/*
 * twa.h:
 *
 * Copyright (c) 2017 James McKenzie <foss@madingley.org>,
 * All rights reserved.
 *
 */

#ifndef _TWA_H_
#define _TWA_H_

#define TWA_PACKED __attribute__ (( packed ))

typedef uint64_t dma_addr_t;


#define TW_SENSE_DATA_LENGTH                  18

#define TW_COMMAND_SIZE (sizeof(dma_addr_t) > 4 ? 5 : 4)
#define TW_APACHE_MAX_SGL_LENGTH (sizeof(dma_addr_t) > 4 ? 72 : 109)
#define TW_ESCALADE_MAX_SGL_LENGTH (sizeof(dma_addr_t) > 4 ? 41 : 62)
#define TW_PADDING_LENGTH (sizeof(dma_addr_t) > 4 ? 8 : 0)

typedef struct TWA_PACKED TAG_TW_SG_Entry
{
  dma_addr_t address;
  uint32_t length;
} TW_SG_Entry;


typedef struct TWA_PACKED TAG_TW_Command_Apache_Header
{
  unsigned char sense_data[TW_SENSE_DATA_LENGTH];
  struct TWA_PACKED
  {
    char reserved[4];
    unsigned short error;
    unsigned char padding;
    unsigned char severity__reserved;
  } status_block;
  unsigned char err_specific_desc[98];
  struct TWA_PACKED
  {
    unsigned char size_header;
    unsigned short reserved;
    unsigned char size_sense;
  } header_desc;
} TW_Command_Apache_Header;


/* Command Packet */
typedef struct TWA_PACKED TW_Command
{
  /* First DWORD */
  struct TWA_PACKED
  {
    unsigned char opcode:5;
    unsigned char sgl_offset:3;
  } byte0;
  unsigned char size;
  unsigned char request_id;
  struct TWA_PACKED
  {
    unsigned char unit:4;
    unsigned char host_id:4;
  } byte3;
  /* Second DWORD */
  unsigned char status;
  unsigned char flags;

  union
  {
    unsigned short block_count;
    unsigned short parameter_count;
    unsigned short message_credits;
  } byte6;
  union
  {
    struct TWA_PACKED
    {
      uint32_t lba;
      TW_SG_Entry sgl[TW_ESCALADE_MAX_SGL_LENGTH];
      dma_addr_t padding;
    } io;
    struct
    {
      TW_SG_Entry sgl[TW_ESCALADE_MAX_SGL_LENGTH];
      uint32_t padding;
      dma_addr_t padding2;
    } param;
  } byte8_offset;
} TW_Command;

typedef struct TWA_PACKED TAG_TW_Command_Apache
{
  unsigned char opcode__reserved;
  unsigned char unit;
  unsigned short request_id__lunl;
  unsigned char status;
  unsigned char sgl_offset;
  unsigned short sgl_entries__lunh;
  unsigned char cdb[16];
  TW_SG_Entry sg_list[TW_APACHE_MAX_SGL_LENGTH];
  unsigned char padding[TW_PADDING_LENGTH];
} TW_Command_Apache;


typedef struct TWA_PACKED TAG_TW_Command_Full
{
  TW_Command_Apache_Header header;
  union
  {
    TW_Command oldcommand;
    TW_Command_Apache newcommand;
  } command;
} TW_Command_Full;



typedef struct TWA_PACKED TAG_TW_Ioctl_Driver_Command
{
  unsigned int control_code;
  unsigned int status;
  unsigned int unique_id;
  unsigned int sequence_id;
  unsigned int os_specific;
  unsigned int buffer_length;
} TW_Ioctl_Driver_Command;



typedef struct TWA_PACKED TAG_TW_Ioctl_Apache
{
  TW_Ioctl_Driver_Command driver_command;
  char padding[488];
  TW_Command_Full firmware_command;
  char data_buffer[0];
} TW_Ioctl_Buf_Apache;

typedef struct TWA_PACKED
{
  unsigned short table_id;
  unsigned short parameter_id;
  unsigned short parameter_size_bytes;
  unsigned short actual_parameter_size_bytes;
  unsigned char data[0];
} TW_Param_Apache, *PTW_Param_Apache;

typedef struct
{
  uint8_t resv;
  uint8_t tw_sec;
  uint8_t tw_min;
  uint8_t tw_hour;
  uint8_t tw_day;
  uint8_t tw_month;
  uint16_t tw_year;
} TW_DateTime;

#define TW_IOCTL_FIRMWARE_PASS_THROUGH 0x108

#define TW_OP_GET_PARAM       0x12
#define TW_OP_SET_PARAM       0x13

#define TW_TIMEKEEP_TABLE                     0x040A
#define TW_TIMEKEEP_DATETIME			0x4


#endif /* _TWA_H_ */