drm/amd/display: Add drm_audio_component support to amdgpu_dm

[Why]
The drm_audio_component can be used to give pin ELD notifications
directly to the sound driver. This fixes audio endpoints disappearing
due to missing unsolicited notifications.

[How]
Send the notification via the audio component whenever we enable or
disable audio state on a stream. This matches what i915 does with
their drm_audio_component and what Takashi Iwai's proposed hack for
radeon/amdpgu did.

This is a bit delayed in when the notification actually occurs, however.
We wait until after all the programming is complete rather than sending
the notification mid sequence.

Particular care is needed for the get ELD callback since it can happen
outside the locking and fencing DRM does for atomic commits.

Cc: Leo Li <sunpeng.li@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/Kconfig

@@ -5,6 +5,7 @@ menu "Display Engine Configuration"
 config DRM_AMD_DC
 	bool "AMD DC - Enable new display engine"
 	default y
+	select SND_HDA_COMPONENT if SND_HDA_CORE
 	select DRM_AMD_DC_DCN1_0 if X86 && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
 	help
 	  Choose this option if you want to use the new display engine

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -56,6 +56,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/pci.h>
 #include <linux/firmware.h>
+#include <linux/component.h>
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_uapi.h>
@@ -65,6 +66,7 @@
 #include <drm/drm_fourcc.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_vblank.h>
+#include <drm/drm_audio_component.h>
 
 #if defined(CONFIG_DRM_AMD_DC_DCN1_0)
 #include "ivsrcid/dcn/irqsrcs_dcn_1_0.h"
@@ -508,6 +510,139 @@ static void amdgpu_dm_fbc_init(struct drm_connector *connector)
 
 }
 
+static int amdgpu_dm_audio_component_get_eld(struct device *kdev, int port,
+					  int pipe, bool *enabled,
+					  unsigned char *buf, int max_bytes)
+{
+	struct drm_device *dev = dev_get_drvdata(kdev);
+	struct amdgpu_device *adev = dev->dev_private;
+	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+	struct amdgpu_dm_connector *aconnector;
+	int ret = 0;
+
+	*enabled = false;
+
+	mutex_lock(&adev->dm.audio_lock);
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		aconnector = to_amdgpu_dm_connector(connector);
+		if (aconnector->audio_inst != port)
+			continue;
+
+		*enabled = true;
+		ret = drm_eld_size(connector->eld);
+		memcpy(buf, connector->eld, min(max_bytes, ret));
+
+		break;
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	mutex_unlock(&adev->dm.audio_lock);
+
+	DRM_DEBUG_KMS("Get ELD : idx=%d ret=%d en=%d\n", port, ret, *enabled);
+
+	return ret;
+}
+
+static const struct drm_audio_component_ops amdgpu_dm_audio_component_ops = {
+	.get_eld = amdgpu_dm_audio_component_get_eld,
+};
+
+static int amdgpu_dm_audio_component_bind(struct device *kdev,
+				       struct device *hda_kdev, void *data)
+{
+	struct drm_device *dev = dev_get_drvdata(kdev);
+	struct amdgpu_device *adev = dev->dev_private;
+	struct drm_audio_component *acomp = data;
+
+	acomp->ops = &amdgpu_dm_audio_component_ops;
+	acomp->dev = kdev;
+	adev->dm.audio_component = acomp;
+
+	return 0;
+}
+
+static void amdgpu_dm_audio_component_unbind(struct device *kdev,
+					  struct device *hda_kdev, void *data)
+{
+	struct drm_device *dev = dev_get_drvdata(kdev);
+	struct amdgpu_device *adev = dev->dev_private;
+	struct drm_audio_component *acomp = data;
+
+	acomp->ops = NULL;
+	acomp->dev = NULL;
+	adev->dm.audio_component = NULL;
+}
+
+static const struct component_ops amdgpu_dm_audio_component_bind_ops = {
+	.bind	= amdgpu_dm_audio_component_bind,
+	.unbind	= amdgpu_dm_audio_component_unbind,
+};
+
+static int amdgpu_dm_audio_init(struct amdgpu_device *adev)
+{
+	int i, ret;
+
+	if (!amdgpu_audio)
+		return 0;
+
+	adev->mode_info.audio.enabled = true;
+
+	adev->mode_info.audio.num_pins = adev->dm.dc->res_pool->audio_count;
+
+	for (i = 0; i < adev->mode_info.audio.num_pins; i++) {
+		adev->mode_info.audio.pin[i].channels = -1;
+		adev->mode_info.audio.pin[i].rate = -1;
+		adev->mode_info.audio.pin[i].bits_per_sample = -1;
+		adev->mode_info.audio.pin[i].status_bits = 0;
+		adev->mode_info.audio.pin[i].category_code = 0;
+		adev->mode_info.audio.pin[i].connected = false;
+		adev->mode_info.audio.pin[i].id =
+			adev->dm.dc->res_pool->audios[i]->inst;
+		adev->mode_info.audio.pin[i].offset = 0;
+	}
+
+	ret = component_add(adev->dev, &amdgpu_dm_audio_component_bind_ops);
+	if (ret < 0)
+		return ret;
+
+	adev->dm.audio_registered = true;
+
+	return 0;
+}
+
+static void amdgpu_dm_audio_fini(struct amdgpu_device *adev)
+{
+	if (!amdgpu_audio)
+		return;
+
+	if (!adev->mode_info.audio.enabled)
+		return;
+
+	if (adev->dm.audio_registered) {
+		component_del(adev->dev, &amdgpu_dm_audio_component_bind_ops);
+		adev->dm.audio_registered = false;
+	}
+
+	/* TODO: Disable audio? */
+
+	adev->mode_info.audio.enabled = false;
+}
+
+void amdgpu_dm_audio_eld_notify(struct amdgpu_device *adev, int pin)
+{
+	struct drm_audio_component *acomp = adev->dm.audio_component;
+
+	if (acomp && acomp->audio_ops && acomp->audio_ops->pin_eld_notify) {
+		DRM_DEBUG_KMS("Notify ELD: %d\n", pin);
+
+		acomp->audio_ops->pin_eld_notify(acomp->audio_ops->audio_ptr,
+						 pin, -1);
+	}
+}
+
 static int amdgpu_dm_init(struct amdgpu_device *adev)
 {
 	struct dc_init_data init_data;
@@ -518,6 +653,7 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 	memset(&init_data, 0, sizeof(init_data));
 
 	mutex_init(&adev->dm.dc_lock);
+	mutex_init(&adev->dm.audio_lock);
 
 	if(amdgpu_dm_irq_init(adev)) {
 		DRM_ERROR("amdgpu: failed to initialize DM IRQ support.\n");
@@ -621,6 +757,8 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 
 static void amdgpu_dm_fini(struct amdgpu_device *adev)
 {
+	amdgpu_dm_audio_fini(adev);
+
 	amdgpu_dm_destroy_drm_device(&adev->dm);
 
 	/* DC Destroy TODO: Replace destroy DAL */
@@ -641,6 +779,7 @@ static void amdgpu_dm_fini(struct amdgpu_device *adev)
 		adev->dm.freesync_module = NULL;
 	}
 
+	mutex_destroy(&adev->dm.audio_lock);
 	mutex_destroy(&adev->dm.dc_lock);
 
 	return;
@@ -1888,6 +2027,10 @@ static int amdgpu_dm_mode_config_init(struct amdgpu_device *adev)
 	if (r)
 		return r;
 
+	r = amdgpu_dm_audio_init(adev);
+	if (r)
+		return r;
+
 	return 0;
 }
 
@@ -4834,6 +4977,7 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 	aconnector->base.stereo_allowed = false;
 	aconnector->base.dpms = DRM_MODE_DPMS_OFF;
 	aconnector->hpd.hpd = AMDGPU_HPD_NONE; /* not used */
+	aconnector->audio_inst = -1;
 	mutex_init(&aconnector->hpd_lock);
 
 	/*
@@ -5728,6 +5872,81 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
 	kfree(bundle);
 }
 
+static void amdgpu_dm_commit_audio(struct drm_device *dev,
+				   struct drm_atomic_state *state)
+{
+	struct amdgpu_device *adev = dev->dev_private;
+	struct amdgpu_dm_connector *aconnector;
+	struct drm_connector *connector;
+	struct drm_connector_state *old_con_state, *new_con_state;
+	struct drm_crtc_state *new_crtc_state;
+	struct dm_crtc_state *new_dm_crtc_state;
+	const struct dc_stream_status *status;
+	int i, inst;
+
+	/* Notify device removals. */
+	for_each_oldnew_connector_in_state(state, connector, old_con_state, new_con_state, i) {
+		if (old_con_state->crtc != new_con_state->crtc) {
+			/* CRTC changes require notification. */
+			goto notify;
+		}
+
+		if (!new_con_state->crtc)
+			continue;
+
+		new_crtc_state = drm_atomic_get_new_crtc_state(
+			state, new_con_state->crtc);
+
+		if (!new_crtc_state)
+			continue;
+
+		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
+			continue;
+
+	notify:
+		aconnector = to_amdgpu_dm_connector(connector);
+
+		mutex_lock(&adev->dm.audio_lock);
+		inst = aconnector->audio_inst;
+		aconnector->audio_inst = -1;
+		mutex_unlock(&adev->dm.audio_lock);
+
+		amdgpu_dm_audio_eld_notify(adev, inst);
+	}
+
+	/* Notify audio device additions. */
+	for_each_new_connector_in_state(state, connector, new_con_state, i) {
+		if (!new_con_state->crtc)
+			continue;
+
+		new_crtc_state = drm_atomic_get_new_crtc_state(
+			state, new_con_state->crtc);
+
+		if (!new_crtc_state)
+			continue;
+
+		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
+			continue;
+
+		new_dm_crtc_state = to_dm_crtc_state(new_crtc_state);
+		if (!new_dm_crtc_state->stream)
+			continue;
+
+		status = dc_stream_get_status(new_dm_crtc_state->stream);
+		if (!status)
+			continue;
+
+		aconnector = to_amdgpu_dm_connector(connector);
+
+		mutex_lock(&adev->dm.audio_lock);
+		inst = status->audio_inst;
+		aconnector->audio_inst = inst;
+		mutex_unlock(&adev->dm.audio_lock);
+
+		amdgpu_dm_audio_eld_notify(adev, inst);
+	}
+}
+
 /*
  * Enable interrupts on CRTCs that are newly active, undergone
  * a modeset, or have active planes again.
@@ -6106,6 +6325,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 	/* Enable interrupts for CRTCs going from 0 to n active planes. */
 	amdgpu_dm_enable_crtc_interrupts(dev, state, false);
 
+	/* Update audio instances for each connector. */
+	amdgpu_dm_commit_audio(dev, state);
+
 	/*
 	 * send vblank event on all events not handled in flip and
 	 * mark consumed event for drm_atomic_helper_commit_hw_done

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h

@@ -143,6 +143,28 @@ struct amdgpu_display_manager {
 	 */
 	struct mutex dc_lock;
 
+	/**
+	 * @audio_lock:
+	 *
+	 * Guards access to audio instance changes.
+	 */
+	struct mutex audio_lock;
+
+	/**
+	 * @audio_component:
+	 *
+	 * Used to notify ELD changes to sound driver.
+	 */
+	struct drm_audio_component *audio_component;
+
+	/**
+	 * @audio_registered:
+	 *
+	 * True if the audio component has been registered
+	 * successfully, false otherwise.
+	 */
+	bool audio_registered;
+
 	/**
 	 * @irq_handler_list_low_tab:
 	 *
@@ -254,6 +276,9 @@ struct amdgpu_dm_connector {
 	int max_vfreq ;
 	int pixel_clock_mhz;
 
+	/* Audio instance - protected by audio_lock. */
+	int audio_inst;
+
 	struct mutex hpd_lock;
 
 	bool fake_enable;