Commit 90e8ac5c authored by Takashi Sakamoto's avatar Takashi Sakamoto Committed by Takashi Iwai
Browse files

ALSA: firewire-tascam: add new hwdep ioctl command to get state image 

In a previous commit, ALSA firewire-tascam driver stores state image
from tx isochronous packets. This image includes states of knob, fader,
button of control surface, level of gain/volume of each physical
inputs/outputs, and so on. It's useful for userspace applications to
read whole of the image.

This commit adds a unique ioctl command for ALSA hwdep interface for the
purpose. For actual meaning of each bits in this image, please refer to
discussion in alsa-devel[1].

[1] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-October/140785.html



Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 33b2e144

include/uapi/sound/firewire.h

+5 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ union snd_firewire_event { 
#define SNDRV_FIREWIRE_IOCTL_GET_INFO _IOR('H', 0xf8, struct snd_firewire_get_info)

#define SNDRV_FIREWIRE_IOCTL_LOCK      _IO('H', 0xf9)

#define SNDRV_FIREWIRE_IOCTL_UNLOCK    _IO('H', 0xfa)

#define SNDRV_FIREWIRE_IOCTL_TASCAM_STATE _IOR('H', 0xfb, struct snd_firewire_tascam_state)



#define SNDRV_FIREWIRE_TYPE_DICE	1

#define SNDRV_FIREWIRE_TYPE_FIREWORKS	2
@@ -90,4 +91,8 @@ struct snd_firewire_get_info { 


#define SNDRV_FIREWIRE_TASCAM_STATE_COUNT	64



struct snd_firewire_tascam_state {

	__be32 data[SNDRV_FIREWIRE_TASCAM_STATE_COUNT];

};



#endif /* _UAPI_SOUND_FIREWIRE_H_INCLUDED */

sound/firewire/tascam/tascam-hwdep.c

+10 −0
Original line number Diff line number Diff line
@@ -123,6 +123,14 @@ static int hwdep_unlock(struct snd_tscm *tscm) 
	return err;

}



static int tscm_hwdep_state(struct snd_tscm *tscm, void __user *arg)

{

	if (copy_to_user(arg, tscm->state, sizeof(tscm->state)))

		return -EFAULT;



	return 0;

}



static int hwdep_release(struct snd_hwdep *hwdep, struct file *file)

{

	struct snd_tscm *tscm = hwdep->private_data;
@@ -147,6 +155,8 @@ static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file, 
		return hwdep_lock(tscm);

	case SNDRV_FIREWIRE_IOCTL_UNLOCK:

		return hwdep_unlock(tscm);

	case SNDRV_FIREWIRE_IOCTL_TASCAM_STATE:

		return tscm_hwdep_state(tscm, (void __user *)arg);

	default:

		return -ENOIOCTLCMD;

	}

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