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Commit 3170b256 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: pcmad: fix analog input data on pcmad12 



According to the PCM-A/D-12/16 Operations Manual:

NOTE: On the PCM-A/D-12 the lower nibble of the hex value will always be 0.

Fix the pcmad_ai_insn_read() function to properly handle this by shifting
the data after it has been read.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7ecc5370

drivers/staging/comedi/drivers/pcmad.c

+4 −0
Original line number Original line Diff line number Diff line
@@ -104,6 +104,10 @@ static int pcmad_ai_insn_read(struct comedi_device *dev, 
		val = inb(dev->iobase + PCMAD_LSB) |

		val = inb(dev->iobase + PCMAD_LSB) |

		      (inb(dev->iobase + PCMAD_MSB) << 8);

		      (inb(dev->iobase + PCMAD_MSB) << 8);





		/* data is shifted on the pcmad12, fix it */

		if (s->maxdata == 0x0fff)

			val >>= 4;



		if (pcmad_range_is_bipolar(s, range)) {

		if (pcmad_range_is_bipolar(s, range)) {

			/* munge the two's complement value */

			/* munge the two's complement value */

			val ^= ((s->maxdata + 1) >> 1);

			val ^= ((s->maxdata + 1) >> 1);