From dcbe7bcfa32c5bc4f9bb6c75d4d41bb4db8c36fc Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Mon, 31 May 2010 13:35:36 +0200 Subject: [PATCH] ALSA: usb-audio: UAC2: clean up parsing of bmaControls Introduce two new static inline functions for a more readable parsing of UAC2 bmaControls. Signed-off-by: Daniel Mack Signed-off-by: Takashi Iwai --- include/linux/usb/audio-v2.h | 10 ++++++++++ sound/usb/mixer.c | 8 ++++---- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/include/linux/usb/audio-v2.h b/include/linux/usb/audio-v2.h index 92f1d99..8f91be3 100644 --- a/include/linux/usb/audio-v2.h +++ b/include/linux/usb/audio-v2.h @@ -18,6 +18,16 @@ /* v1.0 and v2.0 of this standard have many things in common. For the rest * of the definitions, please refer to audio.h */ +static inline bool uac2_control_is_readable(u32 bmControls, u8 control) +{ + return (bmControls >> (control * 2)) & 0x1; +} + +static inline bool uac2_control_is_writeable(u32 bmControls, u8 control) +{ + return (bmControls >> (control * 2)) & 0x2; +} + /* 4.7.2.1 Clock Source Descriptor */ struct uac_clock_source_descriptor { diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 03ce971..43d6417 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1188,9 +1188,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void for (j = 0; j < channels; j++) { unsigned int mask = snd_usb_combine_bytes(bmaControls + csize * (j+1), csize); - if (mask & (1 << (i * 2))) { + if (uac2_control_is_readable(mask, i)) { ch_bits |= (1 << j); - if (~mask & (1 << ((i * 2) + 1))) + if (!uac2_control_is_writeable(mask, i)) ch_read_only |= (1 << j); } } @@ -1198,9 +1198,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void /* FIXME: the whole unit is read-only if any of the channels is marked read-only */ if (ch_bits & 1) /* the first channel must be set (for ease of programming) */ build_feature_ctl(state, _ftr, ch_bits, i, &iterm, unitid, !!ch_read_only); - if (master_bits & (1 << i * 2)) + if (uac2_control_is_readable(master_bits, i)) build_feature_ctl(state, _ftr, 0, i, &iterm, unitid, - ~master_bits & (1 << ((i * 2) + 1))); + !uac2_control_is_writeable(master_bits, i)); } } -- 1.8.2.3