ALSA: hda - fix beep tone calculation for IDT/STAC codecs

[pandora-kernel.git] / sound / pci / hda / hda_beep.c

diff --git a/sound/pci/hda/hda_beep.c b/sound/pci/hda/hda_beep.c
index 4de5bac..b0275a0 100644 (file)
--- a/sound/pci/hda/hda_beep.c
+++ b/sound/pci/hda/hda_beep.c
@@ -45,6 +45,49 @@ 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 93.75Hz in steps of 46.875 Hz
+ */
+static int beep_linear_tone(struct hda_beep *beep, int hz)
+{
+       if (hz <= 0)
+               return 0;
+       hz *= 1000; /* fixed point */
+       hz = hz - DIGBEEP_HZ_MIN
+               + DIGBEEP_HZ_STEP / 2; /* round to nearest step */
+       if (hz < 0)
+               hz = 0; /* turn off PC beep*/
+       else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
+               hz = 1; /* max frequency */
+       else {
+               hz /= DIGBEEP_HZ_STEP;
+               hz = 255 - 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 +98,14 @@ 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);