audio_fw.c

Minix比较全的源码

/* Best viewed with tabsize 4
 *
 * This file contains a standard driver for audio devices.
 * It supports double dma buffering and can be configured to use
 * extra buffer space beside the dma buffer.
 * This driver also support sub devices, which can be independently 
 * opened and closed.   
 *
 * The driver supports the following operations:
 *
 *    m_type      DEVICE    IO_ENDPT     COUNT    POSITION  ADRRESS
 * -----------------------------------------------------------------
 * | DEV_OPEN    | device  | proc nr |         |         |         |
 * |-------------+---------+---------+---------+---------+---------|
 * | DEV_CLOSE   | device  | proc nr |         |         |         |
 * |-------------+---------+---------+---------+---------+---------|
 * | DEV_READ_S  | device  | proc nr |  bytes  |         | buf ptr |
 * |-------------+---------+---------+---------+---------+---------|
 * | DEV_WRITE_S | device  | proc nr |  bytes  |         | buf ptr |
 * |-------------+---------+---------+---------+---------+---------|
 * | DEV_IOCTL_S | device  | proc nr |func code|         | buf ptr |
 * |-------------+---------+---------+---------+---------+---------|
 * | DEV_STATUS  |         |         |         |         |         |
 * |-------------+---------+---------+---------+---------+---------|
 * | HARD_INT    |         |         |         |         |         | 
 * |-------------+---------+---------+---------+---------+---------|
 * | SIG_STOP    |         |         |         |         |         | 
 * ----------------------------------------------------------------- 
 * 
 * The file contains one entry point:
 *
 *   main:	main entry when driver is brought up
 *	
 *	October 2007	Updated audio framework to work with mplayer, added
 *					savecopies (Pieter Hijma)
 *  February 2006   Updated audio framework, 
 *		changed driver-framework relation (Peter Boonstoppel)
 *  November 2005   Created generic DMA driver framework (Laurens Bronwasser)
 *  August 24 2005  Ported audio driver to user space 
 *		(only audio playback) (Peter Boonstoppel)
 *  May 20 1995	    SB16 Driver: Michel R. Prevenier 
 */


#include "audio_fw.h"


FORWARD _PROTOTYPE( int msg_open, (int minor_dev_nr) );
FORWARD _PROTOTYPE( int msg_close, (int minor_dev_nr) );
FORWARD _PROTOTYPE( int msg_ioctl, (message *m_ptr) );
FORWARD _PROTOTYPE( void msg_write, (message *m_ptr) );
FORWARD _PROTOTYPE( void msg_read, (message *m_ptr) );
FORWARD _PROTOTYPE( void msg_hardware, (void) );
FORWARD _PROTOTYPE( void msg_sig_stop, (void) );
FORWARD _PROTOTYPE( void msg_status, (message *m_ptr) );
FORWARD _PROTOTYPE( int init_driver, (void) );
FORWARD _PROTOTYPE( int open_sub_dev, (int sub_dev_nr, int operation) );
FORWARD _PROTOTYPE( int close_sub_dev, (int sub_dev_nr) );
FORWARD _PROTOTYPE( void handle_int_write,(int sub_dev_nr) );
FORWARD _PROTOTYPE( void handle_int_read,(int sub_dev_nr) );
FORWARD _PROTOTYPE( void data_to_user, (sub_dev_t *sub_dev_ptr) );
FORWARD _PROTOTYPE( void data_from_user, (sub_dev_t *sub_dev_ptr) );
FORWARD _PROTOTYPE( int init_buffers, (sub_dev_t *sub_dev_ptr) );
FORWARD _PROTOTYPE( int get_started, (sub_dev_t *sub_dev_ptr) );
FORWARD _PROTOTYPE( void reply,(int code, int replyee, int process,int status));
FORWARD _PROTOTYPE( int io_ctl_length, (int io_request) );
FORWARD _PROTOTYPE( special_file_t* get_special_file, (int minor_dev_nr) );


PRIVATE char io_ctl_buf[_IOCPARM_MASK];
PRIVATE int irq_hook_id = 0;	/* id of irq hook at the kernel */
PRIVATE int irq_hook_set = FALSE;
PRIVATE device_available = 0;/*todo*/


PUBLIC void main(void) 
{	
	int r, caller, proc_nr, chan;
	message mess;

	drv_init();

	/* Here is the main loop of the dma driver.  It waits for a message, 
	   carries it out, and sends a reply. */
	printf("%s up and running\n", drv.DriverName);

	while(1) {
		receive(ANY, &mess);
		caller = mess.m_source;
		proc_nr = mess.IO_ENDPT;


		/* Now carry out the work. */
		switch(mess.m_type) {
			case DEV_OPEN:		/* open the special file ( = parameter) */
				r = msg_open(mess.DEVICE);break;
			case DEV_CLOSE:		/* close the special file ( = parameter) */
				r = msg_close(mess.DEVICE); break;
			case DEV_IOCTL_S:		
				r = msg_ioctl(&mess); break; 
			case DEV_READ_S:		
				msg_read(&mess); continue; /* don't reply */
			case DEV_WRITE_S:		
				msg_write(&mess); continue; /* don't reply */
			case DEV_STATUS:	
				msg_status(&mess);continue; /* don't reply */
			case HARD_INT:
				msg_hardware();continue;  /* don't reply */
			case SYS_SIG:		  
				msg_sig_stop(); continue; /* don't reply */
			default:          
				r = EINVAL;	
				dprint("%s: %d uncaught msg!\n", drv.DriverName, mess.m_type);
				break;
		}
		/* Finally, prepare and send the reply message. */
		reply(TASK_REPLY, caller, proc_nr, r);
	}
}


PRIVATE int init_driver(void) {
	u32_t i; char irq;
	static int executed = 0;
	sub_dev_t* sub_dev_ptr;

	/* init variables, get dma buffers */
	for (i = 0; i < drv.NrOfSubDevices; i++) {

		sub_dev_ptr = &sub_dev[i];

		sub_dev_ptr->Opened = FALSE;
		sub_dev_ptr->DmaBusy = FALSE;
		sub_dev_ptr->DmaMode = NO_DMA;
		sub_dev_ptr->DmaReadNext = 0;
		sub_dev_ptr->DmaFillNext = 0;
		sub_dev_ptr->DmaLength = 0;
		sub_dev_ptr->BufReadNext = 0;
		sub_dev_ptr->BufFillNext = 0;
		sub_dev_ptr->RevivePending = FALSE;
		sub_dev_ptr->OutOfData = FALSE;
		sub_dev_ptr->Nr = i;
	}

	/* initialize hardware*/
	if (drv_init_hw() != OK) {
		error("%s: Could not initialize hardware\n", drv.DriverName, 0);
		return EIO;
	}

	/* get irq from device driver...*/
	if (drv_get_irq(&irq) != OK) {
		error("%s: init driver couldn't get IRQ", drv.DriverName, i);
		return EIO;
	}
	/* todo: execute the rest of this function only once 
	   we don't want to set irq policy twice */
	if (executed) return OK;
	executed = TRUE;

	/* ...and register interrupt vector */
	if ((i=sys_irqsetpolicy(irq, 0, &irq_hook_id )) != OK){
		error("%s: init driver couldn't set IRQ policy", drv.DriverName, i);
		return EIO;
	}
	irq_hook_set = TRUE; /* now msg_sig_stop knows it must unregister policy*/
	return OK;
}


PRIVATE int msg_open (int minor_dev_nr) {
	int r, read_chan, write_chan, io_ctl;
	special_file_t* special_file_ptr;

	dprint("%s: msg_open() special file %d\n", drv.DriverName, minor_dev_nr);

	special_file_ptr = get_special_file(minor_dev_nr);
	if(special_file_ptr == NULL) {
		return EIO;
	}

	read_chan = special_file_ptr->read_chan;
	write_chan = special_file_ptr->write_chan;
	io_ctl = special_file_ptr->io_ctl;

	if (read_chan==NO_CHANNEL && write_chan==NO_CHANNEL && io_ctl==NO_CHANNEL) {
		error("%s: No channel specified for minor device!\n", 
				drv.DriverName, minor_dev_nr);
		return EIO;
	}
	if (read_chan == write_chan && read_chan != NO_CHANNEL) {
		error("%s: Read and write channels are equal!\n", 
				drv.DriverName, minor_dev_nr);
		return EIO;
	}
	/* init driver */
	if (!device_available) {  
		if (init_driver() != OK) {
			error("%s: Couldn't init driver!\n", drv.DriverName, minor_dev_nr);
			return EIO;
		} else {
			device_available = TRUE;
		}
	}  
	/* open the sub devices specified in the interface header file */
	if (write_chan != NO_CHANNEL) {
		/* open sub device for writing */
		if (open_sub_dev(write_chan, DEV_WRITE_S) != OK) return EIO;
	}  
	if (read_chan != NO_CHANNEL) {
		if (open_sub_dev(read_chan, DEV_READ_S) != OK) return EIO;
	}
	if (read_chan == io_ctl || write_chan == io_ctl) {
		/* io_ctl is already opened because it's the same as read or write */
		return OK; /* we're done */
	}
	if (io_ctl != NO_CHANNEL) { /* Ioctl differs from read/write channels, */
		r = open_sub_dev(io_ctl, NO_DMA); /* open it explicitly */
		if (r != OK) return EIO;
	} 
	return OK;
}


PRIVATE int open_sub_dev(int sub_dev_nr, int dma_mode) {
	sub_dev_t* sub_dev_ptr; int i;
	sub_dev_ptr = &sub_dev[sub_dev_nr];

	/* Only one open at a time per sub device */
	if (sub_dev_ptr->Opened) { 
		error("%s: Sub device %d is already opened\n", 
				drv.DriverName, sub_dev_nr);
		return EBUSY;
	}
	if (sub_dev_ptr->DmaBusy) { 
		error("%s: Sub device %d is still busy\n", drv.DriverName, sub_dev_nr);
		return EBUSY;
	}
	/* Setup variables */
	sub_dev_ptr->Opened = TRUE;
	sub_dev_ptr->DmaReadNext = 0;
	sub_dev_ptr->DmaFillNext = 0;
	sub_dev_ptr->DmaLength = 0;
	sub_dev_ptr->DmaMode = dma_mode;
	sub_dev_ptr->BufReadNext = 0;
	sub_dev_ptr->BufFillNext = 0;
	sub_dev_ptr->BufLength = 0;
	sub_dev_ptr->RevivePending = FALSE;
	sub_dev_ptr->OutOfData = TRUE;

	/* arrange DMA */
	if (dma_mode != NO_DMA) { /* sub device uses DMA */
		/* allocate dma buffer and extra buffer space
		   and configure sub device for dma */
		if (init_buffers(sub_dev_ptr) != OK ) return EIO;
	}
	return OK;  
}


PRIVATE int msg_close(int minor_dev_nr) {

	int r, read_chan, write_chan, io_ctl; 
	special_file_t* special_file_ptr;

	dprint("%s: msg_close() minor device %d\n", drv.DriverName, minor_dev_nr);

	special_file_ptr = get_special_file(minor_dev_nr);
	if(special_file_ptr == NULL) {
		return EIO;
	}

	read_chan = special_file_ptr->read_chan;
	write_chan = special_file_ptr->write_chan;
	io_ctl = special_file_ptr->io_ctl;

	/* close all sub devices */
	if (write_chan != NO_CHANNEL) {
		if (close_sub_dev(write_chan) != OK) r = EIO;
	}  
	if (read_chan != NO_CHANNEL) {
		if (close_sub_dev(read_chan) != OK) r = EIO;
	}
	if (read_chan == io_ctl || write_chan == io_ctl) {
		/* io_ctl is already closed because it's the same as read or write */
		return r; /* we're done */
	}
	/* ioctl differs from read/write channels... */
	if (io_ctl != NO_CHANNEL) { 
		if (close_sub_dev(io_ctl) != OK) r = EIO; /* ...close it explicitly */
	} 
	return r;
}


PRIVATE int close_sub_dev(int sub_dev_nr) {
	sub_dev_t *sub_dev_ptr;
	sub_dev_ptr = &sub_dev[sub_dev_nr];
	if (sub_dev_ptr->DmaMode == DEV_WRITE_S && !sub_dev_ptr->OutOfData) {
		/* do nothing, still data in buffers that has to be transferred */
		sub_dev_ptr->Opened = FALSE;  /* keep DMA busy */
		return OK;
	}
	if (sub_dev_ptr->DmaMode == NO_DMA) {
		/* do nothing, there is no dma going on */
		sub_dev_ptr->Opened = FALSE;
		return OK;
	}
	sub_dev_ptr->Opened = FALSE;
	sub_dev_ptr->DmaBusy = FALSE;
	/* stop the device */
	drv_stop(sub_dev_ptr->Nr);
	/* free the buffers */
	free(sub_dev_ptr->DmaBuf);
	free(sub_dev_ptr->ExtraBuf);
}


PRIVATE int msg_ioctl(message *m_ptr)
{
	int status, len, chan;
	phys_bytes user_phys;
	sub_dev_t *sub_dev_ptr;
	special_file_t* special_file_ptr;

	dprint("%s: msg_ioctl() device %d\n", drv.DriverName, m_ptr->DEVICE);

	special_file_ptr = get_special_file(m_ptr->DEVICE);
	if(special_file_ptr == NULL) {
		return EIO;
	}

	chan = special_file_ptr->io_ctl;

	if (chan == NO_CHANNEL) {
		error("%s: No io control channel specified!\n", drv.DriverName);
		return EIO;
	}
	/* get pointer to sub device data */
	sub_dev_ptr = &sub_dev[chan];

	if(!sub_dev_ptr->Opened) {
		error("%s: io control impossible - not opened!\n", drv.DriverName);
		return EIO;
	}


	/* this is a hack...todo: may we intercept reset calls? */
	/*
	if(m_ptr->REQUEST == DSPIORESET) {
		device_available = FALSE;
	}
	*/


	if (m_ptr->REQUEST & _IOC_IN) { /* if there is data for us, copy it */
		len = io_ctl_length(m_ptr->REQUEST);

		if(sys_safecopyfrom(m_ptr->IO_ENDPT, 
					(vir_bytes)m_ptr->ADDRESS, 0,
					(vir_bytes)io_ctl_buf, len, D) != OK) {
			printf("%s:%d: safecopyfrom failed\n", __FILE__, __LINE__);
		}
	}

	/* all ioctl's are passed to the device specific part of the driver */
	status = drv_io_ctl(m_ptr->REQUEST, (void *)io_ctl_buf, &len, chan); 

	/* _IOC_OUT bit -> user expects data */
	if (status == OK && m_ptr->REQUEST & _IOC_OUT) { 
		/* copy result back to user */

		if(sys_safecopyto(m_ptr->IO_ENDPT, (vir_bytes)m_ptr->ADDRESS, 0, 
					(vir_bytes)io_ctl_buf, len, D) != OK) {
			printf("%s:%d: safecopyto failed\n", __FILE__, __LINE__);
		}

	}
	return status;
}


PRIVATE void msg_write(message *m_ptr) 
{
	int s, chan; sub_dev_t *sub_dev_ptr;
	special_file_t* special_file_ptr;

	dprint("%s: msg_write() device %d\n", drv.DriverName, m_ptr->DEVICE);

	special_file_ptr = get_special_file(m_ptr->DEVICE); 
	chan = special_file_ptr->write_chan;

	if (chan == NO_CHANNEL) {
		error("%s: No write channel specified!\n", drv.DriverName);
		reply(TASK_REPLY, m_ptr->m_source, m_ptr->IO_ENDPT, EIO);
		return;
	}
	/* get pointer to sub device data */
	sub_dev_ptr = &sub_dev[chan];

	if (!sub_dev_ptr->DmaBusy) { /* get fragment size on first write */
		if (drv_get_frag_size(&(sub_dev_ptr->FragSize), sub_dev_ptr->Nr) != OK){
			error("%s; Failed to get fragment size!\n", drv.DriverName, 0);
			return;	
		}
	}
	if(m_ptr->COUNT != sub_dev_ptr->FragSize) {
		error("Fragment size does not match user's buffer length\n");
		reply(TASK_REPLY, m_ptr->m_source, m_ptr->IO_ENDPT, EINVAL);		
		return;
	}
	/* if we are busy with something else than writing, return EBUSY */
	if(sub_dev_ptr->DmaBusy && sub_dev_ptr->DmaMode != DEV_WRITE_S) {
		error("Already busy with something else then writing\n");
		reply(TASK_REPLY, m_ptr->m_source, m_ptr->IO_ENDPT, EBUSY);
		return;
	}
	/* unblock the FileSystem, but keep user process blocked until REVIVE*/
	reply(TASK_REPLY, m_ptr->m_source, m_ptr->IO_ENDPT, SUSPEND);
	sub_dev_ptr->RevivePending = TRUE;
	sub_dev_ptr->ReviveProcNr = m_ptr->IO_ENDPT;
	sub_dev_ptr->ReviveGrant = (cp_grant_id_t) m_ptr->ADDRESS;
	sub_dev_ptr->NotifyProcNr = m_ptr->m_source;

	data_from_user(sub_dev_ptr);

	if(!sub_dev_ptr->DmaBusy) { /* Dma tranfer not yet started */
		dprint("starting audio device\n");
		get_started(sub_dev_ptr);    
		sub_dev_ptr->DmaMode = DEV_WRITE_S; /* Dma mode is writing */
	} 
}


PRIVATE void msg_read(message *m_ptr) 
{
	int s, chan; sub_dev_t *sub_dev_ptr;
	special_file_t* special_file_ptr;

	dprint("%s: msg_read() device %d\n", drv.DriverName, m_ptr->DEVICE);

	special_file_ptr = get_special_file(m_ptr->DEVICE);