/*
 * Протокол периферийного контроллера ПМ35/TMS320F28335: регистры, команды и разбор ответов.
 * Этот профиль имеет собственную адресацию и не должен подменяться протоколом основного
 * TMS320F2812.
 */

/**
 * @file periph28335.h
 * @brief Shared PM35/TMS320F28335 register protocol.
 *
 * The protocol is independent from PM67/TMS320F2812 CAN and RS channels.
 * It implements the direct RS232/485 register terminal used by PM35.
 */
#ifndef PERIPH28335_H
#define PERIPH28335_H

#include <stddef.h>
#include <stdint.h>
#include "balsam167_eeprom_layout.h"

#ifdef __cplusplus
extern "C" {
#endif

#define PERIPH28335_REGISTER_COUNT 128U
#define PERIPH28335_REQUEST_SIZE 8U
#define PERIPH28335_COMMAND_COUNT 17U

/* Balsam-167 fitted AT25256B (marking 5EBL): 256 Kbit, NOT 256 Kbyte.
 * All reader positions below count physical EEPROM octets, not C28x words.
 * Four uint32_t fields make the caller-owned state stable for ctypes/JNI. */
#define PERIPH28335_EEPROM_BYTES BALSAM167_EEPROM_BYTES
typedef struct {
    uint32_t controller;
    uint32_t start;
    uint32_t length;
    uint32_t received;
} periph28335_eeprom_reader;

/* No writes or capacity probes. Odd starts/lengths are allowed: the core reads
 * the containing 16-bit word and returns only the requested physical octets. */
int periph28335_eeprom_begin(periph28335_eeprom_reader *reader,
    uint32_t controller, uint32_t start, uint32_t length);
size_t periph28335_eeprom_request(const periph28335_eeprom_reader *reader,
    uint8_t *output, size_t capacity);
/* Returns 1/2 decoded octets, or a negative status; errors do not advance state.
 * PEEK payload = little-endian data WORD + timer WORD, not four memory bytes.
 * SPI16 shifts the data word high-octet first, so physical EEPROM order is
 * response[3], response[2]. This differs from a C28x little-endian RAM dump. */
int periph28335_eeprom_accept(periph28335_eeprom_reader *reader,
    const uint8_t *reply, size_t size, uint8_t *output, size_t capacity);

typedef enum {
    PERIPH28335_OK = 0,
    PERIPH28335_ERROR_ARGUMENT = -1,
    PERIPH28335_ERROR_RANGE = -2,
    PERIPH28335_ERROR_LENGTH = -3,
    PERIPH28335_ERROR_CRC = -4,
    PERIPH28335_ERROR_HEADER = -5,
    PERIPH28335_ERROR_CAPACITY = -6
} periph28335_status_t;

uint16_t periph28335_crc16_modbus(const uint8_t *data, size_t size);

size_t periph28335_append_crc(const uint8_t *payload, size_t payload_size,
                              uint8_t *output, size_t output_size);

size_t periph28335_build_read_registers(
    uint8_t controller, uint16_t start, uint16_t count,
    uint8_t *output, size_t output_size);

size_t periph28335_build_write_register(
    uint8_t controller, uint16_t address, uint16_t value,
    uint8_t *output, size_t output_size);

size_t periph28335_build_command(
    uint8_t controller, uint8_t command_index,
    uint8_t *output, size_t output_size);

size_t periph28335_expected_read_response_size(uint16_t count);

int periph28335_decode_read_response(
    const uint8_t *data, size_t size, uint8_t controller, uint16_t count,
    uint16_t *output, size_t output_count);

int periph28335_validate_write_response(
    const uint8_t *response, size_t response_size,
    const uint8_t *request, size_t request_size);

size_t periph28335_project_count(void);
const char *periph28335_project_name(size_t project_index);
const char *periph28335_command_name(size_t project_index,
                                     size_t command_index);

#ifdef __cplusplus
}
#endif

#endif /* PERIPH28335_H */