ALSA: pcm: add SNDRV_PCM_FORMAT_{S,U}20

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@maciej.szmigiero.name>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

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 {

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 |\

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) /* in four bytes, LSB justified */
+#define	SNDRV_PCM_FORMAT_S20_BE	((__force snd_pcm_format_t) 26) /* in four bytes, LSB justified */
+#define	SNDRV_PCM_FORMAT_U20_LE	((__force snd_pcm_format_t) 27) /* in four bytes, LSB justified */
+#define	SNDRV_PCM_FORMAT_U20_BE	((__force snd_pcm_format_t) 28) /* in four bytes, 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;

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,
 	},