Commit f0ba1d6e authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

staging: comedi: das08: Support read-back of AO subdevice 



Stash the last value written to each AO channel in private data and
support the INSN_READ instruction to read it back.  Don't bother setting
the SDF_READABLE subdevice flag though as the hardware isn't really
readable - we're just faking it.

Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8432eb35

drivers/staging/comedi/drivers/das08.c

+19 −1
Original line number Diff line number Diff line
@@ -373,6 +373,7 @@ static void das08_ao_set_data(struct comedi_device *dev, 
			      unsigned int chan, unsigned int data)

{

	const struct das08_board_struct *thisboard = comedi_board(dev);

	struct das08_private_struct *devpriv = dev->private;

	unsigned char lsb;

	unsigned char msb;
@@ -389,6 +390,7 @@ static void das08_ao_set_data(struct comedi_device *dev, 
		/* load DACs */

		inb(dev->iobase + DAS08AO_AO_UPDATE);

	}

	devpriv->ao_readback[chan] = data;

}



static void das08_ao_initialize(struct comedi_device *dev,
@@ -417,6 +419,22 @@ static int das08_ao_winsn(struct comedi_device *dev, 
	return n;

}



static int das08_ao_rinsn(struct comedi_device *dev,

			  struct comedi_subdevice *s,

			  struct comedi_insn *insn, unsigned int *data)

{

	struct das08_private_struct *devpriv = dev->private;

	unsigned int n;

	unsigned int chan;



	chan = CR_CHAN(insn->chanspec);



	for (n = 0; n < insn->n; n++)

		data[n] = devpriv->ao_readback[chan];



	return n;

}



static void i8254_initialize(struct comedi_device *dev)

{

	const struct das08_board_struct *thisboard = comedi_board(dev);
@@ -670,12 +688,12 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase) 
	/* ao */

	if (thisboard->ao_nbits) {

		s->type = COMEDI_SUBD_AO;

/* XXX lacks read-back insn */

		s->subdev_flags = SDF_WRITABLE;

		s->n_chan = 2;

		s->maxdata = (1 << thisboard->ao_nbits) - 1;

		s->range_table = &range_bipolar5;

		s->insn_write = das08_ao_winsn;

		s->insn_read = das08_ao_rinsn;

		das08_ao_initialize(dev, s);

	} else {

		s->type = COMEDI_SUBD_UNUSED;

drivers/staging/comedi/drivers/das08.h

+1 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ struct das08_private_struct { 
	unsigned int do_bits;	/*  bits for do register on boards with register dedicated to digital out only */

	const unsigned int *pg_gainlist;

	struct pci_dev *pdev;	/*  struct for pci-das08 */

	unsigned int ao_readback[2];	/* assume 2 AO channels */

};



int das08_common_attach(struct comedi_device *dev, unsigned long iobase);