lkml.org 
[lkml]   [2018]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [alsa-devel] [PATCH v2 1/4] ALSA: usb-audio: UAC3. Add support for mixer unit.
From
Date


On 25/04/18 23:35, Ruslan Bilovol wrote:
> On Tue, Apr 24, 2018 at 8:24 PM, Jorge Sanjuan
> <jorge.sanjuan@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.
>
> The patch looks OK in general, but I have few comments

Thanks for the review! I'll submit v3 of this patch with the suggested
changes.

Regards,

Jorge

>
>>
>> Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
>> ---
>> include/uapi/linux/usb/audio.h | 13 +++++--
>> sound/usb/mixer.c | 87 ++++++++++++++++++++++++++++++++++++++++--
>> 2 files changed, 93 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/uapi/linux/usb/audio.h b/include/uapi/linux/usb/audio.h
>> index 3a78e7145689..f9be472cd025 100644
>> --- a/include/uapi/linux/usb/audio.h
>> +++ b/include/uapi/linux/usb/audio.h
>> @@ -285,9 +285,16 @@ 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)
>
> Name of this function is ambiguous, that's because UAC1 mixer unit
> has only bmControls bitmap, whereas UAC2/3 mixer unit has two
> bitmaps (bmMixerControls and bmControls), in latter case this func
> returns pointer to bmMixerControls.
>
> Maybe in the future we will need to rename it, but at least having
> comment which clarifies that in case of UAC2/3 this function actually
> returns pointer to bmMixerControls here will be helpful for code readers.
>
>> {
>> - 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 __u8 uac_mixer_unit_iMixer(struct uac_mixer_unit_descriptor *desc)
>> diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
>> index 301ad61ed426..bf701b466a4e 100644
>> --- a/sound/usb/mixer.c
>> +++ b/sound/usb/mixer.c
>> @@ -719,6 +719,66 @@ static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm
>> }
>>
>> /*
>> + * 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,
>> + le16_to_cpu(desc->baSourceID[desc->bNrInPins]));
>
> It would be good to create and use some helper here, for example implement
> uac3_mixer_unit_wClusterDescrID() similar to uac_mixer_unit_bNrChannels().
> It will put all this conversation to a single place and will improve
> code readability.
>
>> + 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;
>> }
>> @@ -1801,7 +1873,7 @@ static void build_mixer_unit_ctl(struct mixer_build *state,
>> struct usb_audio_term *iterm)
>> {
>> struct usb_mixer_elem_info *cval;
>> - unsigned int num_outs = uac_mixer_unit_bNrChannels(desc);
>> + unsigned int num_outs;
>> unsigned int i, len;
>> struct snd_kcontrol *kctl;
>> const struct usbmix_name_map *map;
>> @@ -1814,6 +1886,10 @@ static void build_mixer_unit_ctl(struct mixer_build *state,
>> if (!cval)
>> return;
>>
>> + num_outs = uac_mixer_unit_get_channels(state, desc);
>> + if (num_outs < 0)
>> + return;
>
> This will produce an extra USB control request in UAC3 case, which we can
> avoid if add num_outs to input parameters of build_mixer_unit_ctl() function.
> This function is used only once inside of parse_audio_mixer_unit() which already
> has channels number request and all needed checks.
>
> Thanks,
> Ruslan
>
>> +
>> snd_usb_mixer_elem_init_std(&cval->head, state->mixer, unitid);
>> cval->control = in_ch + 1; /* based on 1 */
>> cval->val_type = USB_MIXER_S16;
>> @@ -1878,14 +1954,17 @@ 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++) {
>> --
>> 2.11.0
>>
>> _______________________________________________
>> Alsa-devel mailing list
>> Alsa-devel@alsa-project.org
>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>

\
 
 \ /
  Last update: 2018-04-26 18:57    [W:0.085 / U:1.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site