[alsa-devel] [PATCH][ALSA] usbmidi support for Access Music synths.

[Clemens Ladisch]

Sebastien Alaiwan wrote:
> here's a patch that adds MIDI support through USB for one of the
> Access Music synths, the VirusTI. 

Thanks!

Please run the checkpatch script on your patch.

> +	u8 seq[] = { 0x4e, 0x73, 0x52, 0x01 }; // "midi send" enable
> +
> +	err = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x05), seq,
> +			ARRAY_SIZE(seq), &actual_length, 1000);

There are architectures where doing DMA with data on the stack is not
possible.  Have a look at send_bulk_static_data.

>  /*
> + * Detects the endpoints for Access Music Virus TI
> + */
> +static int snd_usbmidi_detect_two_cables_per_endpoint(struct snd_usb_midi* umidi,
> +    struct snd_usb_midi_endpoint_info* endpoints)
> +{
> +	int err, i;
> +
> +	err = snd_usbmidi_detect_endpoints(umidi, endpoints, MIDI_MAX_ENDPOINTS);
> +	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
> +		if (endpoints[i].in_ep) {
> +			printk("Creating two in cables for input EP 0x%.2X\n", endpoints[i].in_ep);

If this is just for debugging, use snd_printdd.

> +			endpoints[i].in_cables = 0x0003;
> +		}
> +		if (endpoints[i].out_ep) {
> +			printk("Creating two out cables for output EP 0x%.2X\n", endpoints[i].out_ep);
> +			endpoints[i].out_cables = 0x0003;
> +		}
> +	}
> +	return err;
> +}

Does this device use more than one endpoint per direction?  If not, this
could be done with QUIRK_MIDI_FIXED_ENDPOINT.

> +++ b/sound/usb/usbquirks.h
> @@ -2105,6 +2105,28 @@
>  	}
>  },
>  
> +/* Access Music devices */
> +{
> +	/* VirusTI Desktop */
> +	USB_DEVICE_VENDOR_SPEC(0x133e, 0x0815),

Please keep the list sorted (as much as possible).

> +		.vendor_name = "AccessMusic",
> +		.product_name = "Virus TI",

These are needed only if the device hasn't vendor/product strings.

> +				// "Virus TI MIDI" and "Virus TI Synth"

If these are port names, put them into the snd_usbmidi_port_info array.


Regards,
Clemens