This is again a big rewrite of the driver; now it touches the code to
process PCM stream transfers.

The most fundamental change is that the driver may support more than
four periods.  Instead of keeping the same index between both the ring
buffer (with the fixed four buffer descriptors) and the PCM buffer
periods, we keep difference indices for both (bd_head and pcm_head
fields).  In addition, when the periods are more than four, we need to
track both head and next indices.  That is, we now have three indices:
bd_head, pcm_head and pcm_filled.

Also, the driver works better for periods < 4, too: the remaining BDs
out of four are marked as invalid, so that the hardware skips those
BDs in its loop.

By this flexibility, we can use even ALSA-lib dmix plugin, which
requires 16 periods as default.

The buffer size could be up to 20bit, so the max buffer size was
increased accordingly.  However, the buffer pre-allocation is kept as
the old value (600kB) as default.  The reason is the limited number of
BDs: since it doesn't suffice for the useful SG page management that
can fit with the usual page allocator like some other drivers, we have
to still allocate continuous pages, hence we shouldn't take too big
memories there.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

... so that the driver can avoid ifdef's for the dead PM callbacks.
The compiler should optimize them out in anyway.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Use had_ prefix consistently to all local helper functions, as well as
had_pcm_ for PCM ops.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The procedure to reset buffer pointers is performed in two places and
still open-coded.  Simplify the helper function and use it
consistently.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The lowlevel register read/write don't have to be careful about the
connection state.  It should be checked in the caller side instead.
By dropping the check, we can simplify the code, and readability.

This patch also refacors the functions slightly: namely,
- drop the useless always-zero return values
- fold the inline functions to the main accessor functions themselves
- move the DP audio hack for AUD_CONFIG to the caller side
- simplify snd_intelhad_eanble_audio() and drop the unused
  had_read_modify()
Signed-off-by: Takashi Iwai <tiwai@suse.de>

LPE audio is capable only up to 32bit address, as it seems.
Then we should limit the DMA addresses accordingly via dma-mapping
API.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Lots of cleanups and refactoring of Intel LPE audio driver.

After the rewrite of the runtime PM code, we have only two driver
status: CONNECTED and DISCONNECTED.  So it's clearer to use a boolean
flag, and name it easier one, "connected".
Signed-off-by: Takashi Iwai <tiwai@suse.de>

- Add a few more comments to functions.

- Move the initialization of some PCM state variables to open and
  prepare callbacks, where these are clearer places.

- Remove superfluous NULL checks.

- Get rid of the bogus drv_status change to CONNECTED at close;
  this doesn't make any sense.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

It's a stand-alone small driver code, and we don't have to describe
too much formalized comments in kernel-doc style for local functions
at all.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This is a guess work.  Usually the DP audio info frame is just 8-bit
shifted from HDMI AI, so let's try to put CA in DIP frame 2 [24-31].
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Like other drivers, expose the ELD bytes via a control element so that
user-space can parse it.

For the simplicity, the code to register the ctl elements is
refactored using an array.  Also, since ELD ctl read copies the bytes
also during disconnection, clear the ELD bytes at hot-unplug, in order
to avoid the leak of the previous bogus ELD.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Many defines and constants are left unused.  Clean them up.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Currently each register definition contains the own prefix in the
union struct itself; for example, union aud_ch_status_0 has
status_0_regx and status_0_regval fields.  These are simply
superfluous, since usually the type of the variable is seen in its
declaration or in its name.

In this patch, we cut off these prefixes.  Now all register
definitions have regx and regval fields consistently, instead.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

We have some constants defined in drm/drm_edid.h, and clean up our own
definitions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The only remaining field in struct had_stream_data is stream_type that
holds the current stream status.  Such information fits better in
struct pcm_stream_info, so move it as a boolean "running" field to be
clearer.

This allows us to get rid or had_stream_data definition and
references.

Also, the superfluous status check get removed in a couple of places
where we can call PCM helpers in anyway.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Although the driver has some PM callbacks, it doesn't do it right:
- the suspend callback doesn't handle to suspend the running PCM,
- the runtime PM ops are missing,
- pm_runtime_get_sync() isn't used at the right place.

This patch covers the above and provides the basic runtime PM
functionality.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The PCM substream is referred not only in the PCM callbacks but also
in the irq handler and in the hotplug/unplug codes.  The latter code
paths don't take the PCM lock, thus the PCM may be released
unexpectedly while calling PCM helper functions or accessing
pcm->runtime fields.

This patch implements a simple refcount to assure the PCM substream
accessibility while the other codes are accessing.  It needed some
code refactoring in the relevant functions for avoiding the doubly
spinlocks.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The struct pcm_stream_info contains a few unused or useless fields.
str_id is always zero, buffer_ptr is volatile, never read, and sfreq
is nowhere referred.  Kill them.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The had_stream_pvt struct assigned to PCM runtime private data tracks
merely the stream running status, and the very same information is
carried by had_stream->stream_type.  Kill it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The state field keeps the connection state and it's basically as same
as drv_status field.  Drop this redundancy.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The flag_underrun flag is used to indicate to escalate the XRUN
reporting at the next position inquiry, but there is a much simpler
method to achieve it: just call snd_pcm_stop_xrun().
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The access to chmap can be racy against the hotplug process, where it
recreates the chmap on the fly.  For protecting against it, a mutex is
introduced in this patch.  It's also used for protecting the change /
reference of eld and state fields, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

We don't need to use irqsave/irqrestore versions for each spin lock,
but judge the context properly and use the simpler versions.

Also add some (still simplistic) comments to functions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Some tables can be defined as const.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Although we dropped the most of the obsoleted *_v1 definitions and
codes, some codes still keep the _v1 or _v2 suffices.  Now they are
ripped off.

The only thing to be done carefully here is the definition of control
offsets.  The original code defines enum hdmi_ctrl_reg_offset_v1 and
a few new elements just for v2 on its top.  After this cleanup, we
remove the old AUD_HDMI_STATUS and AUD_HDMIW_INFOFR definitions and
replace with the v2 values.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Clean up codes, fix indentations, correct comments, etc.
No functional change.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The helper function isn't clearer than the plain condition check
"if (drv_status == HDA_DRV_DISCONNECTED)".  By expanding this, the
compiler could even catch the possible uninitialized cases, so we
could fix them, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The had_get_hwstate() is identical with drv_status==DISCONECTED, which
was already checked before the call.  And, returning an error at
resume is simply bad.  That is, we should just kill this check.

Also, spewing an error at resume for drv_status!=SUSPENDED is also
annoying, as this is the normal case when the suspend was called
without the monitor connection.  Make it debug, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

i915 notification is executed in a spinlock, thus it must not sleep;
i.e. we can't use kmalloc with GFP_KERNEL or such.

For making it working properly, move the notification handler in a
work, and handle it gracefully.  We have already such a work, and it
was used just at the start.  This can be re-used in a more generic
hotplug handling.

Also, the patch adds the proper call of cancel_work_sync() to the
destructor.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

snd_pcm_lib_preallocate_free_for_all() doesn't have to be called from
each driver as it's called in the PCM core.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Also change the flag_underrun to bool to be clearer.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Again another indirect call...  Let's straighten it up.
Also define the had_stream field with a proper type instead of a void
pointer.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The direct access to power.runtime_status is taboo, let's use a helper
macro to avoid the compile error with CONFIG_PM=n.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

dev_xxx() helpers give a tidier output in general.

While we're at it, remove many useless debug prints (e.g. the ones at
each function entry), replace some too verbose errors with debugs, and
use WARN_ON() for some serious errors.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

As the very last step, we fold intel_hdmi_audio_if.c into the main
file, intel_hdmi_audio.c.  This is merely a cleanup, and no functional
change.

By this move, we can mark all functions and variables as static, which
allows the compiler more optimizations.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

This is the final stage for a big clean-up series.  Here we flatten
the two layers into one.  Formerly, the implementation was split to
HDMI "shell" that talks with the platform device, and HDMI audio part
that communicates via caps and other event handlers.  All these would
be good if there were multiple instantiations or if there were data
protection.  But neither are true in our case.  That said, it'll be
easier to have a flat driver structure in the end.

In this patch, the former struct hdmi_lpe_audio_ctx is forged into the
existing struct snd_intelhad.  The latter has already a few members
that are basically the copy from the former.  Only a few new members
for the lowlevel I/O are added by this change.

Then, the had_get_caps() and had_set_caps() are simply replaced with
the direct calls to copy the data in the struct fields.  Also, the
had_event_handler() calls are replaced with the direct call for each
event as well.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

It's used nowhere.  Kill it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The card registration should be done at the last stage of the probe
procedure.  Otherwise user-space may access to the device before the
whole initialization is done.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Just a minor optimization; check the presence of platform_data earlier
in the probe function before actually starting allocation, which makes
the error path easier.
Signed-off-by: Takashi Iwai <tiwai@suse.de>