NetDev_Rx()
The receive/Rx()
function is called by µC/TCP-IP’s Receive task after the Interrupt Service Routine handler has signaled to the Receive task that a receive event has occurred. The Receive function requires that the device driver return a pointer to the data area containing the received data and return the size of the received frame via pointer.
Files
Every device driver’s net_dev.c
Prototype
Note that since every device driver’s Rx()
function is accessed only by function pointer via the device driver’s API structure, it doesn’t need to be globally available and should therefore be declared as ‘static
’.
Arguments
p_if
Pointer to the interface to receive data from a network device.
p_data
Pointer to return the address of the received data.
p_size
Pointer to return the size of the received data.
p_err
Pointer to variable that will receive the return error code from this function.
Returned Value
None.
Required Configuration
None.
Notes / Warnings
The receive function should perform the following actions:
a. Acquire the SPI lock by calling p_dev_bsp->SPI_Lock().
b. Enable the chip select by calling p_dev_bsp->SPI_ChipSelEn()
.
c. Configure the SPI controller for the wireless device by calling p_dev_bsp->SPI_SetCfg()
.
*size
to 0 and *p_data
to (CPU_INT08U *)0
and return. Additional steps may be necessary depending on the device being serviced.*size
equal to the adjusted frame size.NetBuf_GetDataPtr()
. If memory is not available, an error will be returned and the device driver should set *size
to 0 and *p_data
to (CPU_INT08U *)0
.a. Set the frame type of the data received (NET_IF_WIFI_MGMT_FRAME
or NET_IF_WIFI_DATA_PKT
) at the beginning of the network buffer.
b. The data stored within the device should be transferred to the address of the data section (after the frame type) of the network buffer by calling p_dev_bsp->SPI_WrRd()
and by using a global buffer to write data and set *p_data
equal to the address of the obtained data area.
p_dev_bsp->SPI_ChipSelDis()
and unlock the SPI bus access by calling p_dev_bsp->SPI_Unlock()
.p_err
to NET_DEV_ERR_NONE
and return from the receive function. Otherwise, set p_err
to an appropriate network device error code.