USB Audio Class version 2.0 supports three different parameter block sizes for
CUR requests, which are 1 byte (5.2.3.1 Layout 1 Parameter Block), 2 bytes
(5.2.3.2 Layout 2 Parameter Block) and 4 bytes (5.2.3.3 Layout 3 Parameter
Block). Use the correct size according to the specific control as it was
already done for UACv1. The allocated block size for control requests is
increased to support the 4 byte worst case.

Signed-off-by: Julian Scheel <julian@jusst.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This time it's about Xonar U1: add the proper resume support for
"Digital Playback Switch" element.

Also, the status is moved into kcontrol private_value from
usb_mixer_interface struct field.  One more cut.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Rewrite the code to handle LEDs on audigy2nx and co for supporting the
proper resume.  A new internal helper function
add_single_ctl_with_resume() is introduced to manage the
usb_mixer_elem_list more easily.

Also while we're at it, move audigy2nx_leds[] in usb_mixer_interface
struct into the private_value of each kctl, too.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

So far, we blindly assumed that the all usb-audio mixer elements
follow the standard and apply the standard resume method for the
registered elements in the id_elems[] list.  However, some quirks
really need the own resume and it's incomplete for now.

This patch enhances the resume handling in two folds:
- split some fields in struct usb_mixer_elem_info into a smaller
  header struct (usb_mixer_elem_list) for keeping the minimal
  information in the linked-list; the usb_mixer_elem_info embeds this
  header struct instead
- add resume and dump callbacks to usb_mixer_elem_list struct to allow
  quirks providing the own methods

For the standard mixer elements, these new callbacks are set to the
standard ones as default, thus there is no functional change by this
patch yet.

The dump and resume callbacks are typedef'ed for ease of later patches
using arrays of such function pointers.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Make the functions set_cur_mix_value and get_cur_mix_value accessible by files
that include mixer.h. In addition make usb_mixer_elem_free accessible.
This allows reuse of these functions by mixers that may require quirks.

The following summarizes the renamed functions:
  - set_cur_mix_value -> snd_usb_set_cur_mix_value
  - get_cur_mix_value -> snd_usb_get_cur_mix_value
  - usb_mixer_elem_free -> snd_usb_mixer_elem_free

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Add a private_data pointer to usb_mixer_elem_info to allow other mixer
implementations to extend the structure as necessary.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Some functions in mixer.c and endpoint.c receive list_head instead of
the object itself.  This is not obvious and rather error-prone.  Let's
pass the proper object directly instead.

The functions in midi.c still receive list_head and this can't be
changed since the object definition isn't exposed to the outside of
midi.c, so left as is.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Implement reset_resume callback so that the mixer values are properly
restored.  Still no boot quirks are called, so it might not work well
on some devices.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Currently, channel IDs exceeding 31 (0x1f) cannot be used.
The channel ID is derived from the cmask. Extending cmask
to a 64-bit type would only allow it to go up to 63 (0x3f).
Some devices have channel IDs exceeding that as well.
To address that, add an offset to the mixer element which
is then accounted for in the UAC set/get functions.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Rename mixer_vol_tlv to snd_usb_mixer_vol_tlv and export it to make
it reuseable in mixer_quirks.c.

Signed-off-by: Felix Homann <linuxaudio@showlabor.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>