Some ST parts (like STM32F74xxx / STM32F75xxx) allow the USB_OTG_HS core to be used with
either an external high-speed ULPI PHY or an internal full-speed-only (12mbps) PHY. Currently
the code assumes than an ULPI PHY is used unless the chip has an internal high-speed PHY
(`#if defined(USB_HS_PHYC)`), with no provision to use the internal FS PHY.
FIFO is limited to 64 bytes yet MCU is capable of transmitting
larger packets provided that FIFO will be filled on the fly
and USB_USB_TXCx_REG_USB_LAST_Msk bit is set after FIFO is
filled with all the data that should be transmitted.
This change allows to use FIFO level warning interrupt to fill
FIFO. When DMA is available it will be used instead of interrupts.
Some function names were changed to better reflect what each function
does.
Closing endpoints can be important when there are alternate
instances. This adds functionality of closing endpoints
similar to what exists in other drivers.
Internal FIFO for each endpoint is limited to 64 bytes.
It is possible to have longer packets if respective FIFO
is read during actual packet transmission.
This change updates receive data path to allow packets (and
endpoint size) larger then 64 bytes.
If DMA is not used yet DMA is setup for reception of big packets.
If DMA is already assigned to some transfer, code enables FIFO level
warning interrupts and tries to read data before FIFO is filled up.
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.
Current implementation always sets odd/even bit for ISO transactions.
This is a good strategy only if interval is 1.
For ISO endpoint interval in (micro)frames is computed as
2^(interval-1), which means that odd/frame number should stay
same for interval values > 1.
With this change only when interval is 1 odd/even bit is modified.
dcd_edpt_close() no longer modifies FIFO distribution.
Code that that was commented out is removed along with
variables that are no longer used.
FIFO distribution among endpoints is handled upfront
and does not need to be modified in open and close endpoint
functions.
Recommended FIFO allocation schema includes 2 maximum endpoint sizes.
Comment suggested that this is the case while it would work according
to this description only in checked endpoints were ascending sizes.
Also two same size endpoints would be counted as one.
That is fixed by way sz is filled.
Calculation used too much modulo operation while single division was enough
to account for odd FIFO sizes.
Extra space that is evenly distributed between Bulk and control endpoints
was incorrectly calculated it could prevent allocation of ISO endpoint FIFO
when bulk endpoints existed with smaller endpoint numbers.
Minimum endpoint FIFO size is 16 32bit words, FIFO space requirement is
now observed.
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.
Endpoint close was implemented only in one driver so far.
This function is needed for interfaces with several alternate settings.
The way FIFO is allocated in dcd_edpt_open() allows to correctly close
only one IN endpoint (the one that was opened last).
Wrong FIFO was flushed in dcd_edpt_stall().
(epnum - 1) should only be used when accessing DIEPTXF registers.
For DIEPCTL and GRSTCTL epnum is correct index.
For ISO endpoint driver has to specify when data
is to be transmitted (odd or even frame).
Currently code was not updating this bit resulting in
data being sent every other frame.
If interval was 1ms full data packed was sent every 2ms, and
ZLP was sent in between.
In some rare ocasions (bad cable, noise, etc.) data transfer might timeout and hang the endpoint, unless the interrupt flag is cleared.
This pull request targets to solve that case.
While the ST code has a 2 ms stabilization delay for the USBC PHY PLL,
running without this delay showed no problem for at leat 10 USB un/replug
cycles. Observe for problems!
ESP32-S2 has only 5 available endpoint-in FIFOs (including EP0) but 7 available EP IN numbers. This change decouples the fifo number from the endpoint number, providing FIFO numbers until they reach the limit, at which point it will return false and assert an error that too many endpoints were allocated.
Reinhard Panhuber