ISO endpoints were not covered so far by the driver code.
This adds support for ISO IN and OUT endpoint handling.
Registers for ISO IN(OUT) endpoints are placed just after normal IN(OUT)
so in some cases common code could be used for handling all type of
transfers.
Generally code synchronizes ISO endpoint handling to SOF interrupt.
This code does not change the way of how non-ISO endpoints are treated.
Code uses strategy outlined in nRF52840 Produce Specification v1.0
sections 6.35.11.1 and 6.35.11.2.
Closing endpoints can be important when there are alternate
instances. This adds functionality of closing endpoints
similar to what exists in other drivers.
Currently number of endpoints was hard coded to 8.
NRF52 has 9 IN and 9 OUT endpoints.
ISO endpoints are 0x08 and 0x88 and without this change those
two ISO endpoint could not be used.
Operator < used in while condition was obviously incorrect.
Loop starts with checking if unsigned variable is less then 0.
This condition is always false.
This reverses condition to follow intention of of the code.
Fix a bug in writing SysEx messages.
At the start of a new USB packet (4 bytes), while in the middle of a SysEx, the code mistakenly
set the buffer length to 4, not the target length. As a consequence, the 3rd and 4th bytes from
the last packet were included, after every byte of the SysEx after the first packet of three.
The fix is simple, as it was just a typo, as can bee seen from the other branches in the same
section of if/else statements: At the start of a new packet, the code should set up the target
length... the buffer length should be left at 2 (as set on line 180).
define __USE_CMSIS instead of __USE_LPCOPEN will have startup enable FPU
on startup properly. Although it is only relevant to lpx43/40 series,
change all to __USE_CMSIS for consistency