[alsa-devel] [PATCH v2] ALSA: hda - Enable mic mute hotkey and LEDs for an HP machine

[David Henningsson]

On this machine, the mic mute hotkey is connected to GPIO2. We therefore
create an extra input device for this key.

Also enable LEDs connected to GPIO3 and GPIO4.

(Note: if this patch is backported to older kernels, where KEY_MIC_MUTE is
not available, change the KEY_MIC_MUTE to KEY_F20, which was previously used
for mic mute keys.)

BugLink: https://bugs.launchpad.net/bugs/1408295
Tested-by: Keng-Yu Lin <keng-yu.lin at canonical.com>
Signed-off-by: David Henningsson <david.henningsson at canonical.com>
---

Changes since v1 (which was by mistake not posted to alsa-devel)
 - fixes according to Takashi's review comments

 sound/pci/hda/patch_realtek.c | 88 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 65f1f4e..09d2131 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -29,6 +29,7 @@
 #include <linux/pci.h>
 #include <linux/dmi.h>
 #include <linux/module.h>
+#include <linux/input.h>
 #include <sound/core.h>
 #include <sound/jack.h>
 #include "hda_codec.h"
@@ -120,6 +121,9 @@ struct alc_spec {
 	hda_nid_t pll_nid;
 	unsigned int pll_coef_idx, pll_coef_bit;
 	unsigned int coef0;
+#if IS_ENABLED(CONFIG_INPUT)
+	struct input_dev *kb_dev;
+#endif
 };
 
 /*
@@ -3472,6 +3476,84 @@ static void alc280_fixup_hp_gpio4(struct hda_codec *codec,
 	}
 }
 
+#if IS_ENABLED(CONFIG_INPUT)
+static void gpio2_mic_hotkey_event(struct hda_codec *codec,
+				   struct hda_jack_callback *event)
+{
+	struct alc_spec *spec = codec->spec;
+
+	/* GPIO2 just toggles on a keypress/keyrelease cycle. Therefore
+	   send both key on and key off event for every interrupt. */
+	input_report_key(spec->kb_dev, KEY_MICMUTE, 1);
+	input_sync(spec->kb_dev);
+	input_report_key(spec->kb_dev, KEY_MICMUTE, 0);
+	input_sync(spec->kb_dev);
+}
+#endif
+
+static void alc280_fixup_hp_gpio2_mic_hotkey(struct hda_codec *codec,
+					     const struct hda_fixup *fix, int action)
+{
+#if IS_ENABLED(CONFIG_INPUT)
+	/* GPIO1 = set according to SKU external amp
+	   GPIO2 = mic mute hotkey
+	   GPIO3 = mute LED
+	   GPIO4 = mic mute LED */
+	static const struct hda_verb gpio_init[] = {
+		{ 0x01, AC_VERB_SET_GPIO_MASK, 0x1e },
+		{ 0x01, AC_VERB_SET_GPIO_DIRECTION, 0x1a },
+		{ 0x01, AC_VERB_SET_GPIO_DATA, 0x02 },
+		{}
+	};
+
+	struct alc_spec *spec = codec->spec;
+
+	if (action == HDA_FIXUP_ACT_PRE_PROBE) {
+		spec->kb_dev = input_allocate_device();
+		if (!spec->kb_dev) {
+			codec_err(codec, "Out of memory (input_allocate_device)\n");
+			return;
+		}
+		spec->kb_dev->name = "Microphone Mute Button";
+		spec->kb_dev->evbit[0] = BIT_MASK(EV_KEY);
+		spec->kb_dev->keybit[BIT_WORD(KEY_MICMUTE)] = BIT_MASK(KEY_MICMUTE);
+		if (input_register_device(spec->kb_dev)) {
+			codec_err(codec, "input_register_device failed\n");
+			input_free_device(spec->kb_dev);
+			spec->kb_dev = NULL;
+			return;
+		}
+
+		snd_hda_add_verbs(codec, gpio_init);
+		snd_hda_codec_write_cache(codec, codec->afg, 0,
+					  AC_VERB_SET_GPIO_UNSOLICITED_RSP_MASK, 0x04);
+		snd_hda_jack_detect_enable_callback(codec, codec->afg,
+						    gpio2_mic_hotkey_event);
+
+		spec->gen.vmaster_mute.hook = alc_fixup_gpio_mute_hook;
+		spec->gen.cap_sync_hook = alc_fixup_gpio_mic_mute_hook;
+		spec->gpio_led = 0;
+		spec->mute_led_polarity = 0;
+		spec->gpio_mute_led_mask = 0x08;
+		spec->gpio_mic_led_mask = 0x10;
+		return;
+	}
+
+	if (!spec->kb_dev)
+		return;
+
+	switch (action) {
+	case HDA_FIXUP_ACT_PROBE:
+		spec->init_amp = ALC_INIT_DEFAULT;
+		break;
+	case HDA_FIXUP_ACT_FREE:
+		input_unregister_device(spec->kb_dev);
+		input_free_device(spec->kb_dev);
+		spec->kb_dev = NULL;
+	}
+#endif
+}
+
 static void alc269_fixup_hp_line1_mic1_led(struct hda_codec *codec,
 				const struct hda_fixup *fix, int action)
 {
@@ -4341,6 +4423,7 @@ enum {
 	ALC282_FIXUP_ASPIRE_V5_PINS,
 	ALC280_FIXUP_HP_GPIO4,
 	ALC286_FIXUP_HP_GPIO_LED,
+	ALC280_FIXUP_HP_GPIO2_MIC_HOTKEY,
 };
 
 static const struct hda_fixup alc269_fixups[] = {
@@ -4814,6 +4897,10 @@ static const struct hda_fixup alc269_fixups[] = {
 		.type = HDA_FIXUP_FUNC,
 		.v.func = alc286_fixup_hp_gpio_led,
 	},
+	[ALC280_FIXUP_HP_GPIO2_MIC_HOTKEY] = {
+		.type = HDA_FIXUP_FUNC,
+		.v.func = alc280_fixup_hp_gpio2_mic_hotkey,
+	},
 };
 
 static const struct snd_pci_quirk alc269_fixup_tbl[] = {
@@ -4843,6 +4930,7 @@ static const struct snd_pci_quirk alc269_fixup_tbl[] = {
 	SND_PCI_QUIRK(0x103c, 0x1586, "HP", ALC269_FIXUP_HP_MUTE_LED_MIC2),
 	SND_PCI_QUIRK(0x103c, 0x18e6, "HP", ALC269_FIXUP_HP_GPIO_LED),
 	SND_PCI_QUIRK(0x103c, 0x218b, "HP", ALC269_FIXUP_LIMIT_INT_MIC_BOOST_MUTE_LED),
+	SND_PCI_QUIRK(0x103c, 0x225f, "HP", ALC280_FIXUP_HP_GPIO2_MIC_HOTKEY),
 	/* ALC282 */
 	SND_PCI_QUIRK(0x103c, 0x2210, "HP", ALC269_FIXUP_HP_MUTE_LED_MIC1),
 	SND_PCI_QUIRK(0x103c, 0x2214, "HP", ALC269_FIXUP_HP_MUTE_LED_MIC1),
-- 
1.9.1