Commit 89e9057b authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: addi_apci_3120: fix apci3120_ai_insn_read() 



Now that the scanning and interrupt support have been removed from this
function it can be refactored to work correctly.

The comedi core expects (*insn_read) functions to read insn->n values
from the hardware and return the number of samples read. This function
currently just reads one sample but it returns insn->n.

Fix this function to work like the core expects.

Use comedi_timeout() to prevent a possible deadlock in the loop that
waits for the end-of-conversion.

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 22f75dac

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

+40 −50
Original line number Diff line number Diff line
@@ -139,6 +139,19 @@ static int apci3120_setup_chan_list(struct comedi_device *dev, 
	return 1;		/*  we can serve this with scan logic */

}



static int apci3120_ai_eoc(struct comedi_device *dev,

			   struct comedi_subdevice *s,

			   struct comedi_insn *insn,

			   unsigned long context)

{

	unsigned int status;



	status = inw(dev->iobase + APCI3120_RD_STATUS);

	if ((status & APCI3120_EOC) == 0)

		return 0;

	return -EBUSY;

}



static int apci3120_ai_insn_read(struct comedi_device *dev,

				 struct comedi_subdevice *s,

				 struct comedi_insn *insn,
@@ -146,67 +159,44 @@ static int apci3120_ai_insn_read(struct comedi_device *dev, 
{

	struct apci3120_private *devpriv = dev->private;

	unsigned int divisor;

	unsigned int ns;

	unsigned short us_TmpValue;



	/*  fix conversion time to 10 us */

	ns = 10000;



	/*  Clear software registers */

	devpriv->timer_mode = 0;

	devpriv->mode = 0;



	if (insn->unused[0] == 222) {	/*  second insn read */

	} else {

		devpriv->tsk_Current = current;	/*  Save the current process task structure */



		divisor = apci3120_ns_to_timer(dev, 0, ns, CMDF_ROUND_NEAREST);



		us_TmpValue = (unsigned short) devpriv->b_InterruptMode;



		switch (us_TmpValue) {

	int ret;

	int i;



		case APCI3120_EOC_MODE:

			apci3120_ai_reset_fifo(dev);

	/* set mode for A/D conversions by software trigger with timer 0 */

	devpriv->mode = APCI3120_MODE_TIMER2_CLK_OSC |

			APCI3120_MODE_TIMER2_AS_TIMER;

	outb(devpriv->mode, dev->iobase + APCI3120_MODE_REG);



			/*  Initialize the sequence array */

			if (!apci3120_setup_chan_list(dev, s, 1,

					&insn->chanspec))

	/* load chanlist for single channel scan */

	if (!apci3120_setup_chan_list(dev, s, 1, &insn->chanspec))

		return -EINVAL;



			/* Initialize Timer 0 mode 4 */

	/*

	 * Timer 0 is used in MODE4 (software triggered strobe) to set the

	 * conversion time for each acquisition. Each conversion is triggered

	 * when the divisor is written to the timer, The conversion is done

	 * when the EOC bit in the status register is '0'.

	 */

	apci3120_timer_set_mode(dev, 0, APCI3120_TIMER_MODE4);



			outb(devpriv->mode, dev->iobase + APCI3120_MODE_REG);



	apci3120_timer_enable(dev, 0, true);



			/* Set the conversion time */

			apci3120_timer_write(dev, 0, divisor);



			us_TmpValue =

				(unsigned short) inw(dev->iobase + APCI3120_RD_STATUS);

	/* fixed conversion time of 10 us */

	divisor = apci3120_ns_to_timer(dev, 0, 10000, CMDF_ROUND_NEAREST);



			do {

				/*  Waiting for the end of conversion */

				us_TmpValue = inw(dev->iobase +

						  APCI3120_RD_STATUS);

			} while ((us_TmpValue & APCI3120_EOC) == APCI3120_EOC);

	apci3120_ai_reset_fifo(dev);



			/* Read the result in FIFO  and put it in insn data pointer */

			us_TmpValue = inw(dev->iobase + 0);

			*data = us_TmpValue;

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

		/* trigger conversion */

		apci3120_timer_write(dev, 0, divisor);



			apci3120_ai_reset_fifo(dev);

			break;

		default:

			dev_err(dev->class_dev, "inputs wrong\n");

		ret = comedi_timeout(dev, s, insn, apci3120_ai_eoc, 0);

		if (ret)

			return ret;



		}

		data[i] = inw(dev->iobase + 0);

	}



	return insn->n;



}



static int apci3120_reset(struct comedi_device *dev)