[linux-2.6-block.git] / sound / oss / pas2_pcm.c

/*
 * pas2_pcm.c Audio routines for PAS16
 *
 *
 * Copyright (C) by Hannu Savolainen 1993-1997
 *
 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
 * Version 2 (June 1991). See the "COPYING" file distributed with this software
 * for more info.
 *
 *
 * Thomas Sailer   : ioctl code reworked (vmalloc/vfree removed)
 * Alan Cox	   : Swatted a double allocation of device bug. Made a few
 *		     more things module options.
 * Bartlomiej Zolnierkiewicz : Added __init to pas_pcm_init()
 */

#include <linux/init.h>
#include <linux/spinlock.h>
#include <asm/timex.h>
#include "sound_config.h"

#include "pas2.h"

#ifndef DEB
#define DEB(WHAT)
#endif

#define PAS_PCM_INTRBITS (0x08)
/*
 * Sample buffer timer interrupt enable
 */

#define PCM_NON	0
#define PCM_DAC	1
#define PCM_ADC	2

static unsigned long pcm_speed; 	/* sampling rate */
static unsigned char pcm_channels = 1;	/* channels (1 or 2) */
static unsigned char pcm_bits = 8;	/* bits/sample (8 or 16) */
static unsigned char pcm_filter;	/* filter FLAG */
static unsigned char pcm_mode = PCM_NON;
static unsigned long pcm_count;
static unsigned short pcm_bitsok = 8;	/* mask of OK bits */
static int      pcm_busy;
int             pas_audiodev = -1;
static int      open_mode;

extern spinlock_t pas_lock;

static int pcm_set_speed(int arg)
{
	int foo, tmp;
	unsigned long flags;

	if (arg == 0)
		return pcm_speed;

	if (arg > 44100)
		arg = 44100;
	if (arg < 5000)
		arg = 5000;

	if (pcm_channels & 2)
	{
		foo = ((CLOCK_TICK_RATE / 2) + (arg / 2)) / arg;
		arg = ((CLOCK_TICK_RATE / 2) + (foo / 2)) / foo;
	}
	else
	{
		foo = (CLOCK_TICK_RATE + (arg / 2)) / arg;
		arg = (CLOCK_TICK_RATE + (foo / 2)) / foo;
	}

	pcm_speed = arg;

	tmp = pas_read(0x0B8A);

	/*
	 * Set anti-aliasing filters according to sample rate. You really *NEED*
	 * to enable this feature for all normal recording unless you want to
	 * experiment with aliasing effects.
	 * These filters apply to the selected "recording" source.
	 * I (pfw) don't know the encoding of these 5 bits. The values shown
	 * come from the SDK found on ftp.uwp.edu:/pub/msdos/proaudio/.
	 *
	 * I cleared bit 5 of these values, since that bit controls the master
Commit	Line	Data
1da177e4 LT	1	/*
	2	* pas2_pcm.c Audio routines for PAS16
	3	*
	4	*
	5	* Copyright (C) by Hannu Savolainen 1993-1997
	6	*
	7	* OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
	8	* Version 2 (June 1991). See the "COPYING" file distributed with this software
	9	* for more info.
	10	*
	11	*
	12	* Thomas Sailer : ioctl code reworked (vmalloc/vfree removed)
	13	* Alan Cox : Swatted a double allocation of device bug. Made a few
	14	* more things module options.
	15	* Bartlomiej Zolnierkiewicz : Added __init to pas_pcm_init()
	16	*/
	17
	18	#include <linux/init.h>
	19	#include <linux/spinlock.h>
	20	#include <asm/timex.h>
	21	#include "sound_config.h"
	22
	23	#include "pas2.h"
	24
	25	#ifndef DEB
	26	#define DEB(WHAT)
	27	#endif
	28
	29	#define PAS_PCM_INTRBITS (0x08)
	30	/*
	31	* Sample buffer timer interrupt enable
	32	*/
	33
	34	#define PCM_NON 0
	35	#define PCM_DAC 1
	36	#define PCM_ADC 2
	37
	38	static unsigned long pcm_speed; /* sampling rate */
	39	static unsigned char pcm_channels = 1; /* channels (1 or 2) */
	40	static unsigned char pcm_bits = 8; /* bits/sample (8 or 16) */
	41	static unsigned char pcm_filter; /* filter FLAG */
	42	static unsigned char pcm_mode = PCM_NON;
	43	static unsigned long pcm_count;
	44	static unsigned short pcm_bitsok = 8; /* mask of OK bits */
	45	static int pcm_busy;
	46	int pas_audiodev = -1;
	47	static int open_mode;
	48
	49	extern spinlock_t pas_lock;
	50
	51	static int pcm_set_speed(int arg)
	52	{
	53	int foo, tmp;
	54	unsigned long flags;
	55
	56	if (arg == 0)
	57	return pcm_speed;
	58
	59	if (arg > 44100)
	60	arg = 44100;
	61	if (arg < 5000)
	62	arg = 5000;
	63
	64	if (pcm_channels & 2)
65	{
66	foo = ((CLOCK_TICK_RATE / 2) + (arg / 2)) / arg;
67	arg = ((CLOCK_TICK_RATE / 2) + (foo / 2)) / foo;
68	}
69	else
70	{
71	foo = (CLOCK_TICK_RATE + (arg / 2)) / arg;
72	arg = (CLOCK_TICK_RATE + (foo / 2)) / foo;
73	}
74
75	pcm_speed = arg;
76
77	tmp = pas_read(0x0B8A);
78
79	/*
80	* Set anti-aliasing filters according to sample rate. You really NEED
81	* to enable this feature for all normal recording unless you want to
82	* experiment with aliasing effects.
83	* These filters apply to the selected "recording" source.
84	* I (pfw) don't know the encoding of these 5 bits. The values shown
85	* come from the SDK found on ftp.uwp.edu:/pub/msdos/proaudio/.
86	*
87	* I cleared bit 5 of these values, since that bit controls the master
88