soundcard.c

基于组件方式开发操作系统的OSKIT源代码

/*
 * linux/drivers/sound/soundcard.c
 *
 * Sound card driver for Linux
 */
/*
 * 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)
 *                   integrated sound_switch.c
 * Stefan Reinauer : integrated /proc/sound (equals to /dev/sndstat,
 *                   which should disappear in the near future)
 *
 * Rob Riggs		Added persistent DMA buffers support (1998/10/17)
 */

#include <linux/config.h>

#include "sound_config.h"
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/fcntl.h>
#include <linux/ctype.h>
#include <linux/stddef.h>
#include <linux/kmod.h>
#ifdef __KERNEL__
#include <asm/dma.h>
#include <asm/io.h>
#include <asm/segment.h>
#include <linux/wait.h>
#include <linux/malloc.h>
#include <linux/ioport.h>
#endif				/* __KERNEL__ */
#include <linux/delay.h>
#include <linux/proc_fs.h>

#include "soundmodule.h"
struct notifier_block *sound_locker=(struct notifier_block *)0;
static int lock_depth = 0;

#ifdef MODULE
#define modular 1
#else
#define modular 0
#endif

/*
 * This ought to be moved into include/asm/dma.h
 */
#ifndef valid_dma
#define valid_dma(n) ((n) >= 0 && (n) < MAX_DMA_CHANNELS && (n) != 4)
#endif

static int      chrdev_registered = 0;
static int      is_unloading = 0;

/*
 * Table for permanently allocated memory (used when unloading the module)
 */
caddr_t         sound_mem_blocks[1024];
int             sound_nblocks = 0;

/* Persistent DMA buffers */
#ifdef CONFIG_SOUND_DMAP
int		sound_dmap_flag = 1;
#else
int		sound_dmap_flag = 0;
#endif

static int      soundcard_configured = 0;

static char     dma_alloc_map[MAX_DMA_CHANNELS] =
{0};

#define DMA_MAP_UNAVAIL		0
#define DMA_MAP_FREE		1
#define DMA_MAP_BUSY		2


static int in_use = 0;	        /* Total # of open devices */
unsigned long seq_time = 0;	/* Time for /dev/sequencer */

/*
 * Table for configurable mixer volume handling
 */
static mixer_vol_table mixer_vols[MAX_MIXER_DEV];
static int num_mixer_volumes = 0;


int *load_mixer_volumes(char *name, int *levels, int present)
{
	int             i, n;

	for (i = 0; i < num_mixer_volumes; i++)
	{
		if (strcmp(name, mixer_vols[i].name) == 0)
		{
			if (present)
				mixer_vols[i].num = i;
			return mixer_vols[i].levels;
		}
	}
	if (num_mixer_volumes >= MAX_MIXER_DEV)
	{
		printk(KERN_ERR "Sound: Too many mixers (%s)\n", name);
		return levels;
	}
	n = num_mixer_volumes++;

	strcpy(mixer_vols[n].name, name);

	if (present)
		mixer_vols[n].num = n;
	else
		mixer_vols[n].num = -1;

	for (i = 0; i < 32; i++)
		mixer_vols[n].levels[i] = levels[i];
	return mixer_vols[n].levels;
}

static int set_mixer_levels(caddr_t arg)
{
        /* mixer_vol_table is 174 bytes, so IMHO no reason to not allocate it on the stack */
	mixer_vol_table buf;   

	if (__copy_from_user(&buf, arg, sizeof(buf)))
		return -EFAULT;
	load_mixer_volumes(buf.name, buf.levels, 0);
	if (__copy_to_user(arg, &buf, sizeof(buf)))
		return -EFAULT;
	return 0;
}

static int get_mixer_levels(caddr_t arg)
{
	int n;

	if (__get_user(n, (int *)(&(((mixer_vol_table *)arg)->num))))
		return -EFAULT;
	if (n < 0 || n >= num_mixer_volumes)
		return -EINVAL;
	if (__copy_to_user(arg, &mixer_vols[n], sizeof(mixer_vol_table)))
		return -EFAULT;
	return 0;
}

static int sound_proc_get_info(char *buffer, char **start, off_t offset, int length, int inout)
{
	int len, i, drv;
        off_t pos = 0;
        off_t begin = 0;

#ifdef MODULE
#define MODULEPROCSTRING "Driver loaded as a module"
#else
#define MODULEPROCSTRING "Driver compiled into kernel"
#endif

#ifdef OSKIT
	len = sprintf(buffer, "OSS/Free:" SOUND_VERSION_STRING "\n"
		      "Load type: " MODULEPROCSTRING "\n"
		      "Config options: %x\n\nInstalled drivers: \n", 
		      SELECTED_SOUND_OPTIONS);
#else
	down(&uts_sem);	

	len = sprintf(buffer, "OSS/Free:" SOUND_VERSION_STRING "\n"
		      "Load type: " MODULEPROCSTRING "\n"
		      "Kernel: %s %s %s %s %s\n"
		      "Config options: %x\n\nInstalled drivers: \n", 
		      system_utsname.sysname, system_utsname.nodename, system_utsname.release, 
		      system_utsname.version, system_utsname.machine, SELECTED_SOUND_OPTIONS);
	up(&uts_sem);
#endif
	
	for (i = 0; (i < num_sound_drivers) && (pos <= offset + length); i++) {
		if (!sound_drivers[i].card_type)
			continue;
		len += sprintf(buffer + len, "Type %d: %s\n", 
			       sound_drivers[i].card_type, sound_drivers[i].name);
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
	len += sprintf(buffer + len, "\nCard config: \n");

	for (i = 0; (i < num_sound_cards) && (pos <= offset + length); i++) 
	{
		if (!snd_installed_cards[i].card_type)
			continue;
		if (!snd_installed_cards[i].enabled)
			len += sprintf(buffer + len, "(");
		if ((drv = snd_find_driver(snd_installed_cards[i].card_type)) != -1)
			len += sprintf(buffer + len, "%s", sound_drivers[drv].name);
		if (snd_installed_cards[i].config.io_base)
			len += sprintf(buffer + len, " at 0x%x", snd_installed_cards[i].config.io_base);
		if (snd_installed_cards[i].config.irq != 0)
			len += sprintf(buffer + len, " irq %d", abs(snd_installed_cards[i].config.irq));
		if (snd_installed_cards[i].config.dma != -1) {
			len += sprintf(buffer + len, " drq %d", snd_installed_cards[i].config.dma);
			if (snd_installed_cards[i].config.dma2 != -1)
				len += sprintf(buffer + len, ",%d", snd_installed_cards[i].config.dma2);
		}
		if (!snd_installed_cards[i].enabled)
			len += sprintf(buffer + len, ")");
		len += sprintf(buffer + len, "\n");
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
	if (!sound_started)
		len += sprintf(buffer + len, "\n\n***** Sound driver not started *****\n\n");
#ifndef CONFIG_AUDIO
	len += sprintf(buffer + len, "\nAudio devices: NOT ENABLED IN CONFIG\n");
#else
	len += sprintf(buffer + len, "\nAudio devices:\n");
	for (i = 0; (i < num_audiodevs) && (pos <= offset + length); i++) {
		if (audio_devs[i] == NULL)
			continue;
		len += sprintf(buffer + len, "%d: %s%s\n", i, audio_devs[i]->name, 
			       audio_devs[i]->flags & DMA_DUPLEX ? " (DUPLEX)" : "");
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
#endif

#ifndef CONFIG_SEQUENCER
	len += sprintf(buffer + len, "\nSynth devices: NOT ENABLED IN CONFIG\n");
#else
	len += sprintf(buffer + len, "\nSynth devices:\n");
	for (i = 0; (i < num_synths) && (pos <= offset + length); i++) {
		if (synth_devs[i] == NULL)
			continue;
		len += sprintf(buffer + len, "%d: %s\n", i, synth_devs[i]->info->name);
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
#endif

#ifndef CONFIG_MIDI
	len += sprintf(buffer + len, "\nMidi devices: NOT ENABLED IN CONFIG\n");
#else
	len += sprintf(buffer + len, "\nMidi devices:\n");
	for (i = 0; (i < num_midis) && (pos <= offset + length); i++) {
		if (midi_devs[i] == NULL)
			continue;
		len += sprintf(buffer + len, "%d: %s\n", i, midi_devs[i]->info.name);
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
#endif

#ifdef CONFIG_SEQUENCER
	len += sprintf(buffer + len, "\nTimers:\n");

	for (i = 0; (i < num_sound_timers) && (pos <= offset + length); i++) {
		if (sound_timer_devs[i] == NULL)
			continue;
		len += sprintf(buffer + len, "%d: %s\n", i, sound_timer_devs[i]->info.name);
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
#endif

	len += sprintf(buffer + len, "\nMixers:\n");
	for (i = 0; (i < num_mixers) && (pos <= offset + length); i++) {
		if (mixer_devs[i] == NULL)
			continue;
		len += sprintf(buffer + len, "%d: %s\n", i, mixer_devs[i]->name);
		pos = begin + len;
		if (pos < offset) {
			len = 0;
			begin = pos;
		}
	}
	*start = buffer + (offset - begin);
	len -= (offset - begin);
        if (len > length) 
		len = length;
        return len;
}

#ifdef CONFIG_PROC_FS
static struct proc_dir_entry proc_root_sound = {
        PROC_SOUND, 5, "sound",
        S_IFREG | S_IRUGO, 1, 0, 0,
        0, NULL, sound_proc_get_info
};
#endif

#ifndef MIN
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#endif

/* 4K page size but our output routines use some slack for overruns */
#define PROC_BLOCK_SIZE (3*1024)

/*
 * basically copied from fs/proc/generic.c:proc_file_read 
 * should be removed sometime in the future together with /dev/sndstat
 * (a symlink /dev/sndstat -> /proc/sound will do as well)
 */
static ssize_t sndstat_file_read(struct file * file, char * buf, size_t nbytes, loff_t *ppos)
{
        char    *page;
        ssize_t retval=0;
        int     eof=0;
        ssize_t n, count;
        char    *start;

        if (!(page = (char*) __get_free_page(GFP_KERNEL)))
                return -ENOMEM;

        while ((nbytes > 0) && !eof)
        {
                count = MIN(PROC_BLOCK_SIZE, nbytes);

                start = NULL;
		n = sound_proc_get_info(page, &start, *ppos, count, 0);
		if (n < count)
			eof = 1;
                        
                if (!start) {
                        /*
                         * For proc files that are less than 4k
                         */
                        start = page + *ppos;
                        n -= *ppos;
                        if (n <= 0)
                                break;
                        if (n > count)
                                n = count;
                }
                if (n == 0)
                        break;  /* End of file */
                if (n < 0) {
                        if (retval == 0)
                                retval = n;
                        break;
                }
                
                n -= copy_to_user(buf, start, n);       /* BUG ??? */
                if (n == 0) {
                        if (retval == 0)
                                retval = -EFAULT;
                        break;
                }
                
                *ppos += n;     /* Move down the file */
                nbytes -= n;
                buf += n;
                retval += n;
        }
        free_page((unsigned long) page);
        return retval;
}


static ssize_t sound_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
	int dev = MINOR(file->f_dentry->d_inode->i_rdev);

	DEB(printk("sound_read(dev=%d, count=%d)\n", dev, count));
	switch (dev & 0x0f) {
	case SND_DEV_STATUS:
		return sndstat_file_read(file, buf, count, ppos);

#ifdef CONFIG_AUDIO
	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		return audio_read(dev, file, buf, count);
#endif

#ifdef CONFIG_SEQUENCER
	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		return sequencer_read(dev, file, buf, count);
#endif

#ifdef CONFIG_MIDI
	case SND_DEV_MIDIN:
		return MIDIbuf_read(dev, file, buf, count);
#endif

	default:;
	}
	return -EINVAL;
}

static ssize_t sound_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
{
	int dev = MINOR(file->f_dentry->d_inode->i_rdev);

	DEB(printk("sound_write(dev=%d, count=%d)\n", dev, count));
	switch (dev & 0x0f) {
#ifdef CONFIG_SEQUENCER
	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		return sequencer_write(dev, file, buf, count);
#endif

#ifdef CONFIG_AUDIO
	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		return audio_write(dev, file, buf, count);
#endif

#ifdef CONFIG_MIDI
	case SND_DEV_MIDIN:
		return MIDIbuf_write(dev, file, buf, count);
#endif
	}
	return -EINVAL;
}

static long long sound_lseek(struct file *file, long long offset, int orig)
{
	return -ESPIPE;
}

static int sound_open(struct inode *inode, struct file *file)
{
	int dev, retval;

	if (is_unloading) {
		/* printk(KERN_ERR "Sound: Driver partially removed. Can't open device\n");*/
		return -EBUSY;
	}
	dev = MINOR(inode->i_rdev);
	if (!soundcard_configured && dev != SND_DEV_CTL && dev != SND_DEV_STATUS) {
		/* printk("SoundCard Error: The sound system has not been configured\n");*/
		return -ENXIO;
	}
	DEB(printk("sound_open(dev=%d)\n", dev));
	if ((dev >= SND_NDEVS) || (dev < 0)) {
		/* printk(KERN_ERR "Invalid minor device %d\n", dev);*/
		return -ENXIO;
	}
	switch (dev & 0x0f) {
	case SND_DEV_STATUS:
		break;

	case SND_DEV_CTL:
		dev >>= 4;
		if (dev >= 0 && dev < MAX_MIXER_DEV && mixer_devs[dev] == NULL) {
			char modname[20];
			sprintf(modname, "mixer%d", dev);
			request_module(modname);
		}
		if (dev && (dev >= num_mixers || mixer_devs[dev] == NULL))
			return -ENXIO;
		break;

#ifdef CONFIG_SEQUENCER
	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		if ((retval = sequencer_open(dev, file)) < 0)
			return retval;
		break;
#endif

#ifdef CONFIG_MIDI
	case SND_DEV_MIDIN:
		if ((retval = MIDIbuf_open(dev, file)) < 0)
			return retval;
		break;
#endif

#ifdef CONFIG_AUDIO
	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		if ((retval = audio_open(dev, file)) < 0)
			return retval;
		break;
#endif

	default:
		printk(KERN_ERR "Invalid minor device %d\n", dev);
		return -ENXIO;
	}
	in_use++;

#ifdef CONFIG_MODULES
	notifier_call_chain(&sound_locker, 1, 0);
	lock_depth++;
#endif

	return 0;
}

static int sound_release(struct inode *inode, struct file *file)
{
	int dev = MINOR(inode->i_rdev);

	DEB(printk("sound_release(dev=%d)\n", dev));
	switch (dev & 0x0f) {
	case SND_DEV_STATUS:
	case SND_DEV_CTL:
		break;
		
#ifdef CONFIG_SEQUENCER
	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		sequencer_release(dev, file);
		break;
#endif

#ifdef CONFIG_MIDI
	case SND_DEV_MIDIN:
		MIDIbuf_release(dev, file);
		break;
#endif

#ifdef CONFIG_AUDIO
	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		audio_release(dev, file);
		break;
#endif

	default:
		printk(KERN_ERR "Sound error: Releasing unknown device 0x%02x\n", dev);
	}
	in_use--;

#ifdef CONFIG_MODULES
	notifier_call_chain(&sound_locker, 0, 0);
	lock_depth--;
#endif

	return 0;
}

static int get_mixer_info(int dev, caddr_t arg)
{
	mixer_info info;

	strncpy(info.id, mixer_devs[dev]->id, sizeof(info.id));