[mirror_ubuntu-bionic-kernel.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"
#include "quirks.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->bLength >= sizeof(*cs) && 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->bLength >= sizeof(*cs) && cs->bClockID == clock_id) {
			if (cs->bLength < 5 + cs->bNrInPins)
				return NULL;
			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->bLength >= sizeof(*cs) && 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 int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
					unsigned char pin)
{
	int ret;

	ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
			      UAC2_CS_CUR,
			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
			      UAC2_CX_CLOCK_SELECTOR << 8,
			      snd_usb_ctrl_intf(chip) | (selector_id << 8),
			      &pin, sizeof(pin));
	if (ret < 0)
		return ret;

	if (ret != sizeof(pin)) {
		usb_audio_err(chip,
			"setting selector (id %d) unexpected length %d\n",
			selector_id, ret);
		return -EINVAL;
	}

	ret = uac_clock_selector_get_val(chip, selector_id);
	if (ret < 0)
		return ret;

	if (ret != pin) {
		usb_audio_err(chip,
			"setting selector (id %d) to %x failed (current: %d)\n",
			selector_id, pin, ret);
		return -EINVAL;
	}

	return ret;
}

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) {
		dev_warn(&dev->dev,
			 "%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,
				   bool validate)
{
	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)) {
		usb_audio_warn(chip,
			 "%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) {
		entity_id = source->bClockID;
		if (validate && !uac_clock_source_is_valid(chip, entity_id)) {
			usb_audio_err(chip,
				"clock source %d is not valid, cannot use\n",
				entity_id);
			return -ENXIO;
		}
		return entity_id;
	}

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

		/* 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) {
			usb_audio_err(chip,
				"%s(): selector reported illegal value, id %d, ret %d\n",
				__func__, selector->bClockID, ret);

			return -EINVAL;
		}

		cur = ret;
		ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
					       visited, validate);
		if (!validate || ret > 0 || !chip->autoclock)
			return ret;

		/* The current clock source is invalid, try others. */
		for (i = 1; i <= selector->bNrInPins; i++) {
			int err;

			if (i == cur)
				continue;

			ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
				visited, true);
			if (ret < 0)
				continue;

			err = uac_clock_selector_set_val(chip, entity_id, i);
			if (err < 0)
				continue;

			usb_audio_info(chip,
				 "found and selected valid clock source %d\n",
				 ret);
			return ret;
		}

		return -ENXIO;
	}

	/* 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, validate);

	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,
			      bool validate)
{
	DECLARE_BITMAP(visited, 256);
	memset(visited, 0, sizeof(visited));
	return __uac_clock_find_source(chip, entity_id, visited, validate);
}

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;

	if (get_iface_desc(alts)->bNumEndpoints < 1)
		return -EINVAL;
	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) {
		dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
			iface, fmt->altsetting, rate, ep);
		return err;
	}

	/* Don't check the sample rate for devices which we know don't
	 * support reading */
	if (snd_usb_get_sample_rate_quirk(chip))
		return 0;
	/* the firmware is likely buggy, don't repeat to fail too many times */
	if (chip->sample_rate_read_error > 2)
		return 0;

	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) {
		dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
			iface, fmt->altsetting, ep);
		chip->sample_rate_read_error++;
		return 0; /* some devices don't support reading */
	}

	crate = data[0] | (data[1] << 8) | (data[2] << 16);
	if (crate != rate) {
		dev_warn(&dev->dev, "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) {
		dev_warn(&dev->dev, "%d:%d: cannot get freq (v2): err %d\n",
			 iface, altsetting, err);
		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;
	bool writeable;
	struct uac_clock_source_descriptor *cs_desc;

	clock = snd_usb_clock_find_source(chip, fmt->clock, true);
	if (clock < 0)
		return clock;

	prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
	if (prev_rate == rate)
		return 0;

	cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
	writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1);
	if (writeable) {
		data = cpu_to_le32(rate);
		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));
		if (err < 0) {
			usb_audio_err(chip,
				"%d:%d: cannot set freq %d (v2): err %d\n",
				iface, fmt->altsetting, rate, err);
			return err;
		}

		cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
	} else {
		cur_rate = prev_rate;
	}

	if (cur_rate != rate) {
		if (!writeable) {
			usb_audio_warn(chip,
				 "%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
				 iface, fmt->altsetting, rate, cur_rate);
			return -ENXIO;
		}
		usb_audio_dbg(chip,
			"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);
		snd_usb_set_interface_quirk(dev);
		usb_set_interface(dev, iface, fmt->altsetting);
		snd_usb_set_interface_quirk(dev);
	}

	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)
{
	switch (fmt->protocol) {
	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"
21bb5aaf	35	#include "quirks.h"
79f920fb DM	36
	37	static struct uac_clock_source_descriptor *
	38	snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
	39	int clock_id)
	40	{
	41	struct uac_clock_source_descriptor *cs = NULL;
	42
	43	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
	44	ctrl_iface->extralen,
	45	cs, UAC2_CLOCK_SOURCE))) {
0a62d6c9	46	if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
79f920fb DM	47	return cs;
	48	}
	49
	50	return NULL;
	51	}
	52
	53	static struct uac_clock_selector_descriptor *
	54	snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
	55	int clock_id)
	56	{
	57	struct uac_clock_selector_descriptor *cs = NULL;
	58
	59	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
	60	ctrl_iface->extralen,
	61	cs, UAC2_CLOCK_SELECTOR))) {
0a62d6c9 TI	62	if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) {
	63	if (cs->bLength < 5 + cs->bNrInPins)
	64	return NULL;
79f920fb	65	return cs;
0a62d6c9	66	}
79f920fb DM	67	}
	68
	69	return NULL;
	70	}
	71
	72	static struct uac_clock_multiplier_descriptor *
	73	snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
	74	int clock_id)
	75	{
	76	struct uac_clock_multiplier_descriptor *cs = NULL;
	77
	78	while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
	79	ctrl_iface->extralen,
	80	cs, UAC2_CLOCK_MULTIPLIER))) {
0a62d6c9	81	if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
79f920fb DM	82	return cs;
	83	}
	84
	85	return NULL;
	86	}
	87
	88	static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
	89	{
	90	unsigned char buf;
	91	int ret;
	92
	93	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
	94	UAC2_CS_CUR,
	95	USB_RECIP_INTERFACE \| USB_TYPE_CLASS \| USB_DIR_IN,
11bcbc44 DM	96	UAC2_CX_CLOCK_SELECTOR << 8,
11bcbc44 DM	97	snd_usb_ctrl_intf(chip) \| (selector_id << 8),
17d900c4	98	&buf, sizeof(buf));
79f920fb DM	99
	100	if (ret < 0)
	101	return ret;
	102
	103	return buf;
	104	}
	105
8c55af3f EZ	106	static int uac_clock_selector_set_val(struct snd_usb_audio *chip, int selector_id,
	107	unsigned char pin)
	108	{
	109	int ret;
	110
	111	ret = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0),
	112	UAC2_CS_CUR,
	113	USB_RECIP_INTERFACE \| USB_TYPE_CLASS \| USB_DIR_OUT,
	114	UAC2_CX_CLOCK_SELECTOR << 8,
	115	snd_usb_ctrl_intf(chip) \| (selector_id << 8),
	116	&pin, sizeof(pin));
	117	if (ret < 0)
	118	return ret;
	119
	120	if (ret != sizeof(pin)) {
0ba41d91 TI	121	usb_audio_err(chip,
	122	"setting selector (id %d) unexpected length %d\n",
	123	selector_id, ret);
8c55af3f EZ	124	return -EINVAL;
	125	}
	126
	127	ret = uac_clock_selector_get_val(chip, selector_id);
	128	if (ret < 0)
	129	return ret;
	130
	131	if (ret != pin) {
0ba41d91 TI	132	usb_audio_err(chip,
	133	"setting selector (id %d) to %x failed (current: %d)\n",
	134	selector_id, pin, ret);
8c55af3f EZ	135	return -EINVAL;
	136	}
	137
	138	return ret;
	139	}
	140
79f920fb DM	141	static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
	142	{
	143	int err;
	144	unsigned char data;
	145	struct usb_device *dev = chip->dev;
3bc6fbc7 DM	146	struct uac_clock_source_descriptor *cs_desc =
	147	snd_usb_find_clock_source(chip->ctrl_intf, source_id);
	148
	149	if (!cs_desc)
	150	return 0;
	151
	152	/* If a clock source can't tell us whether it's valid, we assume it is */
aff252a8 DM	153	if (!uac2_control_is_readable(cs_desc->bmControls,
aff252a8 DM	154	UAC2_CS_CONTROL_CLOCK_VALID - 1))
3bc6fbc7	155	return 1;
79f920fb DM	156
	157	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
	158	USB_TYPE_CLASS \| USB_RECIP_INTERFACE \| USB_DIR_IN,
11bcbc44 DM	159	UAC2_CS_CONTROL_CLOCK_VALID << 8,
11bcbc44 DM	160	snd_usb_ctrl_intf(chip) \| (source_id << 8),
17d900c4	161	&data, sizeof(data));
79f920fb DM	162
79f920fb DM	163	if (err < 0) {
0ba41d91 TI	164	dev_warn(&dev->dev,
0ba41d91 TI	165	"%s(): cannot get clock validity for id %d\n",
79f920fb	166	__func__, source_id);
3bc6fbc7	167	return 0;
79f920fb DM	168	}
	169
	170	return !!data;
	171	}
	172
79f920fb	173	static int __uac_clock_find_source(struct snd_usb_audio *chip,
06ffc1eb EZ	174	int entity_id, unsigned long *visited,
06ffc1eb EZ	175	bool validate)
79f920fb DM	176	{
	177	struct uac_clock_source_descriptor *source;
	178	struct uac_clock_selector_descriptor *selector;
	179	struct uac_clock_multiplier_descriptor *multiplier;
	180
	181	entity_id &= 0xff;
	182
	183	if (test_and_set_bit(entity_id, visited)) {
0ba41d91 TI	184	usb_audio_warn(chip,
	185	"%s(): recursive clock topology detected, id %d.\n",
	186	__func__, entity_id);
79f920fb DM	187	return -EINVAL;
	188	}
	189
	190	/* first, see if the ID we're looking for is a clock source already */
3d8d4dcf	191	source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id);
06ffc1eb EZ	192	if (source) {
	193	entity_id = source->bClockID;
	194	if (validate && !uac_clock_source_is_valid(chip, entity_id)) {
0ba41d91 TI	195	usb_audio_err(chip,
	196	"clock source %d is not valid, cannot use\n",
	197	entity_id);
06ffc1eb EZ	198	return -ENXIO;
	199	}
	200	return entity_id;
	201	}
79f920fb	202
3d8d4dcf	203	selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id);
79f920fb	204	if (selector) {
8c55af3f	205	int ret, i, cur;
79f920fb DM	206
	207	/* the entity ID we are looking for is a selector.
	208	* find out what it currently selects */
	209	ret = uac_clock_selector_get_val(chip, selector->bClockID);
	210	if (ret < 0)
	211	return ret;
	212
157a57b6 DM	213	/* Selector values are one-based */
157a57b6 DM	214
79f920fb	215	if (ret > selector->bNrInPins \|\| ret < 1) {
0ba41d91	216	usb_audio_err(chip,
79f920fb DM	217	"%s(): selector reported illegal value, id %d, ret %d\n",
	218	__func__, selector->bClockID, ret);
	219
	220	return -EINVAL;
	221	}
	222
8c55af3f EZ	223	cur = ret;
8c55af3f EZ	224	ret = __uac_clock_find_source(chip, selector->baCSourceID[ret - 1],
06ffc1eb	225	visited, validate);
ef02e29b	226	if (!validate \|\| ret > 0 \|\| !chip->autoclock)
8c55af3f EZ	227	return ret;
	228
	229	/* The current clock source is invalid, try others. */
	230	for (i = 1; i <= selector->bNrInPins; i++) {
	231	int err;
	232
	233	if (i == cur)
	234	continue;
	235
	236	ret = __uac_clock_find_source(chip, selector->baCSourceID[i - 1],
	237	visited, true);
	238	if (ret < 0)
	239	continue;
	240
	241	err = uac_clock_selector_set_val(chip, entity_id, i);
	242	if (err < 0)
	243	continue;
	244
0ba41d91 TI	245	usb_audio_info(chip,
	246	"found and selected valid clock source %d\n",
	247	ret);
8c55af3f EZ	248	return ret;
	249	}
	250
	251	return -ENXIO;
79f920fb DM	252	}
	253
	254	/* FIXME: multipliers only act as pass-thru element for now */
3d8d4dcf	255	multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id);
79f920fb	256	if (multiplier)
3d8d4dcf	257	return __uac_clock_find_source(chip, multiplier->bCSourceID,
06ffc1eb	258	visited, validate);
79f920fb DM	259
	260	return -EINVAL;
	261	}
	262
157a57b6 DM	263	/*
	264	* For all kinds of sample rate settings and other device queries,
	265	* the clock source (end-leaf) must be used. However, clock selectors,
	266	* clock multipliers and sample rate converters may be specified as
	267	* clock source input to terminal. This functions walks the clock path
	268	* to its end and tries to find the source.
	269	*
	270	* The 'visited' bitfield is used internally to detect recursive loops.
	271	*
	272	* Returns the clock source UnitID (>=0) on success, or an error.
	273	*/
06ffc1eb EZ	274	int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id,
06ffc1eb EZ	275	bool validate)
79f920fb DM	276	{
	277	DECLARE_BITMAP(visited, 256);
	278	memset(visited, 0, sizeof(visited));
06ffc1eb	279	return __uac_clock_find_source(chip, entity_id, visited, validate);
79f920fb DM	280	}
	281
	282	static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
	283	struct usb_host_interface *alts,
	284	struct audioformat *fmt, int rate)
	285	{
	286	struct usb_device *dev = chip->dev;
	287	unsigned int ep;
	288	unsigned char data[3];
	289	int err, crate;
	290
447d6275 TI	291	if (get_iface_desc(alts)->bNumEndpoints < 1)
447d6275 TI	292	return -EINVAL;
79f920fb DM	293	ep = get_endpoint(alts, 0)->bEndpointAddress;
	294
	295	/* if endpoint doesn't have sampling rate control, bail out */
d32d552e	296	if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE))
79f920fb	297	return 0;
79f920fb DM	298
	299	data[0] = rate;
	300	data[1] = rate >> 8;
	301	data[2] = rate >> 16;
	302	if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
	303	USB_TYPE_CLASS \| USB_RECIP_ENDPOINT \| USB_DIR_OUT,
	304	UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
17d900c4	305	data, sizeof(data))) < 0) {
0ba41d91 TI	306	dev_err(&dev->dev, "%d:%d: cannot set freq %d to ep %#x\n",
0ba41d91 TI	307	iface, fmt->altsetting, rate, ep);
79f920fb DM	308	return err;
	309	}
	310
b62b9980 JT	311	/* Don't check the sample rate for devices which we know don't
	312	* support reading */
	313	if (snd_usb_get_sample_rate_quirk(chip))
	314	return 0;
57dd5414 TI	315	/* the firmware is likely buggy, don't repeat to fail too many times */
	316	if (chip->sample_rate_read_error > 2)
	317	return 0;
b62b9980	318
79f920fb DM	319	if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
	320	USB_TYPE_CLASS \| USB_RECIP_ENDPOINT \| USB_DIR_IN,
	321	UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
17d900c4	322	data, sizeof(data))) < 0) {
0ba41d91 TI	323	dev_err(&dev->dev, "%d:%d: cannot get freq at ep %#x\n",
0ba41d91 TI	324	iface, fmt->altsetting, ep);
57dd5414	325	chip->sample_rate_read_error++;
79f920fb DM	326	return 0; /* some devices don't support reading */
	327	}
	328
	329	crate = data[0] \| (data[1] << 8) \| (data[2] << 16);
	330	if (crate != rate) {
0ba41d91	331	dev_warn(&dev->dev, "current rate %d is different from the runtime rate %d\n", crate, rate);
79f920fb DM	332	// runtime->rate = crate;
	333	}
	334
	335	return 0;
	336	}
	337
7c517465 TI	338	static int get_sample_rate_v2(struct snd_usb_audio *chip, int iface,
	339	int altsetting, int clock)
	340	{
	341	struct usb_device *dev = chip->dev;
f6a8bc70	342	__le32 data;
7c517465 TI	343	int err;
	344
	345	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
	346	USB_TYPE_CLASS \| USB_RECIP_INTERFACE \| USB_DIR_IN,
	347	UAC2_CS_CONTROL_SAM_FREQ << 8,
	348	snd_usb_ctrl_intf(chip) \| (clock << 8),
f6a8bc70	349	&data, sizeof(data));
7c517465	350	if (err < 0) {
0ba41d91 TI	351	dev_warn(&dev->dev, "%d:%d: cannot get freq (v2): err %d\n",
0ba41d91 TI	352	iface, altsetting, err);
7c517465 TI	353	return 0;
	354	}
	355
f6a8bc70	356	return le32_to_cpu(data);
7c517465 TI	357	}
7c517465 TI	358
79f920fb DM	359	static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
	360	struct usb_host_interface *alts,
	361	struct audioformat *fmt, int rate)
	362	{
	363	struct usb_device *dev = chip->dev;
f6a8bc70	364	__le32 data;
690a863f	365	int err, cur_rate, prev_rate;
8c55af3f	366	int clock;
1dc669fe EZ	367	bool writeable;
1dc669fe EZ	368	struct uac_clock_source_descriptor *cs_desc;
79f920fb	369
8c55af3f	370	clock = snd_usb_clock_find_source(chip, fmt->clock, true);
79f920fb DM	371	if (clock < 0)
	372	return clock;
	373
7c517465	374	prev_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
fa92dd77 DH	375	if (prev_rate == rate)
fa92dd77 DH	376	return 0;
690a863f	377
1dc669fe EZ	378	cs_desc = snd_usb_find_clock_source(chip->ctrl_intf, clock);
	379	writeable = uac2_control_is_writeable(cs_desc->bmControls, UAC2_CS_CONTROL_SAM_FREQ - 1);
	380	if (writeable) {
	381	data = cpu_to_le32(rate);
	382	err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
	383	USB_TYPE_CLASS \| USB_RECIP_INTERFACE \| USB_DIR_OUT,
	384	UAC2_CS_CONTROL_SAM_FREQ << 8,
	385	snd_usb_ctrl_intf(chip) \| (clock << 8),
	386	&data, sizeof(data));
	387	if (err < 0) {
0ba41d91 TI	388	usb_audio_err(chip,
	389	"%d:%d: cannot set freq %d (v2): err %d\n",
	390	iface, fmt->altsetting, rate, err);
1dc669fe EZ	391	return err;
1dc669fe EZ	392	}
79f920fb	393
1dc669fe EZ	394	cur_rate = get_sample_rate_v2(chip, iface, fmt->altsetting, clock);
	395	} else {
	396	cur_rate = prev_rate;
	397	}
79f920fb	398
690a863f	399	if (cur_rate != rate) {
1dc669fe	400	if (!writeable) {
0ba41d91 TI	401	usb_audio_warn(chip,
	402	"%d:%d: freq mismatch (RO clock): req %d, clock runs @%d\n",
	403	iface, fmt->altsetting, rate, cur_rate);
1dc669fe EZ	404	return -ENXIO;
1dc669fe EZ	405	}
0ba41d91 TI	406	usb_audio_dbg(chip,
	407	"current rate %d is different from the runtime rate %d\n",
	408	cur_rate, rate);
690a863f TH	409	}
	410
	411	/* Some devices doesn't respond to sample rate changes while the
	412	* interface is active. */
	413	if (rate != prev_rate) {
	414	usb_set_interface(dev, iface, 0);
21bb5aaf	415	snd_usb_set_interface_quirk(dev);
690a863f	416	usb_set_interface(dev, iface, fmt->altsetting);
21bb5aaf	417	snd_usb_set_interface_quirk(dev);
690a863f	418	}
79f920fb DM	419
	420	return 0;
	421	}
	422
	423	int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
	424	struct usb_host_interface *alts,
	425	struct audioformat *fmt, int rate)
	426	{
8f898e92	427	switch (fmt->protocol) {
79f920fb	428	case UAC_VERSION_1:
a2acad82	429	default:
79f920fb DM	430	return set_sample_rate_v1(chip, iface, alts, fmt, rate);
	431
	432	case UAC_VERSION_2:
	433	return set_sample_rate_v2(chip, iface, alts, fmt, rate);
	434	}
79f920fb DM	435	}
79f920fb DM	436