sound/usb/clock.c

   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>
  22 #include <linux/list.h>
  23 #include <linux/slab.h>
  24 #include <linux/string.h>
  25 #include <linux/usb.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/mutex.h>
  28 #include <linux/usb/audio.h>
  29 #include <linux/usb/audio-v2.h>
  30
  31 #include <sound/core.h>
  32 #include <sound/info.h>
  33 #include <sound/pcm.h>
  34 #include <sound/pcm_params.h>
  35 #include <sound/initval.h>
  36
  37 #include "usbaudio.h"
  38 #include "card.h"
  39 #include "midi.h"
  40 #include "mixer.h"
  41 #include "proc.h"
  42 #include "quirks.h"
  43 #include "endpoint.h"
  44 #include "helper.h"
  45 #include "debug.h"
  46 #include "pcm.h"
  47 #include "urb.h"
  48 #include "format.h"
  49
  50 static struct uac_clock_source_descriptor *
  51         snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,
  52                                   int clock_id)
  53 {
  54         struct uac_clock_source_descriptor *cs = NULL;
  55
  56         while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
  57                                              ctrl_iface->extralen,
  58                                              cs, UAC2_CLOCK_SOURCE))) {
  59                 if (cs->bClockID == clock_id)
  60                         return cs;
  61         }
  62
  63         return NULL;
  64 }
  65
  66 static struct uac_clock_selector_descriptor *
  67         snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,
  68                                     int clock_id)
  69 {
  70         struct uac_clock_selector_descriptor *cs = NULL;
  71
  72         while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
  73                                              ctrl_iface->extralen,
  74                                              cs, UAC2_CLOCK_SELECTOR))) {
  75                 if (cs->bClockID == clock_id)
  76                         return cs;
  77         }
  78
  79         return NULL;
  80 }
  81
  82 static struct uac_clock_multiplier_descriptor *
  83         snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,
  84                                       int clock_id)
  85 {
  86         struct uac_clock_multiplier_descriptor *cs = NULL;
  87
  88         while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,
  89                                              ctrl_iface->extralen,
  90                                              cs, UAC2_CLOCK_MULTIPLIER))) {
  91                 if (cs->bClockID == clock_id)
  92                         return cs;
  93         }
  94
  95         return NULL;
  96 }
  97
  98 static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id)
  99 {
 100         unsigned char buf;
 101         int ret;
 102
 103         ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
 104                               UAC2_CS_CUR,
 105                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 106                               UAC2_CX_CLOCK_SELECTOR << 8, selector_id << 8,
 107                               &buf, sizeof(buf), 1000);
 108
 109         if (ret < 0)
 110                 return ret;
 111
 112         return buf;
 113 }
 114
 115 static bool uac_clock_source_is_valid(struct snd_usb_audio *chip, int source_id)
 116 {
 117         int err;
 118         unsigned char data;
 119         struct usb_device *dev = chip->dev;
 120
 121         err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 122                               USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 123                               UAC2_CS_CONTROL_CLOCK_VALID << 8, source_id << 8,
 124                               &data, sizeof(data), 1000);
 125
 126         if (err < 0) {
 127                 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n",
 128                            __func__, source_id);
 129                 return err;
 130         }
 131
 132         return !!data;
 133 }
 134
 135 /* Try to find the clock source ID of a given clock entity */
 136
 137 static int __uac_clock_find_source(struct snd_usb_audio *chip,
 138                                    struct usb_host_interface *host_iface,
 139                                    int entity_id, unsigned long *visited)
 140 {
 141         struct uac_clock_source_descriptor *source;
 142         struct uac_clock_selector_descriptor *selector;
 143         struct uac_clock_multiplier_descriptor *multiplier;
 144
 145         entity_id &= 0xff;
 146
 147         if (test_and_set_bit(entity_id, visited)) {
 148                 snd_printk(KERN_WARNING
 149                         "%s(): recursive clock topology detected, id %d.\n",
 150                         __func__, entity_id);
 151                 return -EINVAL;
 152         }
 153
 154         /* first, see if the ID we're looking for is a clock source already */
 155         source = snd_usb_find_clock_source(host_iface, entity_id);
 156         if (source)
 157                 return source->bClockID;
 158
 159         selector = snd_usb_find_clock_selector(host_iface, entity_id);
 160         if (selector) {
 161                 int ret;
 162
 163                 /* the entity ID we are looking for is a selector.
 164                  * find out what it currently selects */
 165                 ret = uac_clock_selector_get_val(chip, selector->bClockID);
 166                 if (ret < 0)
 167                         return ret;
 168
 169                 if (ret > selector->bNrInPins || ret < 1) {
 170                         printk(KERN_ERR
 171                                 "%s(): selector reported illegal value, id %d, ret %d\n",
 172                                 __func__, selector->bClockID, ret);
 173
 174                         return -EINVAL;
 175                 }
 176
 177                 return __uac_clock_find_source(chip, host_iface,
 178                                                selector->baCSourceID[ret-1],
 179                                                visited);
 180         }
 181
 182         /* FIXME: multipliers only act as pass-thru element for now */
 183         multiplier = snd_usb_find_clock_multiplier(host_iface, entity_id);
 184         if (multiplier)
 185                 return __uac_clock_find_source(chip, host_iface,
 186                                                multiplier->bCSourceID, visited);
 187
 188         return -EINVAL;
 189 }
 190
 191 int snd_usb_clock_find_source(struct snd_usb_audio *chip,
 192                               struct usb_host_interface *host_iface,
 193                               int entity_id)
 194 {
 195         DECLARE_BITMAP(visited, 256);
 196         memset(visited, 0, sizeof(visited));
 197         return __uac_clock_find_source(chip, host_iface, entity_id, visited);
 198 }
 199
 200 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface,
 201                               struct usb_host_interface *alts,
 202                               struct audioformat *fmt, int rate)
 203 {
 204         struct usb_device *dev = chip->dev;
 205         unsigned int ep;
 206         unsigned char data[3];
 207         int err, crate;
 208
 209         ep = get_endpoint(alts, 0)->bEndpointAddress;
 210
 211         /* if endpoint doesn't have sampling rate control, bail out */
 212         if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) {
 213                 snd_printk(KERN_WARNING "%d:%d:%d: endpoint lacks sample rate attribute bit, cannot set.\n",
 214                                    dev->devnum, iface, fmt->altsetting);
 215                 return 0;
 216         }
 217
 218         data[0] = rate;
 219         data[1] = rate >> 8;
 220         data[2] = rate >> 16;
 221         if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
 222                                    USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
 223                                    UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 224                                    data, sizeof(data), 1000)) < 0) {
 225                 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
 226                            dev->devnum, iface, fmt->altsetting, rate, ep);
 227                 return err;
 228         }
 229
 230         if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
 231                                    USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN,
 232                                    UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep,
 233                                    data, sizeof(data), 1000)) < 0) {
 234                 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
 235                            dev->devnum, iface, fmt->altsetting, ep);
 236                 return 0; /* some devices don't support reading */
 237         }
 238
 239         crate = data[0] | (data[1] << 8) | (data[2] << 16);
 240         if (crate != rate) {
 241                 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
 242                 // runtime->rate = crate;
 243         }
 244
 245         return 0;
 246 }
 247
 248 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface,
 249                               struct usb_host_interface *alts,
 250                               struct audioformat *fmt, int rate)
 251 {
 252         struct usb_device *dev = chip->dev;
 253         unsigned char data[4];
 254         int err, crate;
 255         int clock = snd_usb_clock_find_source(chip, chip->ctrl_intf, fmt->clock);
 256
 257         if (clock < 0)
 258                 return clock;
 259
 260         if (!uac_clock_source_is_valid(chip, clock)) {
 261                 snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n",
 262                            dev->devnum, iface, fmt->altsetting, clock);
 263                 return -ENXIO;
 264         }
 265
 266         data[0] = rate;
 267         data[1] = rate >> 8;
 268         data[2] = rate >> 16;
 269         data[3] = rate >> 24;
 270         if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR,
 271                                    USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
 272                                    UAC2_CS_CONTROL_SAM_FREQ << 8, clock << 8,
 273                                    data, sizeof(data), 1000)) < 0) {
 274                 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n",
 275                            dev->devnum, iface, fmt->altsetting, rate);
 276                 return err;
 277         }
 278
 279         if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR,
 280                                    USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
 281                                    UAC2_CS_CONTROL_SAM_FREQ << 8, clock << 8,
 282                                    data, sizeof(data), 1000)) < 0) {
 283                 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n",
 284                            dev->devnum, iface, fmt->altsetting);
 285                 return err;
 286         }
 287
 288         crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
 289         if (crate != rate)
 290                 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
 291
 292         return 0;
 293 }
 294
 295 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface,
 296                              struct usb_host_interface *alts,
 297                              struct audioformat *fmt, int rate)
 298 {
 299         struct usb_interface_descriptor *altsd = get_iface_desc(alts);
 300
 301         switch (altsd->bInterfaceProtocol) {
 302         case UAC_VERSION_1:
 303                 return set_sample_rate_v1(chip, iface, alts, fmt, rate);
 304
 305         case UAC_VERSION_2:
 306                 return set_sample_rate_v2(chip, iface, alts, fmt, rate);
 307         }
 308
 309         return -EINVAL;
 310 }
 311