ALSA: usb-audio: parse clock topology of UAC2 devices

[safe/jmp/linux-2.6] / sound / usb / endpoint.c

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 28ee1ce..9593b91 100644 (file)
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -190,6 +190,38 @@ static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
        return attributes;
 }
 
+static struct uac2_input_terminal_descriptor *
+       snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
+                                              int terminal_id)
+{
+       struct uac2_input_terminal_descriptor *term = NULL;
+
+       while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
+                                              ctrl_iface->extralen,
+                                              term, UAC_INPUT_TERMINAL))) {
+               if (term->bTerminalID == terminal_id)
+                       return term;
+       }
+
+       return NULL;
+}
+
+static struct uac2_output_terminal_descriptor *
+       snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
+                                               int terminal_id)
+{
+       struct uac2_output_terminal_descriptor *term = NULL;
+
+       while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
+                                              ctrl_iface->extralen,
+                                              term, UAC_OUTPUT_TERMINAL))) {
+               if (term->bTerminalID == terminal_id)
+                       return term;
+       }
+
+       return NULL;
+}
+
 int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 {
        struct usb_device *dev;
@@ -199,7 +231,7 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
        int i, altno, err, stream;
        int format = 0, num_channels = 0;
        struct audioformat *fp = NULL;
-       int num, protocol;
+       int num, protocol, clock = 0;
        struct uac_format_type_i_continuous_descriptor *fmt;
 
        dev = chip->dev;
@@ -263,6 +295,8 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
                }
 
                case UAC_VERSION_2: {
+                       struct uac2_input_terminal_descriptor *input_term;
+                       struct uac2_output_terminal_descriptor *output_term;
                        struct uac_as_header_descriptor_v2 *as =
                                snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
 
@@ -281,7 +315,25 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
                        num_channels = as->bNrChannels;
                        format = le32_to_cpu(as->bmFormats);
 
-                       break;
+                       /* lookup the terminal associated to this interface
+                        * to extract the clock */
+                       input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
+                                                                           as->bTerminalLink);
+                       if (input_term) {
+                               clock = input_term->bCSourceID;
+                               break;
+                       }
+
+                       output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
+                                                                             as->bTerminalLink);
+                       if (output_term) {
+                               clock = output_term->bCSourceID;
+                               break;
+                       }
+
+                       snd_printk(KERN_ERR "%d:%u:%d : bogus bTerminalLink %d\n",
+                                  dev->devnum, iface_no, altno, as->bTerminalLink);
+                       continue;
                }
 
                default:
@@ -338,6 +390,7 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
                        fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
                                        * (fp->maxpacksize & 0x7ff);
                fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
+               fp->clock = clock;
 
                /* some quirks for attributes here */