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 <errno.h> 24 25 #include "include/alsa_device_proxy.h" 26 27 #include "include/alsa_logging.h" 28 29 #define DEFAULT_PERIOD_SIZE 1024 30 #define DEFAULT_PERIOD_COUNT 2 31 32 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) 33 34 static const unsigned format_byte_size_map[] = { 35 2, /* PCM_FORMAT_S16_LE */ 36 4, /* PCM_FORMAT_S32_LE */ 37 1, /* PCM_FORMAT_S8 */ 38 4, /* PCM_FORMAT_S24_LE */ 39 3, /* PCM_FORMAT_S24_3LE */ 40 }; 41 42 int proxy_prepare(alsa_device_proxy * proxy, alsa_device_profile* profile, 43 struct pcm_config * config) 44 { 45 int ret = 0; 46 47 ALOGV("proxy_prepare(c:%d, d:%d)", profile->card, profile->device); 48 49 proxy->profile = profile; 50 51 #ifdef LOG_PCM_PARAMS 52 log_pcm_config(config, "proxy_setup()"); 53 #endif 54 55 if (config->format != PCM_FORMAT_INVALID && profile_is_format_valid(profile, config->format)) { 56 proxy->alsa_config.format = config->format; 57 } else { 58 proxy->alsa_config.format = profile->default_config.format; 59 ALOGW("Invalid format %d - using default %d.", 60 config->format, profile->default_config.format); 61 // Indicate override when default format was not requested 62 if (config->format != PCM_FORMAT_INVALID) { 63 ret = -EINVAL; 64 } 65 } 66 67 if (config->rate != 0 && profile_is_sample_rate_valid(profile, config->rate)) { 68 proxy->alsa_config.rate = config->rate; 69 } else { 70 proxy->alsa_config.rate = profile->default_config.rate; 71 ALOGW("Invalid sample rate %u - using default %u.", 72 config->rate, profile->default_config.rate); 73 // Indicate override when default rate was not requested 74 if (config->rate != 0) { 75 ret = -EINVAL; 76 } 77 } 78 79 if (config->channels != 0 && profile_is_channel_count_valid(profile, config->channels)) { 80 proxy->alsa_config.channels = config->channels; 81 } else { 82 proxy->alsa_config.channels = profile_get_closest_channel_count(profile, config->channels); 83 ALOGW("Invalid channel count %u - using closest %u.", 84 config->channels, proxy->alsa_config.channels); 85 // Indicate override when default channel count was not requested 86 if (config->channels != 0) { 87 ret = -EINVAL; 88 } 89 } 90 91 proxy->alsa_config.period_count = profile->default_config.period_count; 92 proxy->alsa_config.period_size = 93 profile_get_period_size(proxy->profile, proxy->alsa_config.rate); 94 95 // Hack for USB accessory audio. 96 // Here we set the correct value for period_count if tinyalsa fails to get it from the 97 // f_audio_source driver. 98 if (proxy->alsa_config.period_count == 0) { 99 proxy->alsa_config.period_count = 4; 100 } 101 102 proxy->pcm = NULL; 103 // config format should be checked earlier against profile. 104 if (config->format >= 0 && (size_t)config->format < ARRAY_SIZE(format_byte_size_map)) { 105 proxy->frame_size = format_byte_size_map[config->format] * proxy->alsa_config.channels; 106 } else { 107 proxy->frame_size = 1; 108 } 109 110 // let's check to make sure we can ACTUALLY use the maximum rate (with the channel count) 111 // Note that profile->sample_rates is sorted highest to lowest, so the scan will get 112 // us the highest working rate 113 int max_rate_index = proxy_scan_rates(proxy, profile->sample_rates); 114 if (max_rate_index >= 0) { 115 if (proxy->alsa_config.rate > profile->sample_rates[max_rate_index]) { 116 ALOGW("Limiting samplnig rate from %u to %u.", 117 proxy->alsa_config.rate, profile->sample_rates[max_rate_index]); 118 proxy->alsa_config.rate = profile->sample_rates[max_rate_index]; 119 ret = -EINVAL; 120 } 121 } 122 return ret; 123 } 124 125 int proxy_open(alsa_device_proxy * proxy) 126 { 127 alsa_device_profile* profile = proxy->profile; 128 ALOGV("proxy_open(card:%d device:%d %s)", profile->card, profile->device, 129 profile->direction == PCM_OUT ? "PCM_OUT" : "PCM_IN"); 130 131 if (profile->card < 0 || profile->device < 0) { 132 return -EINVAL; 133 } 134 135 proxy->pcm = pcm_open(profile->card, profile->device, 136 profile->direction | PCM_MONOTONIC, &proxy->alsa_config); 137 if (proxy->pcm == NULL) { 138 return -ENOMEM; 139 } 140 141 if (!pcm_is_ready(proxy->pcm)) { 142 ALOGE(" proxy_open() pcm_is_ready() failed: %s", pcm_get_error(proxy->pcm)); 143 #if defined(LOG_PCM_PARAMS) 144 log_pcm_config(&proxy->alsa_config, "config"); 145 #endif 146 pcm_close(proxy->pcm); 147 proxy->pcm = NULL; 148 return -ENOMEM; 149 } 150 151 return 0; 152 } 153 154 void proxy_close(alsa_device_proxy * proxy) 155 { 156 ALOGV("proxy_close() [pcm:%p]", proxy->pcm); 157 158 if (proxy->pcm != NULL) { 159 pcm_close(proxy->pcm); 160 proxy->pcm = NULL; 161 } 162 } 163 164 /* 165 * Sample Rate 166 */ 167 unsigned proxy_get_sample_rate(const alsa_device_proxy * proxy) 168 { 169 return proxy->alsa_config.rate; 170 } 171 172 /* 173 * Format 174 */ 175 enum pcm_format proxy_get_format(const alsa_device_proxy * proxy) 176 { 177 return proxy->alsa_config.format; 178 } 179 180 /* 181 * Channel Count 182 */ 183 unsigned proxy_get_channel_count(const alsa_device_proxy * proxy) 184 { 185 return proxy->alsa_config.channels; 186 } 187 188 /* 189 * Other 190 */ 191 unsigned int proxy_get_period_size(const alsa_device_proxy * proxy) 192 { 193 return proxy->alsa_config.period_size; 194 } 195 196 unsigned int proxy_get_period_count(const alsa_device_proxy * proxy) 197 { 198 return proxy->alsa_config.period_count; 199 } 200 201 unsigned proxy_get_latency(const alsa_device_proxy * proxy) 202 { 203 return (proxy_get_period_size(proxy) * proxy_get_period_count(proxy) * 1000) 204 / proxy_get_sample_rate(proxy); 205 } 206 207 int proxy_get_presentation_position(const alsa_device_proxy * proxy, 208 uint64_t *frames, struct timespec *timestamp) 209 { 210 int ret = -EPERM; // -1 211 unsigned int avail; 212 if (proxy->pcm != NULL 213 && pcm_get_htimestamp(proxy->pcm, &avail, timestamp) == 0) { 214 const size_t kernel_buffer_size = 215 proxy->alsa_config.period_size * proxy->alsa_config.period_count; 216 if (avail > kernel_buffer_size) { 217 ALOGE("available frames(%u) > buffer size(%zu)", avail, kernel_buffer_size); 218 } else { 219 int64_t signed_frames = proxy->transferred - kernel_buffer_size + avail; 220 // It is possible to compensate for additional driver and device delay 221 // by changing signed_frames. Example: 222 // signed_frames -= 20 /* ms */ * proxy->alsa_config.rate / 1000; 223 if (signed_frames >= 0) { 224 *frames = signed_frames; 225 ret = 0; 226 } 227 } 228 } 229 return ret; 230 } 231 232 /* 233 * I/O 234 */ 235 int proxy_write(alsa_device_proxy * proxy, const void *data, unsigned int count) 236 { 237 int ret = pcm_write(proxy->pcm, data, count); 238 if (ret == 0) { 239 proxy->transferred += count / proxy->frame_size; 240 } 241 return ret; 242 } 243 244 int proxy_read(const alsa_device_proxy * proxy, void *data, unsigned int count) 245 { 246 return pcm_read(proxy->pcm, data, count); 247 } 248 249 /* 250 * Debugging 251 */ 252 void proxy_dump(const alsa_device_proxy* proxy, int fd) 253 { 254 if (proxy != NULL) { 255 dprintf(fd, " channels: %d\n", proxy->alsa_config.channels); 256 dprintf(fd, " rate: %d\n", proxy->alsa_config.rate); 257 dprintf(fd, " period_size: %d\n", proxy->alsa_config.period_size); 258 dprintf(fd, " period_count: %d\n", proxy->alsa_config.period_count); 259 dprintf(fd, " format: %d\n", proxy->alsa_config.format); 260 } 261 } 262 263 int proxy_scan_rates(alsa_device_proxy * proxy, unsigned sample_rates[]) { 264 alsa_device_profile* profile = proxy->profile; 265 if (profile->card < 0 || profile->device < 0) { 266 return -EINVAL; 267 } 268 269 struct pcm_config alsa_config; 270 memcpy(&alsa_config, &proxy->alsa_config, sizeof(alsa_config)); 271 272 struct pcm * alsa_pcm; 273 int rate_index = 0; 274 while (sample_rates[rate_index] != 0) { 275 alsa_config.rate = sample_rates[rate_index]; 276 alsa_pcm = pcm_open(profile->card, profile->device, 277 profile->direction | PCM_MONOTONIC, &alsa_config); 278 if (alsa_pcm != NULL) { 279 if (pcm_is_ready(alsa_pcm)) { 280 pcm_close(alsa_pcm); 281 return rate_index; 282 } 283 284 pcm_close(alsa_pcm); 285 } 286 287 rate_index++; 288 } 289 290 return -EINVAL; 291 } 292
