From fa7979663190240b838ab8c8bad7f59e618bf77c Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 19 May 2009 12:50:04 +0200
Subject: [PATCH] ALSA: hda - Fix digital beep tone calculation

The digital beep tone is calculated in two different ways depending
on the codec chip.  The standard one is using a divider, and another
one is a linear tone for IDT/STAC codecs.  Currently, only the
latter type is used for all codecs, which resulted in a wrong tone
pitch.

This patch adds the calculation of the standard HD-audio type.
Also clean-up the fields in hda_beep struct.

Reference: bko#13162
	http://bugzilla.kernel.org/show_bug.cgi?id=13162

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/pci/hda/hda_beep.c       | 55 +++++++++++++++++++++++++++++++++---------
 sound/pci/hda/hda_beep.h       |  5 ++--
 sound/pci/hda/patch_sigmatel.c |  2 ++
 3 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/sound/pci/hda/hda_beep.c b/sound/pci/hda/hda_beep.c
index 4de5bac..29272f2 100644
--- a/sound/pci/hda/hda_beep.c
+++ b/sound/pci/hda/hda_beep.c
@@ -45,6 +45,46 @@ static void snd_hda_generate_beep(struct work_struct *work)
 			AC_VERB_SET_BEEP_CONTROL, beep->tone);
 }
 
+/* (non-standard) Linear beep tone calculation for IDT/STAC codecs 
+ *
+ * The tone frequency of beep generator on IDT/STAC codecs is
+ * defined from the 8bit tone parameter, in Hz,
+ *    freq = 48000 * (257 - tone) / 1024
+ * that is from 12kHz to 93.75kHz in step of 46.875 hz
+ */
+static int beep_linear_tone(struct hda_beep *beep, int hz)
+{
+	hz *= 1000; /* fixed point */
+	hz = hz - DIGBEEP_HZ_MIN;
+	if (hz < 0)
+		hz = 0; /* turn off PC beep*/
+	else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
+		hz = 0xff;
+	else {
+		hz /= DIGBEEP_HZ_STEP;
+		hz++;
+	}
+	return hz;
+}
+
+/* HD-audio standard beep tone parameter calculation
+ *
+ * The tone frequency in Hz is calculated as
+ *   freq = 48000 / (tone * 4)
+ * from 47Hz to 12kHz
+ */
+static int beep_standard_tone(struct hda_beep *beep, int hz)
+{
+	if (hz <= 0)
+		return 0; /* disabled */
+	hz = 12000 / hz;
+	if (hz > 0xff)
+		return 0xff;
+	if (hz <= 0)
+		return 1;
+	return hz;
+}
+
 static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
 				unsigned int code, int hz)
 {
@@ -55,21 +95,14 @@ static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
 		if (hz)
 			hz = 1000;
 	case SND_TONE:
-		hz *= 1000; /* fixed point */
-		hz = hz - DIGBEEP_HZ_MIN;
-		if (hz < 0)
-			hz = 0; /* turn off PC beep*/
-		else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
-			hz = 0xff;
-		else {
-			hz /= DIGBEEP_HZ_STEP;
-			hz++;
-		}
+		if (beep->linear_tone)
+			beep->tone = beep_linear_tone(beep, hz);
+		else
+			beep->tone = beep_standard_tone(beep, hz);
 		break;
 	default:
 		return -1;
 	}
-	beep->tone = hz;
 
 	/* schedule beep event */
 	schedule_work(&beep->beep_work);
diff --git a/sound/pci/hda/hda_beep.h b/sound/pci/hda/hda_beep.h
index 51bf6a5..0c3de78 100644
--- a/sound/pci/hda/hda_beep.h
+++ b/sound/pci/hda/hda_beep.h
@@ -30,8 +30,9 @@ struct hda_beep {
 	struct hda_codec *codec;
 	char phys[32];
 	int tone;
-	int nid;
-	int enabled;
+	hda_nid_t nid;
+	unsigned int enabled:1;
+	unsigned int linear_tone:1;	/* linear tone for IDT/STAC codec */
 	struct work_struct beep_work; /* scheduled task for beep event */
 };
 
diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
index 0295098..1731081 100644
--- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -3737,6 +3737,8 @@ static int stac92xx_parse_auto_config(struct hda_codec *codec, hda_nid_t dig_out
 		err = snd_hda_attach_beep_device(codec, nid);
 		if (err < 0)
 			return err;
+		/* IDT/STAC codecs have linear beep tone parameter */
+		codec->beep->linear_tone = 1;
 		/* if no beep switch is available, make its own one */
 		caps = query_amp_caps(codec, nid, HDA_OUTPUT);
 		if (codec->beep &&
-- 
2.7.4