v-usb update from upstream

[dioannidis]

Hi,

a non intrusive update from upstream just to be consistent with the latest v-usb code.

Changes :

• ( usbdrvasm15.inc ) * Fixed length of SE0 on 15 MHz clock. Terminating SE0 was 3 CPU cycles longer than comments indicate.
• ( usbdrvasm20.inc ) * Fixed comments indicating CPU cycles taken. ST instruction uses two cycles while LDI takes one.
• ( usbconfig.h ) Added missing configurations options.

[nerdralph]

It looks OK. Have you tested it already?
Since it doesn't impact the 12MHz V-USB code, I don't see a material benefit to merging it. I probably will anyway, after cloneing your fork and building it for the m8 and for the m88. If the binaries checksum the same as my builds, then I can be sure it's safe to merge.

[dioannidis]

As you said it doesn't impact the main 12MHz code. In my all usbasps, 3 chinese, 1 home etched and 1 on breadboard, works with no problem.

I'm experimenting with different ( higher ) crystal's, trying @akrasuski1's changes ( from https://github.com/akrasuski1/usbasp-uart ) . AFAIU, he used an old V-USB version and yours, except the above changes, are in HEAD with the master V-USB code. This is the main reason I choose your fork as base for adding @akrasuski1's UART or implement UART via HID .

[dioannidis]

Hi,

in the meantime, while I'm waiting for this PR to be resolved...

Are you and @MCUdude interested for a firmware version that uses OS Descriptor on Windows that automatically assigns a winusb driver to the device ? No need to use Zadig or libusb with this approach. Also the Arduino IDE's avrdude it works without a problem.

I can create a PR if you are .

EDIT: This works for windows 8.1 and up ... On Windows 7 you need drivers ...

[nerdralph]

I only have one Windoze box, and it runs Win7.
It would be nice however to see the V-USB descriptor code cleaned up. Part of my reluctance to do more work with V-USB was related to how messy the code is. Desginated initializers has been supported since gcc-3.0, so it should've been used in V-USB from the start.
That's one of the first things I did when I started working with the CH55x devices.
https://github.com/nerdralph/ch554_sdcc/blob/master/examples/CMSIS_DAP/USBconstant.c#L9

[dioannidis]

Hi

It would be nice however to see the V-USB descriptor code cleaned up.

< snip >

Check the #5 PR. It should work as before except that if you connect the USBasp device to a windows 8.1 and up box, it will enumerate as winusb device compatible and use the winusb.sys driver.