Add USB Device implementation, fix a bug for serial

[ChazJin]

Description

Implemented USB Device on GD32F450ZI target.

• Update targets.json for adding USBDEVICE feature

• Added implementation code for USB Device in usb/device/targets/TARGET_GigaDevice/...

Fix a bug for serial when stdio-buffered-serial is enabled.

Pull request type

[x] Fix
[ ] Refactor
[x] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

Reviewers

@0xc0170 @Ronny-Liu I would appreciate if you could review it when you are free.

Release Notes

[ciarmcom]

@ChazJin, thank you for your changes.
@0xc0170 @Ronny-Liu @ARMmbed/mbed-os-maintainers please review.

[0xc0170]

@maciejbocianski - Can you please review?

@ChazJin Can you please rebase? Sorry for the delay to get the review

[0xc0170]

How was this tested ?

[ChazJin]

How was this tested ?

@0xc0170 We have written some test codes such as virtual USB serial port and USB mouse and verified on GD32_F450ZI board. Once these files are merged, we will upload these routines as example programs.

[ChazJin]

Hi @0xc0170,

Here is a simple example of virtual USB serial port, which can be compiled and then downloaded directly to the GD32_F450ZI board to observe the results. Do we have to do some other tests?

#include "mbed.h"
#include "USBSerial.h"
 
/* virtual USB serial port */
USBSerial usb_serial(true, 0x28e9, 0x018a, 0x0001);
 
DigitalOut led(LED1);
 
int main(void)
{
    int i = 0;
 
    /* print on STDIO */
    printf("USB Device Serial test started!\r\n");
 
    while(1) {
         /* print on virtual USB serial port */
        usb_serial.printf("Virtual serial port: %d\r\n", i++);

        /* toggle LED */
        led = !led;
        wait(0.5);
    }
}

@maciejbocianski Could you please help to review when you have some time? Thanks a lot.

[maciejbocianski]

Please provide results from all USB tests.
Tests are here https://github.com/ARMmbed/mbed-os/tree/master/TESTS/usb_device

To runt the test use following command:
mbed test -t COMPILER -m TARGET_NAME -n tests-usb_device-XXX -v

Available USB test:

tests-usb_device-basic
tests-usb_device-hid
tests-usb_device-msd   !!!  test is during update see comment below
tests-usb_device-serial

There is a README file describing all corner cases.
https://github.com/ARMmbed/mbed-os/blob/master/TESTS/usb_device/README.md

Mass storage test was unstable and fix was provided. Before running it please download changes provided in the following PR: #10767

[0xc0170]

@ChazJin Any update for this pull request? There's conflict and requests above from @maciejbocianski

[ChazJin]

@ChazJin Any update for this pull request? There's conflict and requests above from @maciejbocianski

@0xc0170 I am very sorry, we found some problems during the recent USB test. Only TESTS/usb_device/serial can pass the test, and the others all fail. We're looking for reasons.

[0xc0170]

@ChazJin This PR is still opened but has not progressed for 2 months ? I'll close this. Please reopen once updated ,we will review.