ASoC: SOF: Intel: hda-mlink: introduce helpers for 'extended links' PM

Add helpers to program SPA/CPA bits, using a mutex to access the
shared LCTL register if required.

All links are managed with the same LCTLx.SPA bits. However there are
quite a few implementation details to be aware of:

Legacy HDaudio multi-links are powered-up when exiting reset, which
requires the ref_count to be manually set to one when initializing the
link.

Alternate links for SoundWire/DMIC/SSP need to be explicitly
powered-up before accessing the SHIM/IP/Vendor-Specific SHIM space for
each sublink. DMIC/SSP/SoundWire are all different cases with a
different device/dai/hlink relationship.

SoundWire will handle power management with the auxiliary device
resume/suspend routine. The ref_count is not necessary in this case.

The DMIC/SSP will by contrast handle the power management from DAI
.startup and .shutdown callbacks.

The SSP has a 1:1 mapping between sublink and DAI, but it's
bidirectional so the ref_count will help avoid turning off the sublink
when one of the two directions is still in use.

The DMIC has a single link but two DAIs for data generated at
different sampling frequencies, again the ref_count will make sure the
two DAIs can be used concurrently.

And last the SoundWire Intel require power-up/down and bank switch to
be handled with a lock already taken, so the 'eml_lock' is made
optional with the _unlocked versions of the helpers.

Note that the _check_power_active() implementation is similar to
previous helpers in sound/hda/ext, with sleep duration and timeout
aligned with hardware recommendations. If desired, this helper could
be modified in a second step with .e.g. readl_poll_timeout()

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20230404104127.5629-9-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/sound/hda-mlink.h b/include/sound/hda-mlink.h
index 8048bf01c133..6ecb4c29e472 100644
--- a/include/sound/hda-mlink.h
+++ b/include/sound/hda-mlink.h
@@ -12,6 +12,13 @@ struct hdac_bus;
 
 int hda_bus_ml_init(struct hdac_bus *bus);
 void hda_bus_ml_free(struct hdac_bus *bus);
+
+int hdac_bus_eml_power_up(struct hdac_bus *bus, bool alt, int elid, int sublink);
+int hdac_bus_eml_power_up_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink);
+
+int hdac_bus_eml_power_down(struct hdac_bus *bus, bool alt, int elid, int sublink);
+int hdac_bus_eml_power_down_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink);
+
 void hda_bus_ml_put_all(struct hdac_bus *bus);
 void hda_bus_ml_reset_losidv(struct hdac_bus *bus);
 int hda_bus_ml_resume(struct hdac_bus *bus);
@@ -23,6 +30,31 @@ static inline int
 hda_bus_ml_init(struct hdac_bus *bus) { return 0; }
 
 static inline void hda_bus_ml_free(struct hdac_bus *bus) { }
+
+static inline int
+hdac_bus_eml_power_up(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_power_up_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_power_down(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_power_down_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
 static inline void hda_bus_ml_put_all(struct hdac_bus *bus) { }
 static inline void hda_bus_ml_reset_losidv(struct hdac_bus *bus) { }
 static inline int hda_bus_ml_resume(struct hdac_bus *bus) { return 0; }