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pcsp.h
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1 /*
2  * PC-Speaker driver for Linux
3  *
4  * Copyright (C) 1993-1997 Michael Beck
5  * Copyright (C) 1997-2001 David Woodhouse
6  * Copyright (C) 2001-2008 Stas Sergeev
7  */
8 
9 #ifndef __PCSP_H__
10 #define __PCSP_H__
11 
12 #include <linux/hrtimer.h>
13 #include <linux/i8253.h>
14 #include <linux/timex.h>
15 
16 #define PCSP_SOUND_VERSION 0x400 /* read 4.00 */
17 #define PCSP_DEBUG 0
18 
19 /* default timer freq for PC-Speaker: 18643 Hz */
20 #define DIV_18KHZ 64
21 #define MAX_DIV DIV_18KHZ
22 #define CALC_DIV(d) (MAX_DIV >> (d))
23 #define CUR_DIV() CALC_DIV(chip->treble)
24 #define PCSP_MAX_TREBLE 1
25 
26 /* unfortunately, with hrtimers 37KHz does not work very well :( */
27 #define PCSP_DEFAULT_TREBLE 0
28 #define MIN_DIV (MAX_DIV >> PCSP_MAX_TREBLE)
29 
30 /* wild guess */
31 #define PCSP_MIN_LPJ 1000000
32 #define PCSP_DEFAULT_SDIV (DIV_18KHZ >> 1)
33 #define PCSP_DEFAULT_SRATE (PIT_TICK_RATE / PCSP_DEFAULT_SDIV)
34 #define PCSP_INDEX_INC() (1 << (PCSP_MAX_TREBLE - chip->treble))
35 #define PCSP_CALC_RATE(i) (PIT_TICK_RATE / CALC_DIV(i))
36 #define PCSP_RATE() PCSP_CALC_RATE(chip->treble)
37 #define PCSP_MIN_RATE__1 MAX_DIV/PIT_TICK_RATE
38 #define PCSP_MAX_RATE__1 MIN_DIV/PIT_TICK_RATE
39 #define PCSP_MAX_PERIOD_NS (1000000000ULL * PCSP_MIN_RATE__1)
40 #define PCSP_MIN_PERIOD_NS (1000000000ULL * PCSP_MAX_RATE__1)
41 #define PCSP_CALC_NS(div) ({ \
42  u64 __val = 1000000000ULL * (div); \
43  do_div(__val, PIT_TICK_RATE); \
44  __val; \
45 })
46 #define PCSP_PERIOD_NS() PCSP_CALC_NS(CUR_DIV())
47 
48 #define PCSP_MAX_PERIOD_SIZE (64*1024)
49 #define PCSP_MAX_PERIODS 512
50 #define PCSP_BUFFER_SIZE (128*1024)
51 
52 struct snd_pcsp {
53  struct snd_card *card;
54  struct snd_pcm *pcm;
56  struct hrtimer timer;
57  unsigned short port, irq, dma;
60  unsigned int fmt_size;
61  unsigned int is_signed;
62  size_t playback_ptr;
63  size_t period_ptr;
65  int thalf;
67  unsigned char val61;
68  int enable;
70  int treble;
71  int pcspkr;
72 };
73 
74 extern struct snd_pcsp pcsp_chip;
75 
76 extern enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle);
77 extern void pcsp_sync_stop(struct snd_pcsp *chip);
78 
79 extern int snd_pcsp_new_pcm(struct snd_pcsp *chip);
80 extern int snd_pcsp_new_mixer(struct snd_pcsp *chip, int nopcm);
81 
82 #endif