usb: usbd: Partially unconstify .ptr in struct usbd_desc_node

[ndreys]

It is useful to be able to set .ptr to point to a string obtained at runtime, so let's remove the second const qualifier so that the pointer itself can be adjusted.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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[josuah]

Could we know a bit more about the use-case?
This would confirm that what you were trying to do is not already supported in a different way, or that maybe it needs some dedicated API.
Thanks!

[ndreys]

Could we know a bit more about the use-case? This would confirm that what you were trying to do is not already supported in a different way, or that maybe it needs some dedicated API. Thanks!

I'm setting up device serial to contain the contents of a user (read "at manufacturing time") programmable flash. We don't know if that data is valid at compile time, so that's a string that is a result of a function call. Basically I'm doing

    static struct usbd_desc_node sn = {
        .str = {
            .utype = USBD_DUT_STRING_SERIAL_NUMBER,
            .ascii7 = true,
        },
        .bLength = USB_STRING_DESCRIPTOR_LENGTH(...),
        .bDescriptorType = USB_DESC_STRING,
    };

    sn.ptr = unit_serial_get();

older versions of USBD_DESC_STRING_DEFINE() didn't have ascii_##d_name as const, so I was originally just filling that, but it got constified recently, so I can't use that macro anymore.