request usb id

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broucari
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request usb id

Postby broucari » Tue Aug 03, 2021 6:45 pm

Hi,

I volontuer to request usb id from openmoko (https://wiki.openmoko.org/wiki/USB_Product_IDs) for chibios implementation of usb cdc.

Are you interested ?

Bastien

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Giovanni
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Re: request usb id

Postby Giovanni » Tue Aug 03, 2021 7:16 pm

Sure, it would be nice.

Giovanni

broucari
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Re: request usb id

Postby broucari » Tue Aug 03, 2021 8:46 pm

Ok will request for now:
- ChibiOS virtual serial console shell
- ChibiOS virtual serial port

If I can code the null modem stuff I will request:
- ChibiOS virtual null modem master
- ChibiOS virtual null modem slave

And I will implement a usb2uart bridge so I need two more:
- ChibiOS usb2uart bridge basic
- ChibiOS usb2serial (include flow)

What do you think ?

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Giovanni
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Re: request usb id

Postby Giovanni » Wed Aug 04, 2021 5:41 am

Hi,

I would just request codes by device types: CDC, HID, MSC (mass storage if I remember well). It is a finite pool so better don't take too much.

Serial, shell etc are all CDCs.

Giovanni

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Re: request usb id

Postby electronic_eel » Sat Aug 07, 2021 11:27 am

Aren't the USB ids per device type? Within one device, you can have endpoints with several classes, like CDC, HID, MSC. You can differentiate based on class, so to differentiate between a CDC and HID, you wouldn't need different USB ids.

The issue is more that you have multiple devices that implement an endpoint with the same class, like CDC, connected to the same host. One implements for example a shell on CDC, the other the USB to UART bridge on CDC. Now you want to differentiate between them. That is the point where different device ids can make sense.

But on linux this doesn't really matter anymore, because you usually will write udev rules anyway. And then you can use other things in the descriptor than the precious device ids, like the device name or serial number, to differentiate. On windows you'd use the generic CDC driver provided by windows. That will assign a COMnn: device with unknown and unstable number nn. You'd then use a program or powershell script or similar to find the right one, based on data in the usb descriptors again.

So I don't think there is really need for more than one ChibiOS device id.

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Giovanni
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Re: request usb id

Postby Giovanni » Sat Aug 07, 2021 12:42 pm

I tend to agree, one is sufficient, eventually we can ask for more should necessity arise. Additionally, you can have multiple device types on the same USB.

Giovanni


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