[alsa-devel] [PATCH 2/2] usb: Add mode select quirk for Denon/Marantz DACs

[Takashi Iwai]

At Fri, 28 Nov 2014 14:04:31 +0100,
Jurgen Kramer wrote:
> 
> Denon/Marantz USB DACs need a specific vendor command to switch between PCM and
> DSD mode. This patch adds a new quirk function to switch between the two modes
> using the specific USB vendor command.
> 
> This patch applies to the following devices:
> - Marantz SA-14S1
> - Marantz HD-DAC1
> 
> Signed-off-by: Jurgen Kramer <gtmkramer at xs4all.nl>
> ---
>  sound/usb/pcm.c    |  5 +++++
>  sound/usb/quirks.c | 42 ++++++++++++++++++++++++++++++++++++++++++
>  sound/usb/quirks.h |  3 +++
>  3 files changed, 50 insertions(+)
> 
> diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
> index c62a165..0d8aba5 100644
> --- a/sound/usb/pcm.c
> +++ b/sound/usb/pcm.c
> @@ -482,6 +482,11 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
>  	/* set interface */
>  	if (subs->interface != fmt->iface ||
>  	    subs->altset_idx != fmt->altset_idx) {
> +
> +		err = snd_usb_select_mode_quirk(subs, fmt);
> +		if (err < 0)
> +			return -EIO;
> +
>  		err = usb_set_interface(dev, fmt->iface, fmt->altsetting);
>  		if (err < 0) {
>  			dev_err(&dev->dev,
> diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
> index cc07388..40fb87f 100644
> --- a/sound/usb/quirks.c
> +++ b/sound/usb/quirks.c
> @@ -1111,6 +1111,48 @@ void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
>  	}
>  }
>  
> +
> +/* Marantz/Denon USB DACs need a vendor cmd to switch
> + * between PCM and native DSD mode */
> +int snd_usb_select_mode_quirk(struct snd_usb_substream *subs,
> +			      struct audioformat *fmt)
> +{
> +	struct usb_device *dev = subs->dev;
> +	int err;
> +
> +	switch (subs->stream->chip->usb_id) {
> +	case USB_ID(0x154e, 0x3005): /* Marantz HD-DAC1 */
> +	case USB_ID(0x154e, 0x3006): /* Marantz SA-14S1 */
> +
> +		/* First switch to alt set 0, otherwise the mode switch cmd
> +		 * will not be accepted by the DAC */
> +		err = usb_set_interface(dev, fmt->iface, 0);
> +		if (err < 0)
> +			return err;
> +
> +		mdelay(20); /* Delay needed after setting the interface */
> +
> +		switch(fmt->altsetting) {

Put a space between switch and '('.
Found in another patch, too.

> +		case 2: /* DSD mode requested */
> +			err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
> +					      USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
> +					      1, 1, NULL, 0);
> +			if (err < 0)
> +				return err;
> +			break;
> +		case 1: /* PCM mode requested */
> +			err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0,
> +					      USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
> +					      0, 1, NULL, 0);
> +			if (err < 0)
> +				return err;
> +			break;

These two cases can combined one by passing fmt->altsetting-1 as the
argument, right?


thanks,

Takashi