Commit 388674e0 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: adv_pci1724: use subdevice readback for 'ao_value' 



Use the comedi_subdevice 'readback' member and the core provided (*insn_read)
to handle the readback of the write-only analog output subdevice. Remove the
then unused 'ao_value' member from the private data.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 864b52c4

drivers/staging/comedi/drivers/adv_pci1724.c

+5 −24
Original line number Diff line number Diff line
@@ -127,7 +127,6 @@ static const struct comedi_lrange ao_ranges_1724 = { 


/* this structure is for data unique to this hardware driver. */

struct adv_pci1724_private {

	int ao_value[NUM_AO_CHANNELS];

	int offset_value[NUM_AO_CHANNELS];

	int gain_value[NUM_AO_CHANNELS];

};
@@ -170,7 +169,6 @@ static int set_dac(struct comedi_device *dev, unsigned mode, unsigned channel, 
static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s,

		    struct comedi_insn *insn, unsigned int *data)

{

	struct adv_pci1724_private *devpriv = dev->private;

	int channel = CR_CHAN(insn->chanspec);

	int retval;

	int i;
@@ -182,27 +180,8 @@ static int ao_winsn(struct comedi_device *dev, struct comedi_subdevice *s, 
		retval = set_dac(dev, DAC_NORMAL_MODE, channel, data[i]);

		if (retval < 0)

			return retval;

		devpriv->ao_value[channel] = data[i];

	}

	return insn->n;

}



static int ao_readback_insn(struct comedi_device *dev,

			    struct comedi_subdevice *s,

			    struct comedi_insn *insn, unsigned int *data)

{

	struct adv_pci1724_private *devpriv = dev->private;

	int channel = CR_CHAN(insn->chanspec);

	int i;



	if (devpriv->ao_value[channel] < 0) {

		dev_err(dev->class_dev,

			"Cannot read back channels which have not yet been written to\n");

		return -EIO;

		s->readback[channel] = data[i];

	}

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

		data[i] = devpriv->ao_value[channel];



	return insn->n;

}
@@ -306,9 +285,12 @@ static int setup_subdevices(struct comedi_device *dev) 
	s->n_chan = NUM_AO_CHANNELS;

	s->maxdata = 0x3fff;

	s->range_table = &ao_ranges_1724;

	s->insn_read = ao_readback_insn;

	s->insn_write = ao_winsn;



	ret = comedi_alloc_subdev_readback(s);

	if (ret)

		return ret;



	/* offset calibration */

	s = &dev->subdevices[1];

	s->type = COMEDI_SUBD_CALIB;
@@ -346,7 +328,6 @@ static int adv_pci1724_auto_attach(struct comedi_device *dev, 
	/* init software copies of output values to indicate we don't know

	 * what the output value is since it has never been written. */

	for (i = 0; i < NUM_AO_CHANNELS; ++i) {

		devpriv->ao_value[i] = -1;

		devpriv->offset_value[i] = -1;

		devpriv->gain_value[i] = -1;

	}