Not calling pm_runtime_enable() means that runtime PM can't be
enabled at all via sysfs. So we definitely need to call it
from somewhere.

Calling it from the driver seems like a bad idea because it
would have to be paired with a pm_runtime_disable() at driver
unload time, otherwise the core gets upset. Also if there's
no LPE audio driver loaded then we couldn't runtime suspend
i915 either.

So it looks like a better plan is to call it from i915 when
we register the platform device. That seems to match how
pci generally does things. I cargo culted the
pm_runtime_forbid() and pm_runtime_set_active() calls from
pci as well.

The exposed runtime PM API is massive an thorougly misleading, so
I don't actually know if this is how you're supposed to use the API
or not. But it seems to work. I can now runtime suspend i915 again
with or without the LPE audio driver loaded, and reloading the
LPE audio driver also seems to work.

Note that powertop won't auto-tune runtime PM for platform devices,
which is a little annoying. So I'm not sure that leaving runtime
PM in "on" mode by default is the best choice here. But I've left
it like that for now at least.

Also remove the comment about there not being much benefit from
LPE audio runtime PM. Not allowing runtime PM blocks i915 runtime
PM, which will also block s0ix, and that could have a measurable
impact on power consumption.

Cc: stable@vger.kernel.org
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Fixes: 0b6b524f ("ALSA: x86: Don't enable runtime PM as default")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170427160231.13337-2-ville.syrjala@linux.intel.comReviewed-by: NTakashi Iwai <tiwai@suse.de>

Unlike HSW and newer, BYT/CHT devices have no fine control of audio
power domain in i915 side.  Since there is little gain by runtime PM
on BYT/CHT, so far, this commit removes the pm_runtime_enable() call
as default.

User who still wants the runtime PM may adjust the corresponding
sysfs files (power/control and power/autosuspend_delay_ms)
appropriately, of course.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This patch adds a few lines to the driver to use autosuspend for the
runtime PM.  It'll become useful with the combination of the keep-link
feature.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Currently the driver returns -ENODEV when the monitor is disconnected.
But PA alsa module doesn't like this and it starts playing Juliet,
kills itself as if it were a fatal tragedy.

Since we protect the whole read/write at disconnection, just allow the
PCM accesses even during disconnection.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Put the stuff in the right order; notification should be at the end of
the action.

Also dropped a superfluous debug print and incorrect comments.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This shouldn't happen, but just to be sure...
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

It seems that accessing registers during disconnection often leads to
the GPU pipe error.  The original driver had a similar check in the
past, but it was lost through refactoring.  Now put a connection check
in the register access functions.

One exception is the irq handler: it still needs to access the raw
register even while disconnected, because it has to read and write to
ACK the irq mask.  Although the irq shouldn't be raised while
disconnected (the stream should have been disabled), let's make it
safer for now.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

It's not wise to return an error at info/get callback when
disconnected, which happens at any time.
The chmap ctl is supposed to fill zero for such a case, instead.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The previously allocated chmap has to be released before setting the
new one.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This seems more friendly to user-space, as it's notified at least as
an error, instead of forcibly moving the PCM state to SETUP out of
sudden.

Moreover, snd_pcm_stop() needs an extra PCM spinlock I forgot, while
snd_pcm_stop_xrun() takes the spinlock by itself.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This patch implements a jack interface for notifying HDMI/DP
connection.  PA listens to this, so it can handle the monitor
connection more gracefully.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The pcm_stream_info.running field is only set in the PCM trigger
callback but never referred, thus it can be safely removed.

Also, properly cover the spinlock in both the trigger START and STOP
to protect had_enable_audio() calls.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Currently the driver handles some reset procedure at the trigger STOP
and the underrun functions, where both are executed in the interrupt
context.  Especially the underrun function has a sync-loop to clear
the UNDERRUN status bit, and this is supposed to be one of plausible
causes of GPU hangup.

Since the job to be done in the interrupt handler should be minimum,
we move the reset function out of trigger and underrun, and push it
into the prepare (and hw_free) callbacks instead.  Here a new flag,
need_reset, is introduced to indicate the requirement of the reset
procedure.  This is for avoiding the multiple resets when PCM prepare
is called sequentially.

Also in the UNDERRUN bit-clear sync loop, take a longer pause to be in
the safer side.  Taking a longer delay is no longer a problem now
because we're running in the normal context.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Now we support S16 PCM format in addition.  For this, we need to set
packet_mode=1 in AUD_CONFIG register.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The hardware has the support for the left-aligned 24bit format in
32bit packet.  This corresponds to S32 format in ALSA.  We need to set
the msbits restriction as well to inform user-space that only MSB
24bit are available.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In the current implementation, the driver may update the BDs even at
PCM pointer callback.  This allows us to skip the period interrupt
effectively.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

This is an implementation of PCM streaming with only 1 period.
Since the hardware requires the refresh of BDs after each BD
processing finishes, we'd need at least two BDs.  The trick is that
both BDs point to the same content: the address of the PCM buffer
head, and the whole buffer size.  Then it loops over to the whole
buffer again after it finished once.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The PCM engine on LPE audio isn't like a batch-style process any
longer, but rather it deals with the standard ring buffer.  Remove the
BATCH info flag so that PA can handle the buffer in timer-sched mode.

Similarly, the DOUBLE flag is also superfluous.  Drop both bits.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

At enabling the audio, we modify AUD_CONFIG register bit 0.  So far,
it does read-modify-write procedure with a special hack for the
channel bits due to the silicon bug.  But we can optimize it by
remembering the AUD_CONFIG register value privately.  This simplifies
the things a lot.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

We have two header files and everything is mixed up chaotically.
Move the chip-specific definitions like the hardware registers to
intel_hdmi_lpe_audio.h, and the rest, the implementation specific
stuff into intel_hdmi_audio.h.

In addition, put some more comments to the register fields, and fix
the incorrect name prefix for AUD_HDMI_STATUS bits, too.

The whole changes are merely a code shuffling, and there is no
functional change.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The two functions are unused when CONFIG_PM_SLEEP is disabled:

sound/x86/intel_hdmi_audio.c:1633:12: error: 'hdmi_lpe_audio_resume' defined but not used [-Werror=unused-function]
sound/x86/intel_hdmi_audio.c:1622:12: error: 'hdmi_lpe_audio_suspend' defined but not used [-Werror=unused-function]

Marking them as __maybe_unused avoids the warning without introducing an
ugly #ifdef.

Fixes: 182cdf23 ("ALSA: x86: Implement runtime PM")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The driver sets card->driver name string over its size (16 bytes).
Shorten the name string to fit with it.

Also, set more verbose string to card->shortname and ->longname.
This doesn't have to be identical with card->driver at all.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

had_enable_audio_int() came from the LPE audio shell set_caps
callback with ENABLE_INT and DISABLE_INT caps.  I interpreted as these
correspond to enabling / disabling the audio interface, but the actual
implementation is only to clear (send ACK) to both BUFFER_DONE and
BUFFER_UNDERRUN interrupts unconditionally.  And, there is no
counterpart, DISABLE_INT, code at all.

For avoiding the further misunderstanding, rename the function to the
more fitting one, had_ack_irqs(), and drop the calls with enable=false
in allover places.  There is no functional changes at all.

After this patch, there is only one caller at the PCM trigger start.
Then it's doubtful whether this call is still really needed or not; I
bet it not, but let's stay in the safer side for now and keep it as
was.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

U24 format is declared to be supported by the driver, but this looks
really doubtful, as there is no corresponding code.  Better to drop
it.  This format is very uncommon, so there should be practically no
impact by this change.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

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: NTakashi Iwai <tiwai@suse.de>

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

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: NTakashi 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: NTakashi 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: NTakashi 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: NTakashi 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: NTakashi Iwai <tiwai@suse.de>

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

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