Improve granularity of format selection for S32/U32 formats by adding
constants representing 20, 24 and 32 most significant bits.
To make it easy for drivers to utilize those constants, introduce
snd_pcm_subformat_width() and params_bps(). While the former is
self-explanatory, the latter returns the bit-per-sample value based on
format, subformat and msbits characteristics of the provided hw_params.
Signed-off-by: Cezary Rojewski <cezary.rojewski@xxxxxxxxx>
---
include/sound/pcm.h | 8 ++++++++
include/sound/pcm_params.h | 2 ++
include/uapi/sound/asound.h | 5 ++++-
sound/core/pcm_lib.c | 30 ++++++++++++++++++++++++++++++
sound/core/pcm_misc.c | 23 +++++++++++++++++++++++
tools/include/uapi/sound/asound.h | 5 ++++-
6 files changed, 71 insertions(+), 2 deletions(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 19f564606ac4..f78441ff9d85 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -31,6 +31,7 @@
struct snd_pcm_hardware {
unsigned int info; /* SNDRV_PCM_INFO_* */
u64 formats; /* SNDRV_PCM_FMTBIT_* */
+ u64 subformats; /* SNDRV_PCM_SUBFMTBIT_* */
unsigned int rates; /* SNDRV_PCM_RATE_* */
unsigned int rate_min; /* min rate */
unsigned int rate_max; /* max rate */
@@ -219,6 +220,12 @@ struct snd_pcm_ops {
#define SNDRV_PCM_FMTBIT_U20 SNDRV_PCM_FMTBIT_U20_BE
#endif
+#define _SNDRV_PCM_SUBFMTBIT(fmt) BIT((__force int)SNDRV_PCM_SUBFORMAT_##fmt)
+#define SNDRV_PCM_SUBFMTBIT_STD _SNDRV_PCM_SUBFMTBIT(STD)
+#define SNDRV_PCM_SUBFMTBIT_MSBITS_20 _SNDRV_PCM_SUBFMTBIT(MSBITS_20)
+#define SNDRV_PCM_SUBFMTBIT_MSBITS_24 _SNDRV_PCM_SUBFMTBIT(MSBITS_24)
+#define SNDRV_PCM_SUBFMTBIT_MSBITS_32 _SNDRV_PCM_SUBFMTBIT(MSBITS_32)
+
struct snd_pcm_file {
struct snd_pcm_substream *substream;
int no_compat_mmap;
@@ -1130,6 +1137,7 @@ int snd_pcm_format_physical_width(snd_pcm_format_t format); /* in bits */
ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples);
const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format);
int snd_pcm_format_set_silence(snd_pcm_format_t format, void *buf, unsigned int frames);
+int snd_pcm_subformat_width(snd_pcm_subformat_t subformat);
void snd_pcm_set_ops(struct snd_pcm * pcm, int direction,
const struct snd_pcm_ops *ops);
diff --git a/include/sound/pcm_params.h b/include/sound/pcm_params.h
index ba184f49f7e1..f09ae37ed44d 100644
--- a/include/sound/pcm_params.h
+++ b/include/sound/pcm_params.h
@@ -362,6 +362,8 @@ static inline int params_physical_width(const struct snd_pcm_hw_params *p)
return snd_pcm_format_physical_width(params_format(p));
}
+int params_bps(const struct snd_pcm_hw_params *p);
+
static inline void
params_set_format(struct snd_pcm_hw_params *p, snd_pcm_format_t fmt)
{
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index d6864f672630..27db9f3558fd 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -268,7 +268,10 @@ typedef int __bitwise snd_pcm_format_t;
typedef int __bitwise snd_pcm_subformat_t;
#define SNDRV_PCM_SUBFORMAT_STD ((__force snd_pcm_subformat_t) 0)
-#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_STD
+#define SNDRV_PCM_SUBFORMAT_MSBITS_20 ((__force snd_pcm_subformat_t) 1)
+#define SNDRV_PCM_SUBFORMAT_MSBITS_24 ((__force snd_pcm_subformat_t) 2)
+#define SNDRV_PCM_SUBFORMAT_MSBITS_32 ((__force snd_pcm_subformat_t) 3)
+#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_MSBITS_32
#define SNDRV_PCM_INFO_MMAP 0x00000001 /* hardware supports mmap */
#define SNDRV_PCM_INFO_MMAP_VALID 0x00000002 /* period data are valid during transfer */
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 9c121a921b04..4a60632220c2 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1706,6 +1706,36 @@ int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
}
EXPORT_SYMBOL(snd_pcm_hw_param_last);
+/**
+ * params_bps - Get the number of bits per the sample.
+ * @p: hardware parameters
+ *
+ * Return: The number of bits per sample based on the format,
+ * subformat and msbits the specified hw params has.
+ */
+int params_bps(const struct snd_pcm_hw_params *p)
+{
+ snd_pcm_subformat_t subformat = params_subformat(p);
+ snd_pcm_format_t format = params_format(p);
+ int width;
+
+ switch (format) {
+ case SNDRV_PCM_FORMAT_S32_LE:
+ case SNDRV_PCM_FORMAT_U32_LE:
+ case SNDRV_PCM_FORMAT_S32_BE:
+ case SNDRV_PCM_FORMAT_U32_BE:
+ width = snd_pcm_subformat_width(subformat);
+ if (width)
+ return width;
+ if (p->msbits)
+ return (int)p->msbits;
+ fallthrough;
+ default:
+ return snd_pcm_format_width(format);
+ }
+}
+EXPORT_SYMBOL(params_bps);
+
static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
void *arg)
{
diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c
index 5588b6a1ee8b..127bb36fd2e4 100644
--- a/sound/core/pcm_misc.c
+++ b/sound/core/pcm_misc.c
@@ -482,6 +482,29 @@ int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int
}
EXPORT_SYMBOL(snd_pcm_format_set_silence);
+/**
+ * snd_pcm_subformat_width - return the bit-width of the subformat
+ * @subformat: the subformat to check
+ *
+ * Return: The bit-width of the subformat, or a negative error code
+ * otherwise.
+ */
+int snd_pcm_subformat_width(snd_pcm_subformat_t subformat)
+{
+ switch (subformat) {
+ case SNDRV_PCM_SUBFORMAT_MSBITS_20:
+ return 20;
+ case SNDRV_PCM_SUBFORMAT_MSBITS_24:
+ return 24;
+ case SNDRV_PCM_SUBFORMAT_MSBITS_32:
+ return 32;
+ case SNDRV_PCM_SUBFORMAT_STD:
+ default:
+ return 0;
+ }
+}
+EXPORT_SYMBOL(snd_pcm_subformat_width);
+
/**
* snd_pcm_hw_limit_rates - determine rate_min/rate_max fields
* @hw: the pcm hw instance
diff --git a/tools/include/uapi/sound/asound.h b/tools/include/uapi/sound/asound.h
index 0aa955aa8246..eb45a698767f 100644
--- a/tools/include/uapi/sound/asound.h
+++ b/tools/include/uapi/sound/asound.h
@@ -267,7 +267,10 @@ typedef int __bitwise snd_pcm_format_t;
typedef int __bitwise snd_pcm_subformat_t;
#define SNDRV_PCM_SUBFORMAT_STD ((__force snd_pcm_subformat_t) 0)
-#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_STD
+#define SNDRV_PCM_SUBFORMAT_MSBITS_20 ((__force snd_pcm_subformat_t) 1)
+#define SNDRV_PCM_SUBFORMAT_MSBITS_24 ((__force snd_pcm_subformat_t) 2)
+#define SNDRV_PCM_SUBFORMAT_MSBITS_32 ((__force snd_pcm_subformat_t) 3)
+#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_MSBITS_32
#define SNDRV_PCM_INFO_MMAP 0x00000001 /* hardware supports mmap */
#define SNDRV_PCM_INFO_MMAP_VALID 0x00000002 /* period data are valid during transfer */
--
2.25.1
