Re: Updated version of the STM32 USB driver.

[Chris Holgate <chris@zynaptic.com>]

GaurangT wrote:
> Hi Chris,
> 
>        I tried your latest STM32 driver and was successfully add USB
> slave-side serial drivers package.
> when I select enable control the endpoint 0 and enable all usb slave serial
> support in configtool.
> What is defined data structure in USB IN and OUT endpoint structure in stm32
> evel board.

This was discussed a while ago here...

http://ecos.sourceware.org/ml/ecos-devel/2009-05/msg00033.html

In summary, while you can just use something like &usbs_at91_ep1 to get
a pointer to endpoint one of a driver with statically assigned fixed
endpoints, with the STM32 you need to use an 'endpoint getter' function
to return the pointer.  The 'endpoint getter' functions only return
valid endpoint pointers once the USB device has been configured by the host.

So for OUT endpoint 1 it would be a case of replacing...

&usbs_at91_ep1

with...

cyg_usbs_cortexm_stm32_rx_endpoint(1)

This results in me having to use knarly code like the following in my
own class driver:

#if (defined CYGPKG_DEVS_USB_AT91)
#include "cyg/io/usb/usbs_at91.h"
#define  EP1_DATA_STRUCT &usbs_at91_ep1
#define  EP1_INIT_FUNC   usbs_at91_endpoint_init

#elif (defined CYGPKG_DEVS_USB_CORTEXM_STM32)
#include "cyg/io/usb/usb_stm32.h"
#define  EP1_DATA_STRUCT cyg_usbs_cortexm_stm32_rx_endpoint(1)
#define  EP1_INIT_FUNC(_args_...) {}

And then I can use something like:

usbs_start_rx_buffer (EP1_DATA_STRUCT, cmd_buf, MAX_FRAME_SIZE,
completion_handler, 0);

Unfortunately the CDL settings for the serial class driver currently
require you to specify static endpoint names, so it will not work out of
the box with the STM32 driver.

> If I mention default data structure,I got compile error (like undefined
> reference to usbs_at91_ep1 and usbs_at91_ep2)  in usb2serial test program. 

Hopefully the above information explains why this is and what you would
need to do to fix it.  We are stuck with this approach of exposing the
low-level driver API for any drivers which are compatible with the
release 3.0 USB framework.  However, it would be nice to clean this up
for future versions.

Chris.