[RFC PATCH 2/2] ALSA: hda - add connection to thinkpad_acpi to control mute/micmute LEDs

[David Henningsson <david.henningsson@canonical.com>]

Notes/questions:

For mute LEDs we can follow master like we already do on HP machines, but for
mic mutes, we might have several capture switches. Honestly, on these laptops
which almost always have autoswitched mics, there is only one recording source
anyway. Can't we simply remove the extra capture PCMs, that seems easiest?

For some reason CONFIG_THINKPAD_ACPI did not work here (it was not defined),
but maybe it's due to the way I'm testing, or I'm missing something obvious. 
Not sure.

There are Thinkpad's with Realtek codecs as well which have mute/micmute.
Maybe we should consider a more generic solution instead of copy-pasting
between differen patch_* files?

And also, we're missing a symbol_put in this version. Should we add a new
"free" fixup action where we can add a call to symbol_put, or do you have a
better suggestion?

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 sound/pci/hda/patch_conexant.c |   78 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/sound/pci/hda/patch_conexant.c b/sound/pci/hda/patch_conexant.c
index ec68eae..237df7f 100644
--- a/sound/pci/hda/patch_conexant.c
+++ b/sound/pci/hda/patch_conexant.c
@@ -3232,8 +3232,80 @@ enum {
 	CXT_FIXUP_HEADPHONE_MIC_PIN,
 	CXT_FIXUP_HEADPHONE_MIC,
 	CXT_FIXUP_GPIO1,
+	CXT_FIXUP_THINKPAD_ACPI,
 };
 
+/* FIXME: figure out why #ifdef CONFIG_THINKPAD_ACPI does not work */
+
+#if 1 /* #ifdef CONFIG_THINKPAD_ACPI */
+
+#include <linux/thinkpad_acpi.h>
+
+static int (*mute_led_set_func)(int);
+static int (*micmute_led_set_func)(int);
+
+static void update_tpacpi_mute_led(void *private_data, int enabled)
+{
+	struct hda_codec *codec = private_data;
+	struct conexant_spec *spec = codec->spec;
+
+	if (spec->dynamic_eapd)
+		cx_auto_vmaster_hook(private_data, enabled);
+
+	if (mute_led_set_func)
+		mute_led_set_func(!enabled);
+}
+
+static void update_tpacpi_micmute_led(struct hda_codec *codec,
+				      struct snd_ctl_elem_value *ucontrol)
+{
+	int val;
+	if (!ucontrol || !micmute_led_set_func)
+		return;
+	/* TODO: if this is a stereo switch, better check both channels? What about additional capture switches with indices, on other ADCs? */
+	val = ucontrol->value.integer.value[0];
+	if (strcmp("Capture Switch", ucontrol->id.name) == 0 && ucontrol->id.index == 0)
+		micmute_led_set_func(!val);
+
+}
+
+static void cxt_fixup_thinkpad_acpi(struct hda_codec *codec,
+				  const struct hda_fixup *fix, int action)
+{
+	struct conexant_spec *spec = codec->spec;
+	if (action == HDA_FIXUP_ACT_PRE_PROBE) {
+		mute_led_set_func = symbol_request(tpacpi_mute_led_set);
+		if (!mute_led_set_func)
+			snd_printk(KERN_WARNING "Failed to find thinkpad-acpi symbol tpacpi_mute_led_set\n");
+		else if (mute_led_set_func(0) < 0) {
+			symbol_put(mute_led_set_func);
+			mute_led_set_func = NULL;
+		}
+
+		micmute_led_set_func = symbol_request(tpacpi_micmute_led_set);
+		if (!micmute_led_set_func)
+			snd_printk(KERN_WARNING "Failed to find thinkpad-acpi symbol tpacpi_micmute_led_set\n");
+		else if (micmute_led_set_func(0) < 0) {
+			symbol_put(micmute_led_set_func);
+			micmute_led_set_func = NULL;
+		}
+	/* FIXME: when do we call symbol_put? In a new FREE fixup action? */
+	}
+	if (action == HDA_FIXUP_ACT_PROBE && micmute_led_set_func)
+		spec->gen.cap_sync_hook = update_tpacpi_micmute_led;
+	if (action == HDA_FIXUP_ACT_PROBE && mute_led_set_func)
+		spec->gen.vmaster_mute.hook = update_tpacpi_mute_led;
+}
+
+#else
+
+static void cxt_fixup_thinkpad_acpi(struct hda_codec *codec,
+				  const struct hda_fixup *fix, int action)
+{
+}
+
+#endif
+
 static void cxt_fixup_stereo_dmic(struct hda_codec *codec,
 				  const struct hda_fixup *fix, int action)
 {
@@ -3344,6 +3416,8 @@ static const struct hda_fixup cxt_fixups[] = {
 	[CXT_PINCFG_LENOVO_TP410] = {
 		.type = HDA_FIXUP_PINS,
 		.v.pins = cxt_pincfg_lenovo_tp410,
+		.chained = true,
+		.chain_id = CXT_FIXUP_THINKPAD_ACPI,
 	},
 	[CXT_PINCFG_LEMOTE_A1004] = {
 		.type = HDA_FIXUP_PINS,
@@ -3385,6 +3459,10 @@ static const struct hda_fixup cxt_fixups[] = {
 			{ }
 		},
 	},
+	[CXT_FIXUP_THINKPAD_ACPI] = {
+		.type = HDA_FIXUP_FUNC,
+		.v.func = cxt_fixup_thinkpad_acpi,
+	},
 };
 
 static const struct snd_pci_quirk cxt5051_fixups[] = {
-- 
1.7.9.5