Commit fe1184e4 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: cb_pcidas64: use subdevice readback for 'ad8402_state' 



Use the comedi_subdevice 'readback' member and the core provided (*insn_read)
to handle the readback of the write-only calibration subdevice. Remove the
then unused 'ad8402_state' 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 5e2de5e7

drivers/staging/comedi/drivers/cb_pcidas64.c

+11 −22
Original line number Diff line number Diff line
@@ -1105,8 +1105,6 @@ struct pcidas64_private { 
	uint8_t i2c_cal_range_bits;

	/*  configure digital triggers to trigger on falling edge */

	unsigned int ext_trig_falling;

	/*  states of various devices stored to enable read-back */

	unsigned int ad8402_state[2];

	short ai_cmd_running;

	unsigned int ai_fifo_segment_length;

	struct ext_clock_info ext_clock;
@@ -3595,8 +3593,6 @@ static void ad8402_write(struct comedi_device *dev, unsigned int channel, 
	unsigned int bitstream = ((channel & 0x3) << 8) | (value & 0xff);

	static const int ad8402_udelay = 1;



	devpriv->ad8402_state[channel] = value;



	register_bits = SELECT_8402_64XX_BIT;

	udelay(ad8402_udelay);

	writew(register_bits, devpriv->main_iobase + CALIBRATION_REG);
@@ -3622,33 +3618,20 @@ static int ad8402_write_insn(struct comedi_device *dev, 
			     struct comedi_subdevice *s,

			     struct comedi_insn *insn, unsigned int *data)

{

	struct pcidas64_private *devpriv = dev->private;

	int channel = CR_CHAN(insn->chanspec);



	/* return immediately if setting hasn't changed, since

	 * programming these things is slow */

	if (devpriv->ad8402_state[channel] == data[0])

	if (s->readback[channel] == data[0])

		return 1;



	devpriv->ad8402_state[channel] = data[0];

	s->readback[channel] = data[0];



	ad8402_write(dev, channel, data[0]);



	return 1;

}



static int ad8402_read_insn(struct comedi_device *dev,

			    struct comedi_subdevice *s,

			    struct comedi_insn *insn, unsigned int *data)

{

	struct pcidas64_private *devpriv = dev->private;

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



	data[0] = devpriv->ad8402_state[channel];



	return 1;

}



static uint16_t read_eeprom(struct comedi_device *dev, uint8_t address)

{

	struct pcidas64_private *devpriv = dev->private;
@@ -3871,11 +3854,17 @@ 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 = 2;

		s->insn_read = ad8402_read_insn;

		s->insn_write = ad8402_write_insn;

		s->maxdata = 0xff;

		for (i = 0; i < s->n_chan; i++)

		s->insn_write = ad8402_write_insn;



		ret = comedi_alloc_subdev_readback(s);

		if (ret)

			return ret;



		for (i = 0; i < s->n_chan; i++) {

			ad8402_write(dev, i, s->maxdata / 2);

			s->readback[i] = s->maxdata / 2;

		}

	} else

		s->type = COMEDI_SUBD_UNUSED;