Commit c565ad07 authored by Julian Scheel's avatar Julian Scheel Committed by Greg Kroah-Hartman
Browse files

usb: gadget: u_audio: Support multiple sampling rates 



Implement support for multiple sampling rates in u_audio part of the
audio gadget. The currently configured rates are exposed through
read-only amixer controls 'Capture Rate' and 'Playback Rate'.

Signed-off-by: default avatarJulian Scheel <julian@jusst.de>
Signed-off-by: default avatarPavel Hofman <pavel.hofman@ivitera.com>
Link: https://lore.kernel.org/r/20220121155308.48794-3-pavel.hofman@ivitera.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ce6a7bfb

drivers/usb/gadget/function/f_uac1.c

+2 −0
Original line number Diff line number Diff line
@@ -1298,6 +1298,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) 
	audio->in_ep_maxpsize = le16_to_cpu(as_in_ep_desc.wMaxPacketSize);

	audio->params.c_chmask = audio_opts->c_chmask;

	audio->params.c_srate = audio_opts->c_srate;

	audio->params.c_srates[0] = audio_opts->c_srate;

	audio->params.c_ssize = audio_opts->c_ssize;

	if (FUIN_EN(audio_opts)) {

		audio->params.p_fu.id = USB_IN_FU_ID;
@@ -1310,6 +1311,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) 
	}

	audio->params.p_chmask = audio_opts->p_chmask;

	audio->params.p_srate = audio_opts->p_srate;

	audio->params.p_srates[0] = audio_opts->p_srate;

	audio->params.p_ssize = audio_opts->p_ssize;

	if (FUOUT_EN(audio_opts)) {

		audio->params.c_fu.id = USB_OUT_FU_ID;

drivers/usb/gadget/function/f_uac2.c

+2 −0
Original line number Diff line number Diff line
@@ -1210,6 +1210,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) 


	agdev->params.p_chmask = uac2_opts->p_chmask;

	agdev->params.p_srate = uac2_opts->p_srate;

	agdev->params.p_srates[0] = uac2_opts->p_srate;

	agdev->params.p_ssize = uac2_opts->p_ssize;

	if (FUIN_EN(uac2_opts)) {

		agdev->params.p_fu.id = USB_IN_FU_ID;
@@ -1221,6 +1222,7 @@ afunc_bind(struct usb_configuration *cfg, struct usb_function *fn) 
	}

	agdev->params.c_chmask = uac2_opts->c_chmask;

	agdev->params.c_srate = uac2_opts->c_srate;

	agdev->params.c_srates[0] = uac2_opts->c_srate;

	agdev->params.c_ssize = uac2_opts->c_ssize;

	if (FUOUT_EN(uac2_opts)) {

		agdev->params.c_fu.id = USB_OUT_FU_ID;

drivers/usb/gadget/function/u_audio.c

+131 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ enum { 
	UAC_P_PITCH_CTRL,

	UAC_MUTE_CTRL,

	UAC_VOLUME_CTRL,

	UAC_RATE_CTRL,

};



/* Runtime data params for one stream */
@@ -62,6 +63,8 @@ struct uac_rtd_params { 
  s16 volume;

  int mute;



	struct snd_kcontrol *snd_kctl_rate; /* read-only current rate */



  spinlock_t lock; /* lock for control transfers */



};
@@ -493,6 +496,44 @@ static inline void free_ep_fback(struct uac_rtd_params *prm, struct usb_ep *ep) 
		dev_err(uac->card->dev, "%s:%d Error!\n", __func__, __LINE__);

}



int u_audio_set_capture_srate(struct g_audio *audio_dev, int srate)

{

	struct uac_params *params = &audio_dev->params;

	int i;



	dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);

	for (i = 0; i < UAC_MAX_RATES; i++) {

		if (params->c_srates[i] == srate) {

			params->c_srate = srate;

			return 0;

		}

		if (params->c_srates[i] == 0)

			break;

	}



	return -EINVAL;

}

EXPORT_SYMBOL_GPL(u_audio_set_capture_srate);



int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate)

{

	struct uac_params *params = &audio_dev->params;

	int i;



	dev_dbg(&audio_dev->gadget->dev, "%s: srate %d\n", __func__, srate);

	for (i = 0; i < UAC_MAX_RATES; i++) {

		if (params->p_srates[i] == srate) {

			params->p_srate = srate;

			return 0;

		}

		if (params->p_srates[i] == 0)

			break;

	}



	return -EINVAL;

}

EXPORT_SYMBOL_GPL(u_audio_set_playback_srate);



int u_audio_start_capture(struct g_audio *audio_dev)

{

	struct snd_uac_chip *uac = audio_dev->uac;
@@ -504,6 +545,7 @@ int u_audio_start_capture(struct g_audio *audio_dev) 
	struct uac_params *params = &audio_dev->params;

	int req_len, i;



	dev_dbg(dev, "start capture with rate %d\n", params->c_srate);

	ep = audio_dev->out_ep;

	prm = &uac->c_prm;

	config_ep_by_speed(gadget, &audio_dev->func, ep);
@@ -596,6 +638,7 @@ int u_audio_start_playback(struct g_audio *audio_dev) 
	int req_len, i;

	unsigned int p_pktsize;



	dev_dbg(dev, "start playback with rate %d\n", params->p_srate);

	ep = audio_dev->in_ep;

	prm = &uac->p_prm;

	config_ep_by_speed(gadget, &audio_dev->func, ep);
@@ -943,6 +986,68 @@ static int u_audio_volume_put(struct snd_kcontrol *kcontrol, 
	return change;

}



static int get_max_srate(const int *srates)

{

	int i, max_srate = 0;



	for (i = 0; i < UAC_MAX_RATES; i++) {

		if (srates[i] == 0)

			break;

		if (srates[i] > max_srate)

			max_srate = srates[i];

	}

	return max_srate;

}



static int get_min_srate(const int *srates)

{

	int i, min_srate = INT_MAX;



	for (i = 0; i < UAC_MAX_RATES; i++) {

		if (srates[i] == 0)

			break;

		if (srates[i] < min_srate)

			min_srate = srates[i];

	}

	return min_srate;

}



static int u_audio_rate_info(struct snd_kcontrol *kcontrol,

				struct snd_ctl_elem_info *uinfo)

{

	const int *srates;

	struct uac_rtd_params *prm = snd_kcontrol_chip(kcontrol);

	struct snd_uac_chip *uac = prm->uac;

	struct g_audio *audio_dev = uac->audio_dev;

	struct uac_params *params = &audio_dev->params;



	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;

	uinfo->count = 1;



	if (prm == &uac->c_prm)

		srates = params->c_srates;

	else

		srates = params->p_srates;

	uinfo->value.integer.min = get_min_srate(srates);

	uinfo->value.integer.max = get_max_srate(srates);

	return 0;

}



static int u_audio_rate_get(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;

	struct uac_params *params = &audio_dev->params;



	if (prm == &uac->c_prm)

		ucontrol->value.integer.value[0] = params->c_srate;

	else

		ucontrol->value.integer.value[0] = params->p_srate;



	return 0;

}



static struct snd_kcontrol_new u_audio_controls[]  = {

  [UAC_FBACK_CTRL] {
@@ -973,6 +1078,13 @@ static struct snd_kcontrol_new u_audio_controls[] = { 
		.get =		u_audio_volume_get,

		.put =		u_audio_volume_put,

	},

	[UAC_RATE_CTRL] {

		.iface =	SNDRV_CTL_ELEM_IFACE_PCM,

		.name =		"", /* will be filled later */

		.access =	SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,

		.info =		u_audio_rate_info,

		.get =		u_audio_rate_get,

	},

};



int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
@@ -1186,6 +1298,25 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name, 
			prm->volume_min = fu->volume_min;

			prm->volume_res = fu->volume_res;

		}



		/* Add rate control */

		snprintf(ctrl_name, sizeof(ctrl_name),

				"%s Rate", direction);

		u_audio_controls[UAC_RATE_CTRL].name = ctrl_name;



		kctl = snd_ctl_new1(&u_audio_controls[UAC_RATE_CTRL], prm);

		if (!kctl) {

			err = -ENOMEM;

			goto snd_fail;

		}



		kctl->id.device = pcm->device;

		kctl->id.subdevice = 0;



		err = snd_ctl_add(card, kctl);

		if (err < 0)

			goto snd_fail;

		prm->snd_kctl_rate = kctl;

	}



	strscpy(card->driver, card_name, sizeof(card->driver));

drivers/usb/gadget/function/u_audio.h

+8 −2
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#define __U_AUDIO_H



#include <linux/usb/composite.h>

#include "uac_common.h"



/*

 * Same maximum frequency deviation on the slower side as in
@@ -40,13 +41,15 @@ struct uac_fu_params { 
struct uac_params {

	/* playback */

	int p_chmask;	/* channel mask */

	int p_srate;	/* rate in Hz */

	int p_srates[UAC_MAX_RATES];	/* available rates in Hz (0 terminated list) */

	int p_srate;	/* selected 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_srates[UAC_MAX_RATES];	/* available rates in Hz (0 terminated list) */

	int c_srate;	/* selected rate in Hz */

	int c_ssize;	/* sample size */

	struct uac_fu_params c_fu;	/* Feature Unit parameters */
@@ -117,6 +120,9 @@ 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_set_capture_srate(struct g_audio *audio_dev, int srate);

int u_audio_set_playback_srate(struct g_audio *audio_dev, int srate);



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);

drivers/usb/gadget/function/uac_common.h

0 → 100644
+9 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0+ */

/*

 */



#ifndef UAC_COMMON_H

#define UAC_COMMON_H



#define UAC_MAX_RATES 10 /* maximum number of rates configurable by f_uac1/2 */

#endif