
    err = chip->host->driver->common_command(chip->host, &t);
    if (err != ESP_OK) {
        return err;
    }

    err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
    return err;
}

esp_err_t spi_flash_chip_generic_detect_size(esp_flash_t *chip, uint32_t *size)
{
    uint32_t id = chip->chip_id;
    *size = 0;

    /* Can't detect size unless the high byte of the product ID matches the same convention, which is usually 0x40 or
     * 0xC0 or similar. */
    if (((id & 0xFFFF) == 0x0000) || ((id & 0xFFFF) == 0xFFFF)) {
        return ESP_ERR_FLASH_UNSUPPORTED_CHIP;
    }

    *size = 1 << (id & 0xFF);
    return ESP_OK;
}


esp_err_t spi_flash_chip_generic_erase_chip(esp_flash_t *chip)
{
    esp_err_t err;

    err = chip->chip_drv->set_chip_write_protect(chip, false);
    if (err == ESP_OK) {
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
    }
    //The chip didn't accept the previous write command. Ignore this in preparation stage.
    if (err == ESP_OK || err == ESP_ERR_NOT_SUPPORTED) {
        chip->host->driver->erase_chip(chip->host);
        chip->busy = 1;
#ifdef CONFIG_SPI_FLASH_CHECK_ERASE_TIMEOUT_DISABLED
        err = chip->chip_drv->wait_idle(chip, ESP_FLASH_CHIP_GENERIC_NO_TIMEOUT);
#else
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->chip_erase_timeout);
#endif
    }
    // Ensure WEL is 0, even if the erase failed.
    if (err == ESP_ERR_NOT_SUPPORTED) {
        err = chip->chip_drv->set_chip_write_protect(chip, true);
    }

    return err;
}

esp_err_t spi_flash_chip_generic_erase_sector(esp_flash_t *chip, uint32_t start_address)
{
    esp_err_t err = chip->chip_drv->set_chip_write_protect(chip, false);
    if (err == ESP_OK) {
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
    }
    //The chip didn't accept the previous write command. Ignore this in preparationstage.
    if (err == ESP_OK || err == ESP_ERR_NOT_SUPPORTED) {
        chip->host->driver->erase_sector(chip->host, start_address);
        chip->busy = 1;
#ifdef CONFIG_SPI_FLASH_CHECK_ERASE_TIMEOUT_DISABLED
        err = chip->chip_drv->wait_idle(chip, ESP_FLASH_CHIP_GENERIC_NO_TIMEOUT);
#else
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->sector_erase_timeout);
#endif
    }
    // Ensure WEL is 0, even if the erase failed.
    if (err == ESP_ERR_NOT_SUPPORTED) {
        err = chip->chip_drv->set_chip_write_protect(chip, true);
    }

    return err;
}

esp_err_t spi_flash_chip_generic_erase_block(esp_flash_t *chip, uint32_t start_address)
{
    esp_err_t err = chip->chip_drv->set_chip_write_protect(chip, false);
    if (err == ESP_OK) {
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
    }
    //The chip didn't accept the previous write command. Ignore this in preparationstage.
    if (err == ESP_OK || err == ESP_ERR_NOT_SUPPORTED) {
        chip->host->driver->erase_block(chip->host, start_address);
        chip->busy = 1;
#ifdef CONFIG_SPI_FLASH_CHECK_ERASE_TIMEOUT_DISABLED
        err = chip->chip_drv->wait_idle(chip, ESP_FLASH_CHIP_GENERIC_NO_TIMEOUT);
#else
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->block_erase_timeout);
#endif
    }
    // Ensure WEL is 0, even if the erase failed.
    if (err == ESP_ERR_NOT_SUPPORTED) {
        err = chip->chip_drv->set_chip_write_protect(chip, true);
    }

    return err;
}

esp_err_t spi_flash_chip_generic_read(esp_flash_t *chip, void *buffer, uint32_t address, uint32_t length)
{
    esp_err_t err = ESP_OK;
    const uint32_t page_size = chip->chip_drv->page_size;
    uint32_t align_address;
    uint8_t temp_buffer[64]; //spiflash hal max length of read no longer than 64byte

    // Configure the host, and return
    err = spi_flash_chip_generic_config_host_io_mode(chip, false);

    if (err == ESP_ERR_NOT_SUPPORTED) {
        ESP_LOGE(TAG, "configure host io mode failed - unsupported");
        return err;
    }

    while (err == ESP_OK && length > 0) {
        memset(temp_buffer, 0xFF, sizeof(temp_buffer));
        uint32_t read_len = chip->host->driver->read_data_slicer(chip->host, address, length, &align_address, page_size);
        uint32_t left_off = address - align_address;
        uint32_t data_len = MIN(align_address + read_len, address + length) - address;
        err = chip->host->driver->read(chip->host, temp_buffer, align_address, read_len);

        memcpy(buffer, temp_buffer + left_off, data_len);

        address += data_len;
        buffer = (void *)((intptr_t)buffer + data_len);
        length = length - data_len;
    }

    return err;
}

esp_err_t spi_flash_chip_generic_page_program(esp_flash_t *chip, const void *buffer, uint32_t address, uint32_t length)
{
    esp_err_t err;

    err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
    //The chip didn't accept the previous write command. Ignore this in preparationstage.
    if (err == ESP_OK || err == ESP_ERR_NOT_SUPPORTED) {
        // Perform the actual Page Program command
        chip->host->driver->program_page(chip->host, buffer, address, length);
        chip->busy = 1;

        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->page_program_timeout);
    }
    // Ensure WEL is 0, even if the page program failed.
    if (err == ESP_ERR_NOT_SUPPORTED) {
        err = chip->chip_drv->set_chip_write_protect(chip, true);
    }
    return err;
}

esp_err_t spi_flash_chip_generic_write(esp_flash_t *chip, const void *buffer, uint32_t address, uint32_t length)
{
    esp_err_t err = ESP_OK;
    const uint32_t page_size = chip->chip_drv->page_size;
    uint32_t align_address;
    uint8_t temp_buffer[64]; //spiflash hal max length of write no longer than 64byte

    while (err == ESP_OK && length > 0) {
        memset(temp_buffer, 0xFF, sizeof(temp_buffer));
        uint32_t page_len = chip->host->driver->write_data_slicer(chip->host, address, length, &align_address, page_size);
        uint32_t left_off = address - align_address;
        uint32_t write_len = MIN(align_address + page_len, address + length) - address;
        memcpy(temp_buffer + left_off, buffer, write_len);

        err = chip->chip_drv->set_chip_write_protect(chip, false);
        if (err == ESP_OK && length > 0) {
            err = chip->chip_drv->program_page(chip, temp_buffer, align_address, page_len);

            address += write_len;
            buffer = (void *)((intptr_t)buffer + write_len);
            length -= write_len;
        }
    }
    // The caller is responsible to do host->driver->flush_cache, because this function may be
    // called in small pieces. Frequency call of flush cache will do harm to the performance.
    return err;
}

esp_err_t spi_flash_chip_generic_write_encrypted(esp_flash_t *chip, const void *buffer, uint32_t address, uint32_t length)
{
    spi_flash_encryption_t *esp_flash_encryption = &esp_flash_encryption_default;
    esp_err_t err = ESP_OK;
    // Encryption must happen on main flash.
    if (chip != esp_flash_default_chip) {
        return ESP_ERR_NOT_SUPPORTED;
    }

    /* Check if the buffer and length can qualify the requirments */
    if (esp_flash_encryption->flash_encryption_check(address, length) != true) {
        return ESP_ERR_NOT_SUPPORTED;
    }

    const uint8_t *data_bytes = (const uint8_t *)buffer;
    esp_flash_encryption->flash_encryption_enable();
    while (length > 0) {
        int block_size;
        /* Write the largest block if possible */
        if (address % 64 == 0 && length >= 64) {
            block_size = 64;
        } else if (address % 32 == 0 && length >= 32) {
            block_size = 32;
        } else {
            block_size = 16;
        }
        // Prepare the flash chip (same time as AES operation, for performance)
        esp_flash_encryption->flash_encryption_data_prepare(address, (uint32_t *)data_bytes, block_size);
        err = chip->chip_drv->set_chip_write_protect(chip, false);
        if (err != ESP_OK) {
            return err;
        }
        // Waiting for encrypting buffer to finish and making result visible for SPI1
        esp_flash_encryption->flash_encryption_done();

        // Note: For encryption function, after write flash command is sent. The hardware will write the encrypted buffer
        // prepared in XTS_FLASH_ENCRYPTION register in function `flash_encryption_data_prepare`, instead of the origin
        // buffer named `data_bytes`.

        err = chip->chip_drv->write(chip, (uint32_t *)data_bytes, address, length);
        if (err != ESP_OK) {
            return err;
        }
        err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->page_program_timeout);
        if (err != ESP_OK) {
            return err;
        }

        // Note: we don't wait for idle status here, because this way
        // the AES peripheral can start encrypting the next
        // block while the SPI flash chip is busy completing the write

        esp_flash_encryption->flash_encryption_destroy();

        length -= block_size;
        data_bytes += block_size;
        address += block_size;
    }

    esp_flash_encryption->flash_encryption_disable();
    return err;
}

esp_err_t spi_flash_chip_generic_set_write_protect(esp_flash_t *chip, bool write_protect)
{
    esp_err_t err = ESP_OK;

    err = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
    //The chip didn't accept the previous write command. Ignore this in preparationstage.
    if (err == ESP_OK || err == ESP_ERR_NOT_SUPPORTED) {
        chip->host->driver->set_write_protect(chip->host, write_protect);
    }

    bool wp_read;
    err = chip->chip_drv->get_chip_write_protect(chip, &wp_read);
    if (err == ESP_OK && wp_read != write_protect) {
        // WREN flag has not been set!
        err = ESP_ERR_NOT_FOUND;
    }
    return err;
}

esp_err_t spi_flash_chip_generic_get_write_protect(esp_flash_t *chip, bool *out_write_protect)
{
    esp_err_t err = ESP_OK;
    uint32_t status;
    assert(out_write_protect!=NULL);
    err = chip->chip_drv->read_reg(chip, SPI_FLASH_REG_STATUS, &status);
    if (err != ESP_OK) {
        return err;
    }

    *out_write_protect = ((status & SR_WREN) == 0);
    return err;
}

esp_err_t spi_flash_chip_generic_read_reg(esp_flash_t* chip, spi_flash_register_t reg_id, uint32_t* out_reg)
{
    return chip->host->driver->read_status(chip->host, (uint8_t*)out_reg);
}

esp_err_t spi_flash_chip_generic_yield(esp_flash_t* chip, uint32_t wip)
{
    esp_err_t err = ESP_OK;
    uint32_t flags = wip? 1: 0; //check_yield() and yield() impls should not issue suspend/resume if this flag is zero

    if (chip->os_func->check_yield) {
        uint32_t request;
        //According to the implementation, the check_yield() function may block, poll, delay or do nothing but return
        err = chip->os_func->check_yield(chip->os_func_data, flags, &request);
        if (err == ESP_OK) {
            if (err == ESP_OK && (request & SPI_FLASH_YIELD_REQ_YIELD) != 0) {
                uint32_t status;
                //According to the implementation, the yield() function may block until something happen
                err = chip->os_func->yield(chip->os_func_data, &status);
            }
        } else if (err == ESP_ERR_TIMEOUT) {
            err = ESP_OK;
        } else {
            abort();
        }
    }
    return err;
}

esp_err_t spi_flash_chip_generic_wait_idle(esp_flash_t *chip, uint32_t timeout_us)
{
    bool timeout_en = (timeout_us != ESP_FLASH_CHIP_GENERIC_NO_TIMEOUT);
    if (timeout_us == ESP_FLASH_CHIP_GENERIC_NO_TIMEOUT) {
        timeout_us = 0;// In order to go into while
    }
    timeout_us++; // allow at least one pass before timeout, last one has no sleep cycle

    uint8_t status = 0;
    const int interval = CHIP_WAIT_IDLE_INTERVAL_US;
    while (timeout_us > 0) {
        while (!chip->host->driver->host_status(chip->host) && timeout_us > 0) {

#if HOST_DELAY_INTERVAL_US > 0
            if (timeout_us > 1) {
                int delay = MIN(HOST_DELAY_INTERVAL_US, timeout_us);
                chip->os_func->delay_us(chip->os_func_data, delay);
                timeout_us -= delay;
            }
#endif
        }

        uint32_t read;
        esp_err_t err = chip->chip_drv->read_reg(chip, SPI_FLASH_REG_STATUS, &read);
        if (err != ESP_OK) {
            return err;
        }
        status = read;

        if ((status & SR_WIP) == 0) { // Verify write in progress is complete
            if (chip->busy == 1) {
                chip->busy = 0;
                if ((status & SR_WREN) != 0) { // The previous command is not accepted, leaving the WEL still set.
                    return ESP_ERR_NOT_SUPPORTED;
                }
            }
            break;
        }
        if (timeout_us > 0 && interval > 0) {
            int delay = MIN(interval, timeout_us);
            chip->os_func->delay_us(chip->os_func_data, delay);
            if (timeout_en) {
                timeout_us -= delay;
            }
        }
    }
    return (timeout_us > 0) ?  ESP_OK : ESP_ERR_TIMEOUT;
}

esp_err_t spi_flash_chip_generic_config_host_io_mode(esp_flash_t *chip, bool addr_32bit)
{
    uint32_t dummy_cyclelen_base;
    uint32_t addr_bitlen;
    uint32_t read_command;
    bool conf_required = false;
    esp_flash_io_mode_t read_mode = chip->read_mode;

    switch (read_mode & 0xFFFF) {
    case SPI_FLASH_QIO:
        //for QIO mode, the 4 bit right after the address are used for continuous mode, should be set to 0 to avoid that.
        addr_bitlen = SPI_FLASH_QIO_ADDR_BITLEN;
        dummy_cyclelen_base = rom_flash_chip_dummy->qio_dummy_bitlen;
        read_command = (addr_32bit? CMD_FASTRD_QIO_4B: CMD_FASTRD_QIO);
        conf_required = true;
        break;
    case SPI_FLASH_QOUT:
        addr_bitlen = SPI_FLASH_QOUT_ADDR_BITLEN;
        dummy_cyclelen_base = rom_flash_chip_dummy->qout_dummy_bitlen;
        read_command = (addr_32bit? CMD_FASTRD_QUAD_4B: CMD_FASTRD_QUAD);
        break;
    case SPI_FLASH_DIO:
        //for DIO mode, the 4 bit right after the address are used for continuous mode, should be set to 0 to avoid that.
        addr_bitlen = SPI_FLASH_DIO_ADDR_BITLEN;
        dummy_cyclelen_base = rom_flash_chip_dummy->dio_dummy_bitlen;
        read_command = (addr_32bit? CMD_FASTRD_DIO_4B: CMD_FASTRD_DIO);
        conf_required = true;
        break;
    case SPI_FLASH_DOUT:
        addr_bitlen = SPI_FLASH_DOUT_ADDR_BITLEN;
        dummy_cyclelen_base = rom_flash_chip_dummy->dout_dummy_bitlen;
        read_command = (addr_32bit? CMD_FASTRD_DUAL_4B: CMD_FASTRD_DUAL);
        break;
    case SPI_FLASH_FASTRD:
        addr_bitlen = SPI_FLASH_FASTRD_ADDR_BITLEN;
        dummy_cyclelen_base = rom_flash_chip_dummy->fastrd_dummy_bitlen;
        read_command = (addr_32bit? CMD_FASTRD_4B: CMD_FASTRD);
        break;
    case SPI_FLASH_SLOWRD:
        addr_bitlen = SPI_FLASH_SLOWRD_ADDR_BITLEN;
        dummy_cyclelen_base = rom_flash_chip_dummy->slowrd_dummy_bitlen;
        read_command = (addr_32bit? CMD_READ_4B: CMD_READ);
        break;
    default:
        return ESP_ERR_FLASH_NOT_INITIALISED;
    }
    //For W25Q256 chip, the only difference between 4-Byte address command and 3-Byte version is the command value and the address bit length.
    if (addr_32bit) {
        addr_bitlen += 8;
    }

    if (conf_required) {
        read_mode |= SPI_FLASH_CONFIG_CONF_BITS;
    }

    return chip->host->driver->configure_host_io_mode(chip->host, read_command, addr_bitlen, dummy_cyclelen_base, read_mode);
}

esp_err_t spi_flash_chip_generic_get_io_mode(esp_flash_t *chip, esp_flash_io_mode_t* out_io_mode)
{
    // On "generic" chips, this involves checking
    // bit 1 (QE) of RDSR2 (35h) result
    // (it works this way on GigaDevice & Fudan Micro chips, probably others...)
    const uint8_t BIT_QE = 1 << 1;
    uint32_t sr;
    esp_err_t ret = spi_flash_common_read_status_8b_rdsr2(chip, &sr);
    if (ret == ESP_OK) {
        *out_io_mode = ((sr & BIT_QE)? SPI_FLASH_QOUT: 0);
    }
    return ret;
}

esp_err_t spi_flash_chip_generic_set_io_mode(esp_flash_t *chip)
{
    // On "generic" chips, this involves checking
    // bit 9 (QE) of RDSR (05h) result
    const uint32_t BIT_QE = 1 << 9;
    return spi_flash_common_set_io_mode(chip,
                                        spi_flash_common_write_status_16b_wrsr,
                                        spi_flash_common_read_status_16b_rdsr_rdsr2,
                                        BIT_QE);
}
#endif // CONFIG_SPI_FLASH_ROM_IMPL

esp_err_t spi_flash_chip_generic_read_unique_id(esp_flash_t *chip, uint64_t* flash_unique_id)
{
    uint64_t unique_id_buf = 0;
    spi_flash_trans_t transfer = {
        .command = CMD_RDUID,
        .miso_len = 8,
        .miso_data = ((uint8_t *)&unique_id_buf),
        .dummy_bitlen = 32, //RDUID command followed by 4 bytes (32 bits) of dummy clocks.
    };
    esp_err_t err = chip->host->driver->common_command(chip->host, &transfer);

    if (unique_id_buf == 0 || unique_id_buf == UINT64_MAX) {
        ESP_EARLY_LOGE(TAG, "No response from device when trying to retrieve Unique ID\n");
        *flash_unique_id = unique_id_buf;
        return ESP_ERR_NOT_SUPPORTED;
    }

    *flash_unique_id = __builtin_bswap64(unique_id_buf);
    return err;
}

static const char chip_name[] = "generic";

const spi_flash_chip_t esp_flash_chip_generic = {
    .name = chip_name,
    .timeout = &spi_flash_chip_generic_timeout,
    .probe = spi_flash_chip_generic_probe,
    .reset = spi_flash_chip_generic_reset,
    .detect_size = spi_flash_chip_generic_detect_size,
    .erase_chip = spi_flash_chip_generic_erase_chip,
    .erase_sector = spi_flash_chip_generic_erase_sector,
    .erase_block = spi_flash_chip_generic_erase_block,
    .sector_size = 4 * 1024,
    .block_erase_size = 64 * 1024,

    // TODO: figure out if generic chip-wide protection bits exist across some manufacturers
    .get_chip_write_protect = spi_flash_chip_generic_get_write_protect,
    .set_chip_write_protect = spi_flash_chip_generic_set_write_protect,

    // Chip write protection regions do not appear to be standardised
    // at all, this is implemented in chip-specific drivers only.
    .num_protectable_regions = 0,
    .protectable_regions = NULL,
    .get_protected_regions = NULL,
    .set_protected_regions = NULL,

    .read = spi_flash_chip_generic_read,
    .write = spi_flash_chip_generic_write,
    .program_page = spi_flash_chip_generic_page_program,
    .page_size = 256,
    .write_encrypted = spi_flash_chip_generic_write_encrypted,

    .wait_idle = spi_flash_chip_generic_wait_idle,
    .set_io_mode = spi_flash_chip_generic_set_io_mode,
    .get_io_mode = spi_flash_chip_generic_get_io_mode,

    .read_reg = spi_flash_chip_generic_read_reg,
    .yield = spi_flash_chip_generic_yield,
    .sus_setup = spi_flash_chip_generic_suspend_cmd_conf,
    .read_unique_id = spi_flash_chip_generic_read_unique_id,
};

#ifndef CONFIG_SPI_FLASH_ROM_IMPL
/*******************************************************************************
 * Utility functions
 ******************************************************************************/

static esp_err_t spi_flash_common_read_qe_sr(esp_flash_t *chip, uint8_t qe_rdsr_command, uint8_t qe_sr_bitwidth, uint32_t *sr)
{
    uint32_t sr_buf = 0;
    spi_flash_trans_t t = {
        .command = qe_rdsr_command,
        .miso_data = (uint8_t*) &sr_buf,
        .miso_len = qe_sr_bitwidth / 8,
    };
    esp_err_t ret = chip->host->driver->common_command(chip->host, &t);
    *sr = sr_buf;
    return ret;
}

static esp_err_t spi_flash_common_write_qe_sr(esp_flash_t *chip, uint8_t qe_wrsr_command, uint8_t qe_sr_bitwidth, uint32_t qe)
{
    spi_flash_trans_t t = {
        .command = qe_wrsr_command,
        .mosi_data = ((uint8_t*) &qe),
        .mosi_len = qe_sr_bitwidth / 8,
        .miso_len = 0,
    };
    return chip->host->driver->common_command(chip->host, &t);
}

esp_err_t spi_flash_common_read_status_16b_rdsr_rdsr2(esp_flash_t* chip, uint32_t* out_sr)
{
    uint32_t sr, sr2;
    esp_err_t ret = spi_flash_common_read_qe_sr(chip, CMD_RDSR2, 8, &sr2);
    if (ret == ESP_OK) {
        ret = spi_flash_common_read_qe_sr(chip, CMD_RDSR, 8, &sr);
    }
    if (ret == ESP_OK) {
        *out_sr = (sr & 0xff) | ((sr2 & 0xff) << 8);
    }
    return ret;
}

esp_err_t spi_flash_common_read_status_8b_rdsr2(esp_flash_t* chip, uint32_t* out_sr)
{
    return spi_flash_common_read_qe_sr(chip, CMD_RDSR2, 8, out_sr);
}

esp_err_t spi_flash_common_read_status_8b_rdsr(esp_flash_t* chip, uint32_t* out_sr)
{
    return spi_flash_common_read_qe_sr(chip, CMD_RDSR, 8, out_sr);
}

esp_err_t spi_flash_common_write_status_16b_wrsr(esp_flash_t* chip, uint32_t sr)
{
    return spi_flash_common_write_qe_sr(chip, CMD_WRSR, 16, sr);
}

esp_err_t spi_flash_common_write_status_8b_wrsr(esp_flash_t* chip, uint32_t sr)
{
    return spi_flash_common_write_qe_sr(chip, CMD_WRSR, 8, sr);
}

esp_err_t spi_flash_common_write_status_8b_wrsr2(esp_flash_t* chip, uint32_t sr)
{
    return spi_flash_common_write_qe_sr(chip, CMD_WRSR2, 8, sr);
}

esp_err_t spi_flash_common_set_io_mode(esp_flash_t *chip, esp_flash_wrsr_func_t wrsr_func, esp_flash_rdsr_func_t rdsr_func, uint32_t qe_sr_bit)
{
    esp_err_t ret = ESP_OK;
    const bool is_quad_mode = esp_flash_is_quad_mode(chip);
    bool update_config = false;
    /*
     * By default, we don't clear the QE bit even the flash mode is not QIO or QOUT. Force clearing
     * QE bit by the generic chip driver (command 01H with 2 bytes) may cause the output of some
     * chips (MXIC) no longer valid.
     * Enable this option when testing a new flash chip for clearing of QE.
     */
    const bool force_check = false;

    bool need_check = is_quad_mode || force_check;

    uint32_t sr_update;
    if (need_check) {
        // Ensure quad modes are enabled, using the Quad Enable parameters supplied.
        uint32_t sr;
        ret = (*rdsr_func)(chip, &sr);
        if (ret != ESP_OK) {
            return ret;
        }
        ESP_EARLY_LOGD(TAG, "set_io_mode: status before 0x%x", sr);
        if (is_quad_mode) {
            sr_update = sr | qe_sr_bit;
        } else {
            sr_update = sr & (~qe_sr_bit);
        }
        ESP_EARLY_LOGV(TAG, "set_io_mode: status update 0x%x", sr_update);
        if (sr != sr_update) {
            update_config = true;
        }
    }

    if (update_config) {
        //some chips needs the write protect to be disabled before writing to Status Register
        chip->chip_drv->set_chip_write_protect(chip, false);

        ret = (*wrsr_func)(chip, sr_update);
        if (ret != ESP_OK) {
            chip->chip_drv->set_chip_write_protect(chip, true);
            return ret;
        }

        ret = chip->chip_drv->wait_idle(chip, chip->chip_drv->timeout->idle_timeout);
        if (ret == ESP_ERR_NOT_SUPPORTED) {
            chip->chip_drv->set_chip_write_protect(chip, true);
        }
        /* This function is the fallback approach, so we give it higher tolerance.
         *   When the previous WRSR is rejected by the flash,
         *  the result of this function is determined by the result -whether the value of RDSR meets the expectation.
         */
        if (ret != ESP_OK && ret != ESP_ERR_NOT_SUPPORTED) {
            return ret;
        }

        /* Check the new QE bit has stayed set */
        uint32_t sr;
        ret = (*rdsr_func)(chip, &sr);
        if (ret != ESP_OK) {
            return ret;
        }
        ESP_EARLY_LOGD(TAG, "set_io_mode: status after 0x%x", sr);
        if (sr != sr_update) {
            ret = ESP_ERR_FLASH_NO_RESPONSE;
        }
    }
    return ret;
}

#endif // !CONFIG_SPI_FLASH_ROM_IMPL

esp_err_t spi_flash_chip_generic_suspend_cmd_conf(esp_flash_t *chip)
{
    // Only XMC support auto-suspend
    if (chip->chip_id >> 16 != 0x20) {
        ESP_EARLY_LOGE(TAG, "The flash you use doesn't support auto suspend, only \'XMC\' is supported");
        return ESP_ERR_NOT_SUPPORTED;
    }
    spi_flash_sus_cmd_conf sus_conf = {
        .sus_mask = 0x80,
        .cmd_rdsr = CMD_RDSR2,
        .sus_cmd = CMD_SUSPEND,
        .res_cmd = CMD_RESUME,
    };

    return chip->host->driver->sus_setup(chip->host, &sus_conf);
}
