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

#include "project.h"

ssize_t
twa_get_parameter (int fd, int table_id, int parameter_id, void *data,
                   size_t data_len)
{

  TW_Command *command;
  TW_Param_Apache *param;
  TW_Command_Apache_Header *header;
  TW_Ioctl_Buf_Apache *tw_ioctl_apache;
  int rc;
  size_t buffer_len, ret_len;
  char error[512];

  buffer_len = data_len + sizeof (TW_Param_Apache);

  tw_ioctl_apache = xmalloc (sizeof (TW_Ioctl_Buf_Apache) + buffer_len);

  memset (tw_ioctl_apache, 0, sizeof (TW_Ioctl_Buf_Apache) + buffer_len);

  tw_ioctl_apache->driver_command.control_code =
    TW_IOCTL_FIRMWARE_PASS_THROUGH;
  tw_ioctl_apache->driver_command.buffer_length = buffer_len;

  header =
    (TW_Command_Apache_Header *) & (tw_ioctl_apache->firmware_command.header);
  header->header_desc.size_header = sizeof (*header);

  command =
    (TW_Command *) & (tw_ioctl_apache->firmware_command.command.oldcommand);

  command->byte0.opcode = TW_OP_GET_PARAM;
  command->byte0.sgl_offset = 0x2;

  command->size = TW_COMMAND_SIZE;

  command->byte6.parameter_count = cpu_to_le16 (1);

  param = (TW_Param_Apache *) tw_ioctl_apache->data_buffer;

  param->table_id = cpu_to_le16 (table_id | 0x8000);
  param->parameter_id = cpu_to_le16 (parameter_id);
  param->parameter_size_bytes = cpu_to_le16 (data_len);

  rc = ioctl (fd, TW_IOCTL_FIRMWARE_PASS_THROUGH, tw_ioctl_apache);

  if (rc)
    {
      fprintf (stderr,
               "twa_get_parameter: ioctl TW_IOCTL_FIRMWARE_PASS_THROUGH failed: %m\n");
      return -1;
    }

  if (header->status_block.error)
    {
      memset (error, 0, sizeof (error));
      memcpy (error, header->err_specific_desc,
              sizeof (header->err_specific_desc));

      fprintf (stderr,
               "twa_get_parameter: controller returns error: (0x%x) %s\n",
               le16_to_cpu (header->status_block.error), error + 1);
      return -1;
    }

  ret_len = le16_to_cpu (param->actual_parameter_size_bytes);

  if (ret_len > data_len)
    {
      fprintf (stderr,
               "twa_get_parameter: buffer passed for table 0x%x, parameter 0x%x too short: given %d bytes need %d\n",
               table_id, parameter_id, data_len, ret_len);
      return -1;
    }

  memcpy (data, param->data, ret_len);

  return ret_len;
}

int
twa_set_parameter (int fd, int table_id, int parameter_id, void *data,
                   size_t data_len)
{

  TW_Command *command;
  TW_Param_Apache *param;
  TW_Command_Apache_Header *header;
  TW_Ioctl_Buf_Apache *tw_ioctl_apache;
  int rc;
  size_t buffer_len, ret_len;
  char error[512];

  buffer_len = data_len + sizeof (TW_Param_Apache);

  tw_ioctl_apache = xmalloc (sizeof (TW_Ioctl_Buf_Apache) + buffer_len);

  memset (tw_ioctl_apache, 0, sizeof (TW_Ioctl_Buf_Apache) + buffer_len);

  tw_ioctl_apache->driver_command.control_code =
    TW_IOCTL_FIRMWARE_PASS_THROUGH;
  tw_ioctl_apache->driver_command.buffer_length = buffer_len;

  header =
    (TW_Command_Apache_Header *) & (tw_ioctl_apache->firmware_command.header);
  header->header_desc.size_header = sizeof (*header);

  command =
    (TW_Command *) & (tw_ioctl_apache->firmware_command.command.oldcommand);

  command->byte0.opcode = TW_OP_SET_PARAM;
  command->byte0.sgl_offset = 0x2;

  command->size = TW_COMMAND_SIZE;

  command->byte6.parameter_count = cpu_to_le16 (1);

  param = (TW_Param_Apache *) tw_ioctl_apache->data_buffer;

  param->table_id = cpu_to_le16 (table_id | 0x8000);
  param->parameter_id = cpu_to_le16 (parameter_id);
  param->parameter_size_bytes = cpu_to_le16 (data_len);

  memcpy (param->data, data, data_len);

  rc = ioctl (fd, TW_IOCTL_FIRMWARE_PASS_THROUGH, tw_ioctl_apache);

  if (rc)
    {
      fprintf (stderr,
               "twa_get_parameter: ioctl TW_IOCTL_FIRMWARE_PASS_THROUGH failed: %m\n");
      return -1;
    }

  if (header->status_block.error)
    {
      memset (error, 0, sizeof (error));
      memcpy (error, header->err_specific_desc,
              sizeof (header->err_specific_desc));

      fprintf (stderr,
               "twa_get_parameter: controller returns error: (0x%x) %s\n",
               le16_to_cpu (header->status_block.error), error + 1);
      return -1;
    }

  return 0;
}