pcm-indirect2.h
5.05 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/*
* Helper functions for indirect PCM data transfer to a simple FIFO in
* hardware (small, no possibility to read "hardware io position",
* updating position done by interrupt, ...)
*
* Copyright (c) by 2007 Joachim Foerster <JOFT@gmx.de>
*
* Based on "pcm-indirect.h" (alsa-driver-1.0.13) by
*
* Copyright (c) by Takashi Iwai <tiwai@suse.de>
* Jaroslav Kysela <perex@suse.cz>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __SOUND_PCM_INDIRECT2_H
#define __SOUND_PCM_INDIRECT2_H
/* struct snd_pcm_substream, struct snd_pcm_runtime, snd_pcm_uframes_t */
#include <sound/pcm.h>
/* Debug options for code which may be removed completely in a final version */
#ifdef CONFIG_SND_DEBUG
#define SND_PCM_INDIRECT2_STAT /* turn on some "statistics" about the
* process of copying bytes from the
* intermediate buffer to the hardware
* fifo and the other way round
*/
#endif
struct snd_pcm_indirect2 {
unsigned int hw_buffer_size; /* Byte size of hardware buffer */
int hw_ready; /* playback: 1 = hw fifo has room left,
* 0 = hw fifo is full
*/
unsigned int min_multiple;
int min_periods; /* counts number of min. periods until
* min_multiple is reached
*/
int min_period_count; /* counts bytes to count number of
* min. periods
*/
unsigned int sw_buffer_size; /* Byte size of software buffer */
/* sw_data: position in intermediate buffer, where we will read (or
* write) from/to next time (to transfer data to/from HW)
*/
unsigned int sw_data; /* Offset to next dst (or src) in sw
* ring buffer
*/
/* easiest case (playback):
* sw_data is nearly the same as ~ runtime->control->appl_ptr, with the
* exception that sw_data is "behind" by the number if bytes ALSA wrote
* to the intermediate buffer last time.
* A call to ack() callback synchronizes both indirectly.
*/
/* We have no real sw_io pointer here. Usually sw_io is pointing to the
* current playback/capture position _inside_ the hardware. Devices
* with plain FIFOs often have no possibility to publish this position.
* So we say: if sw_data is updated, that means bytes were copied to
* the hardware, we increase sw_io by that amount, because there have
* to be as much bytes which were played. So sw_io will stay behind
* sw_data all the time and has to converge to sw_data at the end of
* playback.
*/
unsigned int sw_io; /* Current software pointer in bytes */
/* sw_ready: number of bytes ALSA copied to the intermediate buffer, so
* it represents the number of bytes which wait for transfer to the HW
*/
int sw_ready; /* Bytes ready to be transferred to/from hw */
/* appl_ptr: last known position of ALSA (where ALSA is going to write
* next time into the intermediate buffer
*/
snd_pcm_uframes_t appl_ptr; /* Last seen appl_ptr */
unsigned int bytes2hw;
int check_alignment;
#ifdef SND_PCM_INDIRECT2_STAT
unsigned int zeros2hw;
unsigned int mul_elapsed;
unsigned int mul_elapsed_real;
unsigned long firstbytetime;
unsigned long lastbytetime;
unsigned long firstzerotime;
unsigned int byte_sizes[64];
unsigned int zero_sizes[64];
unsigned int min_adds[8];
unsigned int mul_adds[8];
unsigned int zero_times[3750]; /* = 15s */
unsigned int zero_times_saved;
unsigned int zero_times_notsaved;
unsigned int irq_occured;
unsigned int pointer_calls;
unsigned int lastdifftime;
#endif
};
typedef size_t (*snd_pcm_indirect2_copy_t) (struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
size_t bytes);
typedef size_t (*snd_pcm_indirect2_zero_t) (struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec);
#ifdef SND_PCM_INDIRECT2_STAT
void snd_pcm_indirect2_stat(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec);
#endif
snd_pcm_uframes_t
snd_pcm_indirect2_pointer(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec);
void
snd_pcm_indirect2_playback_interrupt(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
snd_pcm_indirect2_copy_t copy,
snd_pcm_indirect2_zero_t zero);
void
snd_pcm_indirect2_capture_interrupt(struct snd_pcm_substream *substream,
struct snd_pcm_indirect2 *rec,
snd_pcm_indirect2_copy_t copy,
snd_pcm_indirect2_zero_t null);
#endif /* __SOUND_PCM_INDIRECT2_H */