From f8990d088c226b58c26a918c7de03006a3b1ab3c Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Thu, 20 Nov 2014 15:07:30 -0700 Subject: [PATCH] staging: comedi: ni_at_ao: use subdevice readback for 'caldac' Use the comedi_subdevice 'readback' member and the core provided (*insn_read) to handle the readback of the write-only caldac subdevice. Remove the then unused 'caldac' member from the private data. Tidy up atao_calib_insn_write(). Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ni_at_ao.c | 55 +++++++++-------------- 1 file changed, 21 insertions(+), 34 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_at_ao.c b/drivers/staging/comedi/drivers/ni_at_ao.c index 5fb40cd13b4d..05370a4a74a5 100644 --- a/drivers/staging/comedi/drivers/ni_at_ao.c +++ b/drivers/staging/comedi/drivers/ni_at_ao.c @@ -244,47 +244,31 @@ static int atao_calib_insn_write(struct comedi_device *dev, struct comedi_insn *insn, unsigned int *data) { - struct atao_private *devpriv = dev->private; unsigned int chan = CR_CHAN(insn->chanspec); - unsigned int bitstring; - unsigned int val; - int bit; - if (insn->n == 0) - return 0; + if (insn->n) { + unsigned int val = data[insn->n - 1]; + unsigned int bitstring = ((chan & 0x7) << 8) | val; + unsigned int bits; + int bit; - devpriv->caldac[chan] = data[insn->n - 1] & s->maxdata; + /* write the channel and last data value to the caldac */ + /* clock the bitstring to the caldac; MSB -> LSB */ + for (bit = 1 << 10; bit; bit >>= 1) { + bits = (bit & bitstring) ? ATAO_CFG2_SDATA : 0; - /* write the channel and last data value to the caldac */ - bitstring = ((chan & 0x7) << 8) | devpriv->caldac[chan]; + outw(bits, dev->iobase + ATAO_CFG2_REG); + outw(bits | ATAO_CFG2_SCLK, + dev->iobase + ATAO_CFG2_REG); + } - /* clock the bitstring to the caldac; MSB -> LSB */ - for (bit = 1 << 10; bit; bit >>= 1) { - val = (bit & bitstring) ? ATAO_CFG2_SDATA : 0; + /* strobe the caldac to load the value */ + outw(ATAO_CFG2_CALLD(chan), dev->iobase + ATAO_CFG2_REG); + outw(ATAO_CFG2_CALLD_NOP, dev->iobase + ATAO_CFG2_REG); - outw(val, dev->iobase + ATAO_CFG2_REG); - outw(val | ATAO_CFG2_SCLK, dev->iobase + ATAO_CFG2_REG); + s->readback[chan] = val; } - /* strobe the caldac to load the value */ - outw(ATAO_CFG2_CALLD(chan), dev->iobase + ATAO_CFG2_REG); - outw(ATAO_CFG2_CALLD_NOP, dev->iobase + ATAO_CFG2_REG); - - return insn->n; -} - -static int atao_calib_insn_read(struct comedi_device *dev, - struct comedi_subdevice *s, - struct comedi_insn *insn, - unsigned int *data) -{ - struct atao_private *devpriv = dev->private; - unsigned int chan = CR_CHAN(insn->chanspec); - int i; - - for (i = 0; i < insn->n; i++) - data[i] = devpriv->caldac[chan]; - return insn->n; } @@ -365,9 +349,12 @@ static int atao_attach(struct comedi_device *dev, struct comedi_devconfig *it) s->subdev_flags = SDF_WRITABLE | SDF_INTERNAL; s->n_chan = (board->n_ao_chans * 2) + 1; s->maxdata = 0xff; - s->insn_read = atao_calib_insn_read; s->insn_write = atao_calib_insn_write; + ret = comedi_alloc_subdev_readback(s); + if (ret) + return ret; + /* EEPROM subdevice */ s = &dev->subdevices[3]; s->type = COMEDI_SUBD_UNUSED; -- 2.34.1