diff options
Diffstat (limited to 'sound/usb/helper.c')
| -rw-r--r-- | sound/usb/helper.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/sound/usb/helper.c b/sound/usb/helper.c index bf80e55d013a..497d2b27fb59 100644 --- a/sound/usb/helper.c +++ b/sound/usb/helper.c @@ -62,6 +62,7 @@ void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype } return NULL; } +EXPORT_SYMBOL_GPL(snd_usb_find_csint_desc); /* * Wrapper for usb_control_msg(). @@ -130,3 +131,37 @@ snd_usb_get_host_interface(struct snd_usb_audio *chip, int ifnum, int altsetting return NULL; return usb_altnum_to_altsetting(iface, altsetting); } + +int snd_usb_add_ctrl_interface_link(struct snd_usb_audio *chip, int ifnum, + int ctrlif) +{ + struct usb_device *dev = chip->dev; + struct usb_host_interface *host_iface; + + if (chip->num_intf_to_ctrl >= MAX_CARD_INTERFACES) { + dev_info(&dev->dev, "Too many interfaces assigned to the single USB-audio card\n"); + return -EINVAL; + } + + /* find audiocontrol interface */ + host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0]; + + chip->intf_to_ctrl[chip->num_intf_to_ctrl].interface = ifnum; + chip->intf_to_ctrl[chip->num_intf_to_ctrl].ctrl_intf = host_iface; + chip->num_intf_to_ctrl++; + + return 0; +} + +struct usb_host_interface *snd_usb_find_ctrl_interface(struct snd_usb_audio *chip, + int ifnum) +{ + int i; + + for (i = 0; i < chip->num_intf_to_ctrl; ++i) + if (chip->intf_to_ctrl[i].interface == ifnum) + return chip->intf_to_ctrl[i].ctrl_intf; + + /* Fallback to first audiocontrol interface */ + return chip->ctrl_intf; +} |