ALSA: hda - bind headset buttons to the headphone jack

With the HDA driver, if the headset buttons are supported, an audio
Jack will be created for them. This audio Jack is a bit confusing to
users since it can't report headphone/mic insertion events but it
claims to support these events.

And in addition, the driver already builds a headphone Jack and a mic
Jack, and most of those buttons are used for headphone playback, so
do some change to bind those buttons to the headphone Jack. After this
change, the key events are generated from NID 0x55, and are reported
to the input layer via headphone jack (NID 0x21).

If there is no headphone Jack, then build an audio jack to support
those buttons same as previously.

Signed-off-by: Hui Wang <hui.wang@canonical.com>
Link: https://lore.kernel.org/r/20210305092608.109599-1-hui.wang@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 72 insertions, 1 deletions

diff --git a/sound/pci/hda/hda_jack.c b/sound/pci/hda/hda_jack.c
index b8b568046592..30e9ebf1f341 100644
--- a/sound/pci/hda/hda_jack.c
+++ b/sound/pci/hda/hda_jack.c
@@ -389,6 +389,69 @@ int snd_hda_jack_set_gating_jack(struct hda_codec *codec, hda_nid_t gated_nid,
 EXPORT_SYMBOL_GPL(snd_hda_jack_set_gating_jack);
 
 /**
+ * snd_hda_jack_bind_keymap - bind keys generated from one NID to another jack.
+ * @codec: the HDA codec
+ * @key_nid: key event is generated by this pin NID
+ * @keymap: map of key type and key code
+ * @jack_nid: key reports to the jack of this pin NID
+ *
+ * This function is used in the case of key is generated from one NID while is
+ * reported to the jack of another NID.
+ */
+int snd_hda_jack_bind_keymap(struct hda_codec *codec, hda_nid_t key_nid,
+			     const struct hda_jack_keymap *keymap,
+			     hda_nid_t jack_nid)
+{
+	const struct hda_jack_keymap *map;
+	struct hda_jack_tbl *key_gen = snd_hda_jack_tbl_get(codec, key_nid);
+	struct hda_jack_tbl *report_to = snd_hda_jack_tbl_get(codec, jack_nid);
+
+	WARN_ON(codec->dp_mst);
+
+	if (!key_gen || !report_to || !report_to->jack)
+		return -EINVAL;
+
+	key_gen->key_report_jack = jack_nid;
+
+	if (keymap)
+		for (map = keymap; map->type; map++)
+			snd_jack_set_key(report_to->jack, map->type, map->key);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_hda_jack_bind_keymap);
+
+/**
+ * snd_hda_jack_set_button_state - report button event to the hda_jack_tbl button_state.
+ * @codec: the HDA codec
+ * @jack_nid: the button event reports to the jack_tbl of this NID
+ * @button_state: the button event captured by codec
+ *
+ * Codec driver calls this function to report the button event.
+ */
+void snd_hda_jack_set_button_state(struct hda_codec *codec, hda_nid_t jack_nid,
+				   int button_state)
+{
+	struct hda_jack_tbl *jack = snd_hda_jack_tbl_get(codec, jack_nid);
+
+	if (!jack)
+		return;
+
+	if (jack->key_report_jack) {
+		struct hda_jack_tbl *report_to =
+			snd_hda_jack_tbl_get(codec, jack->key_report_jack);
+
+		if (report_to) {
+			report_to->button_state = button_state;
+			return;
+		}
+	}
+
+	jack->button_state = button_state;
+}
+EXPORT_SYMBOL_GPL(snd_hda_jack_set_button_state);
+
+/**
  * snd_hda_jack_report_sync - sync the states of all jacks and report if changed
  * @codec: the HDA codec
  */
@@ -651,7 +714,15 @@ void snd_hda_jack_unsol_event(struct hda_codec *codec, unsigned int res)
 	}
 	if (!event)
 		return;
-	event->jack_dirty = 1;
+
+	if (event->key_report_jack) {
+		struct hda_jack_tbl *report_to =
+			snd_hda_jack_tbl_get_mst(codec, event->key_report_jack,
+						 event->dev_id);
+		if (report_to)
+			report_to->jack_dirty = 1;
+	} else
+		event->jack_dirty = 1;
 
 	call_jack_callback(codec, res, event);
 	snd_hda_jack_report_sync(codec);