History log of /linux-master/include/uapi/sound/tlv.h
Revision Date Author Comments
# 69ab6f5b 25-Sep-2022 Christophe JAILLET <christophe.jaillet@wanadoo.fr>

ALSA: Remove some left-over license text in include/uapi/sound/

There is already a SPDX-License-Identifier tag, so the corresponding
license text can be removed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/203c1db92c470925f31e361f6e7d180812501f2e.1664112023.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# e6f32bf4 13-May-2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>

ALSA: control: complement TLV macro for db-minmax and db-linear types

A commit 08f9f4485f21 ('ALSA: core api: define offsets for TLV items')
introduced a series of macro for offset of db-scale type of TLV, however
there are some types of TLV to add similar macros.

This commit complements macros for offset of db-minmax and db-linear types
of TLV data.

Cc: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# 08f9f448 09-May-2018 Ranjani Sridharan <ranjani.sridharan@linux.intel.com>

ALSA: core api: define offsets for TLV items

Currently, there are no pre-defined accessors for the elements
in topology TLV data. In the absence of such offsets, the
tlv data will have to be decoded using hardwired offset
numbers 0-N depending on the type of TLV. This patch defines
accessor offsets for the type, length, min and mute/step items
in TLV data for DB_SCALE type tlv's. These will be used by drivers to
decode the TLV data while loading topology thereby improving
code readability. The type and len offsets are common for all TLV
types. The min and step/mute offsets are specific to DB_SCALE tlv type.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# e2be04c7 01-Nov-2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

License cleanup: add SPDX license identifier to uapi header files with a license

Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.

Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.

GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:

NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".

This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.

Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)

SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 318824d3 24-Sep-2016 Takashi Sakamoto <o-takashi@sakamocchi.jp>

ALSA: control: cage TLV_DB_RANGE_HEAD in kernel land because it was obsoleted

In commit bf1d1c9b6179 ("ALSA: tlv: add DECLARE_TLV_DB_RANGE()"), the new
macro was added so that "dB range information can be specified without
having to count the items manually for TLV_DB_RANGE_HEAD()". In short,
TLV_DB_RANGE_HEAD macro was obsoleted.

In commit 46e860f76804 ("ALSA: rename TLV-related macros so that they're
friendly to user applications"), TLV-related macros are exposed for
applications in user land to get content of data structured by
Type/Length/Value shape. The commit managed to expose TLV-related macros
as many as possible, while obsoleted TLV_DB_RANGE_HEAD() was included to
the list of exposed macros.

This situation brings some confusions to application developers because
they might think all exposed macros have their own purpose and useful for
applications.

For the reason, this commit moves TLV_DB_RANGE_HEAD macro from UAPI header
to a header for kernel land, again. The above commit is done within the
same development period for kernel 4.9, thus not published yet. This
commit might certainly brings no confusions to user land.

Reference: commit bf1d1c9b6179 ("ALSA: tlv: add DECLARE_TLV_DB_RANGE()")
Reference: commit 46e860f76804 ("ALSA: rename TLV-related macros so that they're friendly to user applications")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# 46e860f7 14-Sep-2016 Takashi Sakamoto <o-takashi@sakamocchi.jp>

ALSA: rename TLV-related macros so that they're friendly to user applications

In a previous commit, some macros newly appeared to UAPI header for TLV
packet. These macros have short names and they easily bring name conflist
to applications. The conflict can be avoided to rename them with a proper
prefix.

For this purpose, this commit renames these macros with prefix
'SNDRV_CTL_TLVD_'.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# 398fa4db 14-Sep-2016 Takashi Sakamoto <o-takashi@sakamocchi.jp>

ALSA: control: move layout of TLV payload to UAPI header

In ALSA control interface, each element set can have threshold level
information. This information is transferred between drivers/applications,
in a shape of tlv packet. The layout of this packet is defined in
'uapi/sound/asound.h' (struct snd_ctl_tlv):

struct snd_ctl_tlv {
unsigned int numid;
unsigned int length;
unsigned int tlv[0];
};

Data in the payload (struct snd_ctl_tlv.tlv) is expected to be filled
according to our own protocol. This protocol is described in
'include/sound/tlv.h'. A layout of the payload is expected as:

struct snd_ctl_tlv.tlv[0]: one of SNDRV_CTL_TLVT_XXX
struct snd_ctl_tlv.tlv[1]: Length of data
struct snd_ctl_tlv.tlv[2...]: data

Unfortunately, the macro is not exported to user land yet, thus
applications cannot get to know the protocol.

Additionally, ALSA control core has a feature called as 'user-defined'
element set. This allows applications to add/remove arbitrary element sets
with elements to control devices. Elements in the element set can be
operated by the same way as the ones added by in-kernel implementation.

For threshold level information of 'user-defined' element set, applications
need to register the information to an element set. However, as described
above, layout of the payload is closed in kernel land. This is quite
inconvenient, too.

This commit moves the protocol to UAPI header for TLV.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# 932ae880 29-May-2015 Liam Girdwood <liam.r.girdwood@linux.intel.com>

ALSA: topology: Export ID types for TLV controls.

Make sure userspace can define TLV controls for topology using the correct
type numbers and channel mappings.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>