]> sigrok.org Git - libsigrok.git/blame_incremental - hardware/alsa/alsa.c
libsigrok: Rename open/close to opendev/closedev.
[libsigrok.git] / hardware / alsa / alsa.c
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1/*
2 * This file is part of the sigrok project.
3 *
4 * Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "config.h" /* Must come before sigrok.h */
22#include <stdlib.h>
23#include <unistd.h>
24#include <string.h>
25#include <sigrok.h>
26#include <sigrok-internal.h>
27#include <alsa/asoundlib.h>
28
29#define NUM_PROBES 2
30#define SAMPLE_WIDTH 16
31#define AUDIO_DEV "plughw:0,0"
32
33static int capabilities[] = {
34 SR_HWCAP_SAMPLERATE,
35 SR_HWCAP_LIMIT_SAMPLES,
36 SR_HWCAP_CONTINUOUS,
37};
38
39static GSList *device_instances = NULL;
40
41struct alsa {
42 uint64_t cur_rate;
43 uint64_t limit_samples;
44 snd_pcm_t *capture_handle;
45 snd_pcm_hw_params_t *hw_params;
46 gpointer session_id;
47};
48
49static int hw_init(const char *deviceinfo)
50{
51 struct sr_device_instance *sdi;
52 struct alsa *alsa;
53
54 /* Avoid compiler warnings. */
55 deviceinfo = deviceinfo;
56
57 if (!(alsa = g_try_malloc0(sizeof(struct alsa)))) {
58 sr_err("alsa: %s: alsa malloc failed", __func__);
59 return 0;
60 }
61
62 sdi = sr_device_instance_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL);
63 if (!sdi)
64 goto free_alsa;
65
66 sdi->priv = alsa;
67
68 device_instances = g_slist_append(device_instances, sdi);
69
70 return 1;
71free_alsa:
72 g_free(alsa);
73 return 0;
74}
75
76static int hw_opendev(int device_index)
77{
78 struct sr_device_instance *sdi;
79 struct alsa *alsa;
80 int err;
81
82 if (!(sdi = sr_get_device_instance(device_instances, device_index)))
83 return SR_ERR;
84 alsa = sdi->priv;
85
86 err = snd_pcm_open(&alsa->capture_handle, AUDIO_DEV,
87 SND_PCM_STREAM_CAPTURE, 0);
88 if (err < 0) {
89 sr_warn("cannot open audio device %s (%s)", AUDIO_DEV,
90 snd_strerror(err));
91 return SR_ERR;
92 }
93
94 err = snd_pcm_hw_params_malloc(&alsa->hw_params);
95 if (err < 0) {
96 sr_warn("cannot allocate hardware parameter structure (%s)",
97 snd_strerror(err));
98 return SR_ERR;
99 }
100
101 err = snd_pcm_hw_params_any(alsa->capture_handle, alsa->hw_params);
102 if (err < 0) {
103 sr_warn("cannot initialize hardware parameter structure (%s)",
104 snd_strerror(err));
105 return SR_ERR;
106 }
107
108 return SR_OK;
109}
110
111static void hw_closedev(int device_index)
112{
113 struct sr_device_instance *sdi;
114 struct alsa *alsa;
115
116 if (!(sdi = sr_get_device_instance(device_instances, device_index)))
117 return;
118 alsa = sdi->priv;
119 if (!alsa)
120 return;
121
122 if (alsa->hw_params)
123 snd_pcm_hw_params_free(alsa->hw_params);
124 if (alsa->capture_handle)
125 snd_pcm_close(alsa->capture_handle);
126}
127
128static void hw_cleanup(void)
129{
130 struct sr_device_instance *sdi;
131
132 if (!(sdi = sr_get_device_instance(device_instances, 0)))
133 return;
134
135 free(sdi->priv);
136 sr_device_instance_free(sdi);
137}
138
139static void *hw_get_device_info(int device_index, int device_info_id)
140{
141 struct sr_device_instance *sdi;
142 struct alsa *alsa;
143 void *info = NULL;
144
145 if (!(sdi = sr_get_device_instance(device_instances, device_index)))
146 return NULL;
147 alsa = sdi->priv;
148
149 switch (device_info_id) {
150 case SR_DI_INSTANCE:
151 info = sdi;
152 break;
153 case SR_DI_NUM_PROBES:
154 info = GINT_TO_POINTER(NUM_PROBES);
155 break;
156 case SR_DI_CUR_SAMPLERATE:
157 info = &alsa->cur_rate;
158 break;
159 // case SR_DI_PROBE_TYPE:
160 // info = GINT_TO_POINTER(SR_PROBE_TYPE_ANALOG);
161 // break;
162 }
163
164 return info;
165}
166
167static int hw_get_status(int device_index)
168{
169 /* Avoid compiler warnings. */
170 device_index = device_index;
171
172 return SR_ST_ACTIVE;
173}
174
175static int *hw_get_capabilities(void)
176{
177 return capabilities;
178}
179
180static int hw_set_configuration(int device_index, int capability, void *value)
181{
182 struct sr_device_instance *sdi;
183 struct alsa *alsa;
184
185 if (!(sdi = sr_get_device_instance(device_instances, device_index)))
186 return SR_ERR;
187 alsa = sdi->priv;
188
189 switch (capability) {
190 case SR_HWCAP_PROBECONFIG:
191 return SR_OK;
192 case SR_HWCAP_SAMPLERATE:
193 alsa->cur_rate = *(uint64_t *) value;
194 return SR_OK;
195 case SR_HWCAP_LIMIT_SAMPLES:
196 alsa->limit_samples = *(uint64_t *) value;
197 return SR_OK;
198 default:
199 return SR_ERR;
200 }
201}
202
203static int receive_data(int fd, int revents, void *user_data)
204{
205 struct sr_device_instance *sdi = user_data;
206 struct alsa *alsa = sdi->priv;
207 struct sr_datafeed_packet packet;
208 struct sr_analog_sample *sample;
209 unsigned int sample_size = sizeof(struct sr_analog_sample) +
210 (NUM_PROBES * sizeof(struct sr_analog_probe));
211 char *outb;
212 char inb[4096];
213 int i, x, count;
214
215 fd = fd;
216 revents = revents;
217
218 do {
219 memset(inb, 0, sizeof(inb));
220 count = snd_pcm_readi(alsa->capture_handle, inb,
221 MIN(4096/4, alsa->limit_samples));
222 if (count < 1) {
223 sr_warn("Failed to read samples");
224 return FALSE;
225 }
226
227 if (!(outb = g_try_malloc(sample_size * count))) {
228 sr_err("alsa: %s: outb malloc failed", __func__);
229 return FALSE;
230 }
231
232 for (i = 0; i < count; i++) {
233 sample = (struct sr_analog_sample *)
234 (outb + (i * sample_size));
235 sample->num_probes = NUM_PROBES;
236
237 for (x = 0; x < NUM_PROBES; x++) {
238 sample->probes[x].val =
239 *(uint16_t *) (inb + (i * 4) + (x * 2));
240 sample->probes[x].val &= ((1 << 16) - 1);
241 sample->probes[x].res = 16;
242 }
243 }
244
245 packet.type = SR_DF_ANALOG;
246 packet.length = count * sample_size;
247 packet.unitsize = sample_size;
248 packet.payload = outb;
249 sr_session_bus(user_data, &packet);
250 g_free(outb);
251 alsa->limit_samples -= count;
252
253 } while (alsa->limit_samples > 0);
254
255 packet.type = SR_DF_END;
256 sr_session_bus(user_data, &packet);
257
258 return TRUE;
259}
260
261static int hw_start_acquisition(int device_index, gpointer session_device_id)
262{
263 struct sr_device_instance *sdi;
264 struct alsa *alsa;
265 struct sr_datafeed_packet packet;
266 struct sr_datafeed_header header;
267 struct pollfd *ufds;
268 int count;
269 int err;
270
271 if (!(sdi = sr_get_device_instance(device_instances, device_index)))
272 return SR_ERR;
273 alsa = sdi->priv;
274
275 err = snd_pcm_hw_params_set_access(alsa->capture_handle,
276 alsa->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
277 if (err < 0) {
278 sr_warn("cannot set access type (%s)", snd_strerror(err));
279 return SR_ERR;
280 }
281
282 /* FIXME: Hardcoded for 16bits */
283 err = snd_pcm_hw_params_set_format(alsa->capture_handle,
284 alsa->hw_params, SND_PCM_FORMAT_S16_LE);
285 if (err < 0) {
286 sr_warn("cannot set sample format (%s)", snd_strerror(err));
287 return SR_ERR;
288 }
289
290 err = snd_pcm_hw_params_set_rate_near(alsa->capture_handle,
291 alsa->hw_params, (unsigned int *) &alsa->cur_rate, 0);
292 if (err < 0) {
293 sr_warn("cannot set sample rate (%s)", snd_strerror(err));
294 return SR_ERR;
295 }
296
297 err = snd_pcm_hw_params_set_channels(alsa->capture_handle,
298 alsa->hw_params, NUM_PROBES);
299 if (err < 0) {
300 sr_warn("cannot set channel count (%s)", snd_strerror(err));
301 return SR_ERR;
302 }
303
304 err = snd_pcm_hw_params(alsa->capture_handle, alsa->hw_params);
305 if (err < 0) {
306 sr_warn("cannot set parameters (%s)", snd_strerror(err));
307 return SR_ERR;
308 }
309
310 err = snd_pcm_prepare(alsa->capture_handle);
311 if (err < 0) {
312 sr_warn("cannot prepare audio interface for use (%s)",
313 snd_strerror(err));
314 return SR_ERR;
315 }
316
317 count = snd_pcm_poll_descriptors_count(alsa->capture_handle);
318 if (count < 1) {
319 sr_warn("Unable to obtain poll descriptors count");
320 return SR_ERR;
321 }
322
323 if (!(ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
324 sr_warn("alsa: %s: ufds malloc failed", __func__);
325 return SR_ERR_MALLOC;
326 }
327
328 err = snd_pcm_poll_descriptors(alsa->capture_handle, ufds, count);
329 if (err < 0) {
330 sr_warn("Unable to obtain poll descriptors (%s)",
331 snd_strerror(err));
332 g_free(ufds);
333 return SR_ERR;
334 }
335
336 alsa->session_id = session_device_id;
337 sr_source_add(ufds[0].fd, ufds[0].events, 10, receive_data, sdi);
338
339 packet.type = SR_DF_HEADER;
340 packet.length = sizeof(struct sr_datafeed_header);
341 packet.payload = (unsigned char *) &header;
342 header.feed_version = 1;
343 gettimeofday(&header.starttime, NULL);
344 header.samplerate = alsa->cur_rate;
345 header.num_analog_probes = NUM_PROBES;
346 header.num_logic_probes = 0;
347 header.protocol_id = SR_PROTO_RAW;
348 sr_session_bus(session_device_id, &packet);
349 g_free(ufds);
350
351 return SR_OK;
352}
353
354static void hw_stop_acquisition(int device_index, gpointer session_device_id)
355{
356 /* Avoid compiler warnings. */
357 device_index = device_index;
358 session_device_id = session_device_id;
359}
360
361struct sr_device_plugin alsa_plugin_info = {
362 .name = "alsa",
363 .longname = "ALSA driver",
364 .api_version = 1,
365 .init = hw_init,
366 .cleanup = hw_cleanup,
367 .opendev = hw_opendev,
368 .closedev = hw_closedev,
369 .get_device_info = hw_get_device_info,
370 .get_status = hw_get_status,
371 .get_capabilities = hw_get_capabilities,
372 .set_configuration = hw_set_configuration,
373 .start_acquisition = hw_start_acquisition,
374 .stop_acquisition = hw_stop_acquisition,
375};