OMAPDSS: Provide an 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 driver or any other driver interested in
the functionality.

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 reverse operation and is
intended to be called after audio_stop.

While a given DSS device driver 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 any
specific DSS device driver, a struct omap_dss_audio is defined. Its purpose
is to contain all the required parameters for audio configuration. At the
moment, such structure contains pointers to IEC-60958 channel status word and
CEA-861 audio infoframe structures. This should be enough to support HDMI and
DisplayPort, as both are based on CEA-861 and IEC-60958. The omap_dss_audio
structure may be extended in the future if required.

The audio_enable/disable, audio_config and audio_supported functions could be
implemented as functions 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) have been enabled 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: Split audio_enable into audio_enable/disable

To improve readability, split the audio_enable fuction into
two separate functions for enable and disable audio.

While there, update these functions for the OMAP4 IP accordingly.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: Split video_enable into video_enable/disable

To improve readability, split the video_enable HDMI IP operation
into two functions. The video_enable function is modified
to return an error value.

While there, modify the operations for the specific case of OMAP4.

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

Remove the ASoC OMAP HDMI audio codec. The goal of removing the codec
is to, in subsequent patches, give way to the implementation of the HDMI
audio support using the DSS device driver audio interface. This
approach will expose the HDMI audio functionality to any interested entity.

In a separate patch, ASoC will use this new approach to expose HDMI audio
to ALSA.

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 already provided by ALSA.

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

This pach corrects a typo in the naming of a I2S define.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
OMAPDSS: HDMI: OMAP4: Remove invalid I2S settings

According to the most up-to-date documentation from Texas Instruments,
it is not possible to configure the HDMI IP for High Bitrate Audio.
Also, it is not possible to set polarity of the I2S Word Select
signal. This patch implements the required updates.

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

Decouple the enable/disable operation of the HDMI audio wrapper from
audio start/stop. 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: 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, this patch implements the audio config function for OMAP4. The
DMA, format and core config functions are no longer exposed to the
generic HDMI driver as they are IP-specific.

The audio configuration function 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.

At the moment, the rest of the audio functions also are protected
by a hardirq-safe spinlock. In the future, a mutex may have to be
used, as the enablement of resources may take too much time.

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>