#include "avr_isp_prog.h"
#include "avr_isp_prog_cmd.h"

#include <furi.h>

#define AVR_ISP_PROG_TX_RX_BUF_SIZE 320
#define TAG "AvrIspProg"

struct AvrIspProgSignature {
    uint8_t vendor;
    uint8_t part_family;
    uint8_t part_number;
};

typedef struct AvrIspProgSignature AvrIspProgSignature;

struct AvrIspProgCfgDevice {
    uint8_t devicecode;
    uint8_t revision;
    uint8_t progtype;
    uint8_t parmode;
    uint8_t polling;
    uint8_t selftimed;
    uint8_t lockbytes;
    uint8_t fusebytes;
    uint8_t flashpoll;
    uint16_t eeprompoll;
    uint16_t pagesize;
    uint16_t eepromsize;
    uint32_t flashsize;
};

typedef struct AvrIspProgCfgDevice AvrIspProgCfgDevice;

struct AvrIspProg {
    AvrIspSpiSw* spi;
    AvrIspProgCfgDevice* cfg;
    FuriStreamBuffer* stream_rx;
    FuriStreamBuffer* stream_tx;

    uint16_t error;
    uint16_t addr;
    bool pmode;
    bool exit;
    bool rst_active_high;
    uint8_t buff[AVR_ISP_PROG_TX_RX_BUF_SIZE];

    AvrIspProgCallback callback;
    void* context;
};

static void avr_isp_prog_end_pmode(AvrIspProg* instance);

AvrIspProg* avr_isp_prog_init(void) {
    AvrIspProg* instance = malloc(sizeof(AvrIspProg));
    instance->cfg = malloc(sizeof(AvrIspProgCfgDevice));
    instance->stream_rx =
        furi_stream_buffer_alloc(sizeof(int8_t) * AVR_ISP_PROG_TX_RX_BUF_SIZE, sizeof(int8_t));
    instance->stream_tx =
        furi_stream_buffer_alloc(sizeof(int8_t) * AVR_ISP_PROG_TX_RX_BUF_SIZE, sizeof(int8_t));
    instance->rst_active_high = false;
    instance->exit = false;
    return instance;
}

void avr_isp_prog_free(AvrIspProg* instance) {
    furi_assert(instance);
    if(instance->spi) avr_isp_prog_end_pmode(instance);
    furi_stream_buffer_free(instance->stream_tx);
    furi_stream_buffer_free(instance->stream_rx);
    free(instance->cfg);
    free(instance);
}

size_t avr_isp_prog_spaces_rx(AvrIspProg* instance) {
    return furi_stream_buffer_spaces_available(instance->stream_rx);
}

bool avr_isp_prog_rx(AvrIspProg* instance, uint8_t* data, size_t len) {
    furi_assert(instance);
    furi_assert(data);
    furi_assert(len != 0);
    size_t ret = furi_stream_buffer_send(instance->stream_rx, data, sizeof(uint8_t) * len, 0);
    return ret == sizeof(uint8_t) * len;
}

size_t avr_isp_prog_tx(AvrIspProg* instance, uint8_t* data, size_t max_len) {
    furi_assert(instance);
    return furi_stream_buffer_receive(instance->stream_tx, data, sizeof(int8_t) * max_len, 0);
}

void avr_isp_prog_exit(AvrIspProg* instance) {
    furi_assert(instance);
    instance->exit = true;
}

void avr_isp_prog_set_tx_callback(AvrIspProg* instance, AvrIspProgCallback callback, void* context) {
    furi_assert(instance);
    furi_assert(context);
    instance->callback = callback;
    instance->context = context;
}

static void avr_isp_prog_tx_ch(AvrIspProg* instance, uint8_t data) {
    furi_assert(instance);
    furi_stream_buffer_send(instance->stream_tx, &data, sizeof(uint8_t), FuriWaitForever);
}

static uint8_t avr_isp_prog_getch(AvrIspProg* instance) {
    furi_assert(instance);
    uint8_t data[1] = {0};
    while(furi_stream_buffer_receive(instance->stream_rx, &data, sizeof(int8_t), 30) == 0) {
        if(instance->exit) break;
    };
    return data[0];
}

static void avr_isp_prog_fill(AvrIspProg* instance, size_t len) {
    furi_assert(instance);
    for(size_t x = 0; x < len; x++) {
        instance->buff[x] = avr_isp_prog_getch(instance);
    }
}

static void avr_isp_prog_reset_target(AvrIspProg* instance, bool reset) {
    furi_assert(instance);
    avr_isp_spi_sw_res_set(instance->spi, (reset == instance->rst_active_high) ? true : false);
}

static uint8_t avr_isp_prog_spi_transaction(
    AvrIspProg* instance,
    uint8_t cmd,
    uint8_t addr_hi,
    uint8_t addr_lo,
    uint8_t data) {
    furi_assert(instance);

    avr_isp_spi_sw_txrx(instance->spi, cmd);
    avr_isp_spi_sw_txrx(instance->spi, addr_hi);
    avr_isp_spi_sw_txrx(instance->spi, addr_lo);
    return avr_isp_spi_sw_txrx(instance->spi, data);
}

static void avr_isp_prog_empty_reply(AvrIspProg* instance) {
    furi_assert(instance);
    if(avr_isp_prog_getch(instance) == CRC_EOP) {
        avr_isp_prog_tx_ch(instance, STK_INSYNC);
        avr_isp_prog_tx_ch(instance, STK_OK);
    } else {
        instance->error++;
        avr_isp_prog_tx_ch(instance, STK_NOSYNC);
    }
}

static void avr_isp_prog_breply(AvrIspProg* instance, uint8_t data) {
    furi_assert(instance);
    if(avr_isp_prog_getch(instance) == CRC_EOP) {
        avr_isp_prog_tx_ch(instance, STK_INSYNC);
        avr_isp_prog_tx_ch(instance, data);
        avr_isp_prog_tx_ch(instance, STK_OK);
    } else {
        instance->error++;
        avr_isp_prog_tx_ch(instance, STK_NOSYNC);
    }
}

static void avr_isp_prog_get_version(AvrIspProg* instance, uint8_t data) {
    furi_assert(instance);
    switch(data) {
    case STK_HW_VER:
        avr_isp_prog_breply(instance, AVR_ISP_HWVER);
        break;
    case STK_SW_MAJOR:
        avr_isp_prog_breply(instance, AVR_ISP_SWMAJ);
        break;
    case STK_SW_MINOR:
        avr_isp_prog_breply(instance, AVR_ISP_SWMIN);
        break;
    case AVP_ISP_CONNECT_TYPE:
        avr_isp_prog_breply(instance, AVP_ISP_SERIAL_CONNECT_TYPE);
        break;
    default:
        avr_isp_prog_breply(instance, AVR_ISP_RESP_0);
    }
}

static void avr_isp_prog_set_cfg(AvrIspProg* instance) {
    furi_assert(instance);
    // call this after reading cfg packet into buff[]
    instance->cfg->devicecode = instance->buff[0];
    instance->cfg->revision = instance->buff[1];
    instance->cfg->progtype = instance->buff[2];
    instance->cfg->parmode = instance->buff[3];
    instance->cfg->polling = instance->buff[4];
    instance->cfg->selftimed = instance->buff[5];
    instance->cfg->lockbytes = instance->buff[6];
    instance->cfg->fusebytes = instance->buff[7];
    instance->cfg->flashpoll = instance->buff[8];
    // ignore (instance->buff[9] == instance->buff[8]) //FLASH polling value. Same as “flashpoll”
    instance->cfg->eeprompoll = instance->buff[10] << 8 | instance->buff[11];
    instance->cfg->pagesize = instance->buff[12] << 8 | instance->buff[13];
    instance->cfg->eepromsize = instance->buff[14] << 8 | instance->buff[15];
    instance->cfg->flashsize = instance->buff[16] << 24 | instance->buff[17] << 16 |
                               instance->buff[18] << 8 | instance->buff[19];

    // avr devices have active low reset, at89sx are active high
    instance->rst_active_high = (instance->cfg->devicecode >= 0xe0);
}
static bool
    avr_isp_prog_set_pmode(AvrIspProg* instance, uint8_t a, uint8_t b, uint8_t c, uint8_t d) {
    furi_assert(instance);
    uint8_t res = 0;
    avr_isp_spi_sw_txrx(instance->spi, a);
    avr_isp_spi_sw_txrx(instance->spi, b);
    res = avr_isp_spi_sw_txrx(instance->spi, c);
    avr_isp_spi_sw_txrx(instance->spi, d);
    return res == 0x53;
}

static void avr_isp_prog_end_pmode(AvrIspProg* instance) {
    furi_assert(instance);
    if(instance->pmode) {
        avr_isp_prog_reset_target(instance, false);
        // We're about to take the target out of reset
        // so configure SPI pins as input

        if(instance->spi) avr_isp_spi_sw_free(instance->spi);
        instance->spi = NULL;
    }

    instance->pmode = false;
}

static bool avr_isp_prog_start_pmode(AvrIspProg* instance, AvrIspSpiSwSpeed spi_speed) {
    furi_assert(instance);
    // Reset target before driving PIN_SCK or PIN_MOSI

    // SPI.begin() will configure SS as output,
    // so SPI master mode is selected.
    // We have defined RESET as pin 10,
    // which for many arduino's is not the SS pin.
    // So we have to configure RESET as output here,
    // (reset_target() first sets the correct level)
    if(instance->spi) avr_isp_spi_sw_free(instance->spi);
    instance->spi = avr_isp_spi_sw_init(spi_speed);

    avr_isp_prog_reset_target(instance, true);
    // See avr datasheets, chapter "SERIAL_PRG Programming Algorithm":

    // Pulse RESET after PIN_SCK is low:
    avr_isp_spi_sw_sck_set(instance->spi, false);

    // discharge PIN_SCK, value arbitrally chosen
    furi_delay_ms(20);
    avr_isp_prog_reset_target(instance, false);

    // Pulse must be minimum 2 target CPU speed cycles
    // so 100 usec is ok for CPU speeds above 20KHz
    furi_delay_ms(1);

    avr_isp_prog_reset_target(instance, true);

    // Send the enable programming command:
    // datasheet: must be > 20 msec
    furi_delay_ms(50);
    if(avr_isp_prog_set_pmode(instance, AVR_ISP_SET_PMODE)) {
        instance->pmode = true;
        return true;
    }
    return false;
}

static AvrIspProgSignature avr_isp_prog_check_signature(AvrIspProg* instance) {
    furi_assert(instance);
    AvrIspProgSignature signature;
    signature.vendor = avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_VENDOR);
    signature.part_family = avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_PART_FAMILY);
    signature.part_number = avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_PART_NUMBER);
    return signature;
}

static bool avr_isp_prog_auto_set_spi_speed_start_pmode(AvrIspProg* instance) {
    AvrIspSpiSwSpeed spi_speed[] = {
        AvrIspSpiSwSpeed1Mhz,
        AvrIspSpiSwSpeed400Khz,
        AvrIspSpiSwSpeed250Khz,
        AvrIspSpiSwSpeed125Khz,
        AvrIspSpiSwSpeed60Khz,
        AvrIspSpiSwSpeed40Khz,
        AvrIspSpiSwSpeed20Khz,
        AvrIspSpiSwSpeed10Khz,
        AvrIspSpiSwSpeed5Khz,
        AvrIspSpiSwSpeed1Khz,
    };
    for(uint8_t i = 0; i < COUNT_OF(spi_speed); i++) {
        if(avr_isp_prog_start_pmode(instance, spi_speed[i])) {
            AvrIspProgSignature sig = avr_isp_prog_check_signature(instance);
            AvrIspProgSignature sig_examination = avr_isp_prog_check_signature(instance); //-V656
            uint8_t y = 0;
            while(y < 8) {
                if(memcmp(
                       (uint8_t*)&sig, (uint8_t*)&sig_examination, sizeof(AvrIspProgSignature)) !=
                   0)
                    break;
                sig_examination = avr_isp_prog_check_signature(instance);
                y++;
            }
            if(y == 8) {
                if(spi_speed[i] > AvrIspSpiSwSpeed1Mhz) {
                    if(i < (COUNT_OF(spi_speed) - 1)) {
                        avr_isp_prog_end_pmode(instance);
                        i++;
                        return avr_isp_prog_start_pmode(instance, spi_speed[i]);
                    }
                }
                return true;
            }
        }
    }

    if(instance->spi) {
        avr_isp_spi_sw_free(instance->spi);
        instance->spi = NULL;
    }

    return false;
}

static void avr_isp_prog_universal(AvrIspProg* instance) {
    furi_assert(instance);
    uint8_t data;

    avr_isp_prog_fill(instance, 4);
    data = avr_isp_prog_spi_transaction(
        instance, instance->buff[0], instance->buff[1], instance->buff[2], instance->buff[3]);
    avr_isp_prog_breply(instance, data);
}

static void avr_isp_prog_commit(AvrIspProg* instance, uint16_t addr, uint8_t data) {
    furi_assert(instance);
    avr_isp_prog_spi_transaction(instance, AVR_ISP_COMMIT(addr));
    /* polling flash */
    if(data == 0xFF) {
        furi_delay_ms(5);
    } else {
        /* polling flash */
        uint32_t starttime = furi_get_tick();
        while((furi_get_tick() - starttime) < 30) {
            if(avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_FLASH_HI(addr)) != 0xFF) {
                break;
            };
        }
    }
}

static uint16_t avr_isp_prog_current_page(AvrIspProg* instance) {
    furi_assert(instance);
    uint16_t page = 0;
    switch(instance->cfg->pagesize) {
    case 32:
        page = instance->addr & 0xFFFFFFF0;
        break;
    case 64:
        page = instance->addr & 0xFFFFFFE0;
        break;
    case 128:
        page = instance->addr & 0xFFFFFFC0;
        break;
    case 256:
        page = instance->addr & 0xFFFFFF80;
        break;

    default:
        page = instance->addr;
        break;
    }

    return page;
}

static uint8_t avr_isp_prog_write_flash_pages(AvrIspProg* instance, size_t length) {
    furi_assert(instance);
    size_t x = 0;
    uint16_t page = avr_isp_prog_current_page(instance);
    while(x < length) {
        if(page != avr_isp_prog_current_page(instance)) {
            --x;
            avr_isp_prog_commit(instance, page, instance->buff[x++]);
            page = avr_isp_prog_current_page(instance);
        }
        avr_isp_prog_spi_transaction(
            instance, AVR_ISP_WRITE_FLASH_LO(instance->addr, instance->buff[x++]));

        avr_isp_prog_spi_transaction(
            instance, AVR_ISP_WRITE_FLASH_HI(instance->addr, instance->buff[x++]));
        instance->addr++;
    }

    avr_isp_prog_commit(instance, page, instance->buff[--x]);
    return STK_OK;
}

static void avr_isp_prog_write_flash(AvrIspProg* instance, size_t length) {
    furi_assert(instance);
    avr_isp_prog_fill(instance, length);
    if(avr_isp_prog_getch(instance) == CRC_EOP) {
        avr_isp_prog_tx_ch(instance, STK_INSYNC);
        avr_isp_prog_tx_ch(instance, avr_isp_prog_write_flash_pages(instance, length));
    } else {
        instance->error++;
        avr_isp_prog_tx_ch(instance, STK_NOSYNC);
    }
}

// write (length) bytes, (start) is a byte address
static uint8_t
    avr_isp_prog_write_eeprom_chunk(AvrIspProg* instance, uint16_t start, uint16_t length) {
    furi_assert(instance);
    // this writes byte-by-byte,
    // page writing may be faster (4 bytes at a time)
    avr_isp_prog_fill(instance, length);
    for(uint16_t x = 0; x < length; x++) {
        uint16_t addr = start + x;
        avr_isp_prog_spi_transaction(instance, AVR_ISP_WRITE_EEPROM(addr, instance->buff[x]));
        furi_delay_ms(10);
    }
    return STK_OK;
}

static uint8_t avr_isp_prog_write_eeprom(AvrIspProg* instance, size_t length) {
    furi_assert(instance);
    // here is a word address, get the byte address
    uint16_t start = instance->addr * 2;
    uint16_t remaining = length;
    if(length > instance->cfg->eepromsize) {
        instance->error++;
        return STK_FAILED;
    }
    while(remaining > AVR_ISP_EECHUNK) {
        avr_isp_prog_write_eeprom_chunk(instance, start, AVR_ISP_EECHUNK);
        start += AVR_ISP_EECHUNK;
        remaining -= AVR_ISP_EECHUNK;
    }
    avr_isp_prog_write_eeprom_chunk(instance, start, remaining);
    return STK_OK;
}

static void avr_isp_prog_program_page(AvrIspProg* instance) {
    furi_assert(instance);
    uint8_t result = STK_FAILED;
    uint16_t length = avr_isp_prog_getch(instance) << 8 | avr_isp_prog_getch(instance);
    uint8_t memtype = avr_isp_prog_getch(instance);
    // flash memory @addr, (length) bytes
    if(memtype == STK_SET_FLASH_TYPE) {
        avr_isp_prog_write_flash(instance, length);
        return;
    }
    if(memtype == STK_SET_EEPROM_TYPE) {
        result = avr_isp_prog_write_eeprom(instance, length);
        if(avr_isp_prog_getch(instance) == CRC_EOP) {
            avr_isp_prog_tx_ch(instance, STK_INSYNC);
            avr_isp_prog_tx_ch(instance, result);

        } else {
            instance->error++;
            avr_isp_prog_tx_ch(instance, STK_NOSYNC);
        }
        return;
    }
    avr_isp_prog_tx_ch(instance, STK_FAILED);
    return;
}

static uint8_t avr_isp_prog_flash_read_page(AvrIspProg* instance, uint16_t length) {
    furi_assert(instance);
    for(uint16_t x = 0; x < length; x += 2) {
        avr_isp_prog_tx_ch(
            instance,
            avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_FLASH_LO(instance->addr)));
        avr_isp_prog_tx_ch(
            instance,
            avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_FLASH_HI(instance->addr)));
        instance->addr++;
    }
    return STK_OK;
}

static uint8_t avr_isp_prog_eeprom_read_page(AvrIspProg* instance, uint16_t length) {
    furi_assert(instance);
    // here again we have a word address
    uint16_t start = instance->addr * 2;
    for(uint16_t x = 0; x < length; x++) {
        uint16_t addr = start + x;
        avr_isp_prog_tx_ch(
            instance, avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_EEPROM(addr)));
    }
    return STK_OK;
}

static void avr_isp_prog_read_page(AvrIspProg* instance) {
    furi_assert(instance);
    uint8_t result = STK_FAILED;
    uint16_t length = avr_isp_prog_getch(instance) << 8 | avr_isp_prog_getch(instance);
    uint8_t memtype = avr_isp_prog_getch(instance);
    if(avr_isp_prog_getch(instance) != CRC_EOP) {
        instance->error++;
        avr_isp_prog_tx_ch(instance, STK_NOSYNC);
        return;
    }
    avr_isp_prog_tx_ch(instance, STK_INSYNC);
    if(memtype == STK_SET_FLASH_TYPE) result = avr_isp_prog_flash_read_page(instance, length);
    if(memtype == STK_SET_EEPROM_TYPE) result = avr_isp_prog_eeprom_read_page(instance, length);
    avr_isp_prog_tx_ch(instance, result);
}

static void avr_isp_prog_read_signature(AvrIspProg* instance) {
    furi_assert(instance);
    if(avr_isp_prog_getch(instance) != CRC_EOP) {
        instance->error++;
        avr_isp_prog_tx_ch(instance, STK_NOSYNC);
        return;
    }
    avr_isp_prog_tx_ch(instance, STK_INSYNC);

    avr_isp_prog_tx_ch(instance, avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_VENDOR));
    avr_isp_prog_tx_ch(instance, avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_PART_FAMILY));
    avr_isp_prog_tx_ch(instance, avr_isp_prog_spi_transaction(instance, AVR_ISP_READ_PART_NUMBER));

    avr_isp_prog_tx_ch(instance, STK_OK);
}

void avr_isp_prog_avrisp(AvrIspProg* instance) {
    furi_assert(instance);
    uint8_t ch = avr_isp_prog_getch(instance);

    switch(ch) {
    case STK_GET_SYNC:
        FURI_LOG_D(TAG, "cmd STK_GET_SYNC");
        instance->error = 0;
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_GET_SIGN_ON:
        FURI_LOG_D(TAG, "cmd STK_GET_SIGN_ON");
        if(avr_isp_prog_getch(instance) == CRC_EOP) {
            avr_isp_prog_tx_ch(instance, STK_INSYNC);

            avr_isp_prog_tx_ch(instance, 'A');
            avr_isp_prog_tx_ch(instance, 'V');
            avr_isp_prog_tx_ch(instance, 'R');
            avr_isp_prog_tx_ch(instance, ' ');
            avr_isp_prog_tx_ch(instance, 'I');
            avr_isp_prog_tx_ch(instance, 'S');
            avr_isp_prog_tx_ch(instance, 'P');

            avr_isp_prog_tx_ch(instance, STK_OK);
        } else {
            instance->error++;
            avr_isp_prog_tx_ch(instance, STK_NOSYNC);
        }
        break;
    case STK_GET_PARAMETER:
        FURI_LOG_D(TAG, "cmd STK_GET_PARAMETER");
        avr_isp_prog_get_version(instance, avr_isp_prog_getch(instance));
        break;
    case STK_SET_DEVICE:
        FURI_LOG_D(TAG, "cmd STK_SET_DEVICE");
        avr_isp_prog_fill(instance, 20);
        avr_isp_prog_set_cfg(instance);
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_SET_DEVICE_EXT: // ignore for now
        FURI_LOG_D(TAG, "cmd STK_SET_DEVICE_EXT");
        avr_isp_prog_fill(instance, 5);
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_ENTER_PROGMODE:
        FURI_LOG_D(TAG, "cmd STK_ENTER_PROGMODE");
        if(!instance->pmode) avr_isp_prog_auto_set_spi_speed_start_pmode(instance);
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_LOAD_ADDRESS:
        FURI_LOG_D(TAG, "cmd STK_LOAD_ADDRESS");
        instance->addr = avr_isp_prog_getch(instance) | avr_isp_prog_getch(instance) << 8;
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_PROG_FLASH: // ignore for now
        FURI_LOG_D(TAG, "cmd STK_PROG_FLASH");
        avr_isp_prog_getch(instance);
        avr_isp_prog_getch(instance);
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_PROG_DATA: // ignore for now
        FURI_LOG_D(TAG, "cmd STK_PROG_DATA");
        avr_isp_prog_getch(instance);
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_PROG_PAGE:
        FURI_LOG_D(TAG, "cmd STK_PROG_PAGE");
        avr_isp_prog_program_page(instance);
        break;
    case STK_READ_PAGE:
        FURI_LOG_D(TAG, "cmd STK_READ_PAGE");
        avr_isp_prog_read_page(instance);
        break;
    case STK_UNIVERSAL:
        FURI_LOG_D(TAG, "cmd STK_UNIVERSAL");
        avr_isp_prog_universal(instance);
        break;
    case STK_LEAVE_PROGMODE:
        FURI_LOG_D(TAG, "cmd STK_LEAVE_PROGMODE");
        instance->error = 0;
        if(instance->pmode) avr_isp_prog_end_pmode(instance);
        avr_isp_prog_empty_reply(instance);
        break;
    case STK_READ_SIGN:
        FURI_LOG_D(TAG, "cmd STK_READ_SIGN");
        avr_isp_prog_read_signature(instance);
        break;
    // expecting a command, not CRC_EOP
    // this is how we can get back in sync
    case CRC_EOP:
        FURI_LOG_D(TAG, "cmd CRC_EOP");
        instance->error++;
        avr_isp_prog_tx_ch(instance, STK_NOSYNC);
        break;
    // anything else we will return STK_UNKNOWN
    default:
        FURI_LOG_D(TAG, "cmd STK_ERROR_CMD");
        instance->error++;
        if(avr_isp_prog_getch(instance) == CRC_EOP)
            avr_isp_prog_tx_ch(instance, STK_UNKNOWN);
        else
            avr_isp_prog_tx_ch(instance, STK_NOSYNC);
    }

    if(instance->callback) {
        instance->callback(instance->context);
    }
}