Commit 5081162d 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 'gain_value' 



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

The private data is now unnecessary. Remove it and the allocation.

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 38020b55

drivers/staging/comedi/drivers/adv_pci1724.c

+6 −40
Original line number Diff line number Diff line
@@ -125,11 +125,6 @@ static const struct comedi_lrange ao_ranges_1724 = { 
	}

};



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

struct adv_pci1724_private {

	int gain_value[NUM_AO_CHANNELS];

};



static int wait_for_dac_idle(struct comedi_device *dev)

{

	static const int timeout = 10000;
@@ -209,7 +204,6 @@ static int gain_write_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 retval;

	int i;
@@ -221,27 +215,8 @@ static int gain_write_insn(struct comedi_device *dev, 
		retval = set_dac(dev, DAC_GAIN_MODE, channel, data[i]);

		if (retval < 0)

			return retval;

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

	}



	return insn->n;

}



static int gain_read_insn(struct comedi_device *dev,

			  struct comedi_subdevice *s, struct comedi_insn *insn,

			  unsigned int *data)

{

	struct adv_pci1724_private *devpriv = dev->private;

	unsigned int channel = CR_CHAN(insn->chanspec);

	int i;



	if (devpriv->gain_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->gain_value[channel];



	return insn->n;

}
@@ -287,9 +262,12 @@ static int setup_subdevices(struct comedi_device *dev) 
	s->type = COMEDI_SUBD_CALIB;

	s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL;

	s->n_chan = NUM_AO_CHANNELS;

	s->insn_read = gain_read_insn;

	s->insn_write = gain_write_insn;

	s->maxdata = 0x3fff;

	s->insn_write = gain_write_insn;



	ret = comedi_alloc_subdev_readback(s);

	if (ret)

		return ret;



	return 0;

}
@@ -298,21 +276,9 @@ static int adv_pci1724_auto_attach(struct comedi_device *dev, 
				   unsigned long context_unused)

{

	struct pci_dev *pcidev = comedi_to_pci_dev(dev);

	struct adv_pci1724_private *devpriv;

	int i;

	int retval;

	unsigned int board_id;



	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));

	if (!devpriv)

		return -ENOMEM;



	/* 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->gain_value[i] = -1;

	}



	retval = comedi_pci_enable(dev);

	if (retval)

		return retval;