soundcard.c

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/*
 * 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)
 * 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 <linux/config.h>

#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 <asm/dma.h>
#include <asm/io.h>
#include <asm/segment.h>
#include <linux/wait.h>
#include <linux/malloc.h>
#include <linux/ioport.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/major.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/smp_lock.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)
 */
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 char     dma_alloc_map[MAX_DMA_CHANNELS] = {0};

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


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;
}

#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)

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);
	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 *buf, size_t count, loff_t *ppos)
{
	int dev = MINOR(file->f_dentry->d_inode->i_rdev);
	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 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 = MINOR(inode->i_rdev);
	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) {
			char modname[20];
			sprintf(modname, "mixer%d", dev);
			request_module(modname);
		}
		if (dev && (dev >= num_mixers || mixer_devs[dev] == NULL))
			return -ENXIO;

		if (mixer_devs[dev]->owner)
			__MOD_INC_USE_COUNT (mixer_devs[dev]->owner);
		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 = MINOR(inode->i_rdev);

	lock_kernel();
	DEB(printk("sound_release(dev=%d)\n", dev));
	switch (dev & 0x0f) {
	case SND_DEV_CTL:
		dev >>= 4;
		if (mixer_devs[dev]->owner)
			__MOD_DEC_USE_COUNT (mixer_devs[dev]->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, caddr_t arg)
{
	mixer_info info;

	strncpy(info.id, mixer_devs[dev]->id, sizeof(info.id));
	strncpy(info.name, mixer_devs[dev]->name, sizeof(info.name));
	info.name[sizeof(info.name)-1] = 0;
	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, caddr_t arg)
{
	_old_mixer_info info;

 	strncpy(info.id, mixer_devs[dev]->id, sizeof(info.id));
 	strncpy(info.name, mixer_devs[dev]->name, sizeof(info.name));
 	info.name[sizeof(info.name)-1] = 0;	
 	if (copy_to_user(arg, &info,  sizeof(info)))
		return -EFAULT;
	return 0;
}

static int sound_mixer_ioctl(int mixdev, unsigned int cmd, caddr_t arg)
{
 	if (mixdev < 0 || mixdev >= MAX_MIXER_DEV)
 		return -ENXIO;
 	/* Try to load the mixer... */
 	if (mixer_devs[mixdev] == NULL) {
 		char modname[20];
 		sprintf(modname, "mixer%d", mixdev);
 		request_module(modname);
 	}
 	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 err, len = 0, dtype;
	int dev = MINOR(inode->i_rdev);

	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 || arg == 0)
			return -EFAULT;
		if (_SIOC_DIR(cmd) & _SIOC_WRITE)
			if ((err = verify_area(VERIFY_READ, (void *)arg, len)) < 0)
				return err;
		if (_SIOC_DIR(cmd) & _SIOC_READ)
			if ((err = verify_area(VERIFY_WRITE, (void *)arg, len)) < 0)
				return err;
	}
	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 *)arg);
	
	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, (caddr_t)arg);
			
		default:
			return sound_mixer_ioctl(dev >> 4, cmd, (caddr_t)arg);
		}
	}
	switch (dev & 0x0f) {
	case SND_DEV_CTL:
		if (cmd == SOUND_MIXER_GETLEVELS)
			return get_mixer_levels((caddr_t)arg);
		if (cmd == SOUND_MIXER_SETLEVELS)
			return set_mixer_levels((caddr_t)arg);
		return sound_mixer_ioctl(dev >> 4, cmd, (caddr_t)arg);

	case SND_DEV_SEQ:
	case SND_DEV_SEQ2:
		return sequencer_ioctl(dev, file, cmd, (caddr_t)arg);