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)); 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 struct uac_clock_source_descriptor *cs_desc = 108 snd_usb_find_clock_source(chip->ctrl_intf, source_id); 109 110 if (!cs_desc) 111 return 0; 112 113 /* If a clock source can't tell us whether it's valid, we assume it is */ 114 if (!uac2_control_is_readable(cs_desc->bmControls, 115 UAC2_CS_CONTROL_CLOCK_VALID - 1)) 116 return 1; 117 118 err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 119 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 120 UAC2_CS_CONTROL_CLOCK_VALID << 8, 121 snd_usb_ctrl_intf(chip) | (source_id << 8), 122 &data, sizeof(data)); 123 124 if (err < 0) { 125 snd_printk(KERN_WARNING "%s(): cannot get clock validity for id %d\n", 126 __func__, source_id); 127 return 0; 128 } 129 130 return !!data; 131 } 132 133 static int __uac_clock_find_source(struct snd_usb_audio *chip, 134 int entity_id, unsigned long *visited) 135 { 136 struct uac_clock_source_descriptor *source; 137 struct uac_clock_selector_descriptor *selector; 138 struct uac_clock_multiplier_descriptor *multiplier; 139 140 entity_id &= 0xff; 141 142 if (test_and_set_bit(entity_id, visited)) { 143 snd_printk(KERN_WARNING 144 "%s(): recursive clock topology detected, id %d.\n", 145 __func__, entity_id); 146 return -EINVAL; 147 } 148 149 /* first, see if the ID we're looking for is a clock source already */ 150 source = snd_usb_find_clock_source(chip->ctrl_intf, entity_id); 151 if (source) 152 return source->bClockID; 153 154 selector = snd_usb_find_clock_selector(chip->ctrl_intf, entity_id); 155 if (selector) { 156 int ret; 157 158 /* the entity ID we are looking for is a selector. 159 * find out what it currently selects */ 160 ret = uac_clock_selector_get_val(chip, selector->bClockID); 161 if (ret < 0) 162 return ret; 163 164 /* Selector values are one-based */ 165 166 if (ret > selector->bNrInPins || ret < 1) { 167 printk(KERN_ERR 168 "%s(): selector reported illegal value, id %d, ret %d\n", 169 __func__, selector->bClockID, ret); 170 171 return -EINVAL; 172 } 173 174 return __uac_clock_find_source(chip, selector->baCSourceID[ret-1], 175 visited); 176 } 177 178 /* FIXME: multipliers only act as pass-thru element for now */ 179 multiplier = snd_usb_find_clock_multiplier(chip->ctrl_intf, entity_id); 180 if (multiplier) 181 return __uac_clock_find_source(chip, multiplier->bCSourceID, 182 visited); 183 184 return -EINVAL; 185 } 186 187 /* 188 * For all kinds of sample rate settings and other device queries, 189 * the clock source (end-leaf) must be used. However, clock selectors, 190 * clock multipliers and sample rate converters may be specified as 191 * clock source input to terminal. This functions walks the clock path 192 * to its end and tries to find the source. 193 * 194 * The 'visited' bitfield is used internally to detect recursive loops. 195 * 196 * Returns the clock source UnitID (>=0) on success, or an error. 197 */ 198 int snd_usb_clock_find_source(struct snd_usb_audio *chip, int entity_id) 199 { 200 DECLARE_BITMAP(visited, 256); 201 memset(visited, 0, sizeof(visited)); 202 return __uac_clock_find_source(chip, entity_id, visited); 203 } 204 205 static int set_sample_rate_v1(struct snd_usb_audio *chip, int iface, 206 struct usb_host_interface *alts, 207 struct audioformat *fmt, int rate) 208 { 209 struct usb_device *dev = chip->dev; 210 unsigned int ep; 211 unsigned char data[3]; 212 int err, crate; 213 214 ep = get_endpoint(alts, 0)->bEndpointAddress; 215 216 /* if endpoint doesn't have sampling rate control, bail out */ 217 if (!(fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE)) 218 return 0; 219 220 data[0] = rate; 221 data[1] = rate >> 8; 222 data[2] = rate >> 16; 223 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR, 224 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT, 225 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 226 data, sizeof(data))) < 0) { 227 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n", 228 dev->devnum, iface, fmt->altsetting, rate, ep); 229 return err; 230 } 231 232 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR, 233 USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_IN, 234 UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, 235 data, sizeof(data))) < 0) { 236 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n", 237 dev->devnum, iface, fmt->altsetting, ep); 238 return 0; /* some devices don't support reading */ 239 } 240 241 crate = data[0] | (data[1] << 8) | (data[2] << 16); 242 if (crate != rate) { 243 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate); 244 // runtime->rate = crate; 245 } 246 247 return 0; 248 } 249 250 static int set_sample_rate_v2(struct snd_usb_audio *chip, int iface, 251 struct usb_host_interface *alts, 252 struct audioformat *fmt, int rate) 253 { 254 struct usb_device *dev = chip->dev; 255 unsigned char data[4]; 256 int err, crate; 257 int clock = snd_usb_clock_find_source(chip, fmt->clock); 258 259 if (clock < 0) 260 return clock; 261 262 if (!uac_clock_source_is_valid(chip, clock)) { 263 /* TODO: should we try to find valid clock setups by ourself? */ 264 snd_printk(KERN_ERR "%d:%d:%d: clock source %d is not valid, cannot use\n", 265 dev->devnum, iface, fmt->altsetting, clock); 266 return -ENXIO; 267 } 268 269 data[0] = rate; 270 data[1] = rate >> 8; 271 data[2] = rate >> 16; 272 data[3] = rate >> 24; 273 if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC2_CS_CUR, 274 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, 275 UAC2_CS_CONTROL_SAM_FREQ << 8, 276 snd_usb_ctrl_intf(chip) | (clock << 8), 277 data, sizeof(data))) < 0) { 278 snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d (v2)\n", 279 dev->devnum, iface, fmt->altsetting, rate); 280 return err; 281 } 282 283 if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_CUR, 284 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN, 285 UAC2_CS_CONTROL_SAM_FREQ << 8, 286 snd_usb_ctrl_intf(chip) | (clock << 8), 287 data, sizeof(data))) < 0) { 288 snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq (v2)\n", 289 dev->devnum, iface, fmt->altsetting); 290 return err; 291 } 292 293 crate = data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24); 294 if (crate != rate) 295 snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate); 296 297 return 0; 298 } 299 300 int snd_usb_init_sample_rate(struct snd_usb_audio *chip, int iface, 301 struct usb_host_interface *alts, 302 struct audioformat *fmt, int rate) 303 { 304 struct usb_interface_descriptor *altsd = get_iface_desc(alts); 305 306 switch (altsd->bInterfaceProtocol) { 307 case UAC_VERSION_1: 308 default: 309 return set_sample_rate_v1(chip, iface, alts, fmt, rate); 310 311 case UAC_VERSION_2: 312 return set_sample_rate_v2(chip, iface, alts, fmt, rate); 313 } 314 } 315 316