/* -------------------------------------------

  Copyright (C) 2024, Amlal El Mahrouss, all rights reserved.

------------------------------------------- */

/**
 * @file neboot-ahci-driver.cc
 * @author Amlal El Mahrouss (amlal@nekernel.org)
 * @brief SATA Disk support, via AHCI.
 * @version 0.2
 * @date 2024-01-16
 *
 * @copyright Copyright (c) 2024-2025, Amlal El Mahrouss.
 *
 */

#include <lib/boot.h>
#include <lib/pci-tree.h>

#define NB_AHCI_DRIVER_NAME ("@sata")

/// BUGS: 0
/// @brief Generic AHCI support.

/// @brief AHCI HBA port.
typedef struct cb_hba_port {
  uint32_t clb;            // 0x00, command list base address, 1K-byte aligned
  uint32_t clbu;           // 0x04, command list base address upper 32 bits
  uint32_t fb;             // 0x08, FIS base address, 256-byte aligned
  uint32_t fbu;            // 0x0C, FIS base address upper 32 bits
  uint32_t is;             // 0x10, interrupt status
  uint32_t ie;             // 0x14, interrupt enable
  uint32_t cmd;            // 0x18, command and status
  uint32_t reserved0;      // 0x1C, Reserved
  uint32_t tfd;            // 0x20, task file data
  uint32_t sig;            // 0x24, signature
  uint32_t ssts;           // 0x28, SATA status (SCR0:SStatus)
  uint32_t sctl;           // 0x2C, SATA control (SCR2:SControl)
  uint32_t serr;           // 0x30, SATA error (SCR1:SError)
  uint32_t sact;           // 0x34, SATA active (SCR3:SActive)
  uint32_t ci;             // 0x38, command issue
  uint32_t sntf;           // 0x20, SATA notification (SCR4:SNotification)
  uint32_t fbs;            // 0x40, FIS-based switch control
  uint32_t reserved1[11];  // 0x44 ~ 0x6F, Reserved
  uint32_t vendor[4];      // 0x70 ~ 0x7F, vendor specific
} cb_hba_port_t;

/// @brief Check if port is active.
/// @param port host bus address port.
/// @return whether sact is active or not.
static boolean cb_hba_port_active(volatile cb_hba_port_t* port) {
  if (!port) return false;

  return port->sact;
}

/// @brief Start HBA command processor.
/// @param port host bus address port.
/// @return whether it was successful or not.
static boolean cb_hba_start_cmd(volatile cb_hba_port_t* port) {
  if (!port) return false;

  size_t timeout = 1000000;

  while ((port->cmd & 0x8000)) {
    if (!timeout) return false;

    --timeout;
  }

  port->cmd |= 0x0001;
  port->cmd |= 0x0010;

  return true;
}

/// @brief Stop HBA command from processing.
/// @param port host bus address port.
/// @return whether it was successful or not.
static boolean cb_hba_stop_cmd(volatile cb_hba_port_t* port) {
  if (!port) return false;

  port->cmd &= ~0x0001;
  port->cmd &= ~0x0010;

  while (yes) {
    if ((port->cmd & 0x8000)) continue;

    if ((port->cmd & 0x4000)) continue;

    break;
  }

  return true;
}