[alsa-devel] [PATCH v2] ALSA: usb-audio: add front jack channel selector for EMU0204

[Takashi Iwai]

At Wed, 13 Nov 2013 12:32:20 +0300,
Vasily Khoruzhick wrote:
> 
> Add support for front jack channel selector which is present on EMU0204.
> It allows to get 4 channels out of this soundcard.
> 
> Tested-by: Yury Bushmelev <jay at jay-tech.ru>
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
> ---
> v2: - pass constants for bRequest and bRequestType into snd_usb_ctl_msg()
>     - implement control as an enum instead of a switch.
> 
>  sound/usb/mixer_quirks.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 87 insertions(+)
> 
> diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
> index d42a584..83f8ab1 100644
> --- a/sound/usb/mixer_quirks.c
> +++ b/sound/usb/mixer_quirks.c
> @@ -433,6 +433,86 @@ static void snd_audigy2nx_proc_read(struct snd_info_entry *entry,
>  	}
>  }
>  
> +/* EMU0204 */
> +static int snd_emu0204_ch_switch_info(struct snd_kcontrol *kcontrol,
> +				      struct snd_ctl_elem_info *uinfo)
> +{
> +	static const char *texts[4] = {"1/2",
> +				       "3/4"
> +	};

The declared array size doesn't match.


Takashi

> +
> +	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
> +	uinfo->count = 1;
> +	uinfo->value.enumerated.items = 2;
> +	if (uinfo->value.enumerated.item > 1)
> +		uinfo->value.enumerated.item = 1;
> +	strcpy(uinfo->value.enumerated.name,
> +		texts[uinfo->value.enumerated.item]);
> +
> +	return 0;
> +}
> +
> +static int snd_emu0204_ch_switch_get(struct snd_kcontrol *kcontrol,
> +				     struct snd_ctl_elem_value *ucontrol)
> +{
> +	ucontrol->value.enumerated.item[0] = kcontrol->private_value;
> +	return 0;
> +}
> +
> +static int snd_emu0204_ch_switch_put(struct snd_kcontrol *kcontrol,
> +				     struct snd_ctl_elem_value *ucontrol)
> +{
> +	struct usb_mixer_interface *mixer = snd_kcontrol_chip(kcontrol);
> +	int value = ucontrol->value.enumerated.item[0];
> +	int err, changed;
> +	unsigned char buf[2];

Better to have a sanity check of the value.  User-space can pass any
value in theory.


thanks,

Takashi

> +
> +	buf[0] = 0x01;
> +	buf[1] = value ? 0x02 : 0x01;
> +
> +	changed = value != kcontrol->private_value;
> +	down_read(&mixer->chip->shutdown_rwsem);
> +	if (mixer->chip->shutdown) {
> +		err = -ENODEV;
> +		goto out;
> +	}
> +	err = snd_usb_ctl_msg(mixer->chip->dev,
> +		      usb_sndctrlpipe(mixer->chip->dev, 0), UAC_SET_CUR,
> +		      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
> +		      0x0400, 0x0e00, buf, 2);
> + out:
> +	up_read(&mixer->chip->shutdown_rwsem);
> +	if (err < 0)
> +		return err;
> +	kcontrol->private_value = value;
> +	return changed;
> +}
> +
> +
> +static struct snd_kcontrol_new snd_emu0204_controls[] = {
> +	{
> +		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
> +		.name = "Front Jack Channels",
> +		.info = snd_emu0204_ch_switch_info,
> +		.get = snd_emu0204_ch_switch_get,
> +		.put = snd_emu0204_ch_switch_put,
> +		.private_value = 0,
> +	},
> +};
> +
> +static int snd_emu0204_controls_create(struct usb_mixer_interface *mixer)
> +{
> +	int i, err;
> +
> +	for (i = 0; i < ARRAY_SIZE(snd_emu0204_controls); ++i) {
> +		err = snd_ctl_add(mixer->chip->card,
> +			snd_ctl_new1(&snd_emu0204_controls[i], mixer));
> +		if (err < 0)
> +			return err;
> +	}
> +
> +	return 0;
> +}
>  /* ASUS Xonar U1 / U3 controls */
>  
>  static int snd_xonar_u1_switch_get(struct snd_kcontrol *kcontrol,
> @@ -1545,6 +1625,13 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer)
>  					      snd_audigy2nx_proc_read);
>  		break;
>  
> +	/* EMU0204 */
> +	case USB_ID(0x041e, 0x3f19):
> +		err = snd_emu0204_controls_create(mixer);
> +		if (err < 0)
> +			break;
> +		break;
> +
>  	case USB_ID(0x0763, 0x2030): /* M-Audio Fast Track C400 */
>  	case USB_ID(0x0763, 0x2031): /* M-Audio Fast Track C400 */
>  		err = snd_c400_create_mixer(mixer);
> -- 
> 1.8.4.2
>