From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Mon, 25 Aug 2014 23:04:53 +0000 (-0700)
Subject: staging: comedi: rtd520: use comedi_subdevice 'readback'
X-Git-Tag: v3.18-rc1~130^2~999
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3caaf7b7e942c8dce49b02476a8ae8799cf47793;p=karo-tx-linux.git

staging: comedi: rtd520: 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.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/comedi/drivers/rtd520.c b/drivers/staging/comedi/drivers/rtd520.c
index 6fc4ed33f66c..7c7911b24166 100644
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -380,7 +380,6 @@ struct rtd_private {
 	int xfer_count;		/* # to transfer data. 0->1/2FIFO */
 	int flags;		/* flag event modes */
 	DECLARE_BITMAP(chan_is_bipolar, RTD_MAX_CHANLIST);
-	unsigned int ao_readback[2];
 	unsigned fifosz;
 };
 
@@ -1138,7 +1137,7 @@ static int rtd_ao_winsn(struct comedi_device *dev,
 			((chan == 0) ? LAS1_DAC1_FIFO : LAS1_DAC2_FIFO));
 		writew(0, dev->mmio + ((chan == 0) ? LAS0_DAC1 : LAS0_DAC2));
 
-		devpriv->ao_readback[chan] = data[i];
+		s->readback[chan] = data[i];
 
 		ret = comedi_timeout(dev, s, insn, rtd_ao_eoc, 0);
 		if (ret)
@@ -1149,23 +1148,6 @@ static int rtd_ao_winsn(struct comedi_device *dev,
 	return i;
 }
 
-/* AO subdevices should have a read insn as well as a write insn.
- * Usually this means copying a value stored in devpriv. */
-static int rtd_ao_rinsn(struct comedi_device *dev,
-			struct comedi_subdevice *s, struct comedi_insn *insn,
-			unsigned int *data)
-{
-	struct rtd_private *devpriv = dev->private;
-	int i;
-	int chan = CR_CHAN(insn->chanspec);
-
-	for (i = 0; i < insn->n; i++)
-		data[i] = devpriv->ao_readback[chan];
-
-
-	return i;
-}
-
 static int rtd_dio_insn_bits(struct comedi_device *dev,
 			     struct comedi_subdevice *s,
 			     struct comedi_insn *insn,
@@ -1323,7 +1305,11 @@ static int rtd_auto_attach(struct comedi_device *dev,
 	s->maxdata	= 0x0fff;
 	s->range_table	= &rtd_ao_range;
 	s->insn_write	= rtd_ao_winsn;
-	s->insn_read	= rtd_ao_rinsn;
+	s->insn_read	= comedi_readback_insn_read;
+
+	ret = comedi_alloc_subdev_readback(s);
+	if (ret)
+		return ret;
 
 	s = &dev->subdevices[2];
 	/* digital i/o subdevice */