hm2_pktuart_read — read data from a Hostmot2 PktUART buffer


int hm2_pktuart_read ( char *name, unsigned char data[], u8 *num_frames, u16 *max_frame_length, u16 frame_sizes[] )


hm2_pktuart_read reads data from the PktUART name.
name is a unique string given to each PktUART instance during hostmot2 setup.

The names of the available channels are printed to standard output during the driver loading process and take the form:
hm2_<board name>.<board index>.pktuart.<index>
For example

This function reads a variable number of PktUART packets from the specified channel.
It should be used inside a realtime HAL component registered with the main hostmot2 driver using the function hm2_pktuart_setup in the setup code.

(*num_frames) * (*max_frame_length) should be <= sizeof data, which one tries to estimate or guess before calling the function.
If there are more bytes in the buffer than the size of data array is, then RxArraySizeError is returned.

Note that the PktUART MaxFrameSize is 1024 bytes as hard-coded in hostmot2.vhd


Returns the number of bytes read on success and negative error codes on failure.

On return num_frames which pointer is passed by value is set to the number of successfully datagrams read.

Negative error codes are:

-1 - low level read/write error
-EINVAL - any PktUART configuration error per instance
-110 - RxStartbitError, Rx mode register error
-111 - RxOverrunError, Rx mode register error
-114 - RxRCFIFOError, Rx mode register error
-1115 - RxPacketOverrrunError, Rx count register error
-1114 - RxPacketStartbitError, Rx count register error
-1120 - RxPacketSizeZero, the size of the received packet is zero
-1140 - RxArraySizeError, the size of the data array is not large enough


Issued under the terms of the GPL v2 License or any later version


Boris Skegin