--- /dev/null
+/*
+ * 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);
+ }
+}
+
Code Review / kvmfornfv.git / blobdiff