Commit e25e22b0 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: adv_pci1724: use comedi_timeout() to wait for DAC idle state 



Use the comedi_timeout() helper to wait for the DAC to be idle before
writing to it.

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 dcbd4ed8

drivers/staging/comedi/drivers/adv_pci1724.c

+13 −20
Original line number Diff line number Diff line
@@ -53,7 +53,6 @@ supported PCI devices are configured as comedi devices automatically. 
*/



#include <linux/module.h>

#include <linux/delay.h>

#include <linux/pci.h>



#include "../comedidev.h"
@@ -123,34 +122,24 @@ static const struct comedi_lrange ao_ranges_1724 = { 
	}

};



static int wait_for_dac_idle(struct comedi_device *dev)

static int adv_pci1724_dac_idle(struct comedi_device *dev,

				struct comedi_subdevice *s,

				struct comedi_insn *insn,

				unsigned long context)

{

	static const int timeout = 10000;

	int i;

	unsigned int status;



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

		if ((inl(dev->iobase + SYNC_OUTPUT_REG) & DAC_BUSY) == 0)

			break;

		udelay(1);

	}

	if (i == timeout) {

		dev_err(dev->class_dev,

			"Timed out waiting for dac to become idle\n");

		return -EIO;

	}

	status = inl(dev->iobase + SYNC_OUTPUT_REG);

	if ((status & DAC_BUSY) == 0)

		return 0;

	return -EBUSY;

}



static int set_dac(struct comedi_device *dev, unsigned mode, unsigned channel,

		   unsigned data)

{

	int retval;

	unsigned control_bits;



	retval = wait_for_dac_idle(dev);

	if (retval < 0)

		return retval;



	control_bits = mode;

	control_bits |= dac_channel_and_group_select_bits(channel);

	control_bits |= dac_data_bits(data);
@@ -174,6 +163,10 @@ static int adv_pci1724_insn_write(struct comedi_device *dev, 
	for (i = 0; i < insn->n; ++i) {

		unsigned int val = data[i];



		ret = comedi_timeout(dev, s, insn, adv_pci1724_dac_idle, 0);

		if (ret)

			return ret;



		ret = set_dac(dev, mode, chan, val);

		if (ret < 0)

			return ret;