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.htm...
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- include/uapi/sound/firewire.h | 5 +++++ sound/firewire/tascam/tascam-hwdep.c | 10 ++++++++++ 2 files changed, 15 insertions(+)
diff --git a/include/uapi/sound/firewire.h b/include/uapi/sound/firewire.h index b9bc4bb1756b..012f81bf4750 100644 --- a/include/uapi/sound/firewire.h +++ b/include/uapi/sound/firewire.h @@ -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 */ diff --git a/sound/firewire/tascam/tascam-hwdep.c b/sound/firewire/tascam/tascam-hwdep.c index 4e4c1e9020e8..a80397116c48 100644 --- a/sound/firewire/tascam/tascam-hwdep.c +++ b/sound/firewire/tascam/tascam-hwdep.c @@ -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; }