The wait_for() macro in this driver is a bit nasty. It effects control flow
which according to the CodingStyle is a _very_ bad idea.
The mux_busy() and ad_done() macros are also bad since they rely on a local
variable having a specific name.
Remove these macros and use comedi_timeout() to wait for the analog input
mux busy completion and end-of-conversion. Both of these are detected by
reading the same register and testing different bits. Pass the bits to test
as the 'context' to the callback function.
The dt282x_ai_cmd() function also checks for the mux busy completion. The
'insn' is not available here but passing NULL is safe because nothing
uses it.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/dt282x.c | 68 ++++++++++++++++++++-------------
1 file changed, 42 insertions(+), 26 deletions(-)
diff --git a/drivers/staging/comedi/drivers/dt282x.c b/drivers/staging/comedi/drivers/dt282x.c
index 895f73a..f768210 100644
--- a/drivers/staging/comedi/drivers/dt282x.c
+++ b/drivers/staging/comedi/drivers/dt282x.c
@@ -63,7 +63,6 @@ Notes:
#include "comedi_fc.h"
-#define DT2821_TIMEOUT 100 /* 500 us */
#define DT2821_SIZE 0x10
/*
@@ -248,27 +247,6 @@ struct dt282x_private {
* Some useless abstractions
*/
#define chan_to_DAC(a) ((a)&1)
-#define mux_busy() (inw(dev->iobase+DT2821_ADCSR)&DT2821_MUXBUSY)
-#define ad_done() (inw(dev->iobase+DT2821_ADCSR)&DT2821_ADDONE)
-
-/*
- * danger! macro abuse... a is the expression to wait on, and b is
- * the statement(s) to execute if it doesn't happen.
- */
-#define wait_for(a, b) \
- do { \
- int _i; \
- for (_i = 0; _i < DT2821_TIMEOUT; _i++) { \
- if (a) { \
- _i = 0; \
- break; \
- } \
- udelay(5); \
- } \
- if (_i) { \
- b \
- } \
- } while (0)
static int prep_ai_dma(struct comedi_device *dev, int chan, int size);
static int prep_ao_dma(struct comedi_device *dev, int chan, int size);
@@ -530,6 +508,29 @@ static void dt282x_load_changain(struct comedi_device *dev, int n,
outw(n - 1, dev->iobase + DT2821_CHANCSR);
}
+static int dt282x_ai_timeout(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned long context)
+{
+ unsigned int status;
+
+ status = inw(dev->iobase + DT2821_ADCSR);
+ switch (context) {
+ case DT2821_MUXBUSY:
+ if ((status & DT2821_MUXBUSY) == 0)
+ return 0;
+ break;
+ case DT2821_ADDONE:
+ if (status & DT2821_ADDONE)
+ return 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return -EBUSY;
+}
+
/*
* Performs a single A/D conversion.
* - Put channel/gain into channel-gain list
@@ -542,6 +543,7 @@ static int dt282x_ai_insn_read(struct comedi_device *dev,
{
const struct dt282x_board *board = comedi_board(dev);
struct dt282x_private *devpriv = dev->private;
+ int ret;
int i;
/* XXX should we really be enabling the ad clock here? */
@@ -551,13 +553,22 @@ static int dt282x_ai_insn_read(struct comedi_device *dev,
dt282x_load_changain(dev, 1, &insn->chanspec);
outw(devpriv->supcsr | DT2821_PRLD, dev->iobase + DT2821_SUPCSR);
- wait_for(!mux_busy(), comedi_error(dev, "timeout\n"); return -ETIME;);
+ ret = comedi_timeout(dev, s, insn, dt282x_ai_timeout, DT2821_MUXBUSY);
+ if (ret) {
+ comedi_error(dev, "timeout\n");
+ return ret;
+ }
for (i = 0; i < insn->n; i++) {
outw(devpriv->supcsr | DT2821_STRIG,
dev->iobase + DT2821_SUPCSR);
- wait_for(ad_done(), comedi_error(dev, "timeout\n");
- return -ETIME;);
+
+ ret = comedi_timeout(dev, s, insn, dt282x_ai_timeout,
+ DT2821_ADDONE);
+ if (ret) {
+ comedi_error(dev, "timeout\n");
+ return ret;
+ }
data[i] =
inw(dev->iobase +
@@ -646,6 +657,7 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
struct dt282x_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
int timer;
+ int ret;
if (devpriv->usedma == 0) {
comedi_error(dev,
@@ -691,7 +703,11 @@ static int dt282x_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
outw(devpriv->adcsr, dev->iobase + DT2821_ADCSR);
outw(devpriv->supcsr | DT2821_PRLD, dev->iobase + DT2821_SUPCSR);
- wait_for(!mux_busy(), comedi_error(dev, "timeout\n"); return -ETIME;);
+ ret = comedi_timeout(dev, s, NULL, dt282x_ai_timeout, DT2821_MUXBUSY);
+ if (ret) {
+ comedi_error(dev, "timeout\n");
+ return ret;
+ }
if (cmd->scan_begin_src == TRIG_FOLLOW) {
outw(devpriv->supcsr | DT2821_STRIG,
--
1.8.5.2
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