From 304d2e4cc018cf90811821e8ff3e6d6242d0ece5 Mon Sep 17 00:00:00 2001
From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Mon, 10 Feb 2014 11:49:39 -0700
Subject: [PATCH] staging: comedi: daqboard2000: use comedi_timeout()

Use comedi_timeout() to wait for the analog input pipe full, scanning,
amd end-of-conversion status. The status to check it passed as the
'context' to comedi_timeout().

Use comedi_timeout() to wait for the analog output end-of-conversion.

This also fixes a possible bug where invalid data is returned for the
analog input read if the conversion did not complete, The analog
output has a similar possible bug where the cached readback value is
incorrect if the conversion times out.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/comedi/drivers/daqboard2000.c | 82 ++++++++++++++++++---------
 1 file changed, 54 insertions(+), 28 deletions(-)

diff --git a/drivers/staging/comedi/drivers/daqboard2000.c b/drivers/staging/comedi/drivers/daqboard2000.c
index 6ff7d3e1971a..a8f6036ad82b 100644
--- a/drivers/staging/comedi/drivers/daqboard2000.c
+++ b/drivers/staging/comedi/drivers/daqboard2000.c
@@ -333,14 +333,28 @@ static void setup_sampling(struct comedi_device *dev, int chan, int gain)
 	writeAcqScanListEntry(dev, word3);
 }
 
+static int daqboard2000_ai_status(struct comedi_device *dev,
+				  struct comedi_subdevice *s,
+				  struct comedi_insn *insn,
+				  unsigned long context)
+{
+	struct daqboard2000_private *devpriv = dev->private;
+	unsigned int status;
+
+	status = readw(devpriv->daq + acqControl);
+	if (status & context)
+		return 0;
+	return -EBUSY;
+}
+
 static int daqboard2000_ai_insn_read(struct comedi_device *dev,
 				     struct comedi_subdevice *s,
 				     struct comedi_insn *insn,
 				     unsigned int *data)
 {
 	struct daqboard2000_private *devpriv = dev->private;
-	unsigned int val;
-	int gain, chan, timeout;
+	int gain, chan;
+	int ret;
 	int i;
 
 	writew(DAQBOARD2000_AcqResetScanListFifo |
@@ -367,25 +381,24 @@ static int daqboard2000_ai_insn_read(struct comedi_device *dev,
 		/* Enable reading from the scanlist FIFO */
 		writew(DAQBOARD2000_SeqStartScanList,
 		       devpriv->daq + acqControl);
-		for (timeout = 0; timeout < 20; timeout++) {
-			val = readw(devpriv->daq + acqControl);
-			if (val & DAQBOARD2000_AcqConfigPipeFull)
-				break;
-			/* udelay(2); */
-		}
+
+		ret = comedi_timeout(dev, s, insn, daqboard2000_ai_status,
+				     DAQBOARD2000_AcqConfigPipeFull);
+		if (ret)
+			return ret;
+
 		writew(DAQBOARD2000_AdcPacerEnable, devpriv->daq + acqControl);
-		for (timeout = 0; timeout < 20; timeout++) {
-			val = readw(devpriv->daq + acqControl);
-			if (val & DAQBOARD2000_AcqLogicScanning)
-				break;
-			/* udelay(2); */
-		}
-		for (timeout = 0; timeout < 20; timeout++) {
-			val = readw(devpriv->daq + acqControl);
-			if (val & DAQBOARD2000_AcqResultsFIFOHasValidData)
-				break;
-			/* udelay(2); */
-		}
+
+		ret = comedi_timeout(dev, s, insn, daqboard2000_ai_status,
+				     DAQBOARD2000_AcqLogicScanning);
+		if (ret)
+			return ret;
+
+		ret = comedi_timeout(dev, s, insn, daqboard2000_ai_status,
+				     DAQBOARD2000_AcqResultsFIFOHasValidData);
+		if (ret)
+			return ret;
+
 		data[i] = readw(devpriv->daq + acqResultsFIFO);
 		writew(DAQBOARD2000_AdcPacerDisable, devpriv->daq + acqControl);
 		writew(DAQBOARD2000_SeqStopScanList, devpriv->daq + acqControl);
@@ -409,6 +422,21 @@ static int daqboard2000_ao_insn_read(struct comedi_device *dev,
 	return i;
 }
 
+static int daqboard2000_ao_eoc(struct comedi_device *dev,
+			       struct comedi_subdevice *s,
+			       struct comedi_insn *insn,
+			       unsigned long context)
+{
+	struct daqboard2000_private *devpriv = dev->private;
+	unsigned int chan = CR_CHAN(insn->chanspec);
+	unsigned int status;
+
+	status = readw(devpriv->daq + dacControl);
+	if ((status & ((chan + 1) * 0x0010)) == 0)
+		return 0;
+	return -EBUSY;
+}
+
 static int daqboard2000_ao_insn_write(struct comedi_device *dev,
 				      struct comedi_subdevice *s,
 				      struct comedi_insn *insn,
@@ -416,8 +444,7 @@ static int daqboard2000_ao_insn_write(struct comedi_device *dev,
 {
 	struct daqboard2000_private *devpriv = dev->private;
 	int chan = CR_CHAN(insn->chanspec);
-	unsigned int val;
-	int timeout;
+	int ret;
 	int i;
 
 	for (i = 0; i < insn->n; i++) {
@@ -431,12 +458,11 @@ static int daqboard2000_ao_insn_write(struct comedi_device *dev,
 		udelay(1000);
 #endif
 		writew(data[i], devpriv->daq + dacSetting(chan));
-		for (timeout = 0; timeout < 20; timeout++) {
-			val = readw(devpriv->daq + dacControl);
-			if ((val & ((chan + 1) * 0x0010)) == 0)
-				break;
-			/* udelay(2); */
-		}
+
+		ret = comedi_timeout(dev, s, insn, daqboard2000_ao_eoc, 0);
+		if (ret)
+			return ret;
+
 		devpriv->ao_readback[chan] = data[i];
 #if 0
 		/*
-- 
2.11.0