On 3 June 2010 11:33, Stuart Longland redhatter@gentoo.org wrote:
On Thu, Jun 03, 2010 at 10:25:16AM +0200, Clemens Ladisch wrote:
Stuart Longland wrote:
SOC_DOUBLE_R_TLV("PCM Playback Volume", AIC3204_LDACVOL, AIC3204_RDACVOL, 0, 127, 0, dac_tlv),
However; it treats the bitfield as unsigned, which is wrong in this case. The bitfield is a signed integer in two's complement format. How do I convince ALSA that these integers have a sign bit?
ALSA's controls use signed values, it's the SOC_ macros that assume bitfields. You should be able to define a control with your own callbacks like in a non-ASoC driver.
Ahh okay... makes sense... I'll have a closer look; perhaps some additional macros could be written to allow use of signed integer bitfields as well. I'm sure the TLV320AIC3204 is not the only CODEC that uses such beasts.
I am not aware of any codec that uses signed bitfields. (My experience is with AC97, HD-Audio, DSPs and various ADC and DACs.) Your TLV320AIC3204 might be the first!!!
Kind Regards
James