From a7b31d3996a866408ebd6d16992d166b0207c7c1 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 10 Mar 2014 14:07:39 -0700 Subject: [PATCH] staging: comedi: c6xdigio: use comedi_offset_munge() The value read from the encoders is in two's complement format. Use the comedi_offset_munge() helper to convert the value to offset binary. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/c6xdigio.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/c6xdigio.c b/drivers/staging/comedi/drivers/c6xdigio.c index 3937e64..20a5dfe 100644 --- a/drivers/staging/comedi/drivers/c6xdigio.c +++ b/drivers/staging/comedi/drivers/c6xdigio.c @@ -153,7 +153,7 @@ static int c6xdigio_encoder_read(struct comedi_device *dev, c6xdigio_write_data(dev, 0x00, 0x80); - return val ^ 0x800000; + return val; } static int c6xdigio_pwm_insn_write(struct comedi_device *dev, @@ -177,12 +177,17 @@ static int c6xdigio_encoder_insn_read(struct comedi_device *dev, unsigned int *data) { unsigned int chan = CR_CHAN(insn->chanspec); - int n; + unsigned int val; + int i; - for (n = 0; n < insn->n; n++) - data[n] = (c6xdigio_encoder_read(dev, chan) & 0xffffff); + for (i = 0; i < insn->n; i++) { + val = c6xdigio_encoder_read(dev, chan); + + /* munge two's complement value to offset binary */ + data[i] = comedi_offset_munge(s, val); + } - return n; + return insn->n; } static void c6xdigio_init(struct comedi_device *dev) -- 2.7.4