Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Helper functions for indirect PCM data transfer |
| 3 | * |
| 4 | * Copyright (c) by Takashi Iwai <tiwai@suse.de> |
Jaroslav Kysela | c1017a4 | 2007-10-15 09:50:19 +0200 | [diff] [blame] | 5 | * Jaroslav Kysela <perex@perex.cz> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 20 | */ |
| 21 | |
| 22 | #ifndef __SOUND_PCM_INDIRECT_H |
| 23 | #define __SOUND_PCM_INDIRECT_H |
| 24 | |
| 25 | #include <sound/pcm.h> |
| 26 | |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 27 | struct snd_pcm_indirect { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | unsigned int hw_buffer_size; /* Byte size of hardware buffer */ |
| 29 | unsigned int hw_queue_size; /* Max queue size of hw buffer (0 = buffer size) */ |
| 30 | unsigned int hw_data; /* Offset to next dst (or src) in hw ring buffer */ |
| 31 | unsigned int hw_io; /* Ring buffer hw pointer */ |
| 32 | int hw_ready; /* Bytes ready for play (or captured) in hw ring buffer */ |
| 33 | unsigned int sw_buffer_size; /* Byte size of software buffer */ |
| 34 | unsigned int sw_data; /* Offset to next dst (or src) in sw ring buffer */ |
| 35 | unsigned int sw_io; /* Current software pointer in bytes */ |
| 36 | int sw_ready; /* Bytes ready to be transferred to/from hw */ |
| 37 | snd_pcm_uframes_t appl_ptr; /* Last seen appl_ptr */ |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 38 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 40 | typedef void (*snd_pcm_indirect_copy_t)(struct snd_pcm_substream *substream, |
| 41 | struct snd_pcm_indirect *rec, size_t bytes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * helper function for playback ack callback |
| 45 | */ |
Takashi Iwai | 96295812 | 2017-05-19 18:31:03 +0200 | [diff] [blame] | 46 | static inline int |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 47 | snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream, |
| 48 | struct snd_pcm_indirect *rec, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | snd_pcm_indirect_copy_t copy) |
| 50 | { |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 51 | struct snd_pcm_runtime *runtime = substream->runtime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; |
| 53 | snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; |
| 54 | int qsize; |
| 55 | |
| 56 | if (diff) { |
| 57 | if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) |
| 58 | diff += runtime->boundary; |
Takashi Iwai | 96295812 | 2017-05-19 18:31:03 +0200 | [diff] [blame] | 59 | if (diff < 0) |
| 60 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | rec->sw_ready += (int)frames_to_bytes(runtime, diff); |
| 62 | rec->appl_ptr = appl_ptr; |
| 63 | } |
| 64 | qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; |
| 65 | while (rec->hw_ready < qsize && rec->sw_ready > 0) { |
| 66 | unsigned int hw_to_end = rec->hw_buffer_size - rec->hw_data; |
| 67 | unsigned int sw_to_end = rec->sw_buffer_size - rec->sw_data; |
| 68 | unsigned int bytes = qsize - rec->hw_ready; |
| 69 | if (rec->sw_ready < (int)bytes) |
| 70 | bytes = rec->sw_ready; |
| 71 | if (hw_to_end < bytes) |
| 72 | bytes = hw_to_end; |
| 73 | if (sw_to_end < bytes) |
| 74 | bytes = sw_to_end; |
| 75 | if (! bytes) |
| 76 | break; |
| 77 | copy(substream, rec, bytes); |
| 78 | rec->hw_data += bytes; |
| 79 | if (rec->hw_data == rec->hw_buffer_size) |
| 80 | rec->hw_data = 0; |
| 81 | rec->sw_data += bytes; |
| 82 | if (rec->sw_data == rec->sw_buffer_size) |
| 83 | rec->sw_data = 0; |
| 84 | rec->hw_ready += bytes; |
| 85 | rec->sw_ready -= bytes; |
| 86 | } |
Takashi Iwai | 96295812 | 2017-05-19 18:31:03 +0200 | [diff] [blame] | 87 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | } |
| 89 | |
| 90 | /* |
| 91 | * helper function for playback pointer callback |
| 92 | * ptr = current byte pointer |
| 93 | */ |
| 94 | static inline snd_pcm_uframes_t |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 95 | snd_pcm_indirect_playback_pointer(struct snd_pcm_substream *substream, |
| 96 | struct snd_pcm_indirect *rec, unsigned int ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | { |
| 98 | int bytes = ptr - rec->hw_io; |
| 99 | if (bytes < 0) |
| 100 | bytes += rec->hw_buffer_size; |
| 101 | rec->hw_io = ptr; |
| 102 | rec->hw_ready -= bytes; |
| 103 | rec->sw_io += bytes; |
| 104 | if (rec->sw_io >= rec->sw_buffer_size) |
| 105 | rec->sw_io -= rec->sw_buffer_size; |
| 106 | if (substream->ops->ack) |
| 107 | substream->ops->ack(substream); |
| 108 | return bytes_to_frames(substream->runtime, rec->sw_io); |
| 109 | } |
| 110 | |
| 111 | |
| 112 | /* |
| 113 | * helper function for capture ack callback |
| 114 | */ |
Takashi Iwai | 96295812 | 2017-05-19 18:31:03 +0200 | [diff] [blame] | 115 | static inline int |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 116 | snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream, |
| 117 | struct snd_pcm_indirect *rec, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | snd_pcm_indirect_copy_t copy) |
| 119 | { |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 120 | struct snd_pcm_runtime *runtime = substream->runtime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; |
| 122 | snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; |
| 123 | |
| 124 | if (diff) { |
| 125 | if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) |
| 126 | diff += runtime->boundary; |
Takashi Iwai | 96295812 | 2017-05-19 18:31:03 +0200 | [diff] [blame] | 127 | if (diff < 0) |
| 128 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | rec->sw_ready -= frames_to_bytes(runtime, diff); |
| 130 | rec->appl_ptr = appl_ptr; |
| 131 | } |
| 132 | while (rec->hw_ready > 0 && |
| 133 | rec->sw_ready < (int)rec->sw_buffer_size) { |
| 134 | size_t hw_to_end = rec->hw_buffer_size - rec->hw_data; |
| 135 | size_t sw_to_end = rec->sw_buffer_size - rec->sw_data; |
| 136 | size_t bytes = rec->sw_buffer_size - rec->sw_ready; |
| 137 | if (rec->hw_ready < (int)bytes) |
| 138 | bytes = rec->hw_ready; |
| 139 | if (hw_to_end < bytes) |
| 140 | bytes = hw_to_end; |
| 141 | if (sw_to_end < bytes) |
| 142 | bytes = sw_to_end; |
| 143 | if (! bytes) |
| 144 | break; |
| 145 | copy(substream, rec, bytes); |
| 146 | rec->hw_data += bytes; |
| 147 | if ((int)rec->hw_data == rec->hw_buffer_size) |
| 148 | rec->hw_data = 0; |
| 149 | rec->sw_data += bytes; |
| 150 | if (rec->sw_data == rec->sw_buffer_size) |
| 151 | rec->sw_data = 0; |
| 152 | rec->hw_ready -= bytes; |
| 153 | rec->sw_ready += bytes; |
| 154 | } |
Takashi Iwai | 96295812 | 2017-05-19 18:31:03 +0200 | [diff] [blame] | 155 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | } |
| 157 | |
| 158 | /* |
| 159 | * helper function for capture pointer callback, |
| 160 | * ptr = current byte pointer |
| 161 | */ |
| 162 | static inline snd_pcm_uframes_t |
Takashi Iwai | 877211f | 2005-11-17 13:59:38 +0100 | [diff] [blame] | 163 | snd_pcm_indirect_capture_pointer(struct snd_pcm_substream *substream, |
| 164 | struct snd_pcm_indirect *rec, unsigned int ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | { |
| 166 | int qsize; |
| 167 | int bytes = ptr - rec->hw_io; |
| 168 | if (bytes < 0) |
| 169 | bytes += rec->hw_buffer_size; |
| 170 | rec->hw_io = ptr; |
| 171 | rec->hw_ready += bytes; |
| 172 | qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; |
| 173 | if (rec->hw_ready > qsize) |
| 174 | return SNDRV_PCM_POS_XRUN; |
| 175 | rec->sw_io += bytes; |
| 176 | if (rec->sw_io >= rec->sw_buffer_size) |
| 177 | rec->sw_io -= rec->sw_buffer_size; |
| 178 | if (substream->ops->ack) |
| 179 | substream->ops->ack(substream); |
| 180 | return bytes_to_frames(substream->runtime, rec->sw_io); |
| 181 | } |
| 182 | |
| 183 | #endif /* __SOUND_PCM_INDIRECT_H */ |