ALSA: hda: digital pc-beep support hd-audio codecs

Added digital pc-beep support using linear tone generation for hd-codecs along
with initial support for several IDT codecs.

Signed-off-by: Matthew Ranostay <mranostay@embeddedalley.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/hda/hda_beep.c

@@ -0,0 +1,134 @@
+/*
+ * Digital Beep Input Interface for HD-audio codec
+ *
+ * Author: Matthew Ranostay <mranostay@embeddedalley.com>
+ * Copyright (c) 2008 Embedded Alley Solutions Inc
+ *
+ *  This driver is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This driver is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/input.h>
+#include <linux/pci.h>
+#include <linux/workqueue.h>
+#include <sound/core.h>
+#include "hda_beep.h"
+
+enum {
+	DIGBEEP_HZ_STEP = 46875,	/* 46.875 Hz */
+	DIGBEEP_HZ_MIN = 93750,		/* 93.750 Hz */
+	DIGBEEP_HZ_MAX = 12000000,	/* 12 KHz */
+};
+
+static void snd_hda_generate_beep(struct work_struct *work)
+{
+	struct hda_beep *beep =
+		container_of(work, struct hda_beep, beep_work);
+	struct hda_codec *codec = beep->codec;
+
+	/* generate tone */
+	snd_hda_codec_write_cache(codec, beep->nid, 0,
+			AC_VERB_SET_BEEP_CONTROL, beep->tone);
+}
+
+static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
+				unsigned int code, int hz)
+{
+	struct hda_beep *beep = input_get_drvdata(dev);
+
+	switch (code) {
+	case SND_BELL:
+		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++;
+		}
+		break;
+	default:
+		return -1;
+	}
+	beep->tone = hz;
+
+	/* schedule beep event */
+	schedule_work(&beep->beep_work);
+	return 0;
+}
+
+int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
+{
+	struct input_dev *input_dev;
+	struct hda_beep *beep;
+	int err;
+
+	beep = kzalloc(sizeof(*beep), GFP_KERNEL);
+	if (beep == NULL)
+		return -ENOMEM;
+	snprintf(beep->phys, sizeof(beep->phys),
+		"card%d/codec#%d/beep0", codec->bus->card->number, codec->addr);
+	input_dev = input_allocate_device();
+
+	/* setup digital beep device */
+	input_dev->name = "HDA Digital PCBeep";
+	input_dev->phys = beep->phys;
+	input_dev->id.bustype = BUS_PCI;
+
+	input_dev->id.vendor = codec->vendor_id >> 16;
+	input_dev->id.product = codec->vendor_id & 0xffff;
+	input_dev->id.version = 0x01;
+
+	input_dev->evbit[0] = BIT_MASK(EV_SND);
+	input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
+	input_dev->event = snd_hda_beep_event;
+	input_dev->dev.parent = &codec->bus->pci->dev;
+	input_set_drvdata(input_dev, beep);
+
+	err = input_register_device(input_dev);
+	if (err < 0) {
+		kfree(input_dev);
+		kfree(beep);
+		return err;
+	}
+
+	/* enable linear scale */
+	snd_hda_codec_write(codec, nid, 0,
+		AC_VERB_SET_DIGI_CONVERT_2, 0x01);
+
+	beep->nid = nid;
+	beep->dev = input_dev;
+	beep->codec = codec;
+	codec->beep = beep;
+
+	INIT_WORK(&beep->beep_work, &snd_hda_generate_beep);
+	return 0;
+}
+
+void snd_hda_detach_beep_device(struct hda_codec *codec)
+{
+	struct hda_beep *beep = codec->beep;
+	if (beep) {
+		cancel_work_sync(&beep->beep_work);
+		flush_scheduled_work();
+
+		input_unregister_device(beep->dev);
+		kfree(beep);
+	}
+}