Commit | Line | Data |
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74ba9207 | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
1da177e4 LT |
2 | /* |
3 | * Helper functions for indirect PCM data transfer | |
4 | * | |
5 | * Copyright (c) by Takashi Iwai <tiwai@suse.de> | |
c1017a4c | 6 | * Jaroslav Kysela <perex@perex.cz> |
1da177e4 LT |
7 | */ |
8 | ||
9 | #ifndef __SOUND_PCM_INDIRECT_H | |
10 | #define __SOUND_PCM_INDIRECT_H | |
11 | ||
12 | #include <sound/pcm.h> | |
13 | ||
877211f5 | 14 | struct snd_pcm_indirect { |
1da177e4 LT |
15 | unsigned int hw_buffer_size; /* Byte size of hardware buffer */ |
16 | unsigned int hw_queue_size; /* Max queue size of hw buffer (0 = buffer size) */ | |
17 | unsigned int hw_data; /* Offset to next dst (or src) in hw ring buffer */ | |
18 | unsigned int hw_io; /* Ring buffer hw pointer */ | |
19 | int hw_ready; /* Bytes ready for play (or captured) in hw ring buffer */ | |
20 | unsigned int sw_buffer_size; /* Byte size of software buffer */ | |
21 | unsigned int sw_data; /* Offset to next dst (or src) in sw ring buffer */ | |
22 | unsigned int sw_io; /* Current software pointer in bytes */ | |
23 | int sw_ready; /* Bytes ready to be transferred to/from hw */ | |
24 | snd_pcm_uframes_t appl_ptr; /* Last seen appl_ptr */ | |
877211f5 | 25 | }; |
1da177e4 | 26 | |
877211f5 TI |
27 | typedef void (*snd_pcm_indirect_copy_t)(struct snd_pcm_substream *substream, |
28 | struct snd_pcm_indirect *rec, size_t bytes); | |
1da177e4 LT |
29 | |
30 | /* | |
31 | * helper function for playback ack callback | |
32 | */ | |
96295812 | 33 | static inline int |
877211f5 TI |
34 | snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream, |
35 | struct snd_pcm_indirect *rec, | |
1da177e4 LT |
36 | snd_pcm_indirect_copy_t copy) |
37 | { | |
877211f5 | 38 | struct snd_pcm_runtime *runtime = substream->runtime; |
1da177e4 LT |
39 | snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; |
40 | snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; | |
41 | int qsize; | |
42 | ||
43 | if (diff) { | |
44 | if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) | |
45 | diff += runtime->boundary; | |
96295812 | 46 | if (diff < 0) |
0146878c | 47 | return -EPIPE; |
1da177e4 LT |
48 | rec->sw_ready += (int)frames_to_bytes(runtime, diff); |
49 | rec->appl_ptr = appl_ptr; | |
50 | } | |
51 | qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; | |
52 | while (rec->hw_ready < qsize && rec->sw_ready > 0) { | |
53 | unsigned int hw_to_end = rec->hw_buffer_size - rec->hw_data; | |
54 | unsigned int sw_to_end = rec->sw_buffer_size - rec->sw_data; | |
55 | unsigned int bytes = qsize - rec->hw_ready; | |
56 | if (rec->sw_ready < (int)bytes) | |
57 | bytes = rec->sw_ready; | |
58 | if (hw_to_end < bytes) | |
59 | bytes = hw_to_end; | |
60 | if (sw_to_end < bytes) | |
61 | bytes = sw_to_end; | |
62 | if (! bytes) | |
63 | break; | |
64 | copy(substream, rec, bytes); | |
65 | rec->hw_data += bytes; | |
66 | if (rec->hw_data == rec->hw_buffer_size) | |
67 | rec->hw_data = 0; | |
68 | rec->sw_data += bytes; | |
69 | if (rec->sw_data == rec->sw_buffer_size) | |
70 | rec->sw_data = 0; | |
71 | rec->hw_ready += bytes; | |
72 | rec->sw_ready -= bytes; | |
73 | } | |
96295812 | 74 | return 0; |
1da177e4 LT |
75 | } |
76 | ||
77 | /* | |
78 | * helper function for playback pointer callback | |
79 | * ptr = current byte pointer | |
80 | */ | |
81 | static inline snd_pcm_uframes_t | |
877211f5 TI |
82 | snd_pcm_indirect_playback_pointer(struct snd_pcm_substream *substream, |
83 | struct snd_pcm_indirect *rec, unsigned int ptr) | |
1da177e4 LT |
84 | { |
85 | int bytes = ptr - rec->hw_io; | |
0146878c TI |
86 | int err; |
87 | ||
1da177e4 LT |
88 | if (bytes < 0) |
89 | bytes += rec->hw_buffer_size; | |
90 | rec->hw_io = ptr; | |
91 | rec->hw_ready -= bytes; | |
92 | rec->sw_io += bytes; | |
93 | if (rec->sw_io >= rec->sw_buffer_size) | |
94 | rec->sw_io -= rec->sw_buffer_size; | |
0146878c TI |
95 | if (substream->ops->ack) { |
96 | err = substream->ops->ack(substream); | |
97 | if (err == -EPIPE) | |
98 | return SNDRV_PCM_POS_XRUN; | |
99 | } | |
1da177e4 LT |
100 | return bytes_to_frames(substream->runtime, rec->sw_io); |
101 | } | |
102 | ||
103 | ||
104 | /* | |
105 | * helper function for capture ack callback | |
106 | */ | |
96295812 | 107 | static inline int |
877211f5 TI |
108 | snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream, |
109 | struct snd_pcm_indirect *rec, | |
1da177e4 LT |
110 | snd_pcm_indirect_copy_t copy) |
111 | { | |
877211f5 | 112 | struct snd_pcm_runtime *runtime = substream->runtime; |
1da177e4 LT |
113 | snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; |
114 | snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; | |
115 | ||
116 | if (diff) { | |
117 | if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) | |
118 | diff += runtime->boundary; | |
96295812 | 119 | if (diff < 0) |
0146878c | 120 | return -EPIPE; |
1da177e4 LT |
121 | rec->sw_ready -= frames_to_bytes(runtime, diff); |
122 | rec->appl_ptr = appl_ptr; | |
123 | } | |
124 | while (rec->hw_ready > 0 && | |
125 | rec->sw_ready < (int)rec->sw_buffer_size) { | |
126 | size_t hw_to_end = rec->hw_buffer_size - rec->hw_data; | |
127 | size_t sw_to_end = rec->sw_buffer_size - rec->sw_data; | |
128 | size_t bytes = rec->sw_buffer_size - rec->sw_ready; | |
129 | if (rec->hw_ready < (int)bytes) | |
130 | bytes = rec->hw_ready; | |
131 | if (hw_to_end < bytes) | |
132 | bytes = hw_to_end; | |
133 | if (sw_to_end < bytes) | |
134 | bytes = sw_to_end; | |
135 | if (! bytes) | |
136 | break; | |
137 | copy(substream, rec, bytes); | |
138 | rec->hw_data += bytes; | |
139 | if ((int)rec->hw_data == rec->hw_buffer_size) | |
140 | rec->hw_data = 0; | |
141 | rec->sw_data += bytes; | |
142 | if (rec->sw_data == rec->sw_buffer_size) | |
143 | rec->sw_data = 0; | |
144 | rec->hw_ready -= bytes; | |
145 | rec->sw_ready += bytes; | |
146 | } | |
96295812 | 147 | return 0; |
1da177e4 LT |
148 | } |
149 | ||
150 | /* | |
151 | * helper function for capture pointer callback, | |
152 | * ptr = current byte pointer | |
153 | */ | |
154 | static inline snd_pcm_uframes_t | |
877211f5 TI |
155 | snd_pcm_indirect_capture_pointer(struct snd_pcm_substream *substream, |
156 | struct snd_pcm_indirect *rec, unsigned int ptr) | |
1da177e4 LT |
157 | { |
158 | int qsize; | |
159 | int bytes = ptr - rec->hw_io; | |
0146878c TI |
160 | int err; |
161 | ||
1da177e4 LT |
162 | if (bytes < 0) |
163 | bytes += rec->hw_buffer_size; | |
164 | rec->hw_io = ptr; | |
165 | rec->hw_ready += bytes; | |
166 | qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; | |
167 | if (rec->hw_ready > qsize) | |
168 | return SNDRV_PCM_POS_XRUN; | |
169 | rec->sw_io += bytes; | |
170 | if (rec->sw_io >= rec->sw_buffer_size) | |
171 | rec->sw_io -= rec->sw_buffer_size; | |
0146878c TI |
172 | if (substream->ops->ack) { |
173 | err = substream->ops->ack(substream); | |
174 | if (err == -EPIPE) | |
175 | return SNDRV_PCM_POS_XRUN; | |
176 | } | |
1da177e4 LT |
177 | return bytes_to_frames(substream->runtime, rec->sw_io); |
178 | } | |
179 | ||
180 | #endif /* __SOUND_PCM_INDIRECT_H */ |