xref: /openbmc/linux/sound/drivers/pcsp/pcsp.h (revision d9fd5a71)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * PC-Speaker driver for Linux
4  *
5  * Copyright (C) 1993-1997  Michael Beck
6  * Copyright (C) 1997-2001  David Woodhouse
7  * Copyright (C) 2001-2008  Stas Sergeev
8  */
9 
10 #ifndef __PCSP_H__
11 #define __PCSP_H__
12 
13 #include <linux/hrtimer.h>
14 #include <linux/i8253.h>
15 #include <linux/timex.h>
16 
17 #define PCSP_SOUND_VERSION 0x400	/* read 4.00 */
18 #define PCSP_DEBUG 0
19 
20 /* default timer freq for PC-Speaker: 18643 Hz */
21 #define DIV_18KHZ 64
22 #define MAX_DIV DIV_18KHZ
23 #define CALC_DIV(d) (MAX_DIV >> (d))
24 #define CUR_DIV() CALC_DIV(chip->treble)
25 #define PCSP_MAX_TREBLE 1
26 
27 /* unfortunately, with hrtimers 37KHz does not work very well :( */
28 #define PCSP_DEFAULT_TREBLE 0
29 #define MIN_DIV (MAX_DIV >> PCSP_MAX_TREBLE)
30 
31 /* wild guess */
32 #define PCSP_MIN_LPJ 1000000
33 #define PCSP_DEFAULT_SDIV (DIV_18KHZ >> 1)
34 #define PCSP_DEFAULT_SRATE (PIT_TICK_RATE / PCSP_DEFAULT_SDIV)
35 #define PCSP_INDEX_INC() (1 << (PCSP_MAX_TREBLE - chip->treble))
36 #define PCSP_CALC_RATE(i) (PIT_TICK_RATE / CALC_DIV(i))
37 #define PCSP_RATE() PCSP_CALC_RATE(chip->treble)
38 #define PCSP_MIN_RATE__1 MAX_DIV/PIT_TICK_RATE
39 #define PCSP_MAX_RATE__1 MIN_DIV/PIT_TICK_RATE
40 #define PCSP_MAX_PERIOD_NS (1000000000ULL * PCSP_MIN_RATE__1)
41 #define PCSP_MIN_PERIOD_NS (1000000000ULL * PCSP_MAX_RATE__1)
42 #define PCSP_CALC_NS(div) ({ \
43 	u64 __val = 1000000000ULL * (div); \
44 	do_div(__val, PIT_TICK_RATE); \
45 	__val; \
46 })
47 #define PCSP_PERIOD_NS() PCSP_CALC_NS(CUR_DIV())
48 
49 #define PCSP_MAX_PERIOD_SIZE	(64*1024)
50 #define PCSP_MAX_PERIODS	512
51 #define PCSP_BUFFER_SIZE	(128*1024)
52 
53 struct snd_pcsp {
54 	struct snd_card *card;
55 	struct snd_pcm *pcm;
56 	struct input_dev *input_dev;
57 	struct hrtimer timer;
58 	unsigned short port, irq, dma;
59 	spinlock_t substream_lock;
60 	struct snd_pcm_substream *playback_substream;
61 	unsigned int fmt_size;
62 	unsigned int is_signed;
63 	size_t playback_ptr;
64 	size_t period_ptr;
65 	atomic_t timer_active;
66 	int thalf;
67 	u64 ns_rem;
68 	unsigned char val61;
69 	int enable;
70 	int max_treble;
71 	int treble;
72 	int pcspkr;
73 };
74 
75 extern struct snd_pcsp pcsp_chip;
76 
77 extern enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle);
78 extern void pcsp_sync_stop(struct snd_pcsp *chip);
79 
80 extern int snd_pcsp_new_pcm(struct snd_pcsp *chip);
81 extern int snd_pcsp_new_mixer(struct snd_pcsp *chip, int nopcm);
82 
83 #endif
84