xref: /openbmc/qemu/hw/audio/lm4549.c (revision f1020c2c)
1 /*
2  * LM4549 Audio Codec Interface
3  *
4  * Copyright (c) 2011
5  * Written by Mathieu Sonet - www.elasticsheep.com
6  *
7  * This code is licensed under the GPL.
8  *
9  * *****************************************************************
10  *
11  * This driver emulates the LM4549 codec.
12  *
13  * It supports only one playback voice and no record voice.
14  */
15 
16 #include "qemu/osdep.h"
17 #include "hw/hw.h"
18 #include "audio/audio.h"
19 #include "lm4549.h"
20 
21 #if 0
22 #define LM4549_DEBUG  1
23 #endif
24 
25 #if 0
26 #define LM4549_DUMP_DAC_INPUT 1
27 #endif
28 
29 #ifdef LM4549_DEBUG
30 #define DPRINTF(fmt, ...) \
31 do { printf("lm4549: " fmt , ## __VA_ARGS__); } while (0)
32 #else
33 #define DPRINTF(fmt, ...) do {} while (0)
34 #endif
35 
36 #if defined(LM4549_DUMP_DAC_INPUT)
37 static FILE *fp_dac_input;
38 #endif
39 
40 /* LM4549 register list */
41 enum {
42     LM4549_Reset                    = 0x00,
43     LM4549_Master_Volume            = 0x02,
44     LM4549_Line_Out_Volume          = 0x04,
45     LM4549_Master_Volume_Mono       = 0x06,
46     LM4549_PC_Beep_Volume           = 0x0A,
47     LM4549_Phone_Volume             = 0x0C,
48     LM4549_Mic_Volume               = 0x0E,
49     LM4549_Line_In_Volume           = 0x10,
50     LM4549_CD_Volume                = 0x12,
51     LM4549_Video_Volume             = 0x14,
52     LM4549_Aux_Volume               = 0x16,
53     LM4549_PCM_Out_Volume           = 0x18,
54     LM4549_Record_Select            = 0x1A,
55     LM4549_Record_Gain              = 0x1C,
56     LM4549_General_Purpose          = 0x20,
57     LM4549_3D_Control               = 0x22,
58     LM4549_Powerdown_Ctrl_Stat      = 0x26,
59     LM4549_Ext_Audio_ID             = 0x28,
60     LM4549_Ext_Audio_Stat_Ctrl      = 0x2A,
61     LM4549_PCM_Front_DAC_Rate       = 0x2C,
62     LM4549_PCM_ADC_Rate             = 0x32,
63     LM4549_Vendor_ID1               = 0x7C,
64     LM4549_Vendor_ID2               = 0x7E
65 };
66 
67 static void lm4549_reset(lm4549_state *s)
68 {
69     uint16_t *regfile = s->regfile;
70 
71     regfile[LM4549_Reset]               = 0x0d50;
72     regfile[LM4549_Master_Volume]       = 0x8008;
73     regfile[LM4549_Line_Out_Volume]     = 0x8000;
74     regfile[LM4549_Master_Volume_Mono]  = 0x8000;
75     regfile[LM4549_PC_Beep_Volume]      = 0x0000;
76     regfile[LM4549_Phone_Volume]        = 0x8008;
77     regfile[LM4549_Mic_Volume]          = 0x8008;
78     regfile[LM4549_Line_In_Volume]      = 0x8808;
79     regfile[LM4549_CD_Volume]           = 0x8808;
80     regfile[LM4549_Video_Volume]        = 0x8808;
81     regfile[LM4549_Aux_Volume]          = 0x8808;
82     regfile[LM4549_PCM_Out_Volume]      = 0x8808;
83     regfile[LM4549_Record_Select]       = 0x0000;
84     regfile[LM4549_Record_Gain]         = 0x8000;
85     regfile[LM4549_General_Purpose]     = 0x0000;
86     regfile[LM4549_3D_Control]          = 0x0101;
87     regfile[LM4549_Powerdown_Ctrl_Stat] = 0x000f;
88     regfile[LM4549_Ext_Audio_ID]        = 0x0001;
89     regfile[LM4549_Ext_Audio_Stat_Ctrl] = 0x0000;
90     regfile[LM4549_PCM_Front_DAC_Rate]  = 0xbb80;
91     regfile[LM4549_PCM_ADC_Rate]        = 0xbb80;
92     regfile[LM4549_Vendor_ID1]          = 0x4e53;
93     regfile[LM4549_Vendor_ID2]          = 0x4331;
94 }
95 
96 static void lm4549_audio_transfer(lm4549_state *s)
97 {
98     uint32_t written_bytes, written_samples;
99     uint32_t i;
100 
101     /* Activate the voice */
102     AUD_set_active_out(s->voice, 1);
103     s->voice_is_active = 1;
104 
105     /* Try to write the buffer content */
106     written_bytes = AUD_write(s->voice, s->buffer,
107                               s->buffer_level * sizeof(uint16_t));
108     written_samples = written_bytes >> 1;
109 
110 #if defined(LM4549_DUMP_DAC_INPUT)
111     fwrite(s->buffer, sizeof(uint8_t), written_bytes, fp_dac_input);
112 #endif
113 
114     s->buffer_level -= written_samples;
115 
116     if (s->buffer_level > 0) {
117         /* Move the data back to the start of the buffer */
118         for (i = 0; i < s->buffer_level; i++) {
119             s->buffer[i] = s->buffer[i + written_samples];
120         }
121     }
122 }
123 
124 static void lm4549_audio_out_callback(void *opaque, int free)
125 {
126     lm4549_state *s = (lm4549_state *)opaque;
127     static uint32_t prev_buffer_level;
128 
129 #ifdef LM4549_DEBUG
130     int size = AUD_get_buffer_size_out(s->voice);
131     DPRINTF("audio_out_callback size = %i free = %i\n", size, free);
132 #endif
133 
134     /* Detect that no data are consumed
135        => disable the voice */
136     if (s->buffer_level == prev_buffer_level) {
137         AUD_set_active_out(s->voice, 0);
138         s->voice_is_active = 0;
139     }
140     prev_buffer_level = s->buffer_level;
141 
142     /* Check if a buffer transfer is pending */
143     if (s->buffer_level == LM4549_BUFFER_SIZE) {
144         lm4549_audio_transfer(s);
145 
146         /* Request more data */
147         if (s->data_req_cb != NULL) {
148             (s->data_req_cb)(s->opaque);
149         }
150     }
151 }
152 
153 uint32_t lm4549_read(lm4549_state *s, hwaddr offset)
154 {
155     uint16_t *regfile = s->regfile;
156     uint32_t value = 0;
157 
158     /* Read the stored value */
159     assert(offset < 128);
160     value = regfile[offset];
161 
162     DPRINTF("read [0x%02x] = 0x%04x\n", offset, value);
163 
164     return value;
165 }
166 
167 void lm4549_write(lm4549_state *s,
168                   hwaddr offset, uint32_t value)
169 {
170     uint16_t *regfile = s->regfile;
171 
172     assert(offset < 128);
173     DPRINTF("write [0x%02x] = 0x%04x\n", offset, value);
174 
175     switch (offset) {
176     case LM4549_Reset:
177         lm4549_reset(s);
178         break;
179 
180     case LM4549_PCM_Front_DAC_Rate:
181         regfile[LM4549_PCM_Front_DAC_Rate] = value;
182         DPRINTF("DAC rate change = %i\n", value);
183 
184         /* Re-open a voice with the new sample rate */
185         struct audsettings as;
186         as.freq = value;
187         as.nchannels = 2;
188         as.fmt = AUD_FMT_S16;
189         as.endianness = 0;
190 
191         s->voice = AUD_open_out(
192             &s->card,
193             s->voice,
194             "lm4549.out",
195             s,
196             lm4549_audio_out_callback,
197             &as
198         );
199         break;
200 
201     case LM4549_Powerdown_Ctrl_Stat:
202         value &= ~0xf;
203         value |= regfile[LM4549_Powerdown_Ctrl_Stat] & 0xf;
204         regfile[LM4549_Powerdown_Ctrl_Stat] = value;
205         break;
206 
207     case LM4549_Ext_Audio_ID:
208     case LM4549_Vendor_ID1:
209     case LM4549_Vendor_ID2:
210         DPRINTF("Write to read-only register 0x%x\n", (int)offset);
211         break;
212 
213     default:
214         /* Store the new value */
215         regfile[offset] = value;
216         break;
217     }
218 }
219 
220 uint32_t lm4549_write_samples(lm4549_state *s, uint32_t left, uint32_t right)
221 {
222     /* The left and right samples are in 20-bit resolution.
223        The LM4549 has 18-bit resolution and only uses the bits [19:2].
224        This model supports 16-bit playback.
225     */
226 
227     if (s->buffer_level > LM4549_BUFFER_SIZE - 2) {
228         DPRINTF("write_sample Buffer full\n");
229         return 0;
230     }
231 
232     /* Store 16-bit samples in the buffer */
233     s->buffer[s->buffer_level++] = (left >> 4);
234     s->buffer[s->buffer_level++] = (right >> 4);
235 
236     if (s->buffer_level == LM4549_BUFFER_SIZE) {
237         /* Trigger the transfer of the buffer to the audio host */
238         lm4549_audio_transfer(s);
239     }
240 
241     return 1;
242 }
243 
244 static int lm4549_post_load(void *opaque, int version_id)
245 {
246     lm4549_state *s = (lm4549_state *)opaque;
247     uint16_t *regfile = s->regfile;
248 
249     /* Re-open a voice with the current sample rate */
250     uint32_t freq = regfile[LM4549_PCM_Front_DAC_Rate];
251 
252     DPRINTF("post_load freq = %i\n", freq);
253     DPRINTF("post_load voice_is_active = %i\n", s->voice_is_active);
254 
255     struct audsettings as;
256     as.freq = freq;
257     as.nchannels = 2;
258     as.fmt = AUD_FMT_S16;
259     as.endianness = 0;
260 
261     s->voice = AUD_open_out(
262         &s->card,
263         s->voice,
264         "lm4549.out",
265         s,
266         lm4549_audio_out_callback,
267         &as
268     );
269 
270     /* Request data */
271     if (s->voice_is_active == 1) {
272         lm4549_audio_out_callback(s, AUD_get_buffer_size_out(s->voice));
273     }
274 
275     return 0;
276 }
277 
278 void lm4549_init(lm4549_state *s, lm4549_callback data_req_cb, void* opaque)
279 {
280     struct audsettings as;
281 
282     /* Store the callback and opaque pointer */
283     s->data_req_cb = data_req_cb;
284     s->opaque = opaque;
285 
286     /* Init the registers */
287     lm4549_reset(s);
288 
289     /* Register an audio card */
290     AUD_register_card("lm4549", &s->card);
291 
292     /* Open a default voice */
293     as.freq = 48000;
294     as.nchannels = 2;
295     as.fmt = AUD_FMT_S16;
296     as.endianness = 0;
297 
298     s->voice = AUD_open_out(
299         &s->card,
300         s->voice,
301         "lm4549.out",
302         s,
303         lm4549_audio_out_callback,
304         &as
305     );
306 
307     AUD_set_volume_out(s->voice, 0, 255, 255);
308 
309     s->voice_is_active = 0;
310 
311     /* Reset the input buffer */
312     memset(s->buffer, 0x00, sizeof(s->buffer));
313     s->buffer_level = 0;
314 
315 #if defined(LM4549_DUMP_DAC_INPUT)
316     fp_dac_input = fopen("lm4549_dac_input.pcm", "wb");
317     if (!fp_dac_input) {
318         hw_error("Unable to open lm4549_dac_input.pcm for writing\n");
319     }
320 #endif
321 }
322 
323 const VMStateDescription vmstate_lm4549_state = {
324     .name = "lm4549_state",
325     .version_id = 1,
326     .minimum_version_id = 1,
327     .post_load = lm4549_post_load,
328     .fields = (VMStateField[]) {
329         VMSTATE_UINT32(voice_is_active, lm4549_state),
330         VMSTATE_UINT16_ARRAY(regfile, lm4549_state, 128),
331         VMSTATE_UINT16_ARRAY(buffer, lm4549_state, LM4549_BUFFER_SIZE),
332         VMSTATE_UINT32(buffer_level, lm4549_state),
333         VMSTATE_END_OF_LIST()
334     }
335 };
336