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ALSA: hda - Avoid possible race of beep on/off
[~andy/linux] / sound / pci / hda / hda_beep.c
1 /*
2  * Digital Beep Input Interface for HD-audio codec
3  *
4  * Author: Matthew Ranostay <mranostay@embeddedalley.com>
5  * Copyright (c) 2008 Embedded Alley Solutions Inc
6  *
7  *  This driver is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This driver is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  */
21
22 #include <linux/input.h>
23 #include <linux/pci.h>
24 #include <linux/slab.h>
25 #include <linux/workqueue.h>
26 #include <linux/export.h>
27 #include <sound/core.h>
28 #include "hda_beep.h"
29 #include "hda_local.h"
30
31 enum {
32         DIGBEEP_HZ_STEP = 46875,        /* 46.875 Hz */
33         DIGBEEP_HZ_MIN = 93750,         /* 93.750 Hz */
34         DIGBEEP_HZ_MAX = 12000000,      /* 12 KHz */
35 };
36
37 static void snd_hda_generate_beep(struct work_struct *work)
38 {
39         struct hda_beep *beep =
40                 container_of(work, struct hda_beep, beep_work);
41         struct hda_codec *codec = beep->codec;
42
43         if (!beep->enabled)
44                 return;
45
46         /* generate tone */
47         snd_hda_codec_write(codec, beep->nid, 0,
48                         AC_VERB_SET_BEEP_CONTROL, beep->tone);
49 }
50
51 /* (non-standard) Linear beep tone calculation for IDT/STAC codecs 
52  *
53  * The tone frequency of beep generator on IDT/STAC codecs is
54  * defined from the 8bit tone parameter, in Hz,
55  *    freq = 48000 * (257 - tone) / 1024
56  * that is from 12kHz to 93.75Hz in steps of 46.875 Hz
57  */
58 static int beep_linear_tone(struct hda_beep *beep, int hz)
59 {
60         if (hz <= 0)
61                 return 0;
62         hz *= 1000; /* fixed point */
63         hz = hz - DIGBEEP_HZ_MIN
64                 + DIGBEEP_HZ_STEP / 2; /* round to nearest step */
65         if (hz < 0)
66                 hz = 0; /* turn off PC beep*/
67         else if (hz >= (DIGBEEP_HZ_MAX - DIGBEEP_HZ_MIN))
68                 hz = 1; /* max frequency */
69         else {
70                 hz /= DIGBEEP_HZ_STEP;
71                 hz = 255 - hz;
72         }
73         return hz;
74 }
75
76 /* HD-audio standard beep tone parameter calculation
77  *
78  * The tone frequency in Hz is calculated as
79  *   freq = 48000 / (tone * 4)
80  * from 47Hz to 12kHz
81  */
82 static int beep_standard_tone(struct hda_beep *beep, int hz)
83 {
84         if (hz <= 0)
85                 return 0; /* disabled */
86         hz = 12000 / hz;
87         if (hz > 0xff)
88                 return 0xff;
89         if (hz <= 0)
90                 return 1;
91         return hz;
92 }
93
94 static int snd_hda_beep_event(struct input_dev *dev, unsigned int type,
95                                 unsigned int code, int hz)
96 {
97         struct hda_beep *beep = input_get_drvdata(dev);
98
99         switch (code) {
100         case SND_BELL:
101                 if (hz)
102                         hz = 1000;
103         case SND_TONE:
104                 if (beep->linear_tone)
105                         beep->tone = beep_linear_tone(beep, hz);
106                 else
107                         beep->tone = beep_standard_tone(beep, hz);
108                 break;
109         default:
110                 return -1;
111         }
112
113         /* schedule beep event */
114         schedule_work(&beep->beep_work);
115         return 0;
116 }
117
118 static void snd_hda_do_detach(struct hda_beep *beep)
119 {
120         input_unregister_device(beep->dev);
121         beep->dev = NULL;
122         cancel_work_sync(&beep->beep_work);
123         /* turn off beep for sure */
124         snd_hda_codec_write(beep->codec, beep->nid, 0,
125                                   AC_VERB_SET_BEEP_CONTROL, 0);
126 }
127
128 static int snd_hda_do_attach(struct hda_beep *beep)
129 {
130         struct input_dev *input_dev;
131         struct hda_codec *codec = beep->codec;
132         int err;
133
134         input_dev = input_allocate_device();
135         if (!input_dev) {
136                 printk(KERN_INFO "hda_beep: unable to allocate input device\n");
137                 return -ENOMEM;
138         }
139
140         /* setup digital beep device */
141         input_dev->name = "HDA Digital PCBeep";
142         input_dev->phys = beep->phys;
143         input_dev->id.bustype = BUS_PCI;
144
145         input_dev->id.vendor = codec->vendor_id >> 16;
146         input_dev->id.product = codec->vendor_id & 0xffff;
147         input_dev->id.version = 0x01;
148
149         input_dev->evbit[0] = BIT_MASK(EV_SND);
150         input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
151         input_dev->event = snd_hda_beep_event;
152         input_dev->dev.parent = &codec->bus->pci->dev;
153         input_set_drvdata(input_dev, beep);
154
155         err = input_register_device(input_dev);
156         if (err < 0) {
157                 input_free_device(input_dev);
158                 printk(KERN_INFO "hda_beep: unable to register input device\n");
159                 return err;
160         }
161         beep->dev = input_dev;
162         return 0;
163 }
164
165 int snd_hda_enable_beep_device(struct hda_codec *codec, int enable)
166 {
167         struct hda_beep *beep = codec->beep;
168         if (!beep)
169                 return 0;
170         enable = !!enable;
171         if (beep->enabled != enable) {
172                 beep->enabled = enable;
173                 if (!enable) {
174                         cancel_work_sync(&beep->beep_work);
175                         /* turn off beep */
176                         snd_hda_codec_write(beep->codec, beep->nid, 0,
177                                                   AC_VERB_SET_BEEP_CONTROL, 0);
178                 }
179                 return 1;
180         }
181         return 0;
182 }
183 EXPORT_SYMBOL_HDA(snd_hda_enable_beep_device);
184
185 int snd_hda_attach_beep_device(struct hda_codec *codec, int nid)
186 {
187         struct hda_beep *beep;
188         int err;
189
190         if (!snd_hda_get_bool_hint(codec, "beep"))
191                 return 0; /* disabled explicitly by hints */
192         if (codec->beep_mode == HDA_BEEP_MODE_OFF)
193                 return 0; /* disabled by module option */
194
195         beep = kzalloc(sizeof(*beep), GFP_KERNEL);
196         if (beep == NULL)
197                 return -ENOMEM;
198         snprintf(beep->phys, sizeof(beep->phys),
199                 "card%d/codec#%d/beep0", codec->bus->card->number, codec->addr);
200         /* enable linear scale */
201         snd_hda_codec_write(codec, nid, 0,
202                 AC_VERB_SET_DIGI_CONVERT_2, 0x01);
203
204         beep->nid = nid;
205         beep->codec = codec;
206         codec->beep = beep;
207
208         INIT_WORK(&beep->beep_work, &snd_hda_generate_beep);
209         mutex_init(&beep->mutex);
210
211         err = snd_hda_do_attach(beep);
212         if (err < 0) {
213                 kfree(beep);
214                 codec->beep = NULL;
215                 return err;
216         }
217
218         return 0;
219 }
220 EXPORT_SYMBOL_HDA(snd_hda_attach_beep_device);
221
222 void snd_hda_detach_beep_device(struct hda_codec *codec)
223 {
224         struct hda_beep *beep = codec->beep;
225         if (beep) {
226                 if (beep->dev)
227                         snd_hda_do_detach(beep);
228                 codec->beep = NULL;
229                 kfree(beep);
230         }
231 }
232 EXPORT_SYMBOL_HDA(snd_hda_detach_beep_device);
233
234 /* get/put callbacks for beep mute mixer switches */
235 int snd_hda_mixer_amp_switch_get_beep(struct snd_kcontrol *kcontrol,
236                                       struct snd_ctl_elem_value *ucontrol)
237 {
238         struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
239         struct hda_beep *beep = codec->beep;
240         if (beep) {
241                 ucontrol->value.integer.value[0] =
242                         ucontrol->value.integer.value[1] =
243                         beep->enabled;
244                 return 0;
245         }
246         return snd_hda_mixer_amp_switch_get(kcontrol, ucontrol);
247 }
248 EXPORT_SYMBOL_HDA(snd_hda_mixer_amp_switch_get_beep);
249
250 int snd_hda_mixer_amp_switch_put_beep(struct snd_kcontrol *kcontrol,
251                                       struct snd_ctl_elem_value *ucontrol)
252 {
253         struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
254         struct hda_beep *beep = codec->beep;
255         if (beep)
256                 snd_hda_enable_beep_device(codec,
257                                            *ucontrol->value.integer.value);
258         return snd_hda_mixer_amp_switch_put(kcontrol, ucontrol);
259 }
260 EXPORT_SYMBOL_HDA(snd_hda_mixer_amp_switch_put_beep);