Hi Russell,
On 03/30/2015 03:40 PM, Russell King wrote:
Add a helper to create the IEC958 channel status from an ALSA snd_pcm_runtime structure, taking account of the sample rate.
Signed-off-by: Russell King rmk+kernel@arm.linux.org.uk
include/sound/pcm_iec958.h | 9 ++++++ sound/core/Kconfig | 3 ++ sound/core/Makefile | 2 ++ sound/core/pcm_iec958.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 84 insertions(+) create mode 100644 include/sound/pcm_iec958.h create mode 100644 sound/core/pcm_iec958.c
diff --git a/include/sound/pcm_iec958.h b/include/sound/pcm_iec958.h new file mode 100644 index 000000000000..0eed397aca8e --- /dev/null +++ b/include/sound/pcm_iec958.h @@ -0,0 +1,9 @@ +#ifndef __SOUND_PCM_IEC958_H +#define __SOUND_PCM_IEC958_H
+#include <linux/types.h>
+int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
- size_t len);
+#endif diff --git a/sound/core/Kconfig b/sound/core/Kconfig index b534c8a6046b..1507469425ec 100644 --- a/sound/core/Kconfig +++ b/sound/core/Kconfig @@ -9,6 +9,9 @@ config SND_PCM config SND_PCM_ELD bool
+config SND_PCM_IEC958
- bool
- config SND_DMAENGINE_PCM tristate
diff --git a/sound/core/Makefile b/sound/core/Makefile index 591b49157b4d..70ea06712ec2 100644 --- a/sound/core/Makefile +++ b/sound/core/Makefile @@ -14,10 +14,12 @@ snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \ pcm_memory.o memalloc.o snd-pcm-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o snd-pcm-$(CONFIG_SND_PCM_ELD) += pcm_drm_eld.o +snd-pcm-$(CONFIG_SND_PCM_IEC958) += snd-pcm-iec958.o
# for trace-points CFLAGS_pcm_lib.o := -I$(src)
+snd-pcm-iec958-objs := pcm_iec958.o snd-pcm-dmaengine-objs := pcm_dmaengine.o
snd-rawmidi-objs := rawmidi.o diff --git a/sound/core/pcm_iec958.c b/sound/core/pcm_iec958.c new file mode 100644 index 000000000000..e1ff88a17dde --- /dev/null +++ b/sound/core/pcm_iec958.c @@ -0,0 +1,70 @@ +/*
- 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 as published by
- the Free Software Foundation; either version 2 of the License.
- */
+#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;
- 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;- }
- 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;
Pretty good, also suitable to rockchip platform, but why not add the "IEC958_AES2_CON_CHANNEL_MASK" & "IEC958_AES2_CON_WORDLEN" ?
Seems sample frequency & channle number & word length are the basic message :)
Best regards. Yakir Yang
- return len;
+} +EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);