drm/radeon: Add HD-audio component notifier support (v2)

This patch adds the support for the notification of HD-audio hotplug
via the already existing drm_audio_component framework to radeon
driver.  This allows us more reliable hotplug notification and ELD
transfer without accessing HD-audio bus; it's more efficient, and more
importantly, it works without waking up the runtime PM.

The implementation is rather simplistic: radeon driver provides the
get_eld ops for HD-audio, and it notifies the audio hotplug via
pin_eld_notify callback upon each radeon_audio_enable() call.
The pin->id is referred as the port number passed to the notifier
callback, and the corresponding connector is looked through the
encoder list in the get_eld callback in turn.

The bind and unbind callbacks handle the device-link so that it
assures the PM call order.

v2: fix the logic in radeon_audio_component_get_eld to walk the
connector list since that is where the EDID lives and we can
derive the encoder from the connector because the encoder has
not been assigned at this point (i.e., during monitor probe).

Acked-by: Jim Qu <Jim.Qu@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 99 insertions, 0 deletions

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index b17e231ca6f793..73350b19bdd6b0 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -235,6 +235,7 @@ config DRM_RADEON
 	select HWMON
 	select BACKLIGHT_CLASS_DEVICE
 	select INTERVAL_TREE
+	select SND_HDA_COMPONENT if SND_HDA_CORE
 	help
 	  Choose this option if you have an ATI Radeon graphics card.  There
 	  are both PCI and AGP versions.  You don't need to choose this to
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 895776c421d4de..67d0274e8fce04 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -79,6 +79,7 @@
 #include <drm/ttm/ttm_execbuf_util.h>
 
 #include <drm/drm_gem.h>
+#include <drm/drm_audio_component.h>
 
 #include "radeon_family.h"
 #include "radeon_mode.h"
@@ -1797,6 +1798,8 @@ struct r600_audio {
 	struct radeon_audio_funcs *hdmi_funcs;
 	struct radeon_audio_funcs *dp_funcs;
 	struct radeon_audio_basic_funcs *funcs;
+	struct drm_audio_component *component;
+	bool component_registered;
 };
 
 /*
diff --git a/drivers/gpu/drm/radeon/radeon_audio.c b/drivers/gpu/drm/radeon/radeon_audio.c
index 7c5e80d03fc90f..8c6e7979b98800 100644
--- a/drivers/gpu/drm/radeon/radeon_audio.c
+++ b/drivers/gpu/drm/radeon/radeon_audio.c
@@ -23,6 +23,7 @@
  */
 
 #include <linux/gcd.h>
+#include <linux/component.h>
 
 #include <drm/drm_crtc.h>
 #include "dce6_afmt.h"
@@ -180,6 +181,14 @@ static struct radeon_audio_funcs dce6_dp_funcs = {
 	.dpms = evergreen_dp_enable,
 };
 
+static void radeon_audio_component_notify(struct drm_audio_component *acomp,
+					  int port)
+{
+	if (acomp && acomp->audio_ops && acomp->audio_ops->pin_eld_notify)
+		acomp->audio_ops->pin_eld_notify(acomp->audio_ops->audio_ptr,
+						 port, -1);
+}
+
 static void radeon_audio_enable(struct radeon_device *rdev,
 				struct r600_audio_pin *pin, u8 enable_mask)
 {
@@ -207,6 +216,8 @@ static void radeon_audio_enable(struct radeon_device *rdev,
 
 	if (rdev->audio.funcs->enable)
 		rdev->audio.funcs->enable(rdev, pin, enable_mask);
+
+	radeon_audio_component_notify(rdev->audio.component, pin->id);
 }
 
 static void radeon_audio_interface_init(struct radeon_device *rdev)
@@ -230,6 +241,82 @@ static void radeon_audio_interface_init(struct radeon_device *rdev)
 	}
 }
 
+static int radeon_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 drm_encoder *encoder;
+	struct radeon_encoder *radeon_encoder;
+	struct radeon_encoder_atom_dig *dig;
+	struct drm_connector *connector;
+	int ret = 0;
+
+	*enabled = false;
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		const struct drm_connector_helper_funcs *connector_funcs =
+			connector->helper_private;
+		encoder = connector_funcs->best_encoder(connector);
+
+		if (!encoder)
+			continue;
+		if (!radeon_encoder_is_digital(encoder))
+			continue;
+		radeon_encoder = to_radeon_encoder(encoder);
+		dig = radeon_encoder->enc_priv;
+		if (!dig->pin || dig->pin->id != port)
+			continue;
+		*enabled = true;
+		ret = drm_eld_size(connector->eld);
+		memcpy(buf, connector->eld, min(max_bytes, ret));
+		break;
+	}
+
+	return ret;
+}
+
+static const struct drm_audio_component_ops radeon_audio_component_ops = {
+	.get_eld = radeon_audio_component_get_eld,
+};
+
+static int radeon_audio_component_bind(struct device *kdev,
+				       struct device *hda_kdev, void *data)
+{
+	struct drm_device *dev = dev_get_drvdata(kdev);
+	struct radeon_device *rdev = dev->dev_private;
+	struct drm_audio_component *acomp = data;
+
+	if (WARN_ON(!device_link_add(hda_kdev, kdev, DL_FLAG_STATELESS)))
+		return -ENOMEM;
+
+	drm_modeset_lock_all(dev);
+	acomp->ops = &radeon_audio_component_ops;
+	acomp->dev = kdev;
+	rdev->audio.component = acomp;
+	drm_modeset_unlock_all(dev);
+
+	return 0;
+}
+
+static void radeon_audio_component_unbind(struct device *kdev,
+					  struct device *hda_kdev, void *data)
+{
+	struct drm_device *dev = dev_get_drvdata(kdev);
+	struct radeon_device *rdev = dev->dev_private;
+	struct drm_audio_component *acomp = data;
+
+	drm_modeset_lock_all(dev);
+	rdev->audio.component = NULL;
+	acomp->ops = NULL;
+	acomp->dev = NULL;
+	drm_modeset_unlock_all(dev);
+}
+
+static const struct component_ops radeon_audio_component_bind_ops = {
+	.bind	= radeon_audio_component_bind,
+	.unbind	= radeon_audio_component_unbind,
+};
+
 static int radeon_audio_chipset_supported(struct radeon_device *rdev)
 {
 	return ASIC_IS_DCE2(rdev) && !ASIC_IS_NODCE(rdev);
@@ -276,6 +363,9 @@ int radeon_audio_init(struct radeon_device *rdev)
 	for (i = 0; i < rdev->audio.num_pins; i++)
 		radeon_audio_enable(rdev, &rdev->audio.pin[i], 0);
 
+	if (!component_add(rdev->dev, &radeon_audio_component_bind_ops))
+		rdev->audio.component_registered = true;
+
 	return 0;
 }
 
@@ -428,6 +518,11 @@ void radeon_audio_fini(struct radeon_device *rdev)
 		radeon_audio_enable(rdev, &rdev->audio.pin[i], 0);
 
 	rdev->audio.enabled = false;
+
+	if (rdev->audio.component_registered) {
+		component_del(rdev->dev, &radeon_audio_component_bind_ops);
+		rdev->audio.component_registered = false;
+	}
 }
 
 static void radeon_audio_set_dto(struct drm_encoder *encoder, unsigned int clock)