1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "alsa_device_proxy"
18/*#define LOG_NDEBUG 0*/
19/*#define LOG_PCM_PARAMS 0*/
20
21#include <log/log.h>
22
23#include "alsa_device_proxy.h"
24
25#include "logging.h"
26
27#define DEFAULT_PERIOD_SIZE     1024
28#define DEFAULT_PERIOD_COUNT    2
29
30void proxy_prepare(alsa_device_proxy * proxy, alsa_device_profile* profile,
31                   struct pcm_config * config)
32{
33    ALOGV("proxy_prepare()");
34
35    proxy->profile = profile;
36
37#ifdef LOG_PCM_PARAMS
38    log_pcm_config(config, "proxy_setup()");
39#endif
40
41    proxy->alsa_config.format =
42        config->format != PCM_FORMAT_INVALID && profile_is_format_valid(profile, config->format)
43            ? config->format : profile->default_config.format;
44    proxy->alsa_config.rate =
45        config->rate != 0 && profile_is_sample_rate_valid(profile, config->rate)
46            ? config->rate : profile->default_config.rate;
47    proxy->alsa_config.channels =
48        config->channels != 0 && profile_is_channel_count_valid(profile, config->channels)
49            ? config->channels : profile->default_config.channels;
50
51    proxy->alsa_config.period_count = profile->default_config.period_count;
52    proxy->alsa_config.period_size =
53            profile_get_period_size(proxy->profile, proxy->alsa_config.rate);
54
55    // Hack for USB accessory audio.
56    // Here we set the correct value for period_count if tinyalsa fails to get it from the
57    // f_audio_source driver.
58    if (proxy->alsa_config.period_count == 0) {
59        proxy->alsa_config.period_count = 4;
60    }
61
62    proxy->pcm = NULL;
63}
64
65int proxy_open(alsa_device_proxy * proxy)
66{
67    alsa_device_profile* profile = proxy->profile;
68    ALOGV("proxy_open(card:%d device:%d %s)", profile->card, profile->device,
69          profile->direction == PCM_OUT ? "PCM_OUT" : "PCM_IN");
70
71    proxy->pcm = pcm_open(profile->card, profile->device, profile->direction, &proxy->alsa_config);
72    if (proxy->pcm == NULL) {
73        return -ENOMEM;
74    }
75
76    if (!pcm_is_ready(proxy->pcm)) {
77        ALOGE("[%s] proxy_open() pcm_open() failed: %s", LOG_TAG, pcm_get_error(proxy->pcm));
78#ifdef LOG_PCM_PARAMS
79        log_pcm_config(&proxy->alsa_config, "config");
80#endif
81        pcm_close(proxy->pcm);
82        proxy->pcm = NULL;
83        return -ENOMEM;
84    }
85
86    return 0;
87}
88
89void proxy_close(alsa_device_proxy * proxy)
90{
91    ALOGV("proxy_close() [pcm:%p]", proxy->pcm);
92
93    if (proxy->pcm != NULL) {
94        pcm_close(proxy->pcm);
95        proxy->pcm = NULL;
96    }
97}
98
99/*
100 * Sample Rate
101 */
102unsigned proxy_get_sample_rate(const alsa_device_proxy * proxy)
103{
104    return proxy->alsa_config.rate;
105}
106
107/*
108 * Format
109 */
110enum pcm_format proxy_get_format(const alsa_device_proxy * proxy)
111{
112    return proxy->alsa_config.format;
113}
114
115/*
116 * Channel Count
117 */
118unsigned proxy_get_channel_count(const alsa_device_proxy * proxy)
119{
120    return proxy->alsa_config.channels;
121}
122
123/*
124 * Other
125 */
126unsigned int proxy_get_period_size(const alsa_device_proxy * proxy)
127{
128    return proxy->alsa_config.period_size;
129}
130
131unsigned int proxy_get_period_count(const alsa_device_proxy * proxy)
132{
133    return proxy->alsa_config.period_count;
134}
135
136unsigned proxy_get_latency(const alsa_device_proxy * proxy)
137{
138    return (proxy_get_period_size(proxy) * proxy_get_period_count(proxy) * 1000)
139               / proxy_get_sample_rate(proxy);
140}
141
142/*
143 * I/O
144 */
145int proxy_write(const alsa_device_proxy * proxy, const void *data, unsigned int count)
146{
147    return pcm_write(proxy->pcm, data, count);
148}
149
150int proxy_read(const alsa_device_proxy * proxy, void *data, unsigned int count)
151{
152    return pcm_read(proxy->pcm, data, count);
153}
154