OMAPDSS: Provide interface for audio support in DSS

There exist several display technologies and standards that support audio as
well. Hence, it is relevant to update the DSS device driver to provide an audio
interface that may be used by an audio or any other driver interested in the
functionality.

The DSS audio functions are intended to be used as follows:

The audio_enable function is intended to prepare the relevant
IP for playback (e.g., enabling an audio FIFO, taking in/out of reset
some IP, enabling companion chips, etc). It is intended to be called before
audio_start. The audio_disable function performs the revers operation and is
intended to be called before audio_stop.

While the display may support audio, it is possible that for certain
configurations audio is not supported (e.g., an HDMI display using a VESA video
timing). The audio_supported function is intended to query whether the current
configuration of the display supports audio.

The audio_config function is intended to configure all the relevant audio
parameters of the display. In order to make the function independent of DSS
any device driver, it takes a IEC-60958 channel status word as well
as a CEA-861 audio infoframe. At the moment, this should be enough to support
HDMI and DisplayPort, as both are based on CEA-861 and IEC-60958.

The audio_enable/disable, audio_config and audio_supported functions could be
implemented as funcitons that may sleep. Hence, they should not be called
while holding a spinlock or a readlock.

The audio_start/audio_stop function is intended to effectively start/stop audio
playback after the configuration has taken place. These functions are designed
to be used in an atomic context. Hence, audio_start should return quickly and be
called only after all the needed resources for audio playback (audio FIFOs,
DMA channels, companion chips, etc) are be prepared to begin data transfers.
audio_stop is designed to only stop the audio transfers. The resources used
for playback are released using audio_disable.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Update return value of audio_enable HDMI operation

audio_enable function may in theory fail. Hence, the caller needs
to be notified of the failure.

While there, update the return value of the audio_enable function
for the OMAP4 IP.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Remove ASoC codec

Instead of having an ASoC codec embedded into DSS code, use the generic DSS
device driverinterface for audio support. This allows to any potential user,
including an ASoC driver, take advantage of the HDMI audio functionality.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: OMAP4: Remove CEA-861 audio infoframe and IEC-60958 enums

Instead of having its own definitions for CEA-861 and IEC-60958, the HDMI
driver should use those provided by ALSA. This patch removes the definitions
that are not needed.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: OMAP4: Correcty typo in I2S definitions

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: OMAP4: Decouple wrapper enable and audio start

Decouple the enablement of the HDMI audio wrapper from audio start.
Otherwise, an audio FIFO underflow may occur. The audio wrapper
enablement must be done after configuration and before audio playback
is started.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Decouple HDMI audio from ASoC

Instead of having OMAPDSS HDMI audio functionality depending on the
ASoC HDMI audio driver, use a new config option so that
potential users, including ASoC,  may select if needed.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: OMAP4: Expand configuration for IEC-60958 audio

Utilize a snd_aes_iec958 struct to write the parameters of the IEC-60958
channel status word into the HDMI IP registers. Hence, the user of the
driver has full control of what parameters are written in the word.

Also, some of the paramters of the I2S structure have been removed
as they belong to IEC-60958 parameteres.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Relocate N/CTS calculation

The N and CTS parameters are relevant to all HDMI implmentations and
not specific to a given IP. Hence, the calculation is relocated
into the generic HDMI driver.

Also, deep color is not queried but it is still considered in the
calculation of N. This is to be changed when deep color functionality is
implemented in the driver.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Add support for more audio sample rates in N/CTS calculation

Add support for more sample rates when calculating N and CTS. This
covers all the audio sample rates that an HDMI source is allowed
to transmit according to the HDMI 1.4a specification.

Also, reorganize the logic for the calculation when using deep color.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: OMAP4: Add an audio configuration function

The generic HDMI driver does not need to know about the specific
settings of a given IP. Hence, it just passes the audio configuration
and the IP library parses such configuration and sets the IP
accordingly. This patch introduces an IP-specific audio configuration
function. Also the DMA, format and core config functions are no longer
exposed to the generic HDMI driver as they are IP-specific.

The audio configuration functions caters for 16-bit through 24-bit
audio samples with sample rates from 32kHz and up to 192kHz as well
as up to 8 audio channels.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Panel: Simplify the name of the HDMI mutex

As the hdmi_lock mutex is inside the hdmi struct, rename to simply
"lock". This is only a change in the name. There are not changes
in functionality.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Implement DSS driver interface for audio

Implement the DSS device driver audio support interface in the HDMI
panel driver and generic driver. The implementation relies on the
IP-specific functions that are defined at DSS probe time.

A hardirq-safe spinlock is used to protect the audio_start/stop
functions.. This is because such function may be called while
holding a lock. The operation should not take too long to complete
as at this point all the required resources (DMA, audio FIFO,
regulators, companion chips, etc.) should be prepared to start
audio data transfers.

The rest of the audio functions rely on the HDMI panel mutex lock
for protection. As the enablement of resources may take, it is
appropriate to protect with a mutex. For completenes, the audio_config
and audio_supported are also supported by the same mutex.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
ASoC: OMAP: HDMI: Select DSS HDMI audio support

Select the HDMI audio support provided by the DSS device driver.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
ASoC: OMAP: HDMI: Change error values in HDMI CPU DAI

When getting the needed resources fails, return ENODEV. This is more
in line with other drivers do and it gives a more descriptive error.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
ASoC: OMAP: HDMI: Introduce codec

Introduce codec for HDMI. At the moment, this is a dummy codec. In the
future it will parse the EDID to modify the supported parameters, such
as the number of channels and the sample rates. At the moment, it blindly
supports all the sample rates and audio channels described in the HDMI
1.4a specification.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>

Conflicts:

	sound/soc/codecs/Kconfig
	sound/soc/codecs/Makefile
ASoC: OMAP: HDMI: Update the platform device names

In order to utilize the new OMAP HDMI codec and updated CPU DAI,
use the new platform device names.

While there, also update the machine driver to be more generic
and encompass more OMAP processors featuring HDMI and not only OMAP4.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
ASoC: OMAP: HDMI: Update CPU DAI configuration and ops

Add operations to the CPU DAI. This is to configure the HDMI IP
using DSS functionality.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
ASoC: OMAP: HDMI: Expand capabilities of the HDMI DAI

According to the HDMI specification, a source is permitted to
transmit L-PCM audio in the following sample rates: 32kHz, 44.1kHz,
48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz.

It also supports up to 8 audio channels.

The sink may not necessarily support all these sample rates and
channels. However, as this CPU DAI describes the HDMI source, it
makes sense to include them. The limitation of capabilities as
supported by the sink should be done in the ASoC HDMI codec.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
ASoC: OMAP: HDMI: Make build config more generic

Make Kconfig and Makefile more generic to encompass not only
OMAP4 but other OMAP processors featuring HDMI.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>