USB Audio Class 1/2 have ability to change device's
volume and mute by USB Host through class-specific control
requests. Device also can notify Host about volume/mute
change on its side through optional interrupt endpoint.
This patch adds Volume and Mute ALSA controls which can be
used by user to send and receive notifications to/from
the USB Host about Volume and Mute change.
These params come from f_uac* so volume and mute controls
will be created only if the function support and enable
each explicitly
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
---
drivers/usb/gadget/function/u_audio.c | 360 +++++++++++++++++++++++++++++++++-
drivers/usb/gadget/function/u_audio.h | 22 +++
2 files changed, 372 insertions(+), 10 deletions(-)
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index b434e70..f4b850b 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -12,11 +12,14 @@
* Jaswinder Singh (jaswinder.singh@xxxxxxxxxx)
*/
+#include <linux/kernel.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/control.h>
+#include <sound/tlv.h>
+#include <linux/usb/audio.h>
#include "u_audio.h"
@@ -24,6 +27,12 @@
#define PRD_SIZE_MAX PAGE_SIZE
#define MIN_PERIODS 4
+enum {
+ UAC_FBACK_CTRL,
+ UAC_MUTE_CTRL,
+ UAC_VOLUME_CTRL,
+};
+
/* Runtime data params for one stream */
struct uac_rtd_params {
struct snd_uac_chip *uac; /* parent chip */
@@ -44,6 +53,14 @@ struct uac_rtd_params {
unsigned int ffback; /* Real frequency reported by feedback endpoint */
bool fb_ep_enabled; /* if the ep is enabled */
+ /* Volume/Mute controls and their state */
+ int fu_id; /* Feature Unit ID */
+ struct snd_kcontrol *snd_kctl_volume;
+ struct snd_kcontrol *snd_kctl_mute;
+ s16 volume_min, volume_max, volume_res;
+ s16 volume;
+ int mute;
+
spinlock_t lock; /* lock for feedback and control transfers */
};
@@ -599,6 +616,102 @@ void u_audio_stop_playback(struct g_audio *audio_dev)
}
EXPORT_SYMBOL_GPL(u_audio_stop_playback);
+int u_audio_get_volume(struct g_audio *audio_dev, int playback, s16 *val)
+{
+ struct snd_uac_chip *uac = audio_dev->uac;
+ struct uac_rtd_params *prm;
+ unsigned long flags;
+
+ if (playback)
+ prm = &uac->p_prm;
+ else
+ prm = &uac->c_prm;
+
+ spin_lock_irqsave(&prm->lock, flags);
+ *val = prm->volume;
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_get_volume);
+
+int u_audio_set_volume(struct g_audio *audio_dev, int playback, s16 val)
+{
+ struct snd_uac_chip *uac = audio_dev->uac;
+ struct uac_rtd_params *prm;
+ unsigned long flags;
+ int change = 0;
+
+ if (playback)
+ prm = &uac->p_prm;
+ else
+ prm = &uac->c_prm;
+
+ spin_lock_irqsave(&prm->lock, flags);
+ val = clamp(val, prm->volume_min, prm->volume_max);
+ if (prm->volume != val) {
+ prm->volume = val;
+ change = 1;
+ }
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ if (change)
+ snd_ctl_notify(uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
+ &prm->snd_kctl_volume->id);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_volume);
+
+int u_audio_get_mute(struct g_audio *audio_dev, int playback, int *val)
+{
+ struct snd_uac_chip *uac = audio_dev->uac;
+ struct uac_rtd_params *prm;
+ unsigned long flags;
+
+ if (playback)
+ prm = &uac->p_prm;
+ else
+ prm = &uac->c_prm;
+
+ spin_lock_irqsave(&prm->lock, flags);
+ *val = prm->mute;
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_get_mute);
+
+int u_audio_set_mute(struct g_audio *audio_dev, int playback, int val)
+{
+ struct snd_uac_chip *uac = audio_dev->uac;
+ struct uac_rtd_params *prm;
+ unsigned long flags;
+ int change = 0;
+ int mute;
+
+ if (playback)
+ prm = &uac->p_prm;
+ else
+ prm = &uac->c_prm;
+
+ mute = val ? 1 : 0;
+
+ spin_lock_irqsave(&prm->lock, flags);
+ if (prm->mute != mute) {
+ prm->mute = mute;
+ change = 1;
+ }
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ if (change)
+ snd_ctl_notify(uac->card, SNDRV_CTL_EVENT_MASK_VALUE,
+ &prm->snd_kctl_mute->id);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(u_audio_set_mute);
+
static int u_audio_rate_shift_info(struct snd_kcontrol *kcontrol,
struct snd_ctl_elem_info *uinfo)
{
@@ -663,14 +776,157 @@ static int u_audio_rate_shift_put(struct snd_kcontrol *kcontrol,
return change;
}
-static const struct snd_kcontrol_new u_audio_controls[] = {
+static int u_audio_mute_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = 1;
+ uinfo->value.integer.step = 1;
+
+ return 0;
+}
+
+static int u_audio_mute_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
{
- .iface = SNDRV_CTL_ELEM_IFACE_PCM,
- .name = "PCM Feedback Frequency Hz",
- .info = u_audio_rate_shift_info,
- .get = u_audio_rate_shift_get,
- .put = u_audio_rate_shift_put,
-},
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ unsigned long flags;
+
+ spin_lock_irqsave(&prm->lock, flags);
+ ucontrol->value.integer.value[0] = !prm->mute;
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ return 0;
+}
+
+static int u_audio_mute_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ struct snd_uac_chip *uac = prm->uac;
+ struct g_audio *audio_dev = uac->audio_dev;
+ unsigned int val;
+ unsigned long flags;
+ int change = 0;
+
+ val = !ucontrol->value.integer.value[0];
+
+ spin_lock_irqsave(&prm->lock, flags);
+ if (val != prm->mute) {
+ prm->mute = val;
+ change = 1;
+ }
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ if (change && audio_dev->notify)
+ audio_dev->notify(audio_dev, prm->fu_id, UAC_FU_MUTE);
+
+ return change;
+}
+
+/*
+ * TLV callback for mixer volume controls
+ */
+static int u_audio_volume_tlv(struct snd_kcontrol *kcontrol, int op_flag,
+ unsigned int size, unsigned int __user *_tlv)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ DECLARE_TLV_DB_MINMAX(scale, 0, 0);
+
+ if (size < sizeof(scale))
+ return -ENOMEM;
+
+ /* UAC volume resolution is 1/256 dB, TLV is 1/100 dB */
+ scale[2] = (prm->volume_min * 100) / 256;
+ scale[3] = (prm->volume_max * 100) / 256;
+ if (copy_to_user(_tlv, scale, sizeof(scale)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int u_audio_volume_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max =
+ (prm->volume_max - prm->volume_min + prm->volume_res - 1)
+ / prm->volume_res;
+ uinfo->value.integer.step = 1;
+
+ return 0;
+}
+
+static int u_audio_volume_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ unsigned long flags;
+
+ spin_lock_irqsave(&prm->lock, flags);
+ ucontrol->value.integer.value[0] =
+ (prm->volume - prm->volume_min) / prm->volume_res;
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ return 0;
+}
+
+static int u_audio_volume_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);
+ struct snd_uac_chip *uac = prm->uac;
+ struct g_audio *audio_dev = uac->audio_dev;
+ unsigned int val;
+ s16 volume;
+ unsigned long flags;
+ int change = 0;
+
+ val = ucontrol->value.integer.value[0];
+
+ spin_lock_irqsave(&prm->lock, flags);
+ volume = (val * prm->volume_res) + prm->volume_min;
+ volume = clamp(volume, prm->volume_min, prm->volume_max);
+ if (volume != prm->volume) {
+ prm->volume = volume;
+ change = 1;
+ }
+ spin_unlock_irqrestore(&prm->lock, flags);
+
+ if (change && audio_dev->notify)
+ audio_dev->notify(audio_dev, prm->fu_id, UAC_FU_VOLUME);
+
+ return change;
+}
+
+static struct snd_kcontrol_new u_audio_controls[] = {
+ [UAC_FBACK_CTRL] {
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = "PCM Feedback Frequency Hz",
+ .info = u_audio_rate_shift_info,
+ .get = u_audio_rate_shift_get,
+ .put = u_audio_rate_shift_put,
+ },
+ [UAC_MUTE_CTRL] {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .name = "", /* will be filled later */
+ .info = u_audio_mute_info,
+ .get = u_audio_mute_get,
+ .put = u_audio_mute_put,
+ },
+ [UAC_VOLUME_CTRL] {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .name = "", /* will be filled later */
+ .info = u_audio_volume_info,
+ .get = u_audio_volume_get,
+ .put = u_audio_volume_put,
+ },
};
int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
@@ -682,7 +938,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
struct snd_kcontrol *kctl;
struct uac_params *params;
int p_chmask, c_chmask;
- int err;
+ int i, err;
if (!g_audio)
return -EINVAL;
@@ -769,10 +1025,18 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &uac_pcm_ops);
snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &uac_pcm_ops);
- if (c_chmask && g_audio->in_ep_fback) {
+ /*
+ * Create mixer and controls
+ * Create only if it's required on USB side
+ */
+ if ((c_chmask && g_audio->in_ep_fback)
+ || (p_chmask && params->p_fu.id)
+ || (c_chmask && params->c_fu.id))
strscpy(card->mixername, card_name, sizeof(card->mixername));
- kctl = snd_ctl_new1(&u_audio_controls[0], &uac->c_prm);
+ if (c_chmask && g_audio->in_ep_fback) {
+ kctl = snd_ctl_new1(&u_audio_controls[UAC_FBACK_CTRL],
+ &uac->c_prm);
if (!kctl) {
err = -ENOMEM;
goto snd_fail;
@@ -786,6 +1050,82 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
goto snd_fail;
}
+ for (i = 0; i <= SNDRV_PCM_STREAM_LAST; i++) {
+ struct uac_rtd_params *prm;
+ struct uac_fu_params *fu;
+ char ctrl_name[24];
+ char *direction;
+
+ if (!pcm->streams[i].substream_count)
+ continue;
+
+ if (i == SNDRV_PCM_STREAM_PLAYBACK) {
+ prm = &uac->p_prm;
+ fu = ¶ms->p_fu;
+ direction = "Playback";
+ } else {
+ prm = &uac->c_prm;
+ fu = ¶ms->c_fu;
+ direction = "Capture";
+ }
+
+ prm->fu_id = fu->id;
+
+ if (fu->mute_present) {
+ snprintf(ctrl_name, sizeof(ctrl_name),
+ "PCM %s Switch", direction);
+
+ u_audio_controls[UAC_MUTE_CTRL].name = ctrl_name;
+
+ kctl = snd_ctl_new1(&u_audio_controls[UAC_MUTE_CTRL],
+ prm);
+ if (!kctl) {
+ err = -ENOMEM;
+ goto snd_fail;
+ }
+
+ kctl->id.device = pcm->device;
+ kctl->id.subdevice = i;
+
+ err = snd_ctl_add(card, kctl);
+ if (err < 0)
+ goto snd_fail;
+ prm->snd_kctl_mute = kctl;
+ prm->mute = 0;
+ }
+
+ if (fu->volume_present) {
+ snprintf(ctrl_name, sizeof(ctrl_name),
+ "PCM %s Volume", direction);
+
+ u_audio_controls[UAC_VOLUME_CTRL].name = ctrl_name;
+
+ kctl = snd_ctl_new1(&u_audio_controls[UAC_VOLUME_CTRL],
+ prm);
+ if (!kctl) {
+ err = -ENOMEM;
+ goto snd_fail;
+ }
+
+ kctl->id.device = pcm->device;
+ kctl->id.subdevice = i;
+
+
+ kctl->tlv.c = u_audio_volume_tlv;
+ kctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_TLV_READ |
+ SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK;
+
+ err = snd_ctl_add(card, kctl);
+ if (err < 0)
+ goto snd_fail;
+ prm->snd_kctl_volume = kctl;
+ prm->volume = fu->volume_max;
+ prm->volume_max = fu->volume_max;
+ prm->volume_min = fu->volume_min;
+ prm->volume_res = fu->volume_res;
+ }
+ }
+
strscpy(card->driver, card_name, sizeof(card->driver));
strscpy(card->shortname, card_name, sizeof(card->shortname));
sprintf(card->longname, "%s %i", card_name, card->dev->id);
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
index fd70808..4f977f2 100644
--- a/drivers/usb/gadget/function/u_audio.h
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -18,16 +18,30 @@
#define FBACK_FREQ_MIN 80
#define FBACK_FREQ_MAX 120
+/* Feature Unit parameters */
+struct uac_fu_params {
+ int id; /* Feature Unit ID */
+
+ bool mute_present; /* mute control enable */
+
+ bool volume_present; /* volume control enable */
+ s16 volume_min; /* min volume in 1/256 dB */
+ s16 volume_max; /* max volume in 1/256 dB */
+ s16 volume_res; /* volume resolution in 1/256 dB */
+};
+
struct uac_params {
/* playback */
int p_chmask; /* channel mask */
int p_srate; /* rate in Hz */
int p_ssize; /* sample size */
+ struct uac_fu_params p_fu; /* Feature Unit parameters */
/* capture */
int c_chmask; /* channel mask */
int c_srate; /* rate in Hz */
int c_ssize; /* sample size */
+ struct uac_fu_params c_fu; /* Feature Unit parameters */
int req_number; /* number of preallocated requests */
};
@@ -47,6 +61,9 @@ struct g_audio {
/* Max packet size for all out_ep possible speeds */
unsigned int out_ep_maxpsize;
+ /* Notify UAC driver about control change */
+ int (*notify)(struct g_audio *g_audio, int unit_id, int cs);
+
/* The ALSA Sound Card it represents on the USB-Client side */
struct snd_uac_chip *uac;
@@ -92,4 +109,9 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
int u_audio_start_playback(struct g_audio *g_audio);
void u_audio_stop_playback(struct g_audio *g_audio);
+int u_audio_get_volume(struct g_audio *g_audio, int playback, s16 *val);
+int u_audio_set_volume(struct g_audio *g_audio, int playback, s16 val);
+int u_audio_get_mute(struct g_audio *g_audio, int playback, int *val);
+int u_audio_set_mute(struct g_audio *g_audio, int playback, int val);
+
#endif /* __U_AUDIO_H */
--
1.9.1
