[PATCH 1/2] ALSA: add DSD formats

[PATCH 1/2] ALSA: add DSD formats

[Daniel Mack]

This patch adds two formats for Direct Stream Digital (DSD), a
pulse-density encoding format which is described here:
https://en.wikipedia.org/wiki/Direct_Stream_Digital

DSD operates on 2.8, 5.6 or 11.2MHz sample rates and as a 1-bit
stream. In order to provide a compatibility way for pushing samples
of DSD type through ordinary PCM channels, the "DoP open Standard" was
created. See http://www.dsd-guide.com for a copy of the documentation.

The two new types describe streams that are capable of handling DSD
samples in 8-bit or in 16-bit (or at a single or double data rate,
respectively). For applications, the following mapping table is used
to configure the DSD mode by selecting a combination of PCM sample
rates and word lengths:

        352.8kHz       705.6KHz     1411.2KHz

8-bit     2.8MHz         5.6MHz       11.2MHz
16-bit    5.6MHz        11.2MHz

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 include/sound/pcm.h         | 2 ++
 include/uapi/sound/asound.h | 4 +++-
 sound/core/pcm.c            | 2 ++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index aa7b0a8..2dffd55 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -181,6 +181,8 @@ struct snd_pcm_ops {
 #define SNDRV_PCM_FMTBIT_G723_24_1B	_SNDRV_PCM_FMTBIT(G723_24_1B)
 #define SNDRV_PCM_FMTBIT_G723_40	_SNDRV_PCM_FMTBIT(G723_40)
 #define SNDRV_PCM_FMTBIT_G723_40_1B	_SNDRV_PCM_FMTBIT(G723_40_1B)
+#define SNDRV_PCM_FMTBIT_DSD_U8		_SNDRV_PCM_FMTBIT(DSD_U8)
+#define SNDRV_PCM_FMTBIT_DSD_U16	_SNDRV_PCM_FMTBIT(DSD_U16)
 
 #ifdef SNDRV_LITTLE_ENDIAN
 #define SNDRV_PCM_FMTBIT_S16		SNDRV_PCM_FMTBIT_S16_LE
diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index 1774a5c..f9b0d3f 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -214,7 +214,9 @@ typedef int __bitwise snd_pcm_format_t;
 #define	SNDRV_PCM_FORMAT_G723_24_1B	((__force snd_pcm_format_t) 45) /* 1 sample in 1 byte */
 #define	SNDRV_PCM_FORMAT_G723_40	((__force snd_pcm_format_t) 46) /* 8 Samples in 5 bytes */
 #define	SNDRV_PCM_FORMAT_G723_40_1B	((__force snd_pcm_format_t) 47) /* 1 sample in 1 byte */
-#define	SNDRV_PCM_FORMAT_LAST		SNDRV_PCM_FORMAT_G723_40_1B
+#define	SNDRV_PCM_FORMAT_DSD_U8		((__force snd_pcm_format_t) 48) /* DSD in 1 byte */
+#define	SNDRV_PCM_FORMAT_DSD_U16	((__force snd_pcm_format_t) 49) /* DSD in 2 bytes */
+#define	SNDRV_PCM_FORMAT_LAST		SNDRV_PCM_FORMAT_DSD_16U
 
 #ifdef SNDRV_LITTLE_ENDIAN
 #define	SNDRV_PCM_FORMAT_S16		SNDRV_PCM_FORMAT_S16_LE
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 578327e..433efdb 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -209,6 +209,8 @@ static char *snd_pcm_format_names[] = {
 	FORMAT(G723_24_1B),
 	FORMAT(G723_40),
 	FORMAT(G723_40_1B),
+	FORMAT(DSD_U8),
+	FORMAT(DSD_U16),
 };
 
 const char *snd_pcm_format_name(snd_pcm_format_t format)
-- 
1.8.1.4

[PATCH 2/2] ALSA: snd-usb: add quirks handler for DSD streams

[Daniel Mack]

Unfortunately, none of the UAC standards provides a way to identify DSD
(Direct Stream Digital) formats. Hence, this patch adds a quirks
handler to identify USB interfaces that are capable of handling DSD.

If that quirks handler returns /true/, the PCM formats will be augmented
by SNDRV_PCM_FMTBIT_DSD_{U8_U16}, depending on the parsed sample_bytes.

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 sound/usb/format.c | 19 +++++++++++++++++++
 sound/usb/quirks.c |  8 ++++++++
 sound/usb/quirks.h |  3 +++
 3 files changed, 30 insertions(+)

diff --git a/sound/usb/format.c b/sound/usb/format.c
index a695caf..e4c8610 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -136,6 +136,25 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 		snd_printk(KERN_INFO "%d:%u:%d : unsupported format bits %#x\n",
 			   chip->dev->devnum, fp->iface, fp->altsetting, format);
 	}
+
+	/*
+	 * DSD has no designated specifiers in the USB audio spec, so we have
+	 * to rely on a quirks list.
+	 */
+	if (snd_usb_interface_is_dsd(chip->dev, fp->iface, fp->altsetting)) {
+	switch (sample_bytes) {
+	case 1:
+		pcm_formats |= SNDRV_PCM_FMTBIT_DSD_U8;
+		break;
+	case 2:
+		pcm_formats |= SNDRV_PCM_FMTBIT_DSD_U16;
+		break;
+	default:
+		snd_printk(KERN_INFO "%d:%u:%d : unsupported DSD sample bitwidth %d\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, sample_width);
+	}
+	}
+
 	return pcm_formats;
 }
 
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index a2ac004..9d7e95c 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -905,3 +905,11 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 		mdelay(20);
 }
 
+bool snd_usb_interface_is_dsd(struct usb_device *dev,
+			      int interface, int alt_no)
+{
+	if ((le16_to_cpu(dev->descriptor.idVendor) == 0x23ba) && alt_no > 1)
+		return true;
+
+	return false;
+}
diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index 0ca9e91..a777ef0 100644
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -30,4 +30,7 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 			   __u8 request, __u8 requesttype, __u16 value,
 			   __u16 index, void *data, __u16 size);
 
+bool snd_usb_interface_is_dsd(struct usb_device *dev,
+                              int interface, int alt_no);
+
 #endif /* __USBAUDIO_QUIRKS_H */
-- 
1.8.1.4

[PATCH 2/2] ALSA: snd-usb: add quirks handler for DSD streams

[Daniel Mack]

Unfortunately, none of the UAC standards provides a way to identify DSD
(Direct Stream Digital) formats. Hence, this patch adds a quirks
handler to identify USB interfaces that are capable of handling DSD.

That quirks handler can augment the already parsed formats bit-field,
typically by any of the new SNDRV_PCM_FMTBIT_DSD_DOP_{U8_U16}, and it
currently does so for USB devices matching the 'Playback Design'
vendor id.

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 sound/usb/format.c |  3 +++
 sound/usb/quirks.c | 23 +++++++++++++++++++++++
 sound/usb/quirks.h |  4 ++++
 3 files changed, 30 insertions(+)

diff --git a/sound/usb/format.c b/sound/usb/format.c
index a695caf..a73d67a 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -136,6 +136,9 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 		snd_printk(KERN_INFO "%d:%u:%d : unsupported format bits %#x\n",
 			   chip->dev->devnum, fp->iface, fp->altsetting, format);
 	}
+
+	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
+
 	return pcm_formats;
 }
 
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index a2ac004..2fcc984 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -905,3 +905,26 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 		mdelay(20);
 }
 
+/*
+ * snd_usb_interface_dsd_format_quirks() is called from format.c to
+ * augment the PCM format bit-field for DSD types. The UAC standards
+ * don't have a designated bit field to denote DSD-capable interfaces,
+ * hence all hardware that is known to support this format has to be
+ * listed here.
+ */
+u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
+					struct audioformat *fp,
+					unsigned int sample_bytes)
+{
+	if ((le16_to_cpu(chip->dev->descriptor.idVendor) == 0x23ba) &&
+	    fp->altsetting > 1) {
+		switch (sample_bytes) {
+		case 1:
+			return SNDRV_PCM_FMTBIT_DSD_DOP_U8;
+		case 2:
+			return SNDRV_PCM_FMTBIT_DSD_DOP_U16;
+		}
+	}
+
+	return 0;
+}
diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index 0ca9e91..f10d00e 100644
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -30,4 +30,8 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 			   __u8 request, __u8 requesttype, __u16 value,
 			   __u16 index, void *data, __u16 size);
 
+u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
+					struct audioformat *fp,
+					unsigned int sample_bytes);
+
 #endif /* __USBAUDIO_QUIRKS_H */
-- 
1.8.1.4

[PATCH 2/2] ALSA: snd-usb: add quirks handler for DSD streams

[Daniel Mack]

Unfortunately, none of the UAC standards provides a way to identify DSD
(Direct Stream Digital) formats. Hence, this patch adds a quirks
handler to identify USB interfaces that are capable of handling DSD.

That quirks handler can augment the already parsed formats bit-field,
typically by any of the new SNDRV_PCM_FMTBIT_DSD_DOP_{U8_U16}, and it
currently does so for USB devices matching the 'Playback Design'
vendor id.

Signed-off-by: Daniel Mack <zonque@gmail.com>
---
 sound/usb/format.c |  3 +++
 sound/usb/quirks.c | 23 +++++++++++++++++++++++
 sound/usb/quirks.h |  4 ++++
 3 files changed, 30 insertions(+)

diff --git a/sound/usb/format.c b/sound/usb/format.c
index a695caf..a73d67a 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -136,6 +136,9 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
 		snd_printk(KERN_INFO "%d:%u:%d : unsupported format bits %#x\n",
 			   chip->dev->devnum, fp->iface, fp->altsetting, format);
 	}
+
+	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
+
 	return pcm_formats;
 }
 
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index a2ac004..2fcc984 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -905,3 +905,26 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 		mdelay(20);
 }
 
+/*
+ * snd_usb_interface_dsd_format_quirks() is called from format.c to
+ * augment the PCM format bit-field for DSD types. The UAC standards
+ * don't have a designated bit field to denote DSD-capable interfaces,
+ * hence all hardware that is known to support this format has to be
+ * listed here.
+ */
+u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
+					struct audioformat *fp,
+					unsigned int sample_bytes)
+{
+	if ((le16_to_cpu(chip->dev->descriptor.idVendor) == 0x23ba) &&
+	    fp->altsetting > 1) {
+		switch (sample_bytes) {
+		case 1:
+			return SNDRV_PCM_FMTBIT_DSD_DOP_U8;
+		case 2:
+			return SNDRV_PCM_FMTBIT_DSD_DOP_U16;
+		}
+	}
+
+	return 0;
+}
diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
index 0ca9e91..f10d00e 100644
--- a/sound/usb/quirks.h
+++ b/sound/usb/quirks.h
@@ -30,4 +30,8 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
 			   __u8 request, __u8 requesttype, __u16 value,
 			   __u16 index, void *data, __u16 size);
 
+u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
+					struct audioformat *fp,
+					unsigned int sample_bytes);
+
 #endif /* __USBAUDIO_QUIRKS_H */
-- 
1.8.1.4

Re: [PATCH 2/2] ALSA: snd-usb: add quirks handler for DSD streams

[Daniel Mack]

On 06.04.2013 13:44, Daniel Mack wrote:
> Unfortunately, none of the UAC standards provides a way to identify DSD
> (Direct Stream Digital) formats. Hence, this patch adds a quirks
> handler to identify USB interfaces that are capable of handling DSD.
> 
> That quirks handler can augment the already parsed formats bit-field,
> typically by any of the new SNDRV_PCM_FMTBIT_DSD_DOP_{U8_U16}, and it
> currently does so for USB devices matching the 'Playback Design'
> vendor id.

Sorry - this identical message got sent twice unintentionally. Please
ignore one of the two ...


Daniel


> Signed-off-by: Daniel Mack <zonque@gmail.com>
> ---
>  sound/usb/format.c |  3 +++
>  sound/usb/quirks.c | 23 +++++++++++++++++++++++
>  sound/usb/quirks.h |  4 ++++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/sound/usb/format.c b/sound/usb/format.c
> index a695caf..a73d67a 100644
> --- a/sound/usb/format.c
> +++ b/sound/usb/format.c
> @@ -136,6 +136,9 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
>  		snd_printk(KERN_INFO "%d:%u:%d : unsupported format bits %#x\n",
>  			   chip->dev->devnum, fp->iface, fp->altsetting, format);
>  	}
> +
> +	pcm_formats |= snd_usb_interface_dsd_format_quirks(chip, fp, sample_bytes);
> +
>  	return pcm_formats;
>  }
>  
> diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
> index a2ac004..2fcc984 100644
> --- a/sound/usb/quirks.c
> +++ b/sound/usb/quirks.c
> @@ -905,3 +905,26 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
>  		mdelay(20);
>  }
>  
> +/*
> + * snd_usb_interface_dsd_format_quirks() is called from format.c to
> + * augment the PCM format bit-field for DSD types. The UAC standards
> + * don't have a designated bit field to denote DSD-capable interfaces,
> + * hence all hardware that is known to support this format has to be
> + * listed here.
> + */
> +u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
> +					struct audioformat *fp,
> +					unsigned int sample_bytes)
> +{
> +	if ((le16_to_cpu(chip->dev->descriptor.idVendor) == 0x23ba) &&
> +	    fp->altsetting > 1) {
> +		switch (sample_bytes) {
> +		case 1:
> +			return SNDRV_PCM_FMTBIT_DSD_DOP_U8;
> +		case 2:
> +			return SNDRV_PCM_FMTBIT_DSD_DOP_U16;
> +		}
> +	}
> +
> +	return 0;
> +}
> diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
> index 0ca9e91..f10d00e 100644
> --- a/sound/usb/quirks.h
> +++ b/sound/usb/quirks.h
> @@ -30,4 +30,8 @@ void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
>  			   __u8 request, __u8 requesttype, __u16 value,
>  			   __u16 index, void *data, __u16 size);
>  
> +u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
> +					struct audioformat *fp,
> +					unsigned int sample_bytes);
> +
>  #endif /* __USBAUDIO_QUIRKS_H */
>