- 根目录:
- 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->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 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;
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;
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);
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);
}
}