soundcard.c

linux 内核源代码

/*
 * linux/sound/oss/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)
 * Eric Dumas	     : devfs support (22-Jan-98) <[e-mail]> with
 *                   fixups by C. Scott Ananian <[e-mail]>
 * Richard Gooch     : moved common (non OSS-specific) devices to sound_core.c
 * Rob Riggs	     : Added persistent DMA buffers support (1998/10/17)
 * Christoph Hellwig : Some cleanup work (2000/03/01)
 */


#include "sound_config.h"
#include <linux/init.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>
#include <linux/kernel.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/major.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/smp_lock.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/device.h>

/*
 * 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

/*
 * Table for permanently allocated memory (used when unloading the module)
 */
void *          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 char     dma_alloc_map[MAX_DMA_CHANNELS];

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


unsigned long seq_time = 0;	/* Time for /dev/sequencer */
extern struct class *sound_class;

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

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;
}
EXPORT_SYMBOL(load_mixer_volumes);

static int set_mixer_levels(void __user * 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(void __user * arg)
{
	int n;

	if (__get_user(n, (int __user *)(&(((mixer_vol_table __user *)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;
}

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

static ssize_t sound_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	int dev = iminor(file->f_path.dentry->d_inode);
	int ret = -EINVAL;

	/*
	 *	The OSS drivers aren't remotely happy without this locking,
	 *	and unless someone fixes them when they are about to bite the
	 *	big one anyway, we might as well bandage here..
	 */
	 
	lock_kernel();
	
	DEB(printk("sound_read(dev=%d, count=%d)\n", dev, count));
	switch (dev & 0x0f) {
	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		ret = audio_read(dev, file, buf, count);
		break;

	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		ret = sequencer_read(dev, file, buf, count);
		break;

	case SND_DEV_MIDIN:
		ret = MIDIbuf_read(dev, file, buf, count);
	}
	unlock_kernel();
	return ret;
}

static ssize_t sound_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
	int dev = iminor(file->f_path.dentry->d_inode);
	int ret = -EINVAL;
	
	lock_kernel();
	DEB(printk("sound_write(dev=%d, count=%d)\n", dev, count));
	switch (dev & 0x0f) {
	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		ret =  sequencer_write(dev, file, buf, count);
		break;

	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		ret = audio_write(dev, file, buf, count);
		break;

	case SND_DEV_MIDIN:
		ret =  MIDIbuf_write(dev, file, buf, count);
		break;
	}
	unlock_kernel();
	return ret;
}

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

	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_CTL:
		dev >>= 4;
		if (dev >= 0 && dev < MAX_MIXER_DEV && mixer_devs[dev] == NULL) {
			request_module("mixer%d", dev);
		}
		if (dev && (dev >= num_mixers || mixer_devs[dev] == NULL))
			return -ENXIO;
	
		if (!try_module_get(mixer_devs[dev]->owner))
			return -ENXIO;
		break;

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

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

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

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

	return 0;
}

static int sound_release(struct inode *inode, struct file *file)
{
	int dev = iminor(inode);

	lock_kernel();
	DEB(printk("sound_release(dev=%d)\n", dev));
	switch (dev & 0x0f) {
	case SND_DEV_CTL:
		module_put(mixer_devs[dev >> 4]->owner);
		break;
		
	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		sequencer_release(dev, file);
		break;

	case SND_DEV_MIDIN:
		MIDIbuf_release(dev, file);
		break;

	case SND_DEV_DSP:
	case SND_DEV_DSP16:
	case SND_DEV_AUDIO:
		audio_release(dev, file);
		break;

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

	return 0;
}

static int get_mixer_info(int dev, void __user *arg)
{
	mixer_info info;
	memset(&info, 0, sizeof(info));
	strlcpy(info.id, mixer_devs[dev]->id, sizeof(info.id));
	strlcpy(info.name, mixer_devs[dev]->name, sizeof(info.name));
	info.modify_counter = mixer_devs[dev]->modify_counter;
	if (__copy_to_user(arg, &info,  sizeof(info)))
		return -EFAULT;
	return 0;
}

static int get_old_mixer_info(int dev, void __user *arg)
{
	_old_mixer_info info;
	memset(&info, 0, sizeof(info));
 	strlcpy(info.id, mixer_devs[dev]->id, sizeof(info.id));
 	strlcpy(info.name, mixer_devs[dev]->name, sizeof(info.name));
 	if (copy_to_user(arg, &info,  sizeof(info)))
		return -EFAULT;
	return 0;
}

static int sound_mixer_ioctl(int mixdev, unsigned int cmd, void __user *arg)
{
 	if (mixdev < 0 || mixdev >= MAX_MIXER_DEV)
 		return -ENXIO;
 	/* Try to load the mixer... */
 	if (mixer_devs[mixdev] == NULL) {
 		request_module("mixer%d", mixdev);
 	}
 	if (mixdev >= num_mixers || !mixer_devs[mixdev])
 		return -ENXIO;
	if (cmd == SOUND_MIXER_INFO)
		return get_mixer_info(mixdev, arg);
	if (cmd == SOUND_OLD_MIXER_INFO)
		return get_old_mixer_info(mixdev, arg);
	if (_SIOC_DIR(cmd) & _SIOC_WRITE)
		mixer_devs[mixdev]->modify_counter++;
	if (!mixer_devs[mixdev]->ioctl)
		return -EINVAL;
	return mixer_devs[mixdev]->ioctl(mixdev, cmd, arg);
}

static int sound_ioctl(struct inode *inode, struct file *file,
		       unsigned int cmd, unsigned long arg)
{
	int len = 0, dtype;
	int dev = iminor(inode);
	void __user *p = (void __user *)arg;

	if (_SIOC_DIR(cmd) != _SIOC_NONE && _SIOC_DIR(cmd) != 0) {
		/*
		 * Have to validate the address given by the process.
		 */
		len = _SIOC_SIZE(cmd);
		if (len < 1 || len > 65536 || !p)
			return -EFAULT;
		if (_SIOC_DIR(cmd) & _SIOC_WRITE)
			if (!access_ok(VERIFY_READ, p, len))
				return -EFAULT;
		if (_SIOC_DIR(cmd) & _SIOC_READ)
			if (!access_ok(VERIFY_WRITE, p, len))
				return -EFAULT;
	}
	DEB(printk("sound_ioctl(dev=%d, cmd=0x%x, arg=0x%x)\n", dev, cmd, arg));
	if (cmd == OSS_GETVERSION)
		return __put_user(SOUND_VERSION, (int __user *)p);
	
	if (_IOC_TYPE(cmd) == 'M' && num_mixers > 0 &&   /* Mixer ioctl */
	    (dev & 0x0f) != SND_DEV_CTL) {              
		dtype = dev & 0x0f;
		switch (dtype) {
		case SND_DEV_DSP:
		case SND_DEV_DSP16:
		case SND_DEV_AUDIO:
			return sound_mixer_ioctl(audio_devs[dev >> 4]->mixer_dev,
						 cmd, p);
			
		default:
			return sound_mixer_ioctl(dev >> 4, cmd, p);
		}
	}
	switch (dev & 0x0f) {
	case SND_DEV_CTL:
		if (cmd == SOUND_MIXER_GETLEVELS)