ALSA: hda: Refactor display power management

The current HD-audio code manages the DRM audio power via too complex
redirections, and this seems even still unbalanced in a corner case as
Intel DRM CI has been intermittently reporting.  This patch is a big
surgery for addressing the complexity and the possible unbalance.

Basically the patch changes the display PM in the following ways:

- Both HD-audio controller and codec drivers call a single helper,
  snd_hdac_display_power().  (Formerly, the display power control from
  a codec was done indirectly via link_power bus ops.)

- snd_hdac_display_power() receives the codec address index.  For
  turning on/off from the controller, pass HDA_CODEC_IDX_CONTROLLER.

- snd_hdac_display_power() doesn't manage refcounts any longer, but
  keeps the power status in bitmap.  If any of controller or codecs is
  turned on, the function updates the DRM power state via get_power()
  or put_power().

Also this refactor allows us more cleanup:

- The link_power bus ops is dropped, so there is no longer indirect
  management, as mentioned in the above.

- hdac_device link_power_control flag is moved to hda_codec
  display_power_control flag, as it's only for HDA legacy.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106525
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/soc/intel/skylake/skl.c

@@ -334,7 +334,7 @@ static int skl_suspend(struct device *dev)
 	}
 
 	if (IS_ENABLED(CONFIG_SND_SOC_HDAC_HDMI)) {
-		ret = snd_hdac_display_power(bus, false);
+		ret = snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, false);
 		if (ret < 0)
 			dev_err(bus->dev,
 				"Cannot turn OFF display power on i915\n");
@@ -353,7 +353,7 @@ static int skl_resume(struct device *dev)
 
 	/* Turned OFF in HDMI codec driver after codec reconfiguration */
 	if (IS_ENABLED(CONFIG_SND_SOC_HDAC_HDMI)) {
-		ret = snd_hdac_display_power(bus, true);
+		ret = snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, true);
 		if (ret < 0) {
 			dev_err(bus->dev,
 				"Cannot turn on display power on i915\n");
@@ -783,7 +783,7 @@ static int skl_i915_init(struct hdac_bus *bus)
 	if (err < 0)
 		return err;
 
-	err = snd_hdac_display_power(bus, true);
+	err = snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, true);
 	if (err < 0)
 		dev_err(bus->dev, "Cannot turn on display power on i915\n");
 
@@ -838,7 +838,7 @@ static void skl_probe_work(struct work_struct *work)
 		snd_hdac_ext_bus_link_put(bus, hlink);
 
 	if (IS_ENABLED(CONFIG_SND_SOC_HDAC_HDMI)) {
-		err = snd_hdac_display_power(bus, false);
+		err = snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, false);
 		if (err < 0) {
 			dev_err(bus->dev, "Cannot turn off display power on i915\n");
 			skl_machine_device_unregister(skl);
@@ -855,7 +855,7 @@ static void skl_probe_work(struct work_struct *work)
 
 out_err:
 	if (IS_ENABLED(CONFIG_SND_SOC_HDAC_HDMI))
-		err = snd_hdac_display_power(bus, false);
+		err = snd_hdac_display_power(bus, HDA_CODEC_IDX_CONTROLLER, false);
 }
 
 /*