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 } 305 306