nuttx/wireless/ieee802154/mac802154.c

/****************************************************************************
 * wireless/ieee802154/mac802154.c
 *
 *   Copyright (C) 2016 Sebastien Lorquet. All rights reserved.
 *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <string.h>

#include <nuttx/kmalloc.h>
#include <nuttx/wqueue.h>

#include <nuttx/drivers/iob.h>

#include <nuttx/wireless/ieee802154/ieee802154_mac.h>

#include "mac802154.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/
/* Configuration ************************************************************/
/* If processing is not done at the interrupt level, then work queue support
 * is required.
 */

#if !defined(CONFIG_SCHED_WORKQUEUE)
#  error Work queue support is required in this configuration (CONFIG_SCHED_WORKQUEUE)
#else

  /* Use the low priority work queue if possible */

#  if defined(CONFIG_MAC802154_HPWORK)
#    define MAC802154_WORK HPWORK
#  elif defined(CONFIG_MAC802154_LPWORK)
#    define MAC802154_WORK LPWORK
#  else
#    error Neither CONFIG_MAC802154_HPWORK nor CONFIG_MAC802154_LPWORK defined
#  endif
#endif

/****************************************************************************
 * Private Types
 ****************************************************************************/

struct mac802154_trans_s
{
  /* Supports a singly linked list */

  FAR struct mac802154_trans_s *flink;
  FAR struct iob_s *frame;
  uint8_t msdu_handle;
  sem_t sem;
};

struct mac802154_unsec_mhr_s
{
  uint8_t length;
  union
  {
    uint16_t frame_control;
    uint8_t data[IEEE802154_MAX_UNSEC_MHR_OVERHEAD];
  } u;
};

struct mac802154_radiocb_s
{
  struct ieee802154_radiocb_s cb;
  FAR struct ieee802154_privmac_s *priv;
};

/* The privmac structure holds the internal state of the MAC and is the
 * underlying represention of the opaque MACHANDLE.  It contains storage for
 * the IEEE802.15.4 MIB attributes.
 */

struct ieee802154_privmac_s
{
  FAR struct ieee802154_radio_s *radio;     /* Contained IEEE802.15.4 radio dev */
  FAR const struct ieee802154_maccb_s *cb;  /* Contained MAC callbacks */
  FAR struct mac802154_radiocb_s radiocb;   /* Interface to bind to radio */

  sem_t exclsem; /* Support exclusive access */

  struct work_s tx_work;
  struct work_s rx_work;

  /* Support a singly linked list of transactions that will be sent using the
   * CSMA algorithm.  On a non-beacon enabled PAN, these transactions will be
   * sent whenever. On a beacon-enabled PAN, these transactions will be sent
   * during the CAP of the Coordinator's superframe.
   */

  FAR struct mac802154_trans_s *csma_head;
  FAR struct mac802154_trans_s *csma_tail;

  /* Support a singly linked list of transactions that will be sent indirectly.
   * This list should only be used by a MAC acting as a coordinator.  These
   * transactions will stay here until the data is extracted by the destination
   * device sending a Data Request MAC command or if too much time passes. This
   * list should also be used to populate the address list of the outgoing
   * beacon frame.
   */

  FAR struct mac802154_trans_s *indirect_head;
  FAR struct mac802154_trans_s *indirect_tail;

  uint8_t txdesc_count;
  struct ieee802154_txdesc_s txdesc[CONFIG_IEEE802154_NTXDESC];

  /* Support a singly linked list of frames received */
  FAR struct iob_s *rxframes_head;
  FAR struct iob_s *rxframes_tail;

  /* MAC PIB attributes, grouped to save memory */

  /* Holds all address information (Extended, Short, and PAN ID) for the MAC. */

  struct ieee802154_addr_s addr;

  /* Holds all address information (Extended, Short) for Coordinator */

  struct ieee802154_addr_s coord_addr;

  /* The maximum number of symbols to wait for an acknowledgement frame to
   * arrive following a transmitted data frame. [1] pg. 126
   *
   * NOTE: This may be able to be a 16-bit or even an 8-bit number.  I wasn't
   * sure at the time what the range of reasonable values was.
   */

  uint32_t ack_wait_dur;

  /* The maximum time to wait either for a frame intended as a response to a
   * data request frame or for a broadcast frame following a beacon with the
   * Frame Pending field set to one. [1] pg. 127
   *
   * NOTE: This may be able to be a 16-bit or even an 8-bit number.  I wasn't
   * sure at the time what the range of reasonable values was.
   */

  uint32_t max_frame_wait_time;

  /* The maximum time (in unit periods) that a transaction is stored by a
   * coordinator and indicated in its beacon.
   */

  uint16_t trans_persist_time;

  /* Contents of beacon payload */

  uint8_t beacon_payload[IEEE802154_MAX_BEACON_PAYLOAD_LENGTH];
  uint8_t beacon_payload_len;       /* Length of beacon payload */

  uint8_t batt_life_ext_periods;    /* # of backoff periods during which rx is
                                     * enabled after the IFS following beacon */

  uint8_t bsn;                      /* Seq. num added to tx beacon frame */
  uint8_t dsn;                      /* Seq. num added to tx data or MAC frame */
  uint8_t max_retries;              /* Max # of retries alloed after tx failure */

  /* The maximum time, in multiples of aBaseSuperframeDuration, a device shall
   * wait for a response command frame to be available following a request
   * command frame. [1] 128.
   */

  uint8_t resp_wait_time;

  /* The total transmit duration (including PHY header and FCS) specified in
   * symbols. [1] pg. 129.
   */

  uint32_t tx_total_dur;

  /* Start of 32-bit bitfield */

  uint32_t is_assoc           : 1;  /* Are we associated to the PAN */
  uint32_t assoc_permit       : 1;  /* Are we allowing assoc. as a coord. */
  uint32_t auto_req           : 1;  /* Automatically send data req. if addr
                                     * addr is in the beacon frame */

  uint32_t batt_life_ext      : 1;  /* Is BLE enabled */
  uint32_t gts_permit         : 1;  /* Is PAN Coord. accepting GTS reqs. */
  uint32_t promiscuous_mode   : 1;  /* Is promiscuous mode on? */
  uint32_t ranging_supported  : 1;  /* Does MAC sublayer support ranging */
  uint32_t rx_when_idle       : 1;  /* Recvr. on during idle periods */
  uint32_t sec_enabled        : 1;  /* Does MAC sublayer have security en. */

  uint32_t max_csma_backoffs  : 3;  /* Max num backoffs for CSMA algorithm
                                     * before declaring ch access failure */

  uint32_t beacon_order       : 4;  /* Freq. that beacon is transmitted */

  uint32_t superframe_order   : 4;  /* Length of active portion of outgoing
                                     * superframe, including the beacon */

  /* The offset, measured is symbols, between the symbol boundary at which the
   * MLME captures the timestamp of each transmitted and received frame, and
   * the onset of the first symbol past the SFD, namely the first symbol of
   * the frames [1] pg. 129.
   */

  uint32_t sync_symb_offset   : 12;

  /* End of 32-bit bitfield */

  /* Start of 32-bit bitfield */

  uint32_t beacon_tx_time     : 24; /* Time of last beacon transmit */
  uint32_t min_be             : 4;  /* Min value of backoff exponent (BE) */
  uint32_t max_be             : 4;  /* Max value of backoff exponent (BE) */

  /* End of 32-bit bitfield */

  /* Start of 32-bit bitfield */

  uint32_t tx_ctrl_active_dur : 17; /* Duration for which tx is permitted to
                                     * be active */
  uint32_t tx_ctrl_pause_dur  : 1;  /* Duration after tx before another tx is
                                     * permitted. 0=2000, 1= 10000 */
  uint32_t timestamp_support  : 1;  /* Does MAC layer supports timestamping */
  uint32_t is_coord           : 1;  /* Is this device acting as coordinator */
                                    /* 12-bits remaining */

  /* End of 32-bit bitfield. */

  /* TODO: Add Security-related MAC PIB attributes */
};

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

static inline int mac802154_takesem(sem_t *sem);
#define mac802154_givesem(s) sem_post(s);

static void mac802154_txdone_worker(FAR void *arg);
static void mac802154_rxframe_worker(FAR void *arg);

/* Internal Functions */

static int mac802154_defaultmib(FAR struct ieee802154_privmac_s *priv);
static int mac802154_applymib(FAR struct ieee802154_privmac_s *priv);

/* IEEE 802.15.4 PHY Interface OPs */

static int mac802154_poll_csma(FAR const struct ieee802154_radiocb_s *radiocb,
                               FAR struct ieee802154_txdesc_s *tx_desc,
                               FAR struct iob_s **frame);

static int mac802154_poll_gts(FAR const struct ieee802154_radiocb_s *radiocb,
                              FAR struct ieee802154_txdesc_s *tx_desc,
                              FAR struct iob_s **frame);

static void mac802154_txdone(FAR const struct ieee802154_radiocb_s *radiocb,
                             FAR const struct ieee802154_txdesc_s *tx_desc);

static void mac802154_rxframe(FAR const struct ieee802154_radiocb_s *radiocb,
                              FAR const struct ieee802154_rxdesc_s *rx_desc,
                              FAR struct iob_s *frame);

/****************************************************************************
 * Private Data
 ****************************************************************************/

/* Map between ieee802154_addr_mode_e enum and actual address length */

static const uint8_t mac802154_addr_length[4] = {0, 0, 2, 8};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: mac802154_semtake
 *
 * Description:
 *   Acquire the semaphore used for access serialization.
 *
 ****************************************************************************/

static inline int mac802154_takesem(sem_t *sem)
{
  /* Take a count from the semaphore, possibly waiting */

  if (sem_wait(sem) < 0)
    {
      /* EINTR is the only error that we expect */

      int errcode = get_errno();
      DEBUGASSERT(errcode == EINTR);
      return -errcode;
    }

  return OK;
}

/****************************************************************************
 * Name: mac802154_push_csma
 *
 * Description:
 *   Push a CSMA transaction onto the list
 *
 ****************************************************************************/

static void mac802154_push_csma(FAR struct ieee802154_privmac_s *priv,
                                FAR struct mac802154_trans_s *trans)
{
  /* Ensure the transactions forward link is NULL */

  trans->flink = NULL;

  /* If the tail is not empty, make the transaction pointed to by the tail,
   * point to the new transaction */ 
  
  if (priv->csma_tail != NULL)
    {
      priv->csma_tail->flink = trans;
    }
  
  /* Point the tail at the new transaction */

  priv->csma_tail = trans;

  /* If the head is NULL, we need to point it at the transaction since there
   * is only one transaction in the list at this point */

  if (priv->csma_head == NULL)
    {
      priv->csma_head = trans;
    }
}

/****************************************************************************
 * Name: mac802154_pop_csma
 *
 * Description:
 *   Pop a CSMA transaction from the list
 *
 ****************************************************************************/

static FAR struct mac802154_trans_s * 
  mac802154_pop_csma(FAR struct ieee802154_privmac_s *priv)
{
  FAR struct mac802154_trans_s *trans;

  if (priv->csma_head == NULL)
    {
      return NULL;
    }

  /* Get the transaction from the head of the list */

  trans = priv->csma_head;

  /* Move the head pointer to the next transaction */

  priv->csma_head = trans->flink;

  /* If the head is now NULL, the list is empty, so clear the tail too */

  if (priv->csma_head == NULL)
    {
      priv->csma_tail = NULL;
    }

  return trans;
}

/****************************************************************************
 * Name: mac802154_defaultmib
 *
 * Description:
 *   Set the MIB to its default values.
 *
 ****************************************************************************/

static int mac802154_defaultmib(FAR struct ieee802154_privmac_s *priv)
{
  /* TODO: Set all MAC fields to default values */

  return OK;
}

/****************************************************************************
 * Name: mac802154_applymib
 *
 * Description:
 *   Some parts of the MIB must be sent to the radio device. This routine
 *   calls the radio device routines to store the related parameters in the
 *   radio driver. It must be called each time a MIB parameter is changed.
 *
 ****************************************************************************/

static int mac802154_applymib(FAR struct ieee802154_privmac_s *priv)
{
  return OK;
}

/****************************************************************************
 * Name: mac802154_poll_csma
 *
 * Description:
 *   Called from the radio driver through the callback struct.  This function is
 *   called when the radio has room for another CSMA transaction.  If the MAC
 *   layer has a CSMA transaction, it copies it into the supplied buffer and
 *   returns the length.  A descriptor is also populated with the transaction.
 *
 ****************************************************************************/

static int mac802154_poll_csma(FAR const struct ieee802154_radiocb_s *radiocb,
                               FAR struct ieee802154_txdesc_s *tx_desc,
                               FAR struct iob_s **frame)
{
  FAR struct mac802154_radiocb_s *cb =
    (FAR struct mac802154_radiocb_s *)radiocb;
  FAR struct ieee802154_privmac_s *priv;
  FAR struct mac802154_trans_s *trans;

  DEBUGASSERT(cb != NULL && cb->priv != NULL);
  priv = cb->priv;

  /* Get exclusive access to the driver structure.  We don't care about any
   * signals so if we see one, just go back to trying to get access again.
   */

  while (mac802154_takesem(&priv->exclsem) != 0);

  /* Check to see if there are any CSMA transactions waiting */

  trans = mac802154_pop_csma(priv);
  mac802154_givesem(&priv->exclsem);

  if (trans != NULL)
    {
      /* Setup the transmit descriptor */

      tx_desc->handle = trans->msdu_handle;

      *frame = trans->frame;

      /* Now that we've passed off the data, notify the waiting thread.
       * NOTE: The transaction was allocated on the waiting thread's stack so
       * it will be automatically deallocated when that thread awakens and
       * returns. */

      sem_post(&trans->sem);
      return (trans->frame->io_len);
    }

  return 0;
}

/****************************************************************************
 * Name: mac802154_poll_gts
 *
 * Description:
 *   Called from the radio driver through the callback struct.  This function is
 *   called when the radio has room for another GTS transaction.  If the MAC
 *   layer has a GTS transaction, it copies it into the supplied buffer and
 *   returns the length.  A descriptor is also populated with the transaction.
 *
 ****************************************************************************/

static int mac802154_poll_gts(FAR const struct ieee802154_radiocb_s *radiocb,
                              FAR struct ieee802154_txdesc_s *tx_desc,
                              FAR struct iob_s **frame)
{
  FAR struct mac802154_radiocb_s *cb =
    (FAR struct mac802154_radiocb_s *)radiocb;
  FAR struct ieee802154_privmac_s *priv;
  FAR struct mac802154_trans_s *trans;
  int ret = 0;

  DEBUGASSERT(cb != NULL && cb->priv != NULL);
  priv = cb->priv;

  /* Get exclusive access to the driver structure.  We don't care about any
   * signals so if we see one, just go back to trying to get access again.
   */

  while (mac802154_takesem(&priv->exclsem) != 0);

#warning Missing logic.

  mac802154_givesem(&priv->exclsem);

  return 0;
}

/****************************************************************************
 * Name: mac802154_txdone
 *
 * Description:
 *   Called from the radio driver through the callback struct.  This function is
 *   called when the radio has completed a transaction.  The txdesc passed gives
 *   provides information about the completed transaction including the original
 *   handle provided when the transaction was created and the status of the
 *   transaction.  This function copies the descriptor and schedules work to
 *   handle the transaction without blocking the radio.
 *
 ****************************************************************************/

static void mac802154_txdone(FAR const struct ieee802154_radiocb_s *radiocb,
                            FAR const struct ieee802154_txdesc_s *tx_desc)
{
  FAR struct mac802154_radiocb_s *cb =
    (FAR struct mac802154_radiocb_s *)radiocb;
  FAR struct ieee802154_privmac_s *priv;

  DEBUGASSERT(cb != NULL && cb->priv != NULL);
  priv = cb->priv;

  /* Get exclusive access to the driver structure.  We don't care about any
   * signals so if we see one, just go back to trying to get access again.
   */

  while (mac802154_takesem(&priv->exclsem) != 0);

  /* Check to see if there is an available tx descriptor slot.  If there is
   * not we simply drop the notification */

  if (priv->txdesc_count < CONFIG_IEEE802154_NTXDESC)
    {
      /* Copy the txdesc over and link it into our list */

      memcpy(&priv->txdesc[priv->txdesc_count++], tx_desc,
             sizeof(struct ieee802154_txdesc_s));
    }
  else
    {
      wlinfo("MAC802154: No room for TX Desc.\n");
    }

  mac802154_givesem(&priv->exclsem);

  /* Schedule work with the work queue to process the completion further */

  if (work_available(&priv->tx_work))
    {
      work_queue(MAC802154_WORK, &priv->tx_work, mac802154_txdone_worker,
                 (FAR void *)priv, 0);
    }
}

/****************************************************************************
 * Name: mac802154_txdone_worker
 *
 * Description:
 *   Worker function scheduled from mac802154_txdone.  This function pops any
 *   TX descriptors off of the list and calls the next highest layers callback
 *   to inform the layer of the completed transaction and the status of it.
 *
 ****************************************************************************/

static void mac802154_txdone_worker(FAR void *arg)
{
  FAR struct ieee802154_privmac_s *priv = 
    (FAR struct ieee802154_privmac_s *)arg;
  int i = 0;
  
  /* Get exclusive access to the driver structure.  We don't care about any
   * signals so if we see one, just go back to trying to get access again.
   */

  while (mac802154_takesem(&priv->exclsem) != 0);

  /* For each pending TX descriptor, send an application callback */

  for (i = 0; i < priv->txdesc_count; i++)
    {
      priv->cb->mcps_notify(priv->cb, IEEE802154_NOTIFY_CONF_DATA,
                  (FAR const union ieee802154_mcps_notify_u *) &priv->txdesc[i]);
    }

  /* We've handled all the descriptors and no further desc could have been added
   * since we have the struct locked */

  priv->txdesc_count = 0;

  mac802154_givesem(&priv->exclsem);
}

/****************************************************************************
 * Name: mac802154_rxframe
 *
 * Description:
 *   Called from the radio driver through the callback struct.  This function is
 *   called when the radio has received a frame. The frame is passed in an iob,
 *   so that we can free it when we are done processing.  A pointer to the RX
 *   descriptor is passed along with the iob, but it must be copied here as it
 *   is allocated directly on the caller's stack.  We simply link the frame,
 *   copy the RX descriptor, and schedule a worker to process the frame later so
 *   that we do not hold up the radio.
 *
 ****************************************************************************/

static void mac802154_rxframe(FAR const struct ieee802154_radiocb_s *radiocb,
                              FAR const struct ieee802154_rxdesc_s *rx_desc,
                              FAR struct iob_s *frame)
{
  FAR struct mac802154_radiocb_s *cb =
    (FAR struct mac802154_radiocb_s *)radiocb;
  FAR struct ieee802154_privmac_s *priv;
  FAR struct ieee802154_rxdesc_s *desc;

  DEBUGASSERT(cb != NULL && cb->priv != NULL);
  priv = cb->priv;

  /* Get exclusive access to the driver structure.  We don't care about any
   * signals so if we see one, just go back to trying to get access again.
   */

  while (mac802154_takesem(&priv->exclsem) != 0);

  /* TODO: Copy the frame descriptor to some type of list */

  /* Push the iob onto the tail of the frame list for processing */

  priv->rxframes_tail->io_flink = frame;
  priv->rxframes_tail = frame;

  mac802154_givesem(&priv->exclsem);

  /* Schedule work with the work queue to process the completion further */

  if (work_available(&priv->rx_work))
    {
      work_queue(MAC802154_WORK, &priv->rx_work, mac802154_rxframe_worker,
                 (FAR void *)priv, 0);
    }
}

/****************************************************************************
 * Name: mac802154_rxframe_worker
 *
 * Description:
 *   Worker function scheduled from mac802154_rxframe.  This function processes
 *   any frames in the list.  Frames intended to be consumed by the MAC layer
 *   will not produce any callbacks to the next highest layer.  Frames intended
 *   for the application layer will be forwarded to them.
 *
 ****************************************************************************/

static void mac802154_rxframe_worker(FAR void *arg)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)arg;

  /* The radio layer is responsible for handling all ACKs and retries. If for
   * some reason an ACK gets here, just throw it out.
   */
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: mac802154_create
 *
 * Description:
 *   Create a 802.15.4 MAC device from a 802.15.4 compatible radio device.
 *
 *   The returned MAC structure should be passed to either the next highest
 *   layer in the network stack, or registered with a mac802154dev character
 *   or network drivers.  In any of these scenarios, the next highest layer
 *   should  register a set of callbacks with the MAC layer by setting the
 *   mac->cbs member.
 *
 *   NOTE: This API does not create any device accessible to userspace. If
 *   you want to call these APIs from userspace, you have to wrap your mac
 *   in a character device via mac802154_device.c.
 *
 * Input Parameters:
 *   radiodev - an instance of an IEEE 802.15.4 radio
 *
 * Returned Value:
 *   An opaque reference to the MAC state data.
 *
 ****************************************************************************/

MACHANDLE mac802154_create(FAR struct ieee802154_radio_s *radiodev)
{
  FAR struct ieee802154_privmac_s *mac;
  FAR struct ieee802154_radiocb_s *radiocb;

  /* Allocate object */

  mac = (FAR struct ieee802154_privmac_s *)
    kmm_zalloc(sizeof(struct ieee802154_privmac_s));

  if (mac == NULL)
    {
      return NULL;
    }
 
  /* Allow exclusive access to the privmac struct */

  sem_init(&mac->exclsem, 0, 1);

  /* Initialize fields */

  mac->radio = radiodev;

  mac802154_defaultmib(mac);
  mac802154_applymib(mac);

  /* Initialize the Radio callbacks */

  mac->radiocb.priv = mac;

  radiocb              = &mac->radiocb.cb;
  radiocb->poll_csma   = mac802154_poll_csma;
  radiocb->poll_gts    = mac802154_poll_gts;
  radiocb->txdone      = mac802154_txdone;
  radiocb->rxframe     = mac802154_rxframe;

  /* Bind our callback structure */

  radiodev->ops->bind(radiodev, &mac->radiocb.cb);

  return (MACHANDLE)mac;
}

/****************************************************************************
 * Name: mac802154_bind
 *
 * Description:
 *   Bind the MAC callback table to the MAC state.
 *
 * Parameters:
 *   mac - Reference to the MAC driver state structure
 *   cb  - MAC callback operations
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 ****************************************************************************/

int mac802154_bind(MACHANDLE mac, FAR const struct ieee802154_maccb_s *cb)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;

  priv->cb = cb;
  return OK;
}

/****************************************************************************
 * Name: mac802154_ioctl
 *
 * Description:
 *   Handle MAC and radio IOCTL commands directed to the MAC.
 *
 * Parameters:
 *   mac - Reference to the MAC driver state structure
 *   cmd - The IOCTL command
 *   arg - The argument for the IOCTL command
 *
 * Returned Value:
 *   OK on success; Negated errno on failure.
 *
 ****************************************************************************/

int mac802154_ioctl(MACHANDLE mac, int cmd, unsigned long arg)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  int ret = -EINVAL;

  DEBUGASSERT(priv != NULL);

  /* Check for IOCTLs aimed at the IEEE802.15.4 MAC layer */

  if (_MAC802154IOCVALID(cmd))
    {
      /* Handle the MAC IOCTL command */
#warning Missing logic
    }

  /* No, other IOCTLs must be aimed at the IEEE802.15.4 radio layer */

  else
   {
     DEBUGASSERT(priv->radio != NULL &&
                 priv->radio->ops != NULL &&
                 priv->radio->ops->ioctl != NULL);

     ret = priv->radio->ops->ioctl(priv->radio, cmd, arg);
   }

 return ret;
}

/****************************************************************************
 * MAC Interface Operations
 ****************************************************************************/

/****************************************************************************
 * Name: mac802154_get_mhrlen
 *
 * Description:
 *   Calculate the MAC header length given the frame meta-data.
 *
 ****************************************************************************/

int mac802154_get_mhrlen(MACHANDLE mac, 
                         FAR struct ieee802154_frame_meta_s *meta)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  int ret = 3; /* Always frame control (2 bytes) and seq. num (1 byte) */

  /* Check to make sure both the dest address and the source address are not set
   * to NONE */

  if (meta->dest_addr.mode == IEEE802154_ADDRMODE_NONE &&
      meta->src_addr_mode == IEEE802154_ADDRMODE_NONE)  
    {
      return -EINVAL;
    }
  
  /* The source address can only be set to NONE if the device is the PAN coord */

  if (meta->src_addr_mode == IEEE802154_ADDRMODE_NONE && !priv->is_coord)
    {
      return -EINVAL;
    }

  /* Add the destination address length */

  ret += mac802154_addr_length[meta->dest_addr.mode];

  /* Add the source address length */

  ret += mac802154_addr_length[ meta->src_addr_mode];

  /* If both destination and source addressing information is present, the MAC
   * sublayer shall compare the destination and source PAN identifiers.
   * [1] pg. 41.
   */

  if (meta->src_addr_mode  != IEEE802154_ADDRMODE_NONE &&
      meta->dest_addr.mode != IEEE802154_ADDRMODE_NONE)
    {
      /* If the PAN identifiers are identical, the PAN ID Compression field
       * shall be set to one, and the source PAN identifier shall be omitted
       * from the transmitted frame. [1] pg. 41.
       */

      if (meta->dest_addr.panid == priv->addr.panid)
        {
          ret += 2; /* 2 bytes for destination PAN ID */
          return ret;
        }
    }
  
  /* If we are here, PAN ID compression is off, so include the dest and source
   * PAN ID if the respective address is included 
   */

  if (meta->src_addr_mode != IEEE802154_ADDRMODE_NONE)
    {
      ret += 2; /* 2 bytes for source PAN ID */
    }
  
  if (meta->dest_addr.mode != IEEE802154_ADDRMODE_NONE)
    {
      ret += 2; /* 2 bytes for destination PAN ID */
    }

  return ret;
}

/****************************************************************************
 * Name: mac802154_req_data
 *
 * Description:
 *   The MCPS-DATA.request primitive requests the transfer of a data SPDU
 *   (i.e., MSDU) from a local SSCS entity to a single peer SSCS entity.
 *   Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_data callback.
 *
 ****************************************************************************/

int mac802154_req_data(MACHANDLE mac, FAR struct ieee802154_data_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  FAR struct mac802154_trans_s trans;
  FAR struct ieee802154_frame_meta_s *meta = req->meta;
  uint16_t *frame_ctrl;
  uint8_t mhr_len = 3; /* Start assuming frame control and seq. num */
  int ret;
  
  /* Check the required frame size */

  if (req->frame->io_len > IEEE802154_MAX_PHY_PACKET_SIZE)
  {
    return -E2BIG;
  }

  /* Cast the first two bytes of the IOB to a uint16_t frame control field */

  frame_ctrl = (uint16_t *)&req->frame->io_data[0];

  /* Ensure we start with a clear frame control field */

  *frame_ctrl = 0;

  /* Set the frame type to Data */

  *frame_ctrl |= IEEE802154_FRAME_DATA << IEEE802154_FRAMECTRL_SHIFT_FTYPE;

  /* If the msduLength is greater than aMaxMACSafePayloadSize, the MAC
   * sublayer will set the Frame Version to one. [1] pg. 118.
   */

  if (meta->msdu_length > IEEE802154_MAX_SAFE_MAC_PAYLOAD_SIZE)
    {
      *frame_ctrl |= IEEE802154_FRAMECTRL_VERSION;
    }

  /* If the TXOptions parameter specifies that an acknowledged transmission
   * is required, the AR field will be set appropriately, as described in
   * 5.1.6.4 [1] pg. 118.
   */
                         
  *frame_ctrl |= (meta->msdu_flags.ack_tx << IEEE802154_FRAMECTRL_SHIFT_ACKREQ);

  /* If the destination address is present, copy the PAN ID and one of the
   * addresses, depending on mode, into the MHR. 
   */

  if (meta->dest_addr.mode != IEEE802154_ADDRMODE_NONE)
    {
      memcpy(&req->frame->io_data[mhr_len], &meta->dest_addr.panid, 2);
      mhr_len += 2;

      if (meta->dest_addr.mode == IEEE802154_ADDRMODE_SHORT)
        {
          memcpy(&req->frame->io_data[mhr_len], &meta->dest_addr.saddr, 2);
          mhr_len += 2;
        }
      else if (meta->dest_addr.mode == IEEE802154_ADDRMODE_EXTENDED)
        {
          memcpy(&req->frame->io_data[mhr_len], &meta->dest_addr.eaddr, 8);
          mhr_len += 8;
        }
    }

  /* Set the destination addr mode inside the frame control field */

  *frame_ctrl |= (meta->dest_addr.mode << IEEE802154_FRAMECTRL_SHIFT_DADDR);

  /* From this point on, we need exclusive access to the privmac struct */

  ret = mac802154_takesem(&priv->exclsem);
  if (ret < 0)
    {
      wlerr("ERROR: mac802154_takesem failed: %d\n", ret);
      return ret;
    }

  /* If both destination and source addressing information is present, the MAC
   * sublayer shall compare the destination and source PAN identifiers.
   * [1] pg. 41.
   */

  if (meta->src_addr_mode  != IEEE802154_ADDRMODE_NONE &&
      meta->dest_addr.mode != IEEE802154_ADDRMODE_NONE)
    {
      /* If the PAN identifiers are identical, the PAN ID Compression field
       * shall be set to one, and the source PAN identifier shall be omitted
       * from the transmitted frame. [1] pg. 41.
       */

      if (meta->dest_addr.panid == priv->addr.panid)
        {
          *frame_ctrl |= IEEE802154_FRAMECTRL_PANIDCOMP;
        }
    }

  if (meta->src_addr_mode != IEEE802154_ADDRMODE_NONE)
    {
      /* If the destination address is not included, or if PAN ID Compression
       * is off, we need to include the Source PAN ID.
       */

      if ((meta->dest_addr.mode == IEEE802154_ADDRMODE_NONE) ||
          (*frame_ctrl & IEEE802154_FRAMECTRL_PANIDCOMP))
        {
          memcpy(&req->frame->io_data[mhr_len], &priv->addr.panid, 2);
          mhr_len += 2;
        }

      if (meta->src_addr_mode == IEEE802154_ADDRMODE_SHORT)
        {
          memcpy(&req->frame->io_data[mhr_len], &priv->addr.saddr, 2);
          mhr_len += 2;
        }
      else if (meta->src_addr_mode == IEEE802154_ADDRMODE_EXTENDED)
        {
          memcpy(&req->frame->io_data[mhr_len], &priv->addr.eaddr, 8);
          mhr_len += 8;
        }
    }

  /* Set the source addr mode inside the frame control field */

  *frame_ctrl |= (meta->src_addr_mode << IEEE802154_FRAMECTRL_SHIFT_SADDR);

  /* Each time a data or a MAC command frame is generated, the MAC sublayer
   * shall copy the value of macDSN into the Sequence Number field of the MHR
   * of the outgoing frame and then increment it by one. [1] pg. 40.
   */

  req->frame->io_data[2] = priv->dsn++;

  /* The MAC header we just created must never have exceeded where the app
   * data starts.  This should never happen since the offset should have
   * been set via the same logic to calculate the header length as the logic
   * here that created the header
   */

  DEBUGASSERT(mhr_len == req->frame->io_offset);

  req->frame->io_offset = 0; /* Set the offset to 0 to include the header */

  /* Setup our transaction */

  trans.msdu_handle = meta->msdu_handle;
  trans.frame = req->frame;
  sem_init(&trans.sem, 0, 1);

  /* If the TxOptions parameter specifies that a GTS transmission is required,
   * the MAC sublayer will determine whether it has a valid GTS as described
   * 5.1.7.3. If a valid GTS could not be found, the MAC sublayer will discard
   * the MSDU. If a valid GTS was found, the MAC sublayer will defer, if
   * necessary, until the GTS. If the TxOptions parameter specifies that a GTS
   * transmission is not required, the MAC sublayer will transmit the MSDU using
   * either slotted CSMA-CA in the CAP for a beacon-enabled PAN or unslotted
   * CSMA-CA for a nonbeacon-enabled PAN. Specifying a GTS transmission in the
   * TxOptions parameter overrides an indirect transmission request.
   * [1] pg. 118.
   */

  if (meta->msdu_flags.gts_tx)
    {
      /* TODO: Support GTS transmission. This should just change where we link
       * the transaction.  Instead of going in the CSMA transaction list, it
       * should be linked to the GTS' transaction list. We'll need to check if
       * the GTS is valid, and then find the GTS, before linking. Note, we also
       * don't have to try and kick-off any transmission here.
       */

      return -ENOTSUP;
    }
  else
    {
      /* If the TxOptions parameter specifies that an indirect transmission is
       * required and this primitive is received by the MAC sublayer of a
       * coordinator, the data frame is sent using indirect transmission, as
       * described in 5.1.5 and 5.1.6.3. [1]
       */

      if (meta->msdu_flags.indirect_tx)
        {
          /* If the TxOptions parameter specifies that an indirect transmission
           * is required and if the device receiving this primitive is not a
           * coordinator, the destination address is not present, or the
           * TxOptions parameter also specifies a GTS transmission, the indirect
           * transmission option will be ignored. [1]
           */

          if (priv->is_coord && meta->dest_addr.mode != IEEE802154_ADDRMODE_NONE)
            {
              /* Link the transaction into the indirect_trans list */

            }
          else
            {
              /* Override the setting since it wasn't valid */

              meta->msdu_flags.indirect_tx = 0;
            }
        }

      /* If this is a direct transmission not during a GTS */

      if (!meta->msdu_flags.indirect_tx)
        {
          /* Link the transaction into the CSMA transaction list */

          mac802154_push_csma(priv, &trans);

          /* We no longer need to have the MAC layer locked. */

          mac802154_givesem(&priv->exclsem);

          /* Notify the radio driver that there is data available */

          priv->radio->ops->txnotify_csma(priv->radio);

          sem_wait(&trans.sem);
        }
    }

  sem_destroy(&trans.sem);
  return OK;
}

/****************************************************************************
 * Name: mac802154_req_purge
 *
 * Description:
 *   The MCPS-PURGE.request primitive allows the next higher layer to purge
 *   an MSDU from the transaction queue. Confirmation is returned via
 *   the struct ieee802154_maccb_s->conf_purge callback.
 *
 ****************************************************************************/

int mac802154_req_purge(MACHANDLE mac, FAR struct ieee802154_purge_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_associate
 *
 * Description:
 *   The MLME-ASSOCIATE.request primitive allows a device to request an
 *   association with a coordinator. Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_associate callback.
 *
 ****************************************************************************/

int mac802154_req_associate(MACHANDLE mac,
                            FAR struct ieee802154_assoc_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;

  /* Set the channel of the PHY layer */

  /* Set the channel page of the PHY layer */

  /* Set the macPANId */

  /* Set either the macCoordExtendedAddress and macCoordShortAddress
   * depending on the CoordAddrMode in the primitive.
   */

  if (req->coord_addr.mode == IEEE802154_ADDRMODE_EXTENDED)
    {

    }
  else if (req->coord_addr.mode == IEEE802154_ADDRMODE_EXTENDED)
    {

    }
  else
    {
      return -EINVAL;
    }

  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_disassociate
 *
 * Description:
 *   The MLME-DISASSOCIATE.request primitive is used by an associated device to
 *   notify the coordinator of its intent to leave the PAN. It is also used by
 *   the coordinator to instruct an associated device to leave the PAN.
 *   Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_disassociate callback.
 *
 ****************************************************************************/

int mac802154_req_disassociate(MACHANDLE mac,
                               FAR struct ieee802154_disassoc_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_get
 *
 * Description:
 *   The MLME-GET.request primitive requests information about a given PIB
 *   attribute. Actual data is returned via the
 *   struct ieee802154_maccb_s->conf_get callback.
 *
 ****************************************************************************/

int mac802154_req_get(MACHANDLE mac, FAR struct ieee802154_get_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_gts
 *
 * Description:
 *   The MLME-GTS.request primitive allows a device to send a request to the PAN
 *   coordinator to allocate a new GTS or to deallocate an existing GTS.
 *   Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_gts callback.
 *
 ****************************************************************************/

int mac802154_req_gts(MACHANDLE mac, FAR struct ieee802154_gts_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_reset
 *
 * Description:
 *   The MLME-RESET.request primitive allows the next higher layer to request
 *   that the MLME performs a reset operation. Confirmation is returned via
 *   the struct ieee802154_maccb_s->conf_reset callback.
 *
 ****************************************************************************/

int mac802154_req_reset(MACHANDLE mac, FAR struct ieee802154_reset_req_s *req)
{
  FAR struct ieee802154_privmac_s * priv =
    (FAR struct ieee802154_privmac_s *) mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_rxenable
 *
 * Description:
 *   The MLME-RX-ENABLE.request primitive allows the next higher layer to
 *   request that the receiver is enable for a finite period of time.
 *   Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_rxenable callback.
 *
 ****************************************************************************/

int mac802154_req_rxenable(MACHANDLE mac,
                           FAR struct ieee802154_rxenable_req_s *req)
{
  FAR struct ieee802154_privmac_s * priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_scan
 *
 * Description:
 *   The MLME-SCAN.request primitive is used to initiate a channel scan over a
 *   given list of channels. A device can use a channel scan to measure the
 *   energy on the channel, search for the coordinator with which it associated,
 *   or search for all coordinators transmitting beacon frames within the POS of
 *   the scanning device. Scan results are returned
 *   via MULTIPLE calls to the struct ieee802154_maccb_s->conf_scan callback.
 *   This is a difference with the official 802.15.4 specification, implemented
 *   here to save memory.
 *
 ****************************************************************************/

int mac802154_req_scan(MACHANDLE mac, FAR struct ieee802154_scan_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_set
 *
 * Description:
 *   The MLME-SET.request primitive attempts to write the given value to the
 *   indicated MAC PIB attribute. Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_set callback.
 *
 ****************************************************************************/

int mac802154_req_set(MACHANDLE mac, FAR struct ieee802154_set_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_start
 *
 * Description:
 *   The MLME-START.request primitive makes a request for the device to start
 *   using a new superframe configuration. Confirmation is returned
 *   via the struct ieee802154_maccb_s->conf_start callback.
 *
 ****************************************************************************/

int mac802154_req_start(MACHANDLE mac, FAR struct ieee802154_start_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_sync
 *
 * Description:
 *   The MLME-SYNC.request primitive requests to synchronize with the
 *   coordinator by acquiring and, if specified, tracking its beacons.
 *   Confirmation is returned via the
 *   struct ieee802154_maccb_s->int_commstatus callback. TOCHECK.
 *
 ****************************************************************************/

int mac802154_req_sync(MACHANDLE mac, FAR struct ieee802154_sync_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_req_poll
 *
 * Description:
 *   The MLME-POLL.request primitive prompts the device to request data from
 *   the coordinator. Confirmation is returned via the
 *   struct ieee802154_maccb_s->conf_poll callback, followed by a
 *   struct ieee802154_maccb_s->ind_data callback.
 *
 ****************************************************************************/

int mac802154_req_poll(MACHANDLE mac, FAR struct ieee802154_poll_req_s *req)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_rsp_associate
 *
 * Description:
 *   The MLME-ASSOCIATE.response primitive is used to initiate a response to
 *   an MLME-ASSOCIATE.indication primitive.
 *
 ****************************************************************************/

int mac802154_rsp_associate(MACHANDLE mac,
                            FAR struct ieee802154_assoc_resp_s *resp)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}

/****************************************************************************
 * Name: mac802154_rsp_orphan
 *
 * Description:
 *   The MLME-ORPHAN.response primitive allows the next higher layer of a
 *   coordinator to respond to the MLME-ORPHAN.indication primitive.
 *
 ****************************************************************************/

int mac802154_rsp_orphan(MACHANDLE mac,
                         FAR struct ieee802154_orphan_resp_s *resp)
{
  FAR struct ieee802154_privmac_s *priv =
    (FAR struct ieee802154_privmac_s *)mac;
  return -ENOTTY;
}