On Mon 12 Jul 2021 at 14:55, Pavel Hofman <pavel.hofman@xxxxxxxxxxx> wrote:
> From: Ruslan Bilovol <ruslan.bilovol@xxxxxxxxx>
>
> 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>
> Signed-off-by: Pavel Hofman <pavel.hofman@xxxxxxxxxxx>
Hi Greg,
This change made it to usb-testing and usb-next but there are several
indentation errors in it. By itself, without the rest of the series, it
does not make much sense. It adds a couple of alsa controls but those
actually do nothing without the uac1 and uac2 part of the series.
Maybe it would be better to drop this change until the rest of series is
ready (if this is still possible) ?
Cheers
> ---
> drivers/usb/gadget/function/u_audio.c | 369 +++++++++++++++++++++++++-
> drivers/usb/gadget/function/u_audio.h | 22 ++
> 2 files changed, 380 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
> index 018dd0978995..f6b5b9547236 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 */
> @@ -43,6 +52,17 @@ struct uac_rtd_params {
>
> struct usb_request *req_fback; /* Feedback endpoint request */
> 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 control transfers */
> +
> };
>
> struct snd_uac_chip {
> @@ -597,6 +617,103 @@ 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_pitch_info(struct snd_kcontrol *kcontrol,
> struct snd_ctl_elem_info *uinfo)
> {
> @@ -656,14 +773,158 @@ static int u_audio_pitch_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)
> {
> - .iface = SNDRV_CTL_ELEM_IFACE_PCM,
> - .name = "Capture Pitch 1000000",
> - .info = u_audio_pitch_info,
> - .get = u_audio_pitch_get,
> - .put = u_audio_pitch_put,
> -},
> + 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)
> +{
> + 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 = "Capture Pitch 1000000",
> + .info = u_audio_pitch_info,
> + .get = u_audio_pitch_get,
> + .put = u_audio_pitch_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,
> @@ -675,7 +936,7 @@ 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;
> @@ -693,7 +954,8 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
> if (c_chmask) {
> struct uac_rtd_params *prm = &uac->c_prm;
>
> - uac->c_prm.uac = uac;
> + spin_lock_init(&prm->lock);
> + uac->c_prm.uac = uac;
> prm->max_psize = g_audio->out_ep_maxpsize;
>
> prm->reqs = kcalloc(params->req_number,
> @@ -716,6 +978,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
> if (p_chmask) {
> struct uac_rtd_params *prm = &uac->p_prm;
>
> + spin_lock_init(&prm->lock);
> uac->p_prm.uac = uac;
> prm->max_psize = g_audio->in_ep_maxpsize;
>
> @@ -760,10 +1023,18 @@ 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->driver));
>
> - 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;
> @@ -777,6 +1048,82 @@ 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 a218cdf771fe..001a79a46022 100644
> --- a/drivers/usb/gadget/function/u_audio.h
> +++ b/drivers/usb/gadget/function/u_audio.h
> @@ -19,16 +19,30 @@
> */
> #define FBACK_SLOW_MAX 250
>
> +/* 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 */
> int fb_max; /* upper frequency drift feedback limit per-mil */
> @@ -49,6 +63,9 @@ 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;
>
> @@ -94,4 +111,9 @@ void u_audio_stop_capture(struct g_audio *g_audio);
> 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 */
