From e42151f945f7b45e6a1634fc3b665b36f5e42a03 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Thu, 20 Nov 2014 15:07:29 -0700 Subject: [PATCH] staging: comedi: cb_pcidas: use subdevice readback for 'dac08_value' Use the comedi_subdevice 'readback' member and the core provided (*insn_read) to handle the readback of the write-only dac08 calib subdevice. Remove the then unused 'dac08_value' member from the private data. The dac08 calib subdevice only has one channel. For consistency in the driver, modify the subdevice init so that a loop is used to initialize the channels and readback values. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/cb_pcidas.c | 32 +++++++++------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c index 04b6d39d1051..669b1703eb99 100644 --- a/drivers/staging/comedi/drivers/cb_pcidas.c +++ b/drivers/staging/comedi/drivers/cb_pcidas.c @@ -356,7 +356,6 @@ struct cb_pcidas_private { /* divisors of master clock for analog output pacing */ unsigned int ao_divisor1; unsigned int ao_divisor2; - unsigned int dac08_value; unsigned int calibration_source; }; @@ -650,31 +649,20 @@ static int cb_pcidas_dac08_insn_write(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - struct cb_pcidas_private *devpriv = dev->private; + unsigned int chan = CR_CHAN(insn->chanspec); if (insn->n) { unsigned int val = data[insn->n - 1]; - if (devpriv->dac08_value != val) { + if (s->readback[chan] != val) { dac08_write(dev, val); - devpriv->dac08_value = val; + s->readback[chan] = val; } } return insn->n; } -static int dac08_read_insn(struct comedi_device *dev, - struct comedi_subdevice *s, struct comedi_insn *insn, - unsigned int *data) -{ - struct cb_pcidas_private *devpriv = dev->private; - - data[0] = devpriv->dac08_value; - - return 1; -} - static int trimpot_7376_write(struct comedi_device *dev, uint8_t value) { struct cb_pcidas_private *devpriv = dev->private; @@ -1531,11 +1519,17 @@ static int cb_pcidas_auto_attach(struct comedi_device *dev, s->type = COMEDI_SUBD_CALIB; s->subdev_flags = SDF_READABLE | SDF_WRITABLE | SDF_INTERNAL; s->n_chan = NUM_CHANNELS_DAC08; - s->insn_read = dac08_read_insn; - s->insn_write = cb_pcidas_dac08_insn_write; s->maxdata = 0xff; - dac08_write(dev, s->maxdata / 2); - devpriv->dac08_value = s->maxdata / 2; + s->insn_write = cb_pcidas_dac08_insn_write; + + ret = comedi_alloc_subdev_readback(s); + if (ret) + return ret; + + for (i = 0; i < s->n_chan; i++) { + dac08_write(dev, s->maxdata / 2); + s->readback[i] = s->maxdata / 2; + } } else s->type = COMEDI_SUBD_UNUSED; -- 2.34.1