On Fri, 19 Feb 2010, Nurkkala Eero.An (EXT-Offcode/Oulu) wrote:
+ +static const struct snd_kcontrol_new omap_mcbsp2_st_controls[] = { + SOC_SINGLE_EXT("McBSP2 Sidetone Switch", 1, 0, 1, 0, + omap_mcbsp_st_get_mode, omap_mcbsp_st_put_mode), + OMAP_MCBSP_SOC_SINGLE_S16_EXT("McBSP2 Sidetone Channel 0 Volume", + -32768, 32767, + omap_mcbsp2_get_st_ch0_volume, + omap_mcbsp2_set_st_ch0_volume), + OMAP_MCBSP_SOC_SINGLE_S16_EXT("McBSP2 Sidetone Channel 1 Volume", + -32768, 32767, + omap_mcbsp2_get_st_ch1_volume, + omap_mcbsp2_set_st_ch1_volume), +}; + +static const struct snd_kcontrol_new omap_mcbsp3_st_controls[] = { + SOC_SINGLE_EXT("McBSP3 Sidetone Switch", 2, 0, 1, 0, + omap_mcbsp_st_get_mode, omap_mcbsp_st_put_mode), + OMAP_MCBSP_SOC_SINGLE_S16_EXT("McBSP3 Sidetone Channel 0 Volume", + -32768, 32767, + omap_mcbsp3_get_st_ch0_volume, + omap_mcbsp3_set_st_ch0_volume), + OMAP_MCBSP_SOC_SINGLE_S16_EXT("McBSP3 Sidetone Channel 1 Volume", + -32768, 32767, + omap_mcbsp3_get_st_ch1_volume, + omap_mcbsp3_set_st_ch1_volume), +}; +Just a short note, "Gain values are in the interval (-2..2) in Q1.14 format, negative values are expressed in 2's complement."So, from: http://en.wikipedia.org/wiki/Q_(number_format) " The notation used is Qm.n, where:* Q designates that the number is in Q format notation — the Texas Instruments representation for signed fixed-point numbers. * m (optional; default=0) is the number of bits used to designate the two's complement integer portion of the number, exclusive of the sign bit. * n is the number of bits used to designate the two's complement fractional portion of the number, i.e. the number of bits to the right of the binary point. "..so if you do tests, and find out the gains behave "irrationally" occasionally, you can't possibly claim it isn't working as expected ;)
I'm a bit confused. What do you mean by that?AFAICS, Q1.14 defines values [-16384.0, +16383.5], which are mapped in the driver to integers [-32768, 32767], right? Moreover, those Q1.14 values in registers are mapped to [-2, 2] in HW. So is there a problem somewhere?
Cheers, Ilkka
_______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
