xref: /openbmc/qemu/hw/audio/pcspk.c (revision 6fdc5bc1)
1 /*
2  * QEMU PC speaker emulation
3  *
4  * Copyright (c) 2006 Joachim Henke
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "hw/isa/isa.h"
27 #include "hw/audio/soundhw.h"
28 #include "audio/audio.h"
29 #include "qemu/module.h"
30 #include "qemu/timer.h"
31 #include "qemu/error-report.h"
32 #include "hw/timer/i8254.h"
33 #include "migration/vmstate.h"
34 #include "hw/audio/pcspk.h"
35 #include "qapi/error.h"
36 #include "qom/object.h"
37 
38 #define PCSPK_BUF_LEN 1792
39 #define PCSPK_SAMPLE_RATE 32000
40 #define PCSPK_MAX_FREQ (PCSPK_SAMPLE_RATE >> 1)
41 #define PCSPK_MIN_COUNT DIV_ROUND_UP(PIT_FREQ, PCSPK_MAX_FREQ)
42 
43 OBJECT_DECLARE_SIMPLE_TYPE(PCSpkState, PC_SPEAKER)
44 
45 struct PCSpkState {
46     ISADevice parent_obj;
47 
48     MemoryRegion ioport;
49     uint32_t iobase;
50     uint8_t sample_buf[PCSPK_BUF_LEN];
51     QEMUSoundCard card;
52     SWVoiceOut *voice;
53     void *pit;
54     unsigned int pit_count;
55     unsigned int samples;
56     unsigned int play_pos;
57     uint8_t data_on;
58     uint8_t dummy_refresh_clock;
59     bool migrate;
60 };
61 
62 static const char *s_spk = "pcspk";
63 static PCSpkState *pcspk_state;
64 
65 static inline void generate_samples(PCSpkState *s)
66 {
67     unsigned int i;
68 
69     if (s->pit_count) {
70         const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
71         const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
72 
73         /* multiple of wavelength for gapless looping */
74         s->samples = (QEMU_ALIGN_DOWN(PCSPK_BUF_LEN * PIT_FREQ, m) / (PIT_FREQ >> 1) + 1) >> 1;
75         for (i = 0; i < s->samples; ++i)
76             s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
77     } else {
78         s->samples = PCSPK_BUF_LEN;
79         for (i = 0; i < PCSPK_BUF_LEN; ++i)
80             s->sample_buf[i] = 128; /* silence */
81     }
82 }
83 
84 static void pcspk_callback(void *opaque, int free)
85 {
86     PCSpkState *s = opaque;
87     PITChannelInfo ch;
88     unsigned int n;
89 
90     pit_get_channel_info(s->pit, 2, &ch);
91 
92     if (ch.mode != 3) {
93         return;
94     }
95 
96     n = ch.initial_count;
97     /* avoid frequencies that are not reproducible with sample rate */
98     if (n < PCSPK_MIN_COUNT)
99         n = 0;
100 
101     if (s->pit_count != n) {
102         s->pit_count = n;
103         s->play_pos = 0;
104         generate_samples(s);
105     }
106 
107     while (free > 0) {
108         n = MIN(s->samples - s->play_pos, (unsigned int)free);
109         n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
110         if (!n)
111             break;
112         s->play_pos = (s->play_pos + n) % s->samples;
113         free -= n;
114     }
115 }
116 
117 static int pcspk_audio_init(PCSpkState *s)
118 {
119     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUDIO_FORMAT_U8, 0};
120 
121     if (s->voice) {
122         /* already initialized */
123         return 0;
124     }
125 
126     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
127     if (!s->voice) {
128         AUD_log(s_spk, "Could not open voice\n");
129         return -1;
130     }
131 
132     return 0;
133 }
134 
135 static uint64_t pcspk_io_read(void *opaque, hwaddr addr,
136                               unsigned size)
137 {
138     PCSpkState *s = opaque;
139     PITChannelInfo ch;
140 
141     pit_get_channel_info(s->pit, 2, &ch);
142 
143     s->dummy_refresh_clock ^= (1 << 4);
144 
145     return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |
146        (ch.out << 5);
147 }
148 
149 static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val,
150                            unsigned size)
151 {
152     PCSpkState *s = opaque;
153     const int gate = val & 1;
154 
155     s->data_on = (val >> 1) & 1;
156     pit_set_gate(s->pit, 2, gate);
157     if (s->voice) {
158         if (gate) /* restart */
159             s->play_pos = 0;
160         AUD_set_active_out(s->voice, gate & s->data_on);
161     }
162 }
163 
164 static const MemoryRegionOps pcspk_io_ops = {
165     .read = pcspk_io_read,
166     .write = pcspk_io_write,
167     .impl = {
168         .min_access_size = 1,
169         .max_access_size = 1,
170     },
171 };
172 
173 static void pcspk_initfn(Object *obj)
174 {
175     PCSpkState *s = PC_SPEAKER(obj);
176 
177     memory_region_init_io(&s->ioport, OBJECT(s), &pcspk_io_ops, s, "pcspk", 1);
178 
179     object_property_add_link(obj, "pit", TYPE_PIT_COMMON,
180                              (Object **)&s->pit,
181                              qdev_prop_allow_set_link_before_realize,
182                              0);
183 }
184 
185 static void pcspk_realizefn(DeviceState *dev, Error **errp)
186 {
187     ISADevice *isadev = ISA_DEVICE(dev);
188     PCSpkState *s = PC_SPEAKER(dev);
189 
190     isa_register_ioport(isadev, &s->ioport, s->iobase);
191 
192     if (s->card.state && AUD_register_card(s_spk, &s->card, errp)) {
193         pcspk_audio_init(s);
194     }
195 
196     pcspk_state = s;
197 }
198 
199 static bool migrate_needed(void *opaque)
200 {
201     PCSpkState *s = opaque;
202 
203     return s->migrate;
204 }
205 
206 static const VMStateDescription vmstate_spk = {
207     .name = "pcspk",
208     .version_id = 1,
209     .minimum_version_id = 1,
210     .needed = migrate_needed,
211     .fields = (const VMStateField[]) {
212         VMSTATE_UINT8(data_on, PCSpkState),
213         VMSTATE_UINT8(dummy_refresh_clock, PCSpkState),
214         VMSTATE_END_OF_LIST()
215     }
216 };
217 
218 static Property pcspk_properties[] = {
219     DEFINE_AUDIO_PROPERTIES(PCSpkState, card),
220     DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  0x61),
221     DEFINE_PROP_BOOL("migrate", PCSpkState, migrate,  true),
222     DEFINE_PROP_END_OF_LIST(),
223 };
224 
225 static void pcspk_class_initfn(ObjectClass *klass, void *data)
226 {
227     DeviceClass *dc = DEVICE_CLASS(klass);
228 
229     dc->realize = pcspk_realizefn;
230     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
231     dc->vmsd = &vmstate_spk;
232     device_class_set_props(dc, pcspk_properties);
233     /* Reason: realize sets global pcspk_state */
234     /* Reason: pit object link */
235     dc->user_creatable = false;
236 }
237 
238 static const TypeInfo pcspk_info = {
239     .name           = TYPE_PC_SPEAKER,
240     .parent         = TYPE_ISA_DEVICE,
241     .instance_size  = sizeof(PCSpkState),
242     .instance_init  = pcspk_initfn,
243     .class_init     = pcspk_class_initfn,
244 };
245 
246 static void pcspk_register(void)
247 {
248     type_register_static(&pcspk_info);
249 }
250 type_init(pcspk_register)
251