96 lines
2.2 KiB
C
96 lines
2.2 KiB
C
/*
|
|
* PCM DRM helpers
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/export.h>
|
|
#include <linux/types.h>
|
|
#include <sound/asoundef.h>
|
|
#include <sound/pcm.h>
|
|
#include <sound/pcm_iec958.h>
|
|
|
|
/**
|
|
* snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
|
|
* @runtime: pcm runtime structure with ->rate filled in
|
|
* @cs: channel status buffer, at least four bytes
|
|
* @len: length of channel status buffer
|
|
*
|
|
* Create the consumer format channel status data in @cs of maximum size
|
|
* @len corresponding to the parameters of the PCM runtime @runtime.
|
|
*
|
|
* Drivers may wish to tweak the contents of the buffer after creation.
|
|
*
|
|
* Returns: length of buffer, or negative error code if something failed.
|
|
*/
|
|
int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
|
|
size_t len)
|
|
{
|
|
unsigned int fs, ws;
|
|
|
|
if (len < 4)
|
|
return -EINVAL;
|
|
|
|
switch (runtime->rate) {
|
|
case 32000:
|
|
fs = IEC958_AES3_CON_FS_32000;
|
|
break;
|
|
case 44100:
|
|
fs = IEC958_AES3_CON_FS_44100;
|
|
break;
|
|
case 48000:
|
|
fs = IEC958_AES3_CON_FS_48000;
|
|
break;
|
|
case 88200:
|
|
fs = IEC958_AES3_CON_FS_88200;
|
|
break;
|
|
case 96000:
|
|
fs = IEC958_AES3_CON_FS_96000;
|
|
break;
|
|
case 176400:
|
|
fs = IEC958_AES3_CON_FS_176400;
|
|
break;
|
|
case 192000:
|
|
fs = IEC958_AES3_CON_FS_192000;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (len > 4) {
|
|
switch (snd_pcm_format_width(runtime->format)) {
|
|
case 16:
|
|
ws = IEC958_AES4_CON_WORDLEN_20_16;
|
|
break;
|
|
case 18:
|
|
ws = IEC958_AES4_CON_WORDLEN_22_18;
|
|
break;
|
|
case 20:
|
|
ws = IEC958_AES4_CON_WORDLEN_20_16 |
|
|
IEC958_AES4_CON_MAX_WORDLEN_24;
|
|
break;
|
|
case 24:
|
|
ws = IEC958_AES4_CON_WORDLEN_24_20 |
|
|
IEC958_AES4_CON_MAX_WORDLEN_24;
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
memset(cs, 0, len);
|
|
|
|
cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
|
|
cs[1] = IEC958_AES1_CON_GENERAL;
|
|
cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
|
|
cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs;
|
|
|
|
if (len > 4)
|
|
cs[4] = ws;
|
|
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
|