1 /* Copyright 2017 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 * 5 * `dev_io` Handles playback to and capture from open devices. It runs only on 6 * the audio thread. 7 */ 8 9 #ifndef DEV_IO_H_ 10 #define DEV_IO_H_ 11 12 #include "cras_iodev.h" 13 #include "cras_types.h" 14 #include "polled_interval_checker.h" 15 16 /* 17 * Open input/output devices. 18 * dev - The device. 19 * wake_ts - When callback is needed to avoid xrun. 20 * last_non_empty_ts - The last time we know the device played/captured 21 * non-empty (zero) audio. 22 * coarse_rate_adjust - Hack for when the sample rate needs heavy correction. 23 */ 24 struct open_dev { 25 struct cras_iodev *dev; 26 struct timespec wake_ts; 27 struct polled_interval *non_empty_check_pi; 28 struct polled_interval *empty_pi; 29 int coarse_rate_adjust; 30 struct open_dev *prev, *next; 31 }; 32 33 /* 34 * Fetches streams from each device in `odev_list`. 35 * odev_list - The list of open devices. 36 */ 37 void dev_io_playback_fetch(struct open_dev *odev_list); 38 39 /* 40 * Writes the samples fetched from the streams to the playback devices. 41 * odev_list - The list of open devices. Devices will be removed when 42 * writing returns an error. 43 */ 44 int dev_io_playback_write(struct open_dev **odevs, 45 struct cras_fmt_conv *output_converter); 46 47 /* Only public for testing. */ 48 int write_output_samples(struct open_dev **odevs, 49 struct open_dev *adev, 50 struct cras_fmt_conv *output_converter); 51 52 /* 53 * Captures samples from each device in the list. 54 * list - Pointer to the list of input devices. Devices that fail to read 55 * will be removed from the list. 56 */ 57 int dev_io_capture(struct open_dev **list); 58 59 /* 60 * Send samples that have been captured to their streams. 61 */ 62 int dev_io_send_captured_samples(struct open_dev *idev_list); 63 64 /* Reads and/or writes audio samples from/to the devices. */ 65 void dev_io_run(struct open_dev **odevs, struct open_dev **idevs, 66 struct cras_fmt_conv *output_converter); 67 68 /* 69 * Fills min_ts with the next time the system should wake to service input. 70 * Returns the number of devices waiting. 71 */ 72 int dev_io_next_input_wake(struct open_dev **idevs, struct timespec *min_ts); 73 74 /* 75 * Removes a device from a list of devices. 76 * odev_list - A pointer to the list to modify. 77 * dev_to_rm - Find this device in the list and remove it. 78 */ 79 void dev_io_rm_open_dev(struct open_dev **odev_list, 80 struct open_dev *dev_to_rm); 81 82 /* Returns a pointer to an open_dev if it is in the list, otherwise NULL. */ 83 struct open_dev *dev_io_find_open_dev(struct open_dev *odev_list, 84 const struct cras_iodev *dev); 85 86 /* Remove a stream from the provided list of devices. */ 87 int dev_io_remove_stream(struct open_dev **dev_list, 88 struct cras_rstream *stream, 89 struct cras_iodev *dev); 90 91 #endif /* DEV_IO_H_ */ 92