Re: [PATCH v3 1/2] ALSA: pcm: add SNDRV_PCM_FORMAT_{S, U}20
From: Takashi Sakamoto
Date: Mon Nov 27 2017 - 12:40:45 EST
On Nov 27 2017 08:09, Maciej S. Szmigiero wrote:
This format is similar to existing SNDRV_PCM_FORMAT_{S,U}20_3 that keep
20-bit PCM samples in 3 bytes, however i.MX6 platform SSI FIFO does not
allow 3-byte accesses (including DMA) so a 4-byte (more conventional)
format is needed for it.
Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
---
Changes from v1: Drop "_4" suffix from these formats since they aren't
non-standard ones, use empty format slots starting from format number 25
for them, add information that they are LSB justified formats.
Changes from v2: Adapt a comment in sound/core/pcm_misc.c so it still
refers to the same sample formats as before.
Corresponding alsa-lib changes will be posted as soon as this patch is
merged on the kernel side, to keep alsa-lib and kernel synchronized.
include/sound/pcm.h | 8 ++++++++
include/sound/soc-dai.h | 2 ++
include/uapi/sound/asound.h | 9 +++++++++
sound/core/pcm_misc.c | 19 ++++++++++++++++++-
4 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 24febf9e177c..e054c583d3b3 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -169,6 +169,10 @@ struct snd_pcm_ops {
#define SNDRV_PCM_FMTBIT_IMA_ADPCM _SNDRV_PCM_FMTBIT(IMA_ADPCM)
#define SNDRV_PCM_FMTBIT_MPEG _SNDRV_PCM_FMTBIT(MPEG)
#define SNDRV_PCM_FMTBIT_GSM _SNDRV_PCM_FMTBIT(GSM)
+#define SNDRV_PCM_FMTBIT_S20_LE _SNDRV_PCM_FMTBIT(S20_LE)
+#define SNDRV_PCM_FMTBIT_U20_LE _SNDRV_PCM_FMTBIT(U20_LE)
+#define SNDRV_PCM_FMTBIT_S20_BE _SNDRV_PCM_FMTBIT(S20_BE)
+#define SNDRV_PCM_FMTBIT_U20_BE _SNDRV_PCM_FMTBIT(U20_BE)
#define SNDRV_PCM_FMTBIT_SPECIAL _SNDRV_PCM_FMTBIT(SPECIAL)
#define SNDRV_PCM_FMTBIT_S24_3LE _SNDRV_PCM_FMTBIT(S24_3LE)
#define SNDRV_PCM_FMTBIT_U24_3LE _SNDRV_PCM_FMTBIT(U24_3LE)
@@ -202,6 +206,8 @@ struct snd_pcm_ops {
#define SNDRV_PCM_FMTBIT_FLOAT SNDRV_PCM_FMTBIT_FLOAT_LE
#define SNDRV_PCM_FMTBIT_FLOAT64 SNDRV_PCM_FMTBIT_FLOAT64_LE
#define SNDRV_PCM_FMTBIT_IEC958_SUBFRAME SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE
+#define SNDRV_PCM_FMTBIT_S20 SNDRV_PCM_FMTBIT_S20_LE
+#define SNDRV_PCM_FMTBIT_U20 SNDRV_PCM_FMTBIT_U20_LE
#endif
#ifdef SNDRV_BIG_ENDIAN
#define SNDRV_PCM_FMTBIT_S16 SNDRV_PCM_FMTBIT_S16_BE
@@ -213,6 +219,8 @@ struct snd_pcm_ops {
#define SNDRV_PCM_FMTBIT_FLOAT SNDRV_PCM_FMTBIT_FLOAT_BE
#define SNDRV_PCM_FMTBIT_FLOAT64 SNDRV_PCM_FMTBIT_FLOAT64_BE
#define SNDRV_PCM_FMTBIT_IEC958_SUBFRAME SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_BE
+#define SNDRV_PCM_FMTBIT_S20 SNDRV_PCM_FMTBIT_S20_BE
+#define SNDRV_PCM_FMTBIT_U20 SNDRV_PCM_FMTBIT_U20_BE
#endif
struct snd_pcm_file {
diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index 58acd00cae19..d970879944fc 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -102,6 +102,8 @@ struct snd_compr_stream;
SNDRV_PCM_FMTBIT_S16_BE |\
SNDRV_PCM_FMTBIT_S20_3LE |\
SNDRV_PCM_FMTBIT_S20_3BE |\
+ SNDRV_PCM_FMTBIT_S20_LE |\
+ SNDRV_PCM_FMTBIT_S20_BE |\
SNDRV_PCM_FMTBIT_S24_3LE |\
SNDRV_PCM_FMTBIT_S24_3BE |\
SNDRV_PCM_FMTBIT_S32_LE |\
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index c227ccba60ae..7385024041d2 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -214,6 +214,11 @@ typedef int __bitwise snd_pcm_format_t;
#define SNDRV_PCM_FORMAT_IMA_ADPCM ((__force snd_pcm_format_t) 22)
#define SNDRV_PCM_FORMAT_MPEG ((__force snd_pcm_format_t) 23)
#define SNDRV_PCM_FORMAT_GSM ((__force snd_pcm_format_t) 24)
+#define SNDRV_PCM_FORMAT_S20_LE ((__force snd_pcm_format_t) 25) /* \ */
+#define SNDRV_PCM_FORMAT_S20_BE ((__force snd_pcm_format_t) 26) /* | */
+#define SNDRV_PCM_FORMAT_U20_LE ((__force snd_pcm_format_t) 27) /* | in four bytes, */
+#define SNDRV_PCM_FORMAT_U20_BE ((__force snd_pcm_format_t) 28) /* / LSB justified */
+/* gap in the numbering for a future standard linear format */
#define SNDRV_PCM_FORMAT_SPECIAL ((__force snd_pcm_format_t) 31)
#define SNDRV_PCM_FORMAT_S24_3LE ((__force snd_pcm_format_t) 32) /* in three bytes */
#define SNDRV_PCM_FORMAT_S24_3BE ((__force snd_pcm_format_t) 33) /* in three bytes */
@@ -248,6 +253,8 @@ typedef int __bitwise snd_pcm_format_t;
#define SNDRV_PCM_FORMAT_FLOAT SNDRV_PCM_FORMAT_FLOAT_LE
#define SNDRV_PCM_FORMAT_FLOAT64 SNDRV_PCM_FORMAT_FLOAT64_LE
#define SNDRV_PCM_FORMAT_IEC958_SUBFRAME SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
+#define SNDRV_PCM_FORMAT_S20 SNDRV_PCM_FORMAT_S20_LE
+#define SNDRV_PCM_FORMAT_U20 SNDRV_PCM_FORMAT_U20_LE
#endif
#ifdef SNDRV_BIG_ENDIAN
#define SNDRV_PCM_FORMAT_S16 SNDRV_PCM_FORMAT_S16_BE
@@ -259,6 +266,8 @@ typedef int __bitwise snd_pcm_format_t;
#define SNDRV_PCM_FORMAT_FLOAT SNDRV_PCM_FORMAT_FLOAT_BE
#define SNDRV_PCM_FORMAT_FLOAT64 SNDRV_PCM_FORMAT_FLOAT64_BE
#define SNDRV_PCM_FORMAT_IEC958_SUBFRAME SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE
+#define SNDRV_PCM_FORMAT_S20 SNDRV_PCM_FORMAT_S20_BE
+#define SNDRV_PCM_FORMAT_U20 SNDRV_PCM_FORMAT_U20_BE
#endif
typedef int __bitwise snd_pcm_subformat_t;
diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c
index 9be81025372f..c4eb561d2008 100644
--- a/sound/core/pcm_misc.c
+++ b/sound/core/pcm_misc.c
@@ -163,13 +163,30 @@ static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
.width = 32, .phys = 32, .le = 0, .signd = 0,
.silence = { 0x69, 0x69, 0x69, 0x69 },
},
- /* FIXME: the following three formats are not defined properly yet */
+ /* FIXME: the following two formats are not defined properly yet */
[SNDRV_PCM_FORMAT_MPEG] = {
.le = -1, .signd = -1,
},
[SNDRV_PCM_FORMAT_GSM] = {
.le = -1, .signd = -1,
},
+ [SNDRV_PCM_FORMAT_S20_LE] = {
+ .width = 20, .phys = 32, .le = 1, .signd = 1,
+ .silence = {},
+ },
+ [SNDRV_PCM_FORMAT_S20_BE] = {
+ .width = 20, .phys = 32, .le = 0, .signd = 1,
+ .silence = {},
+ },
+ [SNDRV_PCM_FORMAT_U20_LE] = {
+ .width = 20, .phys = 32, .le = 1, .signd = 0,
+ .silence = { 0x00, 0x00, 0x08, 0x00 },
+ },
+ [SNDRV_PCM_FORMAT_U20_BE] = {
+ .width = 20, .phys = 32, .le = 0, .signd = 0,
+ .silence = { 0x00, 0x08, 0x00, 0x00 },
+ },
+ /* FIXME: the following format is not defined properly yet */
[SNDRV_PCM_FORMAT_SPECIAL] = {
.le = -1, .signd = -1,
},
Looks good to me.
Reviewed-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
In next time to post any of your v2 patchset, it's better to add
commenters of v1 patchset to CC list, so that your patch reaches the
person who has practical interests in it.
I'm waiting for your another patch to alsa-lib.
Thanks
Takashi Sakamoto