From c2dfc3a5a295331b76919adfa9ecd4d5aea250a1 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Mon, 25 Aug 2014 16:04:37 -0700 Subject: [PATCH] staging: comedi: das08: use comedi_subdevice 'readback' Use the new comedi_subdevice 'readback' member and the core provided (*insn_read) for the readback of the analog output subdevice channels. The das08_ao_initialize() function is only called when the subdevice is first setup during the attach. It is used to initialize the channels to a known state. Absorb that function to simplify the code a bit. Signed-off-by: H Hartley Sweeten Reviewed-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/das08.c | 51 +++++++++----------------- drivers/staging/comedi/drivers/das08.h | 1 - 2 files changed, 18 insertions(+), 34 deletions(-) diff --git a/drivers/staging/comedi/drivers/das08.c b/drivers/staging/comedi/drivers/das08.c index 9a5a06b79a61..f761a5aae75e 100644 --- a/drivers/staging/comedi/drivers/das08.c +++ b/drivers/staging/comedi/drivers/das08.c @@ -338,7 +338,6 @@ static void das08_ao_set_data(struct comedi_device *dev, unsigned int chan, unsigned int data) { const struct das08_board_struct *thisboard = comedi_board(dev); - struct das08_private_struct *devpriv = dev->private; unsigned char lsb; unsigned char msb; @@ -355,18 +354,6 @@ static void das08_ao_set_data(struct comedi_device *dev, /* load DACs */ inb(dev->iobase + DAS08AO_AO_UPDATE); } - devpriv->ao_readback[chan] = data; -} - -static void das08_ao_initialize(struct comedi_device *dev, - struct comedi_subdevice *s) -{ - int n; - unsigned int data; - - data = s->maxdata / 2; /* should be about 0 volts */ - for (n = 0; n < s->n_chan; n++) - das08_ao_set_data(dev, n, data); } static int das08_ao_insn_write(struct comedi_device *dev, @@ -375,30 +362,18 @@ static int das08_ao_insn_write(struct comedi_device *dev, unsigned int *data) { unsigned int chan = CR_CHAN(insn->chanspec); + unsigned int val = s->readback[chan]; int i; - for (i = 0; i < insn->n; i++) - das08_ao_set_data(dev, chan, data[i]); + for (i = 0; i < insn->n; i++) { + val = data[i]; + das08_ao_set_data(dev, chan, val); + } + s->readback[chan] = val; return insn->n; } -static int das08_ao_rinsn(struct comedi_device *dev, - struct comedi_subdevice *s, - struct comedi_insn *insn, unsigned int *data) -{ - struct das08_private_struct *devpriv = dev->private; - unsigned int n; - unsigned int chan; - - chan = CR_CHAN(insn->chanspec); - - for (n = 0; n < insn->n; n++) - data[n] = devpriv->ao_readback[chan]; - - return n; -} - static void i8254_initialize(struct comedi_device *dev) { const struct das08_board_struct *thisboard = comedi_board(dev); @@ -461,6 +436,7 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase) struct das08_private_struct *devpriv = dev->private; struct comedi_subdevice *s; int ret; + int i; dev->iobase = iobase; @@ -498,8 +474,17 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase) s->maxdata = (1 << thisboard->ao_nbits) - 1; s->range_table = &range_bipolar5; s->insn_write = das08_ao_insn_write; - s->insn_read = das08_ao_rinsn; - das08_ao_initialize(dev, s); + s->insn_read = comedi_readback_insn_read; + + ret = comedi_alloc_subdev_readback(s); + if (ret) + return ret; + + /* intialize all channels to 0V */ + for (i = 0; i < s->n_chan; i++) { + s->readback[i] = s->maxdata / 2; + das08_ao_set_data(dev, i, s->readback[i]); + } } else { s->type = COMEDI_SUBD_UNUSED; } diff --git a/drivers/staging/comedi/drivers/das08.h b/drivers/staging/comedi/drivers/das08.h index 18cc170facd0..f86167da5895 100644 --- a/drivers/staging/comedi/drivers/das08.h +++ b/drivers/staging/comedi/drivers/das08.h @@ -44,7 +44,6 @@ struct das08_private_struct { * without separate do register */ const unsigned int *pg_gainlist; - unsigned int ao_readback[2]; /* assume 2 AO channels */ }; int das08_common_attach(struct comedi_device *dev, unsigned long iobase); -- 2.34.1