Commit 7022781c authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: me4000: introduce me4000_ai_get_sample() 



The hardware returns two's complement values for the analog input
samples. These need to be converted to the unsigned binary format
that the comedi core expects. Introduce a helper function to handle
this.

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 36d59d70

drivers/staging/comedi/drivers/me4000.c

+13 −10
Original line number Diff line number Diff line
@@ -445,6 +445,16 @@ static void me4000_reset(struct comedi_device *dev) 
		outl(0x1, dev->iobase + ME4000_DIO_CTRL_REG);

}



static unsigned int me4000_ai_get_sample(struct comedi_device *dev,

					 struct comedi_subdevice *s)

{

	unsigned int val;



	/* read two's complement value and munge to offset binary */

	val = inl(dev->iobase + ME4000_AI_DATA_REG);

	return comedi_offset_munge(s, val);

}



static int me4000_ai_eoc(struct comedi_device *dev,

			 struct comedi_subdevice *s,

			 struct comedi_insn *insn,
@@ -515,8 +525,7 @@ static int me4000_ai_insn_read(struct comedi_device *dev, 
		if (ret)

			break;



		/* read two's complement value and munge to offset binary */

		val = inl(dev->iobase + ME4000_AI_DATA_REG);

		val = me4000_ai_get_sample(dev, s);

		data[i] = comedi_offset_munge(s, val);

	}
@@ -953,10 +962,7 @@ static irqreturn_t me4000_ai_isr(int irq, void *dev_id) 
		}



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

			/* Read value from data fifo */

			lval = inl(dev->iobase + ME4000_AI_DATA_REG) & 0xFFFF;

			lval ^= 0x8000;



			lval = me4000_ai_get_sample(dev, s);

			if (!comedi_buf_write_samples(s, &lval, 1))

				break;

		}
@@ -976,10 +982,7 @@ static irqreturn_t me4000_ai_isr(int irq, void *dev_id) 
		/* Poll data until fifo empty */

		while (inl(dev->iobase + ME4000_AI_STATUS_REG) &

		       ME4000_AI_STATUS_EF_DATA) {

			/* Read value from data fifo */

			lval = inl(dev->iobase + ME4000_AI_DATA_REG) & 0xFFFF;

			lval ^= 0x8000;



			lval = me4000_ai_get_sample(dev, s);

			if (!comedi_buf_write_samples(s, &lval, 1))

				break;

		}

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