[alsa-devel] [PATCH v4 1/4] ALSA: usb-audio: UAC3. Add support for mixer unit.
Ruslan Bilovol
ruslan.bilovol at gmail.com
Mon May 14 22:54:42 CEST 2018
On Fri, May 11, 2018 at 6:25 PM, Jorge Sanjuan
<jorge.sanjuan at codethink.co.uk> wrote:
> This adds support for the MIXER UNIT in UAC3. All the information
> is obtained from the (HIGH CAPABILITY) Cluster's header. We don't
> read the rest of the logical cluster to obtain the channel config
> as that wont make any difference in the current mixer behaviour.
>
> The name of the mixer unit is not yet requested as there is not
> support for the UAC3 Class Specific String requests.
>
> Tested in an UAC3 device working as a HEADSET with a basic mixer
> unit (same as the one in the BADD spec) with no controls.
I tested this patch in a similar use-case (with a simple mixer unit),
but _with_ controls and along with patch [1] from this series, which
added parsing input terminal's channels.
So everything works fine, I see all needed requests handling and
mixer unit creation on ALSA side, which I can use now.
So, as a bottom line:
Reviewed-by: Ruslan Bilovol <ruslan.bilovol at gmail.com>
Tested-by: Ruslan Bilovol <ruslan.bilovol at gmail.com>
[1] http://mailman.alsa-project.org/pipermail/alsa-devel/2018-May/136030.html
>
> Signed-off-by: Jorge Sanjuan <jorge.sanjuan at codethink.co.uk>
> ---
> include/uapi/linux/usb/audio.h | 19 +++++++--
> sound/usb/mixer.c | 88 ++++++++++++++++++++++++++++++++++++++----
> 2 files changed, 97 insertions(+), 10 deletions(-)
>
> diff --git a/include/uapi/linux/usb/audio.h b/include/uapi/linux/usb/audio.h
> index 3a78e7145689..13d98e6e0db1 100644
> --- a/include/uapi/linux/usb/audio.h
> +++ b/include/uapi/linux/usb/audio.h
> @@ -285,9 +285,22 @@ static inline __u8 uac_mixer_unit_iChannelNames(struct uac_mixer_unit_descriptor
> static inline __u8 *uac_mixer_unit_bmControls(struct uac_mixer_unit_descriptor *desc,
> int protocol)
> {
> - return (protocol == UAC_VERSION_1) ?
> - &desc->baSourceID[desc->bNrInPins + 4] :
> - &desc->baSourceID[desc->bNrInPins + 6];
> + switch (protocol) {
> + case UAC_VERSION_1:
> + return &desc->baSourceID[desc->bNrInPins + 4];
> + case UAC_VERSION_2:
> + return &desc->baSourceID[desc->bNrInPins + 6];
> + case UAC_VERSION_3:
> + return &desc->baSourceID[desc->bNrInPins + 2];
> + default:
> + return NULL;
> + }
> +}
> +
> +static inline __u16 uac3_mixer_unit_wClusterDescrID(struct uac_mixer_unit_descriptor *desc)
> +{
> + return (desc->baSourceID[desc->bNrInPins + 1] << 8) |
> + desc->baSourceID[desc->bNrInPins];
> }
>
> static inline __u8 uac_mixer_unit_iMixer(struct uac_mixer_unit_descriptor *desc)
> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
> index 76417943ff85..129c1397f0cb 100644
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -719,6 +719,66 @@ static int get_term_name(struct snd_usb_audio *chip, struct usb_audio_term *iter
> }
>
> /*
> + * Get logical cluster information for UAC3 devices.
> + */
> +static int get_cluster_channels_v3(struct mixer_build *state, unsigned int cluster_id)
> +{
> + struct uac3_cluster_header_descriptor c_header;
> + int err;
> +
> + err = snd_usb_ctl_msg(state->chip->dev,
> + usb_rcvctrlpipe(state->chip->dev, 0),
> + UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
> + USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
> + cluster_id,
> + snd_usb_ctrl_intf(state->chip),
> + &c_header, sizeof(c_header));
> + if (err < 0)
> + goto error;
> + if (err != sizeof(c_header)) {
> + err = -EIO;
> + goto error;
> + }
> +
> + return c_header.bNrChannels;
> +
> +error:
> + usb_audio_err(state->chip, "cannot request logical cluster ID: %d (err: %d)\n", cluster_id, err);
> + return err;
> +}
> +
> +/*
> + * Get number of channels for a Mixer Unit.
> + */
> +static int uac_mixer_unit_get_channels(struct mixer_build *state,
> + struct uac_mixer_unit_descriptor *desc)
> +{
> + int mu_channels;
> +
> + if (desc->bLength < 11)
> + return -EINVAL;
> + if (!desc->bNrInPins)
> + return -EINVAL;
> +
> + switch (state->mixer->protocol) {
> + case UAC_VERSION_1:
> + case UAC_VERSION_2:
> + default:
> + mu_channels = uac_mixer_unit_bNrChannels(desc);
> + break;
> + case UAC_VERSION_3:
> + mu_channels = get_cluster_channels_v3(state,
> + uac3_mixer_unit_wClusterDescrID(desc));
> + break;
> + }
> +
> + if (!mu_channels)
> + return -EINVAL;
> +
> + return mu_channels;
> +}
> +
> +/*
> * parse the source unit recursively until it reaches to a terminal
> * or a branched unit.
> */
> @@ -865,6 +925,18 @@ static int check_input_term(struct mixer_build *state, int id,
> term->name = le16_to_cpu(d->wClockSourceStr);
> return 0;
> }
> + case UAC3_MIXER_UNIT: {
> + struct uac_mixer_unit_descriptor *d = p1;
> +
> + err = uac_mixer_unit_get_channels(state, d);
> + if (err < 0)
> + return err;
> +
> + term->channels = err;
> + term->type = d->bDescriptorSubtype << 16; /* virtual type */
> +
> + return 0;
> + }
> default:
> return -ENODEV;
> }
> @@ -1798,11 +1870,10 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
> */
> static void build_mixer_unit_ctl(struct mixer_build *state,
> struct uac_mixer_unit_descriptor *desc,
> - int in_pin, int in_ch, int unitid,
> - struct usb_audio_term *iterm)
> + int in_pin, int in_ch, int num_outs,
> + int unitid, struct usb_audio_term *iterm)
> {
> struct usb_mixer_elem_info *cval;
> - unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
> unsigned int i, len;
> struct snd_kcontrol *kctl;
> const struct usbmix_name_map *map;
> @@ -1879,14 +1950,17 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
> int input_pins, num_ins, num_outs;
> int pin, ich, err;
>
> - if (desc->bLength < 11 || !(input_pins = desc->bNrInPins) ||
> - !(num_outs = uac_mixer_unit_bNrChannels(desc))) {
> + err = uac_mixer_unit_get_channels(state, desc);
> + if (err < 0) {
> usb_audio_err(state->chip,
> "invalid MIXER UNIT descriptor %d\n",
> unitid);
> - return -EINVAL;
> + return err;
> }
>
> + num_outs = err;
> + input_pins = desc->bNrInPins;
> +
> num_ins = 0;
> ich = 0;
> for (pin = 0; pin < input_pins; pin++) {
> @@ -1913,7 +1987,7 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
> }
> }
> if (ich_has_controls)
> - build_mixer_unit_ctl(state, desc, pin, ich,
> + build_mixer_unit_ctl(state, desc, pin, ich, num_outs,
> unitid, &iterm);
> }
> }
> --
> 2.11.0
>
--
Best regards,
Ruslan Bilovol
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