13.3 HIF Layer APIs

The interface between the application and the driver is done at the higher layer API interface (Wi-Fi / Socket.) As explained previously, the driver upper layer uses a lower layer API to access the services of the Host Interface Protocol. This section describes the Host Interface APIs that the upper layers use:

The following API functions are described:

  • hif_chip_wake
  • hif_chip_sleep
  • hif_register_cb
  • hif_isr
  • hif_receive
  • hif_send
  • hif_set_sleep_mode
  • hif_get_sleep_mode

For all functions, the return value is either M2M_SUCCESS (zero) in case of success or a negative value in case of failure.

  • sint8 hif_chip_wake (void) – this function wakes the WINC chip from Sleep mode using clockless register access. It sets bit '1' of register 0x01 and sets the value of WAKE_REG register to WAKE_VALUE.

  • sint8 hif_chip_sleep (void) – this function enables Sleep mode for the WINC chip by setting the WAKE_REG register to a value of SLEEP_VALUE and clearing bit '1' of register 0x01.

  • sint8 hif_register_cb (uint8 u8Grp, tpfHifCallBack fn) – this function sets the callback function for different components (for example, M2M_WIFI, M2M_HIF, M2M_OTA and so on.). A callback is registered by upper layers to receive specific events of a specific message group.
  • sint8 hif_isr (void) – this is the host interface interrupt service routine. It handles interrupts generated by the WINC chip and parses the HIF header to call back the appropriate handler.
  • sint8 hif_receive (uint32 u32Addr, uint8 *pu8Buf, uint16 u16Sz, uint8 is Done) – this function causes the host driver to read data from the WINC chip. The location and length of the data must be known in advance and specified. This is typically extracted from an earlier part of a transaction.

  • sint8 hif_send (uint8 u8Gid, uint8 u8Opcode, uint8 *pu8CtrlBuf, uint16 u16CtrlBufSize, uint8 *pu8DataBuf, uint16 u16DataSize, uint16 16DataOffset) – this function causes the host driver to send data to the WINC chip. The WINC chip must be prepared for reception according to the flow described in the previous section.

  • void hif_set_sleep_mode (uint8 u8Pstype) – this function is used to set the Sleep mode of the HIF layer.
  • uint8 hif_get_sleep_mode (void) – this function return the Sleep mode of the HIF layer.