Commit 59706334 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: mf6x4: A/D converter uses 2's complement coding 



According to the user's manual, the A/D converter uses 2's complement
coding. Use the comedi_offset_munge() helper to convert the data to
the offset binary format used by comedi.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
 drivers/staging/comedi/drivers/mf6x4.c | 5 ++---
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c9ab3023

drivers/staging/comedi/drivers/mf6x4.c

+5 −4
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ 
#define MF6X4_GPIOC_DACEN	BIT(26)



/* BAR1 registers */

#define MF6X4_ADDATA_R		0x00

#define MF6X4_ADDATA_REG	0x00

#define MF6X4_ADCTRL_REG	0x00

#define MF6X4_ADCTRL_CHAN(x)	BIT(chan)

#define MF6X4_DIN_R		0x10
@@ -134,9 +134,9 @@ static int mf6x4_ai_insn_read(struct comedi_device *dev, 
			      unsigned int *data)

{

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

	unsigned int d;

	int ret;

	int i;

	int d;



	/* Set the ADC channel number in the scan list */

	iowrite16(MF6X4_ADCTRL_CHAN(chan), dev->mmio + MF6X4_ADCTRL_REG);
@@ -150,9 +150,10 @@ static int mf6x4_ai_insn_read(struct comedi_device *dev, 
			return ret;



		/* Read the actual value */

		d = ioread16(dev->mmio + MF6X4_ADDATA_R);

		d = ioread16(dev->mmio + MF6X4_ADDATA_REG);

		d &= s->maxdata;

		data[i] = d;

		/* munge the 2's complement data to offset binary */

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

	}



	iowrite16(0x0, dev->mmio + MF6X4_ADCTRL_REG);

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