/*
   * The DSP56001 Device Driver, saviour of the Free World(tm)
   *
   * Authors: Fredrik Noring   <noring@nocrew.org>
   *          lars brinkhoff   <lars@nocrew.org>
   *          Tomas Berndtsson <tomas@nocrew.org>
   *
   * First version May 1996
   *
   * History:
   *  97-01-29   Tomas Berndtsson,
   *               Integrated with Linux 2.1.21 kernel sources.
   *  97-02-15   Tomas Berndtsson,
   *               Fixed for kernel 2.1.26
   *
   * BUGS:
   *  Hmm... there must be something here :)
   *
   * Copyright (C) 1996,1997 Fredrik Noring, lars brinkhoff & Tomas Berndtsson
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive
   * for more details.
   */
  
  #include <linux/module.h>

  #include <linux/major.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/delay.h>	/* guess what */
  #include <linux/fs.h>
  #include <linux/mm.h>
  #include <linux/init.h>

  #include <linux/device.h>

  #include <linux/mutex.h>

  #include <linux/firmware.h>
  #include <linux/platform_device.h>

  #include <linux/uaccess.h>	/* For put_user and get_user */

  
  #include <asm/atarihw.h>
  #include <asm/traps.h>

  
  #include <asm/dsp56k.h>
  
  /* minor devices */
  #define DSP56K_DEV_56001        0    /* The only device so far */
  
  #define TIMEOUT    10   /* Host port timeout in number of tries */
  #define MAXIO    2048   /* Maximum number of words before sleep */
  #define DSP56K_MAX_BINARY_LENGTH (3*64*1024)
  
  #define DSP56K_TX_INT_ON	dsp56k_host_interface.icr |=  DSP56K_ICR_TREQ
  #define DSP56K_RX_INT_ON	dsp56k_host_interface.icr |=  DSP56K_ICR_RREQ
  #define DSP56K_TX_INT_OFF	dsp56k_host_interface.icr &= ~DSP56K_ICR_TREQ
  #define DSP56K_RX_INT_OFF	dsp56k_host_interface.icr &= ~DSP56K_ICR_RREQ
  
  #define DSP56K_TRANSMIT		(dsp56k_host_interface.isr & DSP56K_ISR_TXDE)
  #define DSP56K_RECEIVE		(dsp56k_host_interface.isr & DSP56K_ISR_RXDF)
  
  #define handshake(count, maxio, timeout, ENABLE, f) \
  { \
  	long i, t, m; \
  	while (count > 0) { \
  		m = min_t(unsigned long, count, maxio); \
  		for (i = 0; i < m; i++) { \
  			for (t = 0; t < timeout && !ENABLE; t++) \
  				msleep(20); \
  			if(!ENABLE) \
  				return -EIO; \
  			f; \
  		} \
  		count -= m; \
  		if (m == maxio) msleep(20); \
  	} \
  }
  
  #define tx_wait(n) \
  { \
  	int t; \
  	for(t = 0; t < n && !DSP56K_TRANSMIT; t++) \
  		msleep(10); \
  	if(!DSP56K_TRANSMIT) { \
  		return -EIO; \
  	} \
  }
  
  #define rx_wait(n) \
  { \
  	int t; \
  	for(t = 0; t < n && !DSP56K_RECEIVE; t++) \
  		msleep(10); \
  	if(!DSP56K_RECEIVE) { \
  		return -EIO; \
  	} \
  }

  static DEFINE_MUTEX(dsp56k_mutex);

  static struct dsp56k_device {

  	unsigned long in_use;

  	long maxio, timeout;
  	int tx_wsize, rx_wsize;
  } dsp56k;

  static struct class *dsp56k_class;

  
  static int dsp56k_reset(void)
  {
  	u_char status;
  	
  	/* Power down the DSP */
  	sound_ym.rd_data_reg_sel = 14;
  	status = sound_ym.rd_data_reg_sel & 0xef;
  	sound_ym.wd_data = status;
  	sound_ym.wd_data = status | 0x10;
    
  	udelay(10);
    
  	/* Power up the DSP */
  	sound_ym.rd_data_reg_sel = 14;
  	sound_ym.wd_data = sound_ym.rd_data_reg_sel & 0xef;
  
  	return 0;
  }

  static int dsp56k_upload(u_char __user *bin, int len)

  {

  	struct platform_device *pdev;
  	const struct firmware *fw;
  	const char fw_name[] = "dsp56k/bootstrap.bin";
  	int err;

  	int i;

  	dsp56k_reset();

  
  	pdev = platform_device_register_simple("dsp56k", 0, NULL, 0);
  	if (IS_ERR(pdev)) {
  		printk(KERN_ERR "Failed to register device for \"%s\"
  ",
  		       fw_name);
  		return -EINVAL;
  	}
  	err = request_firmware(&fw, fw_name, &pdev->dev);
  	platform_device_unregister(pdev);
  	if (err) {
  		printk(KERN_ERR "Failed to load image \"%s\" err %d
  ",
  		       fw_name, err);
  		return err;
  	}
  	if (fw->size % 3) {
  		printk(KERN_ERR "Bogus length %d in image \"%s\"
  ",
  		       fw->size, fw_name);
  		release_firmware(fw);
  		return -EINVAL;
  	}
  	for (i = 0; i < fw->size; i = i + 3) {

  		/* tx_wait(10); */

  		dsp56k_host_interface.data.b[1] = fw->data[i];
  		dsp56k_host_interface.data.b[2] = fw->data[i + 1];
  		dsp56k_host_interface.data.b[3] = fw->data[i + 2];

  	}

  	release_firmware(fw);

  	for (; i < 512; i++) {
  		/* tx_wait(10); */
  		dsp56k_host_interface.data.b[1] = 0;
  		dsp56k_host_interface.data.b[2] = 0;
  		dsp56k_host_interface.data.b[3] = 0;
  	}
    
  	for (i = 0; i < len; i++) {
  		tx_wait(10);
  		get_user(dsp56k_host_interface.data.b[1], bin++);
  		get_user(dsp56k_host_interface.data.b[2], bin++);
  		get_user(dsp56k_host_interface.data.b[3], bin++);
  	}
  
  	tx_wait(10);
  	dsp56k_host_interface.data.l = 3;    /* Magic execute */
  
  	return 0;
  }

  static ssize_t dsp56k_read(struct file *file, char __user *buf, size_t count,

  			   loff_t *ppos)
  {

  	struct inode *inode = file->f_path.dentry->d_inode;

  	int dev = iminor(inode) & 0x0f;
  
  	switch(dev)
  	{
  	case DSP56K_DEV_56001:
  	{
  
  		long n;
  
  		/* Don't do anything if nothing is to be done */
  		if (!count) return 0;
  
  		n = 0;
  		switch (dsp56k.rx_wsize) {
  		case 1:  /* 8 bit */
  		{
  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
  				  put_user(dsp56k_host_interface.data.b[3], buf+n++));
  			return n;
  		}
  		case 2:  /* 16 bit */
  		{

  			short __user *data;

  
  			count /= 2;

  			data = (short __user *) buf;

  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
  				  put_user(dsp56k_host_interface.data.w[1], data+n++));
  			return 2*n;
  		}
  		case 3:  /* 24 bit */
  		{
  			count /= 3;
  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
  				  put_user(dsp56k_host_interface.data.b[1], buf+n++);
  				  put_user(dsp56k_host_interface.data.b[2], buf+n++);
  				  put_user(dsp56k_host_interface.data.b[3], buf+n++));
  			return 3*n;
  		}
  		case 4:  /* 32 bit */
  		{

  			long __user *data;

  
  			count /= 4;

  			data = (long __user *) buf;

  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_RECEIVE,
  				  put_user(dsp56k_host_interface.data.l, data+n++));
  			return 4*n;
  		}
  		}
  		return -EFAULT;
  	}
  
  	default:
  		printk(KERN_ERR "DSP56k driver: Unknown minor device: %d
  ", dev);
  		return -ENXIO;
  	}
  }

  static ssize_t dsp56k_write(struct file *file, const char __user *buf, size_t count,

  			    loff_t *ppos)
  {

  	struct inode *inode = file->f_path.dentry->d_inode;

  	int dev = iminor(inode) & 0x0f;
  
  	switch(dev)
  	{
  	case DSP56K_DEV_56001:
  	{
  		long n;
  
  		/* Don't do anything if nothing is to be done */
  		if (!count) return 0;
  
  		n = 0;
  		switch (dsp56k.tx_wsize) {
  		case 1:  /* 8 bit */
  		{
  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
  				  get_user(dsp56k_host_interface.data.b[3], buf+n++));
  			return n;
  		}
  		case 2:  /* 16 bit */
  		{

  			const short __user *data;

  
  			count /= 2;

  			data = (const short __user *)buf;

  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
  				  get_user(dsp56k_host_interface.data.w[1], data+n++));
  			return 2*n;
  		}
  		case 3:  /* 24 bit */
  		{
  			count /= 3;
  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
  				  get_user(dsp56k_host_interface.data.b[1], buf+n++);
  				  get_user(dsp56k_host_interface.data.b[2], buf+n++);
  				  get_user(dsp56k_host_interface.data.b[3], buf+n++));
  			return 3*n;
  		}
  		case 4:  /* 32 bit */
  		{

  			const long __user *data;

  
  			count /= 4;

  			data = (const long __user *)buf;

  			handshake(count, dsp56k.maxio, dsp56k.timeout, DSP56K_TRANSMIT,
  				  get_user(dsp56k_host_interface.data.l, data+n++));
  			return 4*n;
  		}
  		}
  
  		return -EFAULT;
  	}
  	default:
  		printk(KERN_ERR "DSP56k driver: Unknown minor device: %d
  ", dev);
  		return -ENXIO;
  	}
  }

  static long dsp56k_ioctl(struct file *file, unsigned int cmd,

  			 unsigned long arg)

  {

  	int dev = iminor(file->f_path.dentry->d_inode) & 0x0f;

  	void __user *argp = (void __user *)arg;

  
  	switch(dev)
  	{
  	case DSP56K_DEV_56001:
  
  		switch(cmd) {
  		case DSP56K_UPLOAD:
  		{

  			char __user *bin;

  			int r, len;

  			struct dsp56k_upload __user *binary = argp;

      
  			if(get_user(len, &binary->len) < 0)
  				return -EFAULT;
  			if(get_user(bin, &binary->bin) < 0)
  				return -EFAULT;
  		
  			if (len == 0) {
  				return -EINVAL;      /* nothing to upload?!? */
  			}
  			if (len > DSP56K_MAX_BINARY_LENGTH) {
  				return -EINVAL;
  			}

  			mutex_lock(&dsp56k_mutex);

  			r = dsp56k_upload(bin, len);

  			mutex_unlock(&dsp56k_mutex);

  			if (r < 0) {
  				return r;
  			}
      
  			break;
  		}
  		case DSP56K_SET_TX_WSIZE:
  			if (arg > 4 || arg < 1)
  				return -EINVAL;

  			mutex_lock(&dsp56k_mutex);

  			dsp56k.tx_wsize = (int) arg;

  			mutex_unlock(&dsp56k_mutex);

  			break;
  		case DSP56K_SET_RX_WSIZE:
  			if (arg > 4 || arg < 1)
  				return -EINVAL;

  			mutex_lock(&dsp56k_mutex);

  			dsp56k.rx_wsize = (int) arg;

  			mutex_unlock(&dsp56k_mutex);

  			break;
  		case DSP56K_HOST_FLAGS:
  		{
  			int dir, out, status;

  			struct dsp56k_host_flags __user *hf = argp;

      
  			if(get_user(dir, &hf->dir) < 0)
  				return -EFAULT;
  			if(get_user(out, &hf->out) < 0)
  				return -EFAULT;

  			mutex_lock(&dsp56k_mutex);

  			if ((dir & 0x1) && (out & 0x1))
  				dsp56k_host_interface.icr |= DSP56K_ICR_HF0;
  			else if (dir & 0x1)
  				dsp56k_host_interface.icr &= ~DSP56K_ICR_HF0;
  			if ((dir & 0x2) && (out & 0x2))
  				dsp56k_host_interface.icr |= DSP56K_ICR_HF1;
  			else if (dir & 0x2)
  				dsp56k_host_interface.icr &= ~DSP56K_ICR_HF1;
  
  			status = 0;
  			if (dsp56k_host_interface.icr & DSP56K_ICR_HF0) status |= 0x1;
  			if (dsp56k_host_interface.icr & DSP56K_ICR_HF1) status |= 0x2;
  			if (dsp56k_host_interface.isr & DSP56K_ISR_HF2) status |= 0x4;
  			if (dsp56k_host_interface.isr & DSP56K_ISR_HF3) status |= 0x8;

  			mutex_unlock(&dsp56k_mutex);

  			return put_user(status, &hf->status);
  		}
  		case DSP56K_HOST_CMD:
  			if (arg > 31 || arg < 0)
  				return -EINVAL;

  			mutex_lock(&dsp56k_mutex);

  			dsp56k_host_interface.cvr = (u_char)((arg & DSP56K_CVR_HV_MASK) |
  							     DSP56K_CVR_HC);

  			mutex_unlock(&dsp56k_mutex);

  			break;
  		default:
  			return -EINVAL;
  		}
  		return 0;
  
  	default:
  		printk(KERN_ERR "DSP56k driver: Unknown minor device: %d
  ", dev);
  		return -ENXIO;
  	}
  }
  
  /* As of 2.1.26 this should be dsp56k_poll,
   * but how do I then check device minor number?
   * Do I need this function at all???
   */
  #if 0
  static unsigned int dsp56k_poll(struct file *file, poll_table *wait)
  {

  	int dev = iminor(file->f_path.dentry->d_inode) & 0x0f;

  
  	switch(dev)
  	{
  	case DSP56K_DEV_56001:
  		/* poll_wait(file, ???, wait); */
  		return POLLIN | POLLRDNORM | POLLOUT;
  
  	default:
  		printk("DSP56k driver: Unknown minor device: %d
  ", dev);
  		return 0;
  	}
  }
  #endif
  
  static int dsp56k_open(struct inode *inode, struct file *file)
  {
  	int dev = iminor(inode) & 0x0f;

  	int ret = 0;

  	mutex_lock(&dsp56k_mutex);

  	switch(dev)
  	{
  	case DSP56K_DEV_56001:

  		if (test_and_set_bit(0, &dsp56k.in_use)) {
  			ret = -EBUSY;
  			goto out;
  		}

  
  		dsp56k.timeout = TIMEOUT;
  		dsp56k.maxio = MAXIO;
  		dsp56k.rx_wsize = dsp56k.tx_wsize = 4; 
  
  		DSP56K_TX_INT_OFF;
  		DSP56K_RX_INT_OFF;
  
  		/* Zero host flags */
  		dsp56k_host_interface.icr &= ~DSP56K_ICR_HF0;
  		dsp56k_host_interface.icr &= ~DSP56K_ICR_HF1;
  
  		break;
  
  	default:

  		ret = -ENODEV;

  	}

  out:

  	mutex_unlock(&dsp56k_mutex);

  	return ret;

  }
  
  static int dsp56k_release(struct inode *inode, struct file *file)
  {
  	int dev = iminor(inode) & 0x0f;
  
  	switch(dev)
  	{
  	case DSP56K_DEV_56001:
  		clear_bit(0, &dsp56k.in_use);
  		break;
  	default:
  		printk(KERN_ERR "DSP56k driver: Unknown minor device: %d
  ", dev);
  		return -ENXIO;
  	}
  
  	return 0;
  }

  static const struct file_operations dsp56k_fops = {

  	.owner		= THIS_MODULE,
  	.read		= dsp56k_read,
  	.write		= dsp56k_write,

  	.unlocked_ioctl	= dsp56k_ioctl,

  	.open		= dsp56k_open,
  	.release	= dsp56k_release,

  	.llseek		= noop_llseek,

  };
  
  
  /****** Init and module functions ******/
  
  static char banner[] __initdata = KERN_INFO "DSP56k driver installed
  ";
  
  static int __init dsp56k_init_driver(void)
  {
  	int err = 0;
  
  	if(!MACH_IS_ATARI || !ATARIHW_PRESENT(DSP56K)) {
  		printk("DSP56k driver: Hardware not present
  ");
  		return -ENODEV;
  	}
  
  	if(register_chrdev(DSP56K_MAJOR, "dsp56k", &dsp56k_fops)) {
  		printk("DSP56k driver: Unable to register driver
  ");
  		return -ENODEV;
  	}

  	dsp56k_class = class_create(THIS_MODULE, "dsp56k");

  	if (IS_ERR(dsp56k_class)) {
  		err = PTR_ERR(dsp56k_class);
  		goto out_chrdev;
  	}

  	device_create(dsp56k_class, NULL, MKDEV(DSP56K_MAJOR, 0), NULL,
  		      "dsp56k");

  	printk(banner);
  	goto out;

  out_chrdev:
  	unregister_chrdev(DSP56K_MAJOR, "dsp56k");
  out:
  	return err;
  }
  module_init(dsp56k_init_driver);
  
  static void __exit dsp56k_cleanup_driver(void)
  {

  	device_destroy(dsp56k_class, MKDEV(DSP56K_MAJOR, 0));

  	class_destroy(dsp56k_class);

  	unregister_chrdev(DSP56K_MAJOR, "dsp56k");

  }
  module_exit(dsp56k_cleanup_driver);
  
  MODULE_LICENSE("GPL");

  MODULE_FIRMWARE("dsp56k/bootstrap.bin");