From: Cezary Rojewski <cezary.rojewski@intel.com>
Date: Fri, 4 Aug 2023 08:13:40 +0000 (+0200)
Subject: pcm: Add MSBITS subformat options
X-Git-Tag: v1.2.11~24
X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=d8000f57fc458a46d1bdb5f6cedafd44fd52691f;p=alsa-lib.git

pcm: Add MSBITS subformat options

Improve granularity of format selection for S32/U32 formats by adding
masks representing 20, 24 and 32 most significant bits.

Closes: https://github.com/alsa-project/alsa-lib/pull/342
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---

diff --git a/include/pcm.h b/include/pcm.h
index f18620be..102ff812 100644
--- a/include/pcm.h
+++ b/include/pcm.h
@@ -286,7 +286,13 @@ typedef enum _snd_pcm_subformat {
 	SND_PCM_SUBFORMAT_UNKNOWN = -1,
 	/** Standard */
 	SND_PCM_SUBFORMAT_STD = 0,
-	SND_PCM_SUBFORMAT_LAST = SND_PCM_SUBFORMAT_STD
+	/** Maximum bits based on PCM format */
+	SND_PCM_SUBFORMAT_MSBITS_MAX = 1,
+	/** 20 most significant bits */
+	SND_PCM_SUBFORMAT_MSBITS_20 = 2,
+	/** 24 most significant bits */
+	SND_PCM_SUBFORMAT_MSBITS_24 = 3,
+	SND_PCM_SUBFORMAT_LAST = SND_PCM_SUBFORMAT_MSBITS_24
 } snd_pcm_subformat_t;
 
 /** PCM state */
diff --git a/include/sound/uapi/asound.h b/include/sound/uapi/asound.h
index 32095ef7..f3b2b94d 100644
--- a/include/sound/uapi/asound.h
+++ b/include/sound/uapi/asound.h
@@ -274,7 +274,10 @@ typedef int __bitwise snd_pcm_format_t;
 
 typedef int __bitwise snd_pcm_subformat_t;
 #define	SNDRV_PCM_SUBFORMAT_STD		((snd_pcm_subformat_t) 0)
-#define	SNDRV_PCM_SUBFORMAT_LAST	SNDRV_PCM_SUBFORMAT_STD
+#define	SNDRV_PCM_SUBFORMAT_MSBITS_MAX	((snd_pcm_subformat_t) 1)
+#define	SNDRV_PCM_SUBFORMAT_MSBITS_20	((snd_pcm_subformat_t) 2)
+#define	SNDRV_PCM_SUBFORMAT_MSBITS_24	((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/src/pcm/pcm.c b/src/pcm/pcm.c
index 8aae5afd..4bb5c759 100644
--- a/src/pcm/pcm.c
+++ b/src/pcm/pcm.c
@@ -2070,10 +2070,16 @@ static const char *const snd_pcm_type_names[] = {
 
 static const char *const snd_pcm_subformat_names[] = {
 	SUBFORMAT(STD), 
+	SUBFORMAT(MSBITS_MAX),
+	SUBFORMAT(MSBITS_20),
+	SUBFORMAT(MSBITS_24),
 };
 
 static const char *const snd_pcm_subformat_descriptions[] = {
 	SUBFORMATD(STD, "Standard"), 
+	SUBFORMATD(MSBITS_MAX, "Maximum based on PCM format"),
+	SUBFORMATD(MSBITS_20, "20 most significant bits"),
+	SUBFORMATD(MSBITS_24, "24 most significant bits"),
 };
 
 static const char *const snd_pcm_start_mode_names[] = {
diff --git a/src/pcm/pcm_params.c b/src/pcm/pcm_params.c
index 26c70132..c2f78634 100644
--- a/src/pcm/pcm_params.c
+++ b/src/pcm/pcm_params.c
@@ -2008,7 +2008,10 @@ static const snd_mask_t refine_masks[SND_PCM_HW_PARAM_LAST_MASK - SND_PCM_HW_PAR
 	},
 	[SND_PCM_HW_PARAM_SUBFORMAT - SND_PCM_HW_PARAM_FIRST_MASK] = {
 		.bits = {
-			PCM_BIT(SNDRV_PCM_SUBFORMAT_STD)
+			PCM_BIT(SNDRV_PCM_SUBFORMAT_STD) |
+			PCM_BIT(SNDRV_PCM_SUBFORMAT_MSBITS_MAX) |
+			PCM_BIT(SNDRV_PCM_SUBFORMAT_MSBITS_20) |
+			PCM_BIT(SNDRV_PCM_SUBFORMAT_MSBITS_24),
 		},
 	},
 };