// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "lib/mipi-dsi/mipi-dsi.h"

namespace mipi_dsi {

zx_status_t MipiDsi::CreateCommand(const uint8_t* tbuf, size_t tlen, uint8_t* rbuf, size_t rlen,
                                   bool is_dcs, mipi_dsi_cmd_t* cmd) {
  // Create a command packet
  cmd->virt_chn_id = MIPI_DSI_VIRTUAL_CHAN_ID;
  cmd->pld_data_list = tbuf;  // tbuf is allowed to be null
  cmd->pld_data_count = tlen;
  cmd->rsp_data_list = rbuf;  // rbuf is allowed to be null if rlen is 0
  cmd->rsp_data_count = rlen;
  cmd->flags = 0;
  cmd->dsi_data_type = MIPI_DSI_DT_UNKNOWN;

  switch (tlen) {
    case 0:
      if (is_dcs) {
        printf("Missing DCS Command\n");
        return ZX_ERR_INVALID_ARGS;
      }
      if (rbuf && rlen > 0) {
        cmd->dsi_data_type = MIPI_DSI_DT_GEN_SHORT_READ_0;
        cmd->flags |= MIPI_DSI_CMD_FLAGS_ACK | MIPI_DSI_CMD_FLAGS_SET_MAX;
      } else {
        cmd->dsi_data_type = MIPI_DSI_DT_GEN_SHORT_WRITE_0;
      }
      break;
    case 1:
      if (rbuf && rlen > 0) {
        cmd->dsi_data_type = is_dcs ? MIPI_DSI_DT_DCS_READ_0 : MIPI_DSI_DT_GEN_SHORT_READ_1;
        cmd->flags |= MIPI_DSI_CMD_FLAGS_ACK | MIPI_DSI_CMD_FLAGS_SET_MAX;
      } else {
        cmd->dsi_data_type = is_dcs ? MIPI_DSI_DT_DCS_SHORT_WRITE_0 : MIPI_DSI_DT_GEN_SHORT_WRITE_1;
      }
      break;
    case 2:
      if (rbuf && rlen > 0) {
        if (is_dcs) {
          printf("Invalid DCS GEN READ Command!\n");
          return ZX_ERR_INVALID_ARGS;
        }
        cmd->dsi_data_type = MIPI_DSI_DT_GEN_SHORT_READ_2;
        cmd->flags |= MIPI_DSI_CMD_FLAGS_ACK | MIPI_DSI_CMD_FLAGS_SET_MAX;
      } else {
        cmd->dsi_data_type = is_dcs ? MIPI_DSI_DT_DCS_SHORT_WRITE_1 : MIPI_DSI_DT_GEN_SHORT_WRITE_2;
      }
      break;
    default:
      if (rbuf || rlen > 0) {
        printf("Invalid DSI GEN READ Command!\n");
        return ZX_ERR_INVALID_ARGS;
      } else {
        cmd->dsi_data_type = is_dcs ? MIPI_DSI_DT_DCS_LONG_WRITE : MIPI_DSI_DT_GEN_LONG_WRITE;
      }
      break;
  }

  // packet command has been created.
  return ZX_OK;
}

}  // namespace mipi_dsi