wf_midi.c

iis s3c2410-uda1341语音系统的 开发

/*
 * sound/wf_midi.c
 *
 * The low level driver for the WaveFront ICS2115 MIDI interface(s)
 * Note that there is also an MPU-401 emulation (actually, a UART-401
 * emulation) on the CS4232 on the Tropez Plus. This code has nothing
 * to do with that interface at all.
 *
 * The interface is essentially just a UART-401, but is has the
 * interesting property of supporting what Turtle Beach called
 * "Virtual MIDI" mode. In this mode, there are effectively *two*
 * MIDI buses accessible via the interface, one that is routed
 * solely to/from the external WaveFront synthesizer and the other
 * corresponding to the pin/socket connector used to link external
 * MIDI devices to the board.
 *
 * This driver fully supports this mode, allowing two distinct
 * midi devices (/dev/midiNN and /dev/midiNN+1) to be used
 * completely independently, giving 32 channels of MIDI routing,
 * 16 to the WaveFront synth and 16 to the external MIDI bus.
 *
 * Switching between the two is accomplished externally by the driver
 * using the two otherwise unused MIDI bytes. See the code for more details.
 *
 * NOTE: VIRTUAL MIDI MODE IS ON BY DEFAULT (see wavefront.c)
 *
 * The main reason to turn off Virtual MIDI mode is when you want to
 * tightly couple the WaveFront synth with an external MIDI
 * device. You won't be able to distinguish the source of any MIDI
 * data except via SysEx ID, but thats probably OK, since for the most
 * part, the WaveFront won't be sending any MIDI data at all.
 *  
 * The main reason to turn on Virtual MIDI Mode is to provide two
 * completely independent 16-channel MIDI buses, one to the
 * WaveFront and one to any external MIDI devices. Given the 32
 * voice nature of the WaveFront, its pretty easy to find a use
 * for all 16 channels driving just that synth.
 *
 */

/*
 * Copyright (C) by Paul Barton-Davis 1998
 * Some portions of this file are derived from work that is:
 *
 *    CopyriGht (C) by Hannu Savolainen 1993-1996
 *
 * USS/Lite 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.
 */

#include <linux/init.h>
#include "sound_config.h"

#include <linux/wavefront.h>

#ifdef MODULE

struct wf_mpu_config {
	int             base;
#define	DATAPORT(d)   (d)->base
#define	COMDPORT(d)   (d)->base+1
#define	STATPORT(d)   (d)->base+1

	int             irq;
	int             opened;
	int             devno;
	int             synthno;
	int             mode;
#define MODE_MIDI	1
#define MODE_SYNTH	2

	void            (*inputintr) (int dev, unsigned char data);
	char isvirtual;                /* do virtual I/O stuff */
};

static struct wf_mpu_config  devs[2];
static struct wf_mpu_config *phys_dev = &devs[0];
static struct wf_mpu_config *virt_dev = &devs[1];

static void start_uart_mode (void);

#define	OUTPUT_READY	0x40
#define	INPUT_AVAIL	0x80
#define	MPU_ACK		0xFE
#define	UART_MODE_ON	0x3F

static inline int wf_mpu_status (void)
{
	return inb (STATPORT (phys_dev));
}

static inline int input_avail (void)
{
	return !(wf_mpu_status() & INPUT_AVAIL);
}

static inline int output_ready (void)
{
	return !(wf_mpu_status() & OUTPUT_READY);
}

static inline int  read_data (void)
{
	return inb (DATAPORT (phys_dev));
}

static inline void write_data (unsigned char byte)
{
	outb (byte, DATAPORT (phys_dev));
}

/*
 * States for the input scanner (should be in dev_table.h)
 */

#define MST_SYSMSG		100	/* System message (sysx etc). */
#define MST_MTC			102	/* Midi Time Code (MTC) qframe msg */
#define MST_SONGSEL		103	/* Song select */
#define MST_SONGPOS		104	/* Song position pointer */
#define MST_TIMED		105	/* Leading timing byte rcvd */

/* buffer space check for input scanner */

#define BUFTEST(mi) if (mi->m_ptr >= MI_MAX || mi->m_ptr < 0) \
{printk(KERN_ERR "WF-MPU: Invalid buffer pointer %d/%d, s=%d\n", \
	mi->m_ptr, mi->m_left, mi->m_state);mi->m_ptr--;}

static unsigned char len_tab[] =	/* # of data bytes following a status
					 */
{
	2,				/* 8x */
	2,				/* 9x */
	2,				/* Ax */
	2,				/* Bx */
	1,				/* Cx */
	1,				/* Dx */
	2,				/* Ex */
	0				/* Fx */
};

static int
wf_mpu_input_scanner (int devno, int synthdev, unsigned char midic)

{
	struct midi_input_info *mi = &midi_devs[devno]->in_info;

	switch (mi->m_state) {
	case MST_INIT:
		switch (midic) {
		case 0xf8:
			/* Timer overflow */
			break;
		
		case 0xfc:
			break;
		
		case 0xfd:
			/* XXX do something useful with this. If there is
			   an external MIDI timer (e.g. a hardware sequencer,
			   a useful timer can be derived ...
		   
			   For now, no timer support.
			*/
			break;
		
		case 0xfe:
			return MPU_ACK;
			break;
		
		case 0xf0:
		case 0xf1:
		case 0xf2:
		case 0xf3:
		case 0xf4:
		case 0xf5:
		case 0xf6:
		case 0xf7:
			break;
		
		case 0xf9:
			break;
		
		case 0xff:
			mi->m_state = MST_SYSMSG;
			break;
		
		default:
			if (midic <= 0xef) {
				mi->m_state = MST_TIMED;
			}
			else
				printk (KERN_ERR "<MPU: Unknown event %02x> ",
					midic);
		}
		break;
	  
	case MST_TIMED:
	{
		int             msg = ((int) (midic & 0xf0) >> 4);
	  
		mi->m_state = MST_DATA;
	  
		if (msg < 8) {	/* Data byte */
	      
			msg = ((int) (mi->m_prev_status & 0xf0) >> 4);
			msg -= 8;
			mi->m_left = len_tab[msg] - 1;
	      
			mi->m_ptr = 2;
			mi->m_buf[0] = mi->m_prev_status;
			mi->m_buf[1] = midic;

			if (mi->m_left <= 0) {
				mi->m_state = MST_INIT;
				do_midi_msg (synthdev, mi->m_buf, mi->m_ptr);
				mi->m_ptr = 0;
			}
		} else if (msg == 0xf) {	/* MPU MARK */
	      
			mi->m_state = MST_INIT;

			switch (midic) {
			case 0xf8:
				break;
		    
			case 0xf9:
				break;
		    
			case 0xfc:
				break;
		    
			default:
				break;
			}
		} else {
			mi->m_prev_status = midic;
			msg -= 8;
			mi->m_left = len_tab[msg];
	      
			mi->m_ptr = 1;
			mi->m_buf[0] = midic;
	      
			if (mi->m_left <= 0) {
				mi->m_state = MST_INIT;
				do_midi_msg (synthdev, mi->m_buf, mi->m_ptr);
				mi->m_ptr = 0;
			}
		}
	}
	break;

	case MST_SYSMSG:
		switch (midic) {
		case 0xf0:
			mi->m_state = MST_SYSEX;
			break;
	    
		case 0xf1:
			mi->m_state = MST_MTC;
			break;

		case 0xf2:
			mi->m_state = MST_SONGPOS;
			mi->m_ptr = 0;
			break;
	    
		case 0xf3:
			mi->m_state = MST_SONGSEL;
			break;
	    
		case 0xf6:
			mi->m_state = MST_INIT;
	    
			/*
			 *    Real time messages
			 */
		case 0xf8:
			/* midi clock */
			mi->m_state = MST_INIT;
			/* XXX need ext MIDI timer support */
			break;
	    
		case 0xfA:
			mi->m_state = MST_INIT;
			/* XXX need ext MIDI timer support */
			break;
	    
		case 0xFB:
			mi->m_state = MST_INIT;
			/* XXX need ext MIDI timer support */
			break;
	    
		case 0xFC:
			mi->m_state = MST_INIT;
			/* XXX need ext MIDI timer support */
			break;
	    
		case 0xFE:
			/* active sensing */
			mi->m_state = MST_INIT;
			break;
	    
		case 0xff:
			mi->m_state = MST_INIT;
			break;

		default:
			printk (KERN_ERR "unknown MIDI sysmsg %0x\n", midic);
			mi->m_state = MST_INIT;
		}
		break;

	case MST_MTC:
		mi->m_state = MST_INIT;
		break;

	case MST_SYSEX:
		if (midic == 0xf7) {
			mi->m_state = MST_INIT;
		} else {
			/* XXX fix me */
		}
		break;

	case MST_SONGPOS:
		BUFTEST (mi);
		mi->m_buf[mi->m_ptr++] = midic;
		if (mi->m_ptr == 2) {
			mi->m_state = MST_INIT;
			mi->m_ptr = 0;
			/* XXX need ext MIDI timer support */
		}
		break;

	case MST_DATA:
		BUFTEST (mi);
		mi->m_buf[mi->m_ptr++] = midic;
		if ((--mi->m_left) <= 0) {
			mi->m_state = MST_INIT;
			do_midi_msg (synthdev, mi->m_buf, mi->m_ptr);
			mi->m_ptr = 0;
		}
		break;

	default:
		printk (KERN_ERR "Bad state %d ", mi->m_state);
		mi->m_state = MST_INIT;
	}

	return 1;
}

void
wf_mpuintr (int irq, void *dev_id, struct pt_regs *dummy)

{
	struct wf_mpu_config *physical_dev = dev_id;
	static struct wf_mpu_config *input_dev = 0;
	struct midi_input_info *mi = &midi_devs[physical_dev->devno]->in_info;
	int n;

	if (!input_avail()) { /* not for us */
		return;
	}

	if (mi->m_busy) return;
	mi->m_busy = 1;
	sti (); 

	if (!input_dev) {
		input_dev = physical_dev;
	}

	n = 50; /* XXX why ? */

	do {
		unsigned char c = read_data ();
      
		if (phys_dev->isvirtual) {

			if (c == WF_EXTERNAL_SWITCH) {
				input_dev = virt_dev;
				continue;
			} else if (c == WF_INTERNAL_SWITCH) { 
				input_dev = phys_dev;
				continue;
			} /* else just leave it as it is */

		} else {
			input_dev = phys_dev;
		}

		if (input_dev->mode == MODE_SYNTH) {
	  
			wf_mpu_input_scanner (input_dev->devno,
					      input_dev->synthno, c);
	  
		} else if (input_dev->opened & OPEN_READ) {
	  
			if (input_dev->inputintr) {
				input_dev->inputintr (input_dev->devno, c);
			} 
		}

	} while (input_avail() && n-- > 0);

	mi->m_busy = 0;
}

static int
wf_mpu_open (int dev, int mode,
	     void            (*input) (int dev, unsigned char data),
	     void            (*output) (int dev)
	)
{
	struct wf_mpu_config *devc;

	if (dev < 0 || dev >= num_midis || midi_devs[dev]==NULL)
		return -(ENXIO);

	if (phys_dev->devno == dev) {
		devc = phys_dev;
	} else if (phys_dev->isvirtual && virt_dev->devno == dev) {
		devc = virt_dev;
	} else {
		printk (KERN_ERR "WF-MPU: unknown device number %d\n", dev);
		return -(EINVAL);
	}

	if (devc->opened) {
		return -(EBUSY);
	}

	devc->mode = MODE_MIDI;
	devc->opened = mode;
	devc->synthno = 0;

	devc->inputintr = input;
	return 0;
}