ALSA: usb: add UAC3 BADD profiles support

Recently released USB Audio Class 3.0 specification
contains BADD (Basic Audio Device Definition) document
which describes pre-defined UAC3 configurations.

BADD support is mandatory for UAC3 devices, it should be
implemented as a separate USB device configuration.
As per BADD document, class-specific descriptors
shall not be included in the Device’s Configuration
descriptor ("inferred"), but host can guess them
from BADD profile number, number of endpoints and
their max packed sizes.

This patch adds support of all BADD profiles from the spec

Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Tested-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 74 insertions, 9 deletions

diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index 764be07474a8..de8bbb304199 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -817,15 +817,67 @@ snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
         struct uac3_input_terminal_descriptor *input_term;
         struct uac3_output_terminal_descriptor *output_term;
         struct uac3_cluster_header_descriptor *cluster;
-        struct uac3_as_header_descriptor *as;
+        struct uac3_as_header_descriptor *as = NULL;
         struct uac3_hc_descriptor_header hc_header;
         struct snd_pcm_chmap_elem *chmap;
+        unsigned char badd_profile;
+        u64 badd_formats = 0;
         unsigned int num_channels;
         struct audioformat *fp;
         u16 cluster_id, wLength;
         int clock = 0;
         int err;
 
+        badd_profile = chip->badd_profile;
+
+        if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
+                unsigned int maxpacksize =
+                        le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
+
+                switch (maxpacksize) {
+                default:
+                        dev_err(&dev->dev,
+                                "%u:%d : incorrect wMaxPacketSize for BADD profile\n",
+                                iface_no, altno);
+                        return NULL;
+                case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
+                case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
+                        badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
+                        num_channels = 1;
+                        break;
+                case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
+                case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
+                        badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
+                        num_channels = 1;
+                        break;
+                case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
+                case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
+                        badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
+                        num_channels = 2;
+                        break;
+                case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
+                case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
+                        badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
+                        num_channels = 2;
+                        break;
+                }
+
+                chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
+                if (!chmap)
+                        return ERR_PTR(-ENOMEM);
+
+                if (num_channels == 1) {
+                        chmap->map[0] = SNDRV_CHMAP_MONO;
+                } else {
+                        chmap->map[0] = SNDRV_CHMAP_FL;
+                        chmap->map[1] = SNDRV_CHMAP_FR;
+                }
+
+                chmap->channels = num_channels;
+                clock = UAC3_BADD_CS_ID9;
+                goto found_clock;
+        }
+
         as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
                                      NULL, UAC_AS_GENERAL);
         if (!as) {
@@ -931,16 +983,29 @@ found_clock:
         if (!fp)
                 return ERR_PTR(-ENOMEM);
 
-        fp->attributes = parse_uac_endpoint_attributes(chip, alts,
-                                                       UAC_VERSION_3,
-                                                       iface_no);
         fp->chmap = chmap;
 
-        /* ok, let's parse further... */
-        if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
-                kfree(fp->rate_table);
-                kfree(fp);
-                return NULL;
+        if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
+                fp->attributes = 0; /* No attributes */
+
+                fp->fmt_type = UAC_FORMAT_TYPE_I;
+                fp->formats = badd_formats;
+
+                fp->nr_rates = 0;       /* SNDRV_PCM_RATE_CONTINUOUS */
+                fp->rate_min = UAC3_BADD_SAMPLING_RATE;
+                fp->rate_max = UAC3_BADD_SAMPLING_RATE;
+                fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
+
+        } else {
+                fp->attributes = parse_uac_endpoint_attributes(chip, alts,
+                                                               UAC_VERSION_3,
+                                                               iface_no);
+                /* ok, let's parse further... */
+                if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
+                        kfree(fp->rate_table);
+                        kfree(fp);
+                        return NULL;
+                }
         }
 
         return fp;