Improve granularity of format selection for linear formats by adding constants representing MAX, 20, 24 most significant bits.
The MAX means the maximum number of significant bits which can the physical format hold. For 32-bit formats, MAX is related to 32 bits. For 8-bit formats, MAX is related to 8 bits etc.
The drivers may use snd_pcm_hw_constraint_subformats with a simple format -> subformats table.
Original proposal - https://lore.kernel.org/alsa-devel/20230811164853.1797547-1-cezary.rojewski@...
Cc: Cezary Rojewski cezary.rojewski@intel.com Signed-off-by: Jaroslav Kysela perex@perex.cz
---
v2: - added link to the original proposal (RFC) - reshuffle declarations in snd_pcm_hw_rule_subformats - remove nmemd from description - snd_pcm_hw_constraint_subformats - more strict handling for SNDRV_PCM_SUBFORMAT_MSBITS_MAX in fixup_unreferenced_params - fixed sparse warning (unsigned int -> snd_pcm_format_t) --- include/sound/pcm.h | 17 +++++++++ include/uapi/sound/asound.h | 7 ++-- sound/core/pcm_lib.c | 59 +++++++++++++++++++++++++++++++ sound/core/pcm_native.c | 25 ++++++++++--- tools/include/uapi/sound/asound.h | 7 ++-- 5 files changed, 107 insertions(+), 8 deletions(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 2a815373dac1..59ad45b42e03 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -217,6 +217,12 @@ 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_MAX _SNDRV_PCM_SUBFMTBIT(MSBITS_MAX) +#define SNDRV_PCM_SUBFMTBIT_MSBITS_20 _SNDRV_PCM_SUBFMTBIT(MSBITS_20) +#define SNDRV_PCM_SUBFMTBIT_MSBITS_24 _SNDRV_PCM_SUBFMTBIT(MSBITS_24) + struct snd_pcm_file { struct snd_pcm_substream *substream; int no_compat_mmap; @@ -290,6 +296,13 @@ struct snd_pcm_hw_constraint_ranges { unsigned int mask; };
+#define SNDRV_PCM_FORMAT_CONSTRAINT_END (~0) + +struct snd_pcm_hw_constraint_subformat { + snd_pcm_format_t format; /* SNDRV_PCM_FORMAT_* */ + u32 subformats; /* SNDRV_PCM_SUBFMTBIT_* */ +}; + /* * userspace-provided audio timestamp config to kernel, * structure is for internal use only and filled with dedicated unpack routine @@ -375,6 +388,7 @@ struct snd_pcm_runtime { unsigned int rate_num; unsigned int rate_den; unsigned int no_period_wakeup: 1; + unsigned int subformat_constraint: 1;
/* -- SW params; see struct snd_pcm_sw_params for comments -- */ int tstamp_mode; @@ -1068,6 +1082,9 @@ int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ratdens *r); +int snd_pcm_hw_constraint_subformats(struct snd_pcm_runtime *runtime, + unsigned int cond, + struct snd_pcm_hw_constraint_subformat *subformats); int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, unsigned int cond, unsigned int width, diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h index f9939da41122..d5b9cfbd9cea 100644 --- a/include/uapi/sound/asound.h +++ b/include/uapi/sound/asound.h @@ -142,7 +142,7 @@ struct snd_hwdep_dsp_image { * * *****************************************************************************/
-#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 15) +#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 16)
typedef unsigned long snd_pcm_uframes_t; typedef signed long snd_pcm_sframes_t; @@ -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_MAX ((__force snd_pcm_subformat_t) 1) +#define SNDRV_PCM_SUBFORMAT_MSBITS_20 ((__force snd_pcm_subformat_t) 2) +#define SNDRV_PCM_SUBFORMAT_MSBITS_24 ((__force snd_pcm_subformat_t) 3) +#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_MSBITS_24
#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 a11cd7d6295f..cb376e428f59 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1404,6 +1404,65 @@ int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, } EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
+static int snd_pcm_hw_rule_subformats(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + const struct snd_pcm_hw_constraint_subformat *sf; + snd_pcm_format_t k; + struct snd_mask m; + struct snd_mask *fmask = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT); + struct snd_mask *mask = hw_param_mask(params, SNDRV_PCM_HW_PARAM_SUBFORMAT); + bool found; + + snd_mask_none(&m); + snd_mask_set(&m, (__force unsigned)SNDRV_PCM_SUBFORMAT_STD); + pcm_for_each_format(k) { + if (!snd_mask_test(fmask, k)) + continue; + found = false; + for (sf = rule->private; sf && sf->format != SNDRV_PCM_FORMAT_CONSTRAINT_END; sf++) { + if (sf->format != k) + continue; + found = true; + m.bits[0] |= sf->subformats; + break; + } + if (!found && snd_pcm_format_linear(k)) + snd_mask_set(&m, (__force unsigned)SNDRV_PCM_SUBFORMAT_MSBITS_MAX); + } + return snd_mask_refine(mask, &m); +} + +/** + * snd_pcm_hw_constraint_subformats - add a hw constraint subformats rule + * @runtime: PCM runtime instance + * @cond: condition bits + * @subformats: array with struct snd_pcm_subformat elements + * + * This constraint will set relation between format and subformats. + * The STD and MAX subformats are handled automatically. If the driver + * does not set this constraint, only STD and MAX subformats are handled. + * + * Return: Zero if successful, or a negative error code on failure. + */ +int snd_pcm_hw_constraint_subformats(struct snd_pcm_runtime *runtime, + unsigned int cond, + struct snd_pcm_hw_constraint_subformat *subformats) +{ + int ret; + + ret = snd_pcm_hw_rule_add(runtime, cond, -1, + snd_pcm_hw_rule_subformats, + (void*) subformats, + SNDRV_PCM_HW_PARAM_SUBFORMAT, + SNDRV_PCM_HW_PARAM_FORMAT, -1); + if (ret < 0) + return ret; + runtime->subformat_constraint = 1; + return 0; +} +EXPORT_SYMBOL(snd_pcm_hw_constraint_subformats); + static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule) { diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index bd9ddf412b46..d4442b458c3c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -479,6 +479,7 @@ static int fixup_unreferenced_params(struct snd_pcm_substream *substream, { const struct snd_interval *i; const struct snd_mask *m; + struct snd_mask *m_rw; int err;
if (!params->msbits) { @@ -487,6 +488,21 @@ static int fixup_unreferenced_params(struct snd_pcm_substream *substream, params->msbits = snd_interval_value(i); }
+ if (params->msbits) { + m = hw_param_mask_c(params, SNDRV_PCM_HW_PARAM_FORMAT); + if (snd_mask_single(m)) { + snd_pcm_format_t format = (__force snd_pcm_format_t)snd_mask_min(m); + if (snd_pcm_format_linear(format) && + snd_pcm_format_width(format) != params->msbits) { + m_rw = hw_param_mask(params, SNDRV_PCM_HW_PARAM_SUBFORMAT); + snd_mask_reset(m_rw, + (__force unsigned)SNDRV_PCM_SUBFORMAT_MSBITS_MAX); + if (snd_mask_empty(m_rw)) + return -EINVAL; + } + } + } + if (!params->rate_den) { i = hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE); if (snd_interval_single(i)) { @@ -2634,10 +2650,11 @@ static int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream) if (err < 0) return err;
- err = snd_pcm_hw_constraint_mask(runtime, SNDRV_PCM_HW_PARAM_SUBFORMAT, - PARAM_MASK_BIT(SNDRV_PCM_SUBFORMAT_STD)); - if (err < 0) - return err; + if (!runtime->subformat_constraint) { + err = snd_pcm_hw_constraint_subformats(runtime, 0, NULL); + if (err < 0) + return err; + }
err = snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_CHANNELS, hw->channels_min, hw->channels_max); diff --git a/tools/include/uapi/sound/asound.h b/tools/include/uapi/sound/asound.h index f9939da41122..d5b9cfbd9cea 100644 --- a/tools/include/uapi/sound/asound.h +++ b/tools/include/uapi/sound/asound.h @@ -142,7 +142,7 @@ struct snd_hwdep_dsp_image { * * *****************************************************************************/
-#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 15) +#define SNDRV_PCM_VERSION SNDRV_PROTOCOL_VERSION(2, 0, 16)
typedef unsigned long snd_pcm_uframes_t; typedef signed long snd_pcm_sframes_t; @@ -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_MAX ((__force snd_pcm_subformat_t) 1) +#define SNDRV_PCM_SUBFORMAT_MSBITS_20 ((__force snd_pcm_subformat_t) 2) +#define SNDRV_PCM_SUBFORMAT_MSBITS_24 ((__force snd_pcm_subformat_t) 3) +#define SNDRV_PCM_SUBFORMAT_LAST SNDRV_PCM_SUBFORMAT_MSBITS_24
#define SNDRV_PCM_INFO_MMAP 0x00000001 /* hardware supports mmap */ #define SNDRV_PCM_INFO_MMAP_VALID 0x00000002 /* period data are valid during transfer */