skel.c

rtlinux-3.2-pre3.tar.bz2 rtlinux3.2-pre3的源代码

 * "instructions" read/write data in "one-shot" or "software-triggered"
 * mode.
 */
static int skel_ai_rinsn(comedi_device *dev,comedi_subdevice *s,comedi_insn *insn,lsampl_t *data)
{
	int n,i;
	unsigned int d;
	unsigned int status;

	/* a typical programming sequence */

	/* write channel to multiplexer */
	//outw(chan,dev->iobase + SKEL_MUX);

	/* don't wait for mux to settle */

	/* convert n samples */
	for(n=0;n<insn->n;n++){
		/* trigger conversion */
		//outw(0,dev->iobase + SKEL_CONVERT);

#define TIMEOUT 100
		/* wait for conversion to end */
		for(i=0;i<TIMEOUT;i++){
			status = 1;
			//status = inb(dev->iobase + SKEL_STATUS);
			if(status)break;
		}
		if(i==TIMEOUT){
			/* rt_printk() should be used instead of printk()
			 * whenever the code can be called from real-time. */
			rt_printk("timeout\n");
			return -ETIMEDOUT;
		}

		/* read data */
		//d = inw(dev->iobase + SKEL_AI_DATA);
		d = 0;

		/* mangle the data as necessary */
		d ^= 1<<(thisboard->ai_bits-1);

		data[n] = d;
	}

	/* return the number of samples read/written */
	return n;
}

static int skel_ai_cmdtest(comedi_device *dev,comedi_subdevice *s,
	comedi_cmd *cmd)
{
	int err=0;
	int tmp;

	/* cmdtest tests a particular command to see if it is valid.
	 * Using the cmdtest ioctl, a user can create a valid cmd
	 * and then have it executes by the cmd ioctl.
	 *
	 * cmdtest returns 1,2,3,4 or 0, depending on which tests
	 * the command passes. */

	/* step 1: make sure trigger sources are trivially valid */

	tmp=cmd->start_src;
	cmd->start_src &= TRIG_NOW;
	if(!cmd->start_src || tmp!=cmd->start_src)err++;

	tmp=cmd->scan_begin_src;
	cmd->scan_begin_src &= TRIG_TIMER|TRIG_EXT;
	if(!cmd->scan_begin_src || tmp!=cmd->scan_begin_src)err++;

	tmp=cmd->convert_src;
	cmd->convert_src &= TRIG_TIMER|TRIG_EXT;
	if(!cmd->convert_src || tmp!=cmd->convert_src)err++;

	tmp=cmd->scan_end_src;
	cmd->scan_end_src &= TRIG_COUNT;
	if(!cmd->scan_end_src || tmp!=cmd->scan_end_src)err++;

	tmp=cmd->stop_src;
	cmd->stop_src &= TRIG_COUNT|TRIG_NONE;
	if(!cmd->stop_src || tmp!=cmd->stop_src)err++;

	if(err)return 1;

	/* step 2: make sure trigger sources are unique and mutually compatible */

	/* note that mutual compatiblity is not an issue here */
	if(cmd->scan_begin_src!=TRIG_TIMER &&
	   cmd->scan_begin_src!=TRIG_EXT)err++;
	if(cmd->convert_src!=TRIG_TIMER &&
	   cmd->convert_src!=TRIG_EXT)err++;
	if(cmd->stop_src!=TRIG_COUNT &&
	   cmd->stop_src!=TRIG_NONE)err++;

	if(err)return 2;

	/* step 3: make sure arguments are trivially compatible */

	if(cmd->start_arg!=0){
		cmd->start_arg=0;
		err++;
	}

#define MAX_SPEED	10000		/* in nanoseconds */
#define MIN_SPEED	1000000000	/* in nanoseconds */

	if(cmd->scan_begin_src==TRIG_TIMER){
		if(cmd->scan_begin_arg<MAX_SPEED){
			cmd->scan_begin_arg=MAX_SPEED;
			err++;
		}
		if(cmd->scan_begin_arg>MIN_SPEED){
			cmd->scan_begin_arg=MIN_SPEED;
			err++;
		}
	}else{
		/* external trigger */
		/* should be level/edge, hi/lo specification here */
		/* should specify multiple external triggers */
		if(cmd->scan_begin_arg>9){
			cmd->scan_begin_arg=9;
			err++;
		}
	}
	if(cmd->convert_src==TRIG_TIMER){
		if(cmd->convert_arg<MAX_SPEED){
			cmd->convert_arg=MAX_SPEED;
			err++;
		}
		if(cmd->convert_arg>MIN_SPEED){
			cmd->convert_arg=MIN_SPEED;
			err++;
		}
	}else{
		/* external trigger */
		/* see above */
		if(cmd->convert_arg>9){
			cmd->convert_arg=9;
			err++;
		}
	}

	if(cmd->scan_end_arg!=cmd->chanlist_len){
		cmd->scan_end_arg=cmd->chanlist_len;
		err++;
	}
	if(cmd->stop_src==TRIG_COUNT){
		if(cmd->stop_arg>0x00ffffff){
			cmd->stop_arg=0x00ffffff;
			err++;
		}
	}else{
		/* TRIG_NONE */
		if(cmd->stop_arg!=0){
			cmd->stop_arg=0;
			err++;
		}
	}

	if(err)return 3;

	/* step 4: fix up any arguments */

	if(cmd->scan_begin_src==TRIG_TIMER){
		tmp=cmd->scan_begin_arg;
		skel_ns_to_timer(&cmd->scan_begin_arg,cmd->flags&TRIG_ROUND_MASK);
		if(tmp!=cmd->scan_begin_arg)err++;
	}
	if(cmd->convert_src==TRIG_TIMER){
		tmp=cmd->convert_arg;
		skel_ns_to_timer(&cmd->convert_arg,cmd->flags&TRIG_ROUND_MASK);
		if(tmp!=cmd->convert_arg)err++;
		if(cmd->scan_begin_src==TRIG_TIMER &&
		  cmd->scan_begin_arg<cmd->convert_arg*cmd->scan_end_arg){
			cmd->scan_begin_arg=cmd->convert_arg*cmd->scan_end_arg;
			err++;
		}
	}

	if(err)return 4;

	return 0;
}

/* This function doesn't require a particular form, this is just
 * what happens to be used in some of the drivers.  It should
 * convert ns nanoseconds to a counter value suitable for programming
 * the device.  Also, it should adjust ns so that it cooresponds to
 * the actual time that the device will use. */
static int skel_ns_to_timer(unsigned int *ns,int round)
{
	/* trivial timer */
	/* if your timing is done through two cascaded timers, the
	 * i8253_cascade_ns_to_timer() function in 8253.h can be
	 * very helpful.  There are also i8254_load() and i8254_mm_load()
	 * which can be used to load values into the ubiquitous 8254 counters
	 */

	return *ns;
}


static int skel_ao_winsn(comedi_device *dev,comedi_subdevice *s,comedi_insn *insn,lsampl_t *data)
{
	int i;
	int chan = CR_CHAN(insn->chanspec);

printk("skel_ao_winsn\n");
	/* Writing a list of values to an AO channel is probably not
	 * very useful, but that's how the interface is defined. */
	for(i=0;i<insn->n;i++){
		/* a typical programming sequence */
		//outw(data[i],dev->iobase + SKEL_DA0 + chan);
		devpriv->ao_readback[chan] = data[i];
	}

	/* return the number of samples read/written */
	return i;
}

/* AO subdevices should have a read insn as well as a write insn.
 * Usually this means copying a value stored in devpriv. */
static int skel_ao_rinsn(comedi_device *dev,comedi_subdevice *s,comedi_insn *insn,lsampl_t *data)
{
	int i;
	int chan = CR_CHAN(insn->chanspec);

	for(i=0;i<insn->n;i++)
		data[i] = devpriv->ao_readback[chan];

	return i;
}

/* DIO devices are slightly special.  Although it is possible to
 * implement the insn_read/insn_write interface, it is much more
 * useful to applications if you implement the insn_bits interface.
 * This allows packed reading/writing of the DIO channels.  The
 * comedi core can convert between insn_bits and insn_read/write */
static int skel_dio_insn_bits(comedi_device *dev,comedi_subdevice *s,
	comedi_insn *insn,lsampl_t *data)
{
	if(insn->n!=2)return -EINVAL;

	/* The insn data is a mask in data[0] and the new data
	 * in data[1], each channel cooresponding to a bit. */
	if(data[0]){
		s->state &= ~data[0];
		s->state |= data[0]&data[1];
		/* Write out the new digital output lines */
		//outw(s->state,dev->iobase + SKEL_DIO);
	}

	/* on return, data[1] contains the value of the digital
	 * input and output lines. */
	//data[1]=inw(dev->iobase + SKEL_DIO);
	/* or we could just return the software copy of the output values if
	 * it was a purely digital output subdevice */
	//data[1]=s->state;

	return 2;
}

static int skel_dio_insn_config(comedi_device *dev,comedi_subdevice *s,
	comedi_insn *insn,lsampl_t *data)
{
	int chan=CR_CHAN(insn->chanspec);

	if(insn->n!=1)return -EINVAL;

	/* The input or output configuration of each digital line is
	 * configured by a special insn_config instruction.  chanspec
	 * contains the channel to be changed, and data[0] contains the
	 * value COMEDI_INPUT or COMEDI_OUTPUT. */

	if(data[0]==COMEDI_OUTPUT){
		s->io_bits |= 1<<chan;
	}else{
		s->io_bits &= ~(1<<chan);
	}
	//outw(s->io_bits,dev->iobase + SKEL_DIO_CONFIG);

	return 1;
}

/*
 * A convenient macro that defines init_module() and cleanup_module(),
 * as necessary.
 */
COMEDI_INITCLEANUP(driver_skel);