/*
* 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))
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 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;
unsigned char data[4];
int err, crate;
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;
}
data[0] = rate;
data[1] = rate >> 8;
data[2] = rate >> 16;
data[3] = rate >> 24;
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;
}
if ((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))) < 0) {
snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
dev->devnum, iface, fmt->altsetting);
return err;
}
crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
if (crate != rate)
snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
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);
}
}
