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