xref: /linux/Documentation/sound/cards/img-spdif-in.rst (revision 9095bf25ea08135a5b74875dd0e3eeaddc4218a0)
1*f336c3f0STakashi Iwai================================================
2*f336c3f0STakashi IwaiImagination Technologies SPDIF Input Controllers
3*f336c3f0STakashi Iwai================================================
4*f336c3f0STakashi Iwai
5*f336c3f0STakashi IwaiThe Imagination Technologies SPDIF Input controller contains the following
6*f336c3f0STakashi Iwaicontrols:
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8*f336c3f0STakashi Iwai* name='IEC958 Capture Mask',index=0
9*f336c3f0STakashi Iwai
10*f336c3f0STakashi IwaiThis control returns a mask that shows which of the IEC958 status bits
11*f336c3f0STakashi Iwaican be read using the 'IEC958 Capture Default' control.
12*f336c3f0STakashi Iwai
13*f336c3f0STakashi Iwai* name='IEC958 Capture Default',index=0
14*f336c3f0STakashi Iwai
15*f336c3f0STakashi IwaiThis control returns the status bits contained within the SPDIF stream that
16*f336c3f0STakashi Iwaiis being received. The 'IEC958 Capture Mask' shows which bits can be read
17*f336c3f0STakashi Iwaifrom this control.
18*f336c3f0STakashi Iwai
19*f336c3f0STakashi Iwai* name='SPDIF In Multi Frequency Acquire',index=0
20*f336c3f0STakashi Iwai* name='SPDIF In Multi Frequency Acquire',index=1
21*f336c3f0STakashi Iwai* name='SPDIF In Multi Frequency Acquire',index=2
22*f336c3f0STakashi Iwai* name='SPDIF In Multi Frequency Acquire',index=3
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24*f336c3f0STakashi IwaiThis control is used to attempt acquisition of up to four different sample
25*f336c3f0STakashi Iwairates. The active rate can be obtained by reading the 'SPDIF In Lock Frequency'
26*f336c3f0STakashi Iwaicontrol.
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28*f336c3f0STakashi IwaiWhen the value of this control is set to {0,0,0,0}, the rate given to hw_params
29*f336c3f0STakashi Iwaiwill determine the single rate the block will capture. Else, the rate given to
30*f336c3f0STakashi Iwaihw_params will be ignored, and the block will attempt capture for each of the
31*f336c3f0STakashi Iwaifour sample rates set here.
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33*f336c3f0STakashi IwaiIf less than four rates are required, the same rate can be specified more than
34*f336c3f0STakashi Iwaionce
35*f336c3f0STakashi Iwai
36*f336c3f0STakashi Iwai* name='SPDIF In Lock Frequency',index=0
37*f336c3f0STakashi Iwai
38*f336c3f0STakashi IwaiThis control returns the active capture rate, or 0 if a lock has not been
39*f336c3f0STakashi Iwaiacquired
40*f336c3f0STakashi Iwai
41*f336c3f0STakashi Iwai* name='SPDIF In Lock TRK',index=0
42*f336c3f0STakashi Iwai
43*f336c3f0STakashi IwaiThis control is used to modify the locking/jitter rejection characteristics
44*f336c3f0STakashi Iwaiof the block. Larger values increase the locking range, but reduce jitter
45*f336c3f0STakashi Iwairejection.
46*f336c3f0STakashi Iwai
47*f336c3f0STakashi Iwai* name='SPDIF In Lock Acquire Threshold',index=0
48*f336c3f0STakashi Iwai
49*f336c3f0STakashi IwaiThis control is used to change the threshold at which a lock is acquired.
50*f336c3f0STakashi Iwai
51*f336c3f0STakashi Iwai* name='SPDIF In Lock Release Threshold',index=0
52*f336c3f0STakashi Iwai
53*f336c3f0STakashi IwaiThis control is used to change the threshold at which a lock is released.
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