[PATCH v4 2/4] ALSA: hda/realtek: Support ACPI Notification framework via component binding

[Stefan Binding]

For systems which have support for ACPI notifications, add a mechanism to
register a handler for ACPI notifications and then call the acpi_notify
api on the bound components.

Registering a handler in the Realtek HDA driver, allows a single handler to
be registered, which then calls into all the components, rather than
attempting to register the same handler multiple times, once for each
component.

Signed-off-by: Stefan Binding <sbinding@xxxxxxxxxxxxxxxxxxxxx>
---
 sound/pci/hda/patch_realtek.c | 83 ++++++++++++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 751783f3a15c..1cd897ac6586 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -10,6 +10,7 @@
  *                    Jonathan Woithe <jwoithe@xxxxxxxxxx>
  */
 
+#include <linux/acpi.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
@@ -6704,12 +6705,91 @@ static void alc287_fixup_legion_15imhg05_speakers(struct hda_codec *codec,
 	}
 }
 
+#ifdef CONFIG_ACPI
+static void comp_acpi_device_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct hda_codec *cdc = data;
+	struct alc_spec *spec = cdc->spec;
+	int i;
+
+	codec_info(cdc, "ACPI Notification %d\n", event);
+
+	for (i = 0; i < HDA_MAX_COMPONENTS; i++) {
+		if (spec->comps[i].dev && spec->comps[i].acpi_notify)
+			spec->comps[i].acpi_notify(acpi_device_handle(spec->comps[i].adev), event,
+						   spec->comps[i].dev);
+	}
+}
+
+static int comp_bind_acpi(struct device *dev)
+{
+	struct hda_codec *cdc = dev_to_hda_codec(dev);
+	struct alc_spec *spec = cdc->spec;
+	bool support_notifications = false;
+	struct acpi_device *adev;
+	int ret;
+	int i;
+
+	adev = spec->comps[0].adev;
+	if (!acpi_device_handle(adev))
+		return 0;
+
+	for (i = 0; i < HDA_MAX_COMPONENTS; i++)
+		support_notifications = support_notifications ||
+			spec->comps[i].acpi_notifications_supported;
+
+	if (support_notifications) {
+		ret = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
+						comp_acpi_device_notify, cdc);
+		if (ret < 0) {
+			codec_warn(cdc, "Failed to install notify handler: %d\n", ret);
+			return 0;
+		}
+
+		codec_dbg(cdc, "Notify handler installed\n");
+	}
+
+	return 0;
+}
+
+static void comp_unbind_acpi(struct device *dev)
+{
+	struct hda_codec *cdc = dev_to_hda_codec(dev);
+	struct alc_spec *spec = cdc->spec;
+	struct acpi_device *adev;
+	int ret;
+
+	adev = spec->comps[0].adev;
+	if (!acpi_device_handle(adev))
+		return;
+
+	ret = acpi_remove_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
+					 comp_acpi_device_notify);
+	if (ret < 0)
+		codec_warn(cdc, "Failed to uninstall notify handler: %d\n", ret);
+}
+#else
+static int comp_bind_acpi(struct device *dev)
+{
+	return 0;
+}
+
+static void comp_unbind_acpi(struct device *dev)
+{
+}
+#endif
+
 static int comp_bind(struct device *dev)
 {
 	struct hda_codec *cdc = dev_to_hda_codec(dev);
 	struct alc_spec *spec = cdc->spec;
+	int ret;
+
+	ret = component_bind_all(dev, spec->comps);
+	if (ret)
+		return ret;
 
-	return component_bind_all(dev, spec->comps);
+	return comp_bind_acpi(dev);
 }
 
 static void comp_unbind(struct device *dev)
@@ -6717,6 +6797,7 @@ static void comp_unbind(struct device *dev)
 	struct hda_codec *cdc = dev_to_hda_codec(dev);
 	struct alc_spec *spec = cdc->spec;
 
+	comp_unbind_acpi(dev);
 	component_unbind_all(dev, spec->comps);
 }
 
-- 
2.34.1