xref: /OK3568_Linux_fs/kernel/Documentation/sound/cards/img-spdif-in.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
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2*4882a593SmuzhiyunImagination Technologies SPDIF Input Controllers
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5*4882a593SmuzhiyunThe Imagination Technologies SPDIF Input controller contains the following
6*4882a593Smuzhiyuncontrols:
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8*4882a593Smuzhiyun* name='IEC958 Capture Mask',index=0
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunThis control returns a mask that shows which of the IEC958 status bits
11*4882a593Smuzhiyuncan be read using the 'IEC958 Capture Default' control.
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun* name='IEC958 Capture Default',index=0
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15*4882a593SmuzhiyunThis control returns the status bits contained within the SPDIF stream that
16*4882a593Smuzhiyunis being received. The 'IEC958 Capture Mask' shows which bits can be read
17*4882a593Smuzhiyunfrom this control.
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19*4882a593Smuzhiyun* name='SPDIF In Multi Frequency Acquire',index=0
20*4882a593Smuzhiyun* name='SPDIF In Multi Frequency Acquire',index=1
21*4882a593Smuzhiyun* name='SPDIF In Multi Frequency Acquire',index=2
22*4882a593Smuzhiyun* name='SPDIF In Multi Frequency Acquire',index=3
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24*4882a593SmuzhiyunThis control is used to attempt acquisition of up to four different sample
25*4882a593Smuzhiyunrates. The active rate can be obtained by reading the 'SPDIF In Lock Frequency'
26*4882a593Smuzhiyuncontrol.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunWhen the value of this control is set to {0,0,0,0}, the rate given to hw_params
29*4882a593Smuzhiyunwill determine the single rate the block will capture. Else, the rate given to
30*4882a593Smuzhiyunhw_params will be ignored, and the block will attempt capture for each of the
31*4882a593Smuzhiyunfour sample rates set here.
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33*4882a593SmuzhiyunIf less than four rates are required, the same rate can be specified more than
34*4882a593Smuzhiyunonce
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun* name='SPDIF In Lock Frequency',index=0
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38*4882a593SmuzhiyunThis control returns the active capture rate, or 0 if a lock has not been
39*4882a593Smuzhiyunacquired
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun* name='SPDIF In Lock TRK',index=0
42*4882a593Smuzhiyun
43*4882a593SmuzhiyunThis control is used to modify the locking/jitter rejection characteristics
44*4882a593Smuzhiyunof the block. Larger values increase the locking range, but reduce jitter
45*4882a593Smuzhiyunrejection.
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun* name='SPDIF In Lock Acquire Threshold',index=0
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49*4882a593SmuzhiyunThis control is used to change the threshold at which a lock is acquired.
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun* name='SPDIF In Lock Release Threshold',index=0
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53*4882a593SmuzhiyunThis control is used to change the threshold at which a lock is released.
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