[deliverable/linux.git] / sound / usb / clock.c

/*
 *   Clock domain and sample rate management functions
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>

#include <sound/core.h>
#include <sound/info.h>
#include <sound/pcm.h>

#include "usbaudio.h"
#include "card.h"
#include "helper.h"
#include "clock.h"

static struct uac_clock_source_descriptor *
	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
				  int clock_id)
{
	struct uac_clock_source_descriptor *cs = NULL;

	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
					     ctrl_iface->extralen,
					     cs, UAC2_CLOCK_SOURCE))) {
		if (cs->bClockID == clock_id)
			return cs;
	}

	return NULL;
}

static struct uac_clock_selector_descriptor *
	snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
				    int clock_id)
{
	struct uac_clock_selector_descriptor *cs = NULL;

	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
					     ctrl_iface->extralen,
					     cs, UAC2_CLOCK_SELECTOR))) {
		if (cs->bClockID == clock_id)
			return cs;
	}

	return NULL;
}

static struct uac_clock_multiplier_descriptor *
	snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
				      int clock_id)
{
	struct uac_clock_multiplier_descriptor *cs = NULL;

	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
					     ctrl_iface->extralen,
					     cs, UAC2_CLOCK_MULTIPLIER))) {
		if (cs->bClockID == clock_id)
			return cs;
	}

	return NULL;
}

static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
{
	unsigned char buf;
	int ret;

	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
			      UAC2_CS_CUR,
			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
			      UAC2_CX_CLOCK_SELECTOR << 8,
			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
			      &buf, sizeof(buf));

	if (ret < 0)
		return ret;

	return buf;
}

static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
{
	int err;
	unsigned char data;
	struct usb_device *dev = chip->dev;
	struct uac_clock_source_descriptor *cs_desc =
		snd_usb_find_clock_source(chip->ctrl_intf, source_id);

	if (!cs_desc)
		return 0;

	/* If a clock source can't tell us whether it's valid, we assume it is */
	if (!uac2_control_is_readable(cs_desc->bmControls,
				      UAC2_CS_CONTROL_CLOCK_VALID - 1))
		return 1;

	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
			      UAC2_CS_CONTROL_CLOCK_VALID << 8,
			      snd_usb_ctrl_intf(chip) | (source_id << 8),
			      &data, sizeof(data));

	if (err < 0) {
		snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
			   __func__, source_id);
		return 0;
	}

	return !!data;
}

static int __uac_clock_find_source(struct snd_usb_audio *chip,
				   int entity_id, unsigned long *visited)
{
	struct uac_clock_source_descriptor *source;
	struct uac_clock_selector_descriptor *selector;
	struct uac_clock_multiplier_descriptor *multiplier;

	entity_id &= 0xff;

	if (test_and_set_bit(entity_id, visited)) {
		snd_printk(KERN_WARNING
			"%s(): recursive clock topology detected, id %d.\n",
			__func__, entity_id);
		return -EINVAL;
	}

	/* first, see if the ID we're looking for is a clock source already */
	source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
	if (source)
		return source->bClockID;

	selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
	if (selector) {
		int ret;

		/* the entity ID we are looking for is a selector.
		 * find out what it currently selects */
		ret = uac_clock_selector_get_val(chip, selector->bClockID);
		if (ret < 0)
			return ret;

		/* Selector values are one-based */

		if (ret > selector->bNrInPins || ret < 1) {
			printk(KERN_ERR
				"%s(): selector reported illegal value, id %d, ret %d\n",
				__func__, selector->bClockID, ret);

			return -EINVAL;
		}

		return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],
					       visited);
	}

	/* FIXME: multipliers only act as pass-thru element for now */
	multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
	if (multiplier)
		return __uac_clock_find_source(chip, multiplier->bCSourceID,
						visited);

	return -EINVAL;
}

/*
 * For all kinds of sample rate settings and other device queries,
 * the clock source (end-leaf) must be used. However, clock selectors,
 * clock multipliers and sample rate converters may be specified as
 * clock source input to terminal. This functions walks the clock path
 * to its end and tries to find the source.
 *
 * The 'visited' bitfield is used internally to detect recursive loops.
 *
 * Returns the clock source UnitID (>=0) on success, or an error.
 */
int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id)
{
	DECLARE_BITMAP(visited, 256);
	memset(visited, 0, sizeof(visited));
	return __uac_clock_find_source(chip, entity_id, visited);
}

static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
			      struct usb_host_interface *alts,
			      struct audioformat *fmt, int rate)
{
	struct usb_device *dev = chip->dev;
	unsigned int ep;
	unsigned char data[3];
	int err, crate;

	ep = get_endpoint(alts, 0)->bEndpointAddress;

	/* if endpoint doesn't have sampling rate control, bail out */
	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
		return 0;

	data[0] = rate;
	data[1] = rate >> 8;
	data[2] = rate >> 16;
	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
				   data, sizeof(data))) < 0) {
		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
			   dev->devnum, iface, fmt->altsetting, rate, ep);
		return err;
	}

	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
				   data, sizeof(data))) < 0) {
		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
			   dev->devnum, iface, fmt->altsetting, ep);
		return 0; /* some devices don't support reading */
	}

	crate = data[0] | (data[1] << 8) | (data[2] << 16);
	if (crate != rate) {
		snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
		// runtime->rate = crate;
	}

	return 0;
}

static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
			      int altsetting, int clock)
{
	struct usb_device *dev = chip->dev;
	__le32 data;
	int err;

	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
			      UAC2_CS_CONTROL_SAM_FREQ << 8,
			      snd_usb_ctrl_intf(chip) | (clock << 8),
			      &data, sizeof(data));
	if (err < 0) {
		snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
			   dev->devnum, iface, altsetting);
		return 0;
	}

	return le32_to_cpu(data);
}

static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
			      struct usb_host_interface *alts,
			      struct audioformat *fmt, int rate)
{
	struct usb_device *dev = chip->dev;
	__le32 data;
	int err, cur_rate, prev_rate;
	int clock = snd_usb_clock_find_source(chip, fmt->clock);

	if (clock < 0)
		return clock;

	if (!uac_clock_source_is_valid(chip, clock)) {
		/* TODO: should we try to find valid clock setups by ourself? */
		snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
			   dev->devnum, iface, fmt->altsetting, clock);
		return -ENXIO;
	}

	prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);

	data = cpu_to_le32(rate);
	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
				   USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
				   UAC2_CS_CONTROL_SAM_FREQ << 8,
				   snd_usb_ctrl_intf(chip) | (clock << 8),
				   &data, sizeof(data))) < 0) {
		snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
			   dev->devnum, iface, fmt->altsetting, rate);
		return err;
	}

	cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);

	if (cur_rate != rate) {
		snd_printd(KERN_WARNING
			   "current rate %d is different from the runtime rate %d\n",
			   cur_rate, rate);
	}

	/* Some devices doesn't respond to sample rate changes while the
	 * interface is active. */
	if (rate != prev_rate) {
		usb_set_interface(dev, iface, 0);
		usb_set_interface(dev, iface, fmt->altsetting);
	}

	return 0;
}

int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
			     struct usb_host_interface *alts,
			     struct audioformat *fmt, int rate)
{
	struct usb_interface_descriptor *altsd = get_iface_desc(alts);

	switch (altsd->bInterfaceProtocol) {
	case UAC_VERSION_1:
	default:
		return set_sample_rate_v1(chip, iface, alts, fmt, rate);

	case UAC_VERSION_2:
		return set_sample_rate_v2(chip, iface, alts, fmt, rate);
	}
}
Commit	Line	Data
79f920fb DM	1	/*
	2	* Clock domain and sample rate management functions
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	*
	18	*/
	19
	20	#include <linux/bitops.h>
	21	#include <linux/init.h>
79f920fb DM	22	#include <linux/string.h>
79f920fb DM	23	#include <linux/usb.h>
79f920fb DM	24	#include <linux/usb/audio.h>
	25	#include <linux/usb/audio-v2.h>
	26
	27	#include <sound/core.h>
	28	#include <sound/info.h>
	29	#include <sound/pcm.h>
79f920fb DM	30
	31	#include "usbaudio.h"
	32	#include "card.h"
79f920fb	33	#include "helper.h"
f22aa949	34	#include "clock.h"
79f920fb DM	35
	36	static struct uac_clock_source_descriptor *
	37	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
	38	int clock_id)
	39	{
	40	struct uac_clock_source_descriptor *cs = NULL;
	41
	42	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
	43	ctrl_iface->extralen,
	44	cs, UAC2_CLOCK_SOURCE))) {
	45	if (cs->bClockID == clock_id)
	46	return cs;
	47	}
	48
	49	return NULL;
	50	}
	51
	52	static struct uac_clock_selector_descriptor *
	53	snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
	54	int clock_id)
	55	{
	56	struct uac_clock_selector_descriptor *cs = NULL;
	57
	58	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
	59	ctrl_iface->extralen,
	60	cs, UAC2_CLOCK_SELECTOR))) {
	61	if (cs->bClockID == clock_id)
	62	return cs;
	63	}
	64
	65	return NULL;
	66	}
	67
	68	static struct uac_clock_multiplier_descriptor *
	69	snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
	70	int clock_id)
	71	{
	72	struct uac_clock_multiplier_descriptor *cs = NULL;
	73
	74	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
	75	ctrl_iface->extralen,
	76	cs, UAC2_CLOCK_MULTIPLIER))) {
	77	if (cs->bClockID == clock_id)
	78	return cs;
	79	}
	80
	81	return NULL;
	82	}
	83
	84	static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
	85	{
	86	unsigned char buf;
	87	int ret;
	88
	89	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
	90	UAC2_CS_CUR,
	91	USB_RECIP_INTERFACE \| USB_TYPE_CLASS \| USB_DIR_IN,
11bcbc44 DM	92	UAC2_CX_CLOCK_SELECTOR << 8,
11bcbc44 DM	93	snd_usb_ctrl_intf(chip) \| (selector_id << 8),
17d900c4	94	&buf, sizeof(buf));
79f920fb DM	95
	96	if (ret < 0)
	97	return ret;
	98
	99	return buf;
	100	}
	101
	102	static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
	103	{
	104	int err;
	105	unsigned char data;
	106	struct usb_device *dev = chip->dev;
3bc6fbc7 DM	107	struct uac_clock_source_descriptor *cs_desc =
	108	snd_usb_find_clock_source(chip->ctrl_intf, source_id);
	109
	110	if (!cs_desc)
	111	return 0;
	112
	113	/* If a clock source can't tell us whether it's valid, we assume it is */
aff252a8 DM	114	if (!uac2_control_is_readable(cs_desc->bmControls,
aff252a8 DM	115	UAC2_CS_CONTROL_CLOCK_VALID - 1))
3bc6fbc7	116	return 1;
79f920fb DM	117
	118	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
	119	USB_TYPE_CLASS \| USB_RECIP_INTERFACE \| USB_DIR_IN,
11bcbc44 DM	120	UAC2_CS_CONTROL_CLOCK_VALID << 8,
11bcbc44 DM	121	snd_usb_ctrl_intf(chip) \| (source_id << 8),
17d900c4	122	&data, sizeof(data));
79f920fb DM	123
	124	if (err < 0) {
	125	snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
	126	__func__, source_id);
3bc6fbc7	127	return 0;
79f920fb DM	128	}
	129
	130	return !!data;
	131	}
	132
79f920fb	133	static int __uac_clock_find_source(struct snd_usb_audio *chip,
79f920fb DM	134	int entity_id, unsigned long *visited)
	135	{
	136	struct uac_clock_source_descriptor *source;
	137	struct uac_clock_selector_descriptor *selector;
	138	struct uac_clock_multiplier_descriptor *multiplier;
	139
	140	entity_id &= 0xff;
	141
	142	if (test_and_set_bit(entity_id, visited)) {
	143	snd_printk(KERN_WARNING
	144	"%s(): recursive clock topology detected, id %d.\n",
	145	__func__, entity_id);
	146	return -EINVAL;
	147	}
	148
	149	/* first, see if the ID we're looking for is a clock source already */
3d8d4dcf	150	source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
79f920fb DM	151	if (source)
	152	return source->bClockID;
	153
3d8d4dcf	154	selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
79f920fb DM	155	if (selector) {
	156	int ret;
	157
	158	/* the entity ID we are looking for is a selector.
	159	* find out what it currently selects */
	160	ret = uac_clock_selector_get_val(chip, selector->bClockID);
	161	if (ret < 0)
	162	return ret;
	163
157a57b6 DM	164	/* Selector values are one-based */
157a57b6 DM	165
79f920fb DM	166	if (ret > selector->bNrInPins \|\| ret < 1) {
	167	printk(KERN_ERR
	168	"%s(): selector reported illegal value, id %d, ret %d\n",
	169	__func__, selector->bClockID, ret);
	170
	171	return -EINVAL;
	172	}
	173
3d8d4dcf	174	return __uac_clock_find_source(chip, selector->baCSourceID[ret-1],
79f920fb DM	175	visited);
	176	}
	177
	178	/* FIXME: multipliers only act as pass-thru element for now */
3d8d4dcf	179	multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
79f920fb	180	if (multiplier)
3d8d4dcf DM	181	return __uac_clock_find_source(chip, multiplier->bCSourceID,
3d8d4dcf DM	182	visited);
79f920fb DM	183
	184	return -EINVAL;
	185	}
	186
157a57b6 DM	187	/*
	188	* For all kinds of sample rate settings and other device queries,
	189	* the clock source (end-leaf) must be used. However, clock selectors,
	190	* clock multipliers and sample rate converters may be specified as
	191	* clock source input to terminal. This functions walks the clock path
	192	* to its end and tries to find the source.
	193	*
	194	* The 'visited' bitfield is used internally to detect recursive loops.
	195	*
	196	* Returns the clock source UnitID (>=0) on success, or an error.
	197	*/
3d8d4dcf	198	int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id)
79f920fb DM	199	{
	200	DECLARE_BITMAP(visited, 256);
	201	memset(visited, 0, sizeof(visited));
3d8d4dcf	202	return __uac_clock_find_source(chip, entity_id, visited);
79f920fb DM	203	}
	204
	205	static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
	206	struct usb_host_interface *alts,
	207	struct audioformat *fmt, int rate)
	208	{
	209	struct usb_device *dev = chip->dev;
	210	unsigned int ep;
	211	unsigned char data[3];
	212	int err, crate;
	213
	214	ep = get_endpoint(alts, 0)->bEndpointAddress;
	215
	216	/* if endpoint doesn't have sampling rate control, bail out */
d32d552e	217	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
79f920fb	218	return 0;
79f920fb DM	219
	220	data[0] = rate;
	221	data[1] = rate >> 8;
	222	data[2] = rate >> 16;
	223	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
	224	USB_TYPE_CLASS \| USB_RECIP_ENDPOINT \| USB_DIR_OUT,
	225	UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
17d900c4	226	data, sizeof(data))) < 0) {
79f920fb DM	227	snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
	228	dev->devnum, iface, fmt->altsetting, rate, ep);
	229	return err;
	230	}
	231
	232	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
	233	USB_TYPE_CLASS \| USB_RECIP_ENDPOINT \| USB_DIR_IN,
	234	UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
17d900c4	235	data, sizeof(data))) < 0) {
79f920fb DM	236	snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
	237	dev->devnum, iface, fmt->altsetting, ep);
	238	return 0; /* some devices don't support reading */
	239	}
	240
	241	crate = data[0] \| (data[1] << 8) \| (data[2] << 16);
	242	if (crate != rate) {
	243	snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
	244	// runtime->rate = crate;
	245	}
	246
	247	return 0;
	248	}
	249
7c517465 TI	250	static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
	251	int altsetting, int clock)
	252	{
	253	struct usb_device *dev = chip->dev;
f6a8bc70	254	__le32 data;
7c517465 TI	255	int err;
	256
	257	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
	258	USB_TYPE_CLASS \| USB_RECIP_INTERFACE \| USB_DIR_IN,
	259	UAC2_CS_CONTROL_SAM_FREQ << 8,
	260	snd_usb_ctrl_intf(chip) \| (clock << 8),
f6a8bc70	261	&data, sizeof(data));
7c517465 TI	262	if (err < 0) {
	263	snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
	264	dev->devnum, iface, altsetting);
	265	return 0;
	266	}
	267
f6a8bc70	268	return le32_to_cpu(data);
7c517465 TI	269	}
7c517465 TI	270
79f920fb DM	271	static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
	272	struct usb_host_interface *alts,
	273	struct audioformat *fmt, int rate)
	274	{
	275	struct usb_device *dev = chip->dev;
f6a8bc70	276	__le32 data;
690a863f	277	int err, cur_rate, prev_rate;
3d8d4dcf	278	int clock = snd_usb_clock_find_source(chip, fmt->clock);
79f920fb DM	279
	280	if (clock < 0)
	281	return clock;
	282
	283	if (!uac_clock_source_is_valid(chip, clock)) {
157a57b6	284	/* TODO: should we try to find valid clock setups by ourself? */
79f920fb DM	285	snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
	286	dev->devnum, iface, fmt->altsetting, clock);
	287	return -ENXIO;
	288	}
	289
7c517465	290	prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
690a863f	291
f6a8bc70	292	data = cpu_to_le32(rate);
79f920fb DM	293	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
79f920fb DM	294	USB_TYPE_CLASS \| USB_RECIP_INTERFACE \| USB_DIR_OUT,
11bcbc44 DM	295	UAC2_CS_CONTROL_SAM_FREQ << 8,
11bcbc44 DM	296	snd_usb_ctrl_intf(chip) \| (clock << 8),
f6a8bc70	297	&data, sizeof(data))) < 0) {
79f920fb DM	298	snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
	299	dev->devnum, iface, fmt->altsetting, rate);
	300	return err;
	301	}
	302
7c517465	303	cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
79f920fb	304
690a863f TH	305	if (cur_rate != rate) {
	306	snd_printd(KERN_WARNING
	307	"current rate %d is different from the runtime rate %d\n",
	308	cur_rate, rate);
	309	}
	310
	311	/* Some devices doesn't respond to sample rate changes while the
	312	* interface is active. */
	313	if (rate != prev_rate) {
	314	usb_set_interface(dev, iface, 0);
	315	usb_set_interface(dev, iface, fmt->altsetting);
	316	}
79f920fb DM	317
	318	return 0;
	319	}
	320
	321	int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
	322	struct usb_host_interface *alts,
	323	struct audioformat *fmt, int rate)
	324	{
	325	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
	326
	327	switch (altsd->bInterfaceProtocol) {
	328	case UAC_VERSION_1:
a2acad82	329	default:
79f920fb DM	330	return set_sample_rate_v1(chip, iface, alts, fmt, rate);
	331
	332	case UAC_VERSION_2:
	333	return set_sample_rate_v2(chip, iface, alts, fmt, rate);
	334	}
79f920fb DM	335	}
79f920fb DM	336