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 TI |
46 | if (diff < 0) |
47 | return -EINVAL; | |
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; | |
86 | if (bytes < 0) | |
87 | bytes += rec->hw_buffer_size; | |
88 | rec->hw_io = ptr; | |
89 | rec->hw_ready -= bytes; | |
90 | rec->sw_io += bytes; | |
91 | if (rec->sw_io >= rec->sw_buffer_size) | |
92 | rec->sw_io -= rec->sw_buffer_size; | |
93 | if (substream->ops->ack) | |
94 | substream->ops->ack(substream); | |
95 | return bytes_to_frames(substream->runtime, rec->sw_io); | |
96 | } | |
97 | ||
98 | ||
99 | /* | |
100 | * helper function for capture ack callback | |
101 | */ | |
96295812 | 102 | static inline int |
877211f5 TI |
103 | snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream, |
104 | struct snd_pcm_indirect *rec, | |
1da177e4 LT |
105 | snd_pcm_indirect_copy_t copy) |
106 | { | |
877211f5 | 107 | struct snd_pcm_runtime *runtime = substream->runtime; |
1da177e4 LT |
108 | snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; |
109 | snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; | |
110 | ||
111 | if (diff) { | |
112 | if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) | |
113 | diff += runtime->boundary; | |
96295812 TI |
114 | if (diff < 0) |
115 | return -EINVAL; | |
1da177e4 LT |
116 | rec->sw_ready -= frames_to_bytes(runtime, diff); |
117 | rec->appl_ptr = appl_ptr; | |
118 | } | |
119 | while (rec->hw_ready > 0 && | |
120 | rec->sw_ready < (int)rec->sw_buffer_size) { | |
121 | size_t hw_to_end = rec->hw_buffer_size - rec->hw_data; | |
122 | size_t sw_to_end = rec->sw_buffer_size - rec->sw_data; | |
123 | size_t bytes = rec->sw_buffer_size - rec->sw_ready; | |
124 | if (rec->hw_ready < (int)bytes) | |
125 | bytes = rec->hw_ready; | |
126 | if (hw_to_end < bytes) | |
127 | bytes = hw_to_end; | |
128 | if (sw_to_end < bytes) | |
129 | bytes = sw_to_end; | |
130 | if (! bytes) | |
131 | break; | |
132 | copy(substream, rec, bytes); | |
133 | rec->hw_data += bytes; | |
134 | if ((int)rec->hw_data == rec->hw_buffer_size) | |
135 | rec->hw_data = 0; | |
136 | rec->sw_data += bytes; | |
137 | if (rec->sw_data == rec->sw_buffer_size) | |
138 | rec->sw_data = 0; | |
139 | rec->hw_ready -= bytes; | |
140 | rec->sw_ready += bytes; | |
141 | } | |
96295812 | 142 | return 0; |
1da177e4 LT |
143 | } |
144 | ||
145 | /* | |
146 | * helper function for capture pointer callback, | |
147 | * ptr = current byte pointer | |
148 | */ | |
149 | static inline snd_pcm_uframes_t | |
877211f5 TI |
150 | snd_pcm_indirect_capture_pointer(struct snd_pcm_substream *substream, |
151 | struct snd_pcm_indirect *rec, unsigned int ptr) | |
1da177e4 LT |
152 | { |
153 | int qsize; | |
154 | int bytes = ptr - rec->hw_io; | |
155 | if (bytes < 0) | |
156 | bytes += rec->hw_buffer_size; | |
157 | rec->hw_io = ptr; | |
158 | rec->hw_ready += bytes; | |
159 | qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; | |
160 | if (rec->hw_ready > qsize) | |
161 | return SNDRV_PCM_POS_XRUN; | |
162 | rec->sw_io += bytes; | |
163 | if (rec->sw_io >= rec->sw_buffer_size) | |
164 | rec->sw_io -= rec->sw_buffer_size; | |
165 | if (substream->ops->ack) | |
166 | substream->ops->ack(substream); | |
167 | return bytes_to_frames(substream->runtime, rec->sw_io); | |
168 | } | |
169 | ||
170 | #endif /* __SOUND_PCM_INDIRECT_H */ |