diff options
| author | Takashi Iwai <tiwai@suse.de> | 2020-11-23 09:53:22 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2020-11-23 15:13:47 +0100 |
| commit | e42a09bc520e94375501a8f8e769b867d8063d9d (patch) | |
| tree | ea21c41927922dbf767558e1dfb8a2a6883aa787 /sound/usb/helper.c | |
| parent | ALSA: usb-audio: Drop keep_interface flag again (diff) | |
| download | linux-e42a09bc520e94375501a8f8e769b867d8063d9d.tar.xz linux-e42a09bc520e94375501a8f8e769b867d8063d9d.zip | |
ALSA: usb-audio: Add snd_usb_get_host_interface() helper
Add a helper function to retrieve the usb_host_interface object from
the given interface and altsetting number pair, which is a commonly
used procedure in the driver code.
No functional changes, just minor code refactoring.
Tested-by: Keith Milner <kamilner@superlative.org>
Tested-by: Dylan Robinson <dylan_robinson@motu.com>
Link: https://lore.kernel.org/r/20201123085347.19667-17-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/helper.c')
| -rw-r--r-- | sound/usb/helper.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/sound/usb/helper.c b/sound/usb/helper.c index cf92d7110773..a4410267bf70 100644 --- a/sound/usb/helper.c +++ b/sound/usb/helper.c @@ -121,3 +121,13 @@ unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip, return 0; } +struct usb_host_interface * +snd_usb_get_host_interface(struct snd_usb_audio *chip, int ifnum, int altsetting) +{ + struct usb_interface *iface; + + iface = usb_ifnum_to_if(chip->dev, ifnum); + if (!iface) + return NULL; + return usb_altnum_to_altsetting(iface, altsetting); +} |