/* * sound/sb16_midi.c *  * The low level driver for the MPU-401 UART emulation of the SB16. *  * Copyright by Hannu Savolainen 1993 *  * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. 2. * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. *  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. *  */#include "sound_config.h"#ifdef CONFIGURE_SOUNDCARD#if !defined(EXCLUDE_SB) && !defined(EXCLUDE_SB16) && !defined(EXCLUDE_MIDI)#define	DATAPORT   (sb16midi_base)	/* MPU-401 Data I/O Port on IBM */#define	COMDPORT   (sb16midi_base+1)	/* MPU-401 Command Port on IBM */#define	STATPORT   (sb16midi_base+1)	/* MPU-401 Status Port on IBM */#define sb16midi_status()		INB(STATPORT)#define input_avail()		(!(sb16midi_status()&INPUT_AVAIL))#define output_ready()		(!(sb16midi_status()&OUTPUT_READY))#define sb16midi_cmd(cmd)		OUTB(cmd, COMDPORT)#define sb16midi_read()		INB(DATAPORT)#define sb16midi_write(byte)	OUTB(byte, DATAPORT)#define	OUTPUT_READY	0x40	/* Mask for Data Read Redy Bit */#define	INPUT_AVAIL	0x80	/* Mask for Data Send Ready Bit */#define	MPU_ACK		0xFE	/* MPU-401 Acknowledge Response */#define	MPU_RESET	0xFF	/* MPU-401 Total Reset Command */#define	UART_MODE_ON	0x3F	/* MPU-401 "Dumb UART Mode" */static int      sb16midi_opened = 0;static int      sb16midi_base = 0x330;static int      sb16midi_detected = 0;static int      my_dev;static int      reset_sb16midi (void);static void     (*midi_input_intr) (int dev, unsigned char data);static voidsb16midi_input_loop (void){  int             count;  count = 10;  while (count)			/* Not timed out */    if (input_avail ())      {	unsigned char   c = sb16midi_read ();	count = 100;	if (sb16midi_opened & OPEN_READ)	  midi_input_intr (my_dev, c);      }    else      while (!input_avail () && count)	count--;}voidsb16midiintr (int unit){  if (input_avail ())    sb16midi_input_loop ();}/* * It looks like there is no input interrupts in the UART mode. Let's try * polling. */static voidpoll_sb16midi (unsigned long dummy){  unsigned long   flags;  DEFINE_TIMER(sb16midi_timer, poll_sb16midi);  if (!(sb16midi_opened & OPEN_READ))    return;			/* No longer required */  DISABLE_INTR (flags);  if (input_avail ())    sb16midi_input_loop ();  ACTIVATE_TIMER(sb16midi_timer, poll_sb16midi, 1); /* Come back later */  RESTORE_INTR (flags);}static intsb16midi_open (int dev, int mode,	     void            (*input) (int dev, unsigned char data),	     void            (*output) (int dev)){  if (sb16midi_opened)    {      return RET_ERROR (EBUSY);    }  sb16midi_input_loop ();  midi_input_intr = input;  sb16midi_opened = mode;  poll_sb16midi (0);		/* Enable input polling */  return 0;}static voidsb16midi_close (int dev){  sb16midi_opened = 0;}static intsb16midi_out (int dev, unsigned char midi_byte){  int             timeout;  unsigned long   flags;  /*   * Test for input since pending input seems to block the output.   */  DISABLE_INTR (flags);  if (input_avail ())    sb16midi_input_loop ();  RESTORE_INTR (flags);  /*   * Sometimes it takes about 13000 loops before the output becomes ready   * (After reset). Normally it takes just about 10 loops.   */  for (timeout = 30000; timeout > 0 && !output_ready (); timeout--);	/* Wait */  if (!output_ready ())    {      printk ("MPU-401: Timeout\n");      return 0;    }  sb16midi_write (midi_byte);  return 1;}static intsb16midi_command (int dev, unsigned char midi_byte){  return 1;}static intsb16midi_start_read (int dev){  return 0;}static intsb16midi_end_read (int dev){  return 0;}static intsb16midi_ioctl (int dev, unsigned cmd, unsigned arg){  return RET_ERROR (EINVAL);}static voidsb16midi_kick (int dev){}static intsb16midi_buffer_status (int dev){  return 0;			/* No data in buffers */}static struct midi_operations sb16midi_operations ={  {"SoundBlaster MPU-401", 0, 0, SNDCARD_SB16MIDI},  sb16midi_open,  sb16midi_close,  sb16midi_ioctl,  sb16midi_out,  sb16midi_start_read,  sb16midi_end_read,  sb16midi_kick,  sb16midi_command,  sb16midi_buffer_status};longattach_sb16midi (long mem_start, struct address_info *hw_config){  int             ok, timeout;  unsigned long   flags;  sb16midi_base = hw_config->io_base;  if (!sb16midi_detected)    return RET_ERROR (EIO);  DISABLE_INTR (flags);  for (timeout = 30000; timeout < 0 && !output_ready (); timeout--);	/* Wait */  sb16midi_cmd (UART_MODE_ON);  ok = 0;  for (timeout = 50000; timeout > 0 && !ok; timeout--)    if (input_avail ())      if (sb16midi_read () == MPU_ACK)	ok = 1;  RESTORE_INTR (flags);  printk (" <SoundBlaster MPU-401>");  my_dev = num_midis;  midi_devs[num_midis++] = &sb16midi_operations;  return mem_start;}static intreset_sb16midi (void){  unsigned long   flags;  int             ok, timeout, n;  /*   * Send the RESET command. Try again if no success at the first time.   */  ok = 0;  DISABLE_INTR (flags);  for (n = 0; n < 2 && !ok; n++)    {      for (timeout = 30000; timeout < 0 && !output_ready (); timeout--);	/* Wait */      sb16midi_cmd (MPU_RESET);	/* Send MPU-401 RESET Command */      /*       * Wait at least 25 msec. This method is not accurate so let's make the       * loop bit longer. Cannot sleep since this is called during boot.       */      for (timeout = 50000; timeout > 0 && !ok; timeout--)	if (input_avail ())	  if (sb16midi_read () == MPU_ACK)	    ok = 1;    }  sb16midi_opened = 0;  if (ok)    sb16midi_input_loop ();	/* Flush input before enabling interrupts */  RESTORE_INTR (flags);  return ok;}intprobe_sb16midi (struct address_info *hw_config){  int             ok = 0;  sb16midi_base = hw_config->io_base;  if (sb_get_irq () < 0)    return 0;  ok = reset_sb16midi ();  sb16midi_detected = ok;  return ok;}#endif#endif