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staging: comedi: s526: remove s526_ai_insn_config()

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This (*insn_config) does not follow the comedi core API. It also
would not work as expected.

It appears to be trying to configure the analog input subdevice so
that the (*insn_read) would read multiple channels (data[0]) and
optionally enable the 15us delay (data[1]) needed for the multiplexor
to change channels between samples.

Unfortunately, the comedi core expects (*insn_read) operations to
return 1 or more samples for a single channel, which is what the
(*insn_read) in this driver does.

The (*insn_config) is also enabling the analog input end-of-conversion
interrupt. This isn't needed, and might be a problem since the driver
does not currently request and interrupt. The enable bit does not
need to be set for the end-of-conversion to occur in the interrupt
status register.

Remove the (*insn_config) and modify the (*insn_read) to automatically
handle the 15us delay when needed.

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>
This commit is contained in:
H Hartley Sweeten 2015-08-17 16:58:24 -07:00 • committed by Greg Kroah-Hartman
commit 21424e3fa8
1 changed files with 11 additions and 38 deletions
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49
drivers/staging/comedi/drivers/s526.c
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@ -133,7 +133,7 @@ union cmReg {
struct s526_private {
unsigned int gpct_config[4];
unsigned short ai_config;
unsigned short ai_ctrl;
};
static void s526_gpct_write(struct comedi_device *dev,
@ -388,36 +388,6 @@ static int s526_gpct_winsn(struct comedi_device *dev,
return insn->n;
}
static int s526_ai_insn_config(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
{
struct s526_private *devpriv = dev->private;
int result = -EINVAL;
if (insn->n < 1)
return result;
result = insn->n;
/* data[0] : channels was set in relevant bits.
data[1] : delay
*/
/* COMMENT: abbotti 2008-07-24: I don't know why you'd want to
* enable channels here. The channel should be enabled in the
* INSN_READ handler. */
/* Enable ADC interrupt */
outw(S526_INT_AI, dev->iobase + S526_INT_ENA_REG);
devpriv->ai_config = (data[0] & 0x3ff) << 5;
if (data[1] > 0)
devpriv->ai_config |= S526_AI_CTRL_DELAY;/* set the delay */
devpriv->ai_config |= 0x0001; /* ADC start bit */
return result;
}
static int s526_eoc(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn,
@ -446,17 +416,21 @@ static int s526_ai_insn_read(struct comedi_device *dev,
int ret;
int i;
/*
* Set configured delay, enable conversion and read for requested
* channel only, set "ADC start" bit.
*/
ctrl = (devpriv->ai_config & S526_AI_CTRL_DELAY) |
S526_AI_CTRL_CONV(chan) | S526_AI_CTRL_READ(chan) |
ctrl = S526_AI_CTRL_CONV(chan) | S526_AI_CTRL_READ(chan) |
S526_AI_CTRL_START;
if (ctrl != devpriv->ai_ctrl) {
/*
* The multiplexor needs to change, enable the 15us
* delay for the first sample.
*/
devpriv->ai_ctrl = ctrl;
ctrl |= S526_AI_CTRL_DELAY;
}
for (i = 0; i < insn->n; i++) {
/* trigger conversion */
outw(ctrl, dev->iobase + S526_AI_CTRL_REG);
ctrl &= ~S526_AI_CTRL_DELAY;
/* wait for conversion to end */
ret = comedi_timeout(dev, s, insn, s526_eoc, S526_INT_AI);
@ -590,7 +564,6 @@ static int s526_attach(struct comedi_device *dev, struct comedi_devconfig *it)
s->range_table = &range_bipolar10;
s->len_chanlist = 16;
s->insn_read = s526_ai_insn_read;
s->insn_config = s526_ai_insn_config;
/* Analog Output subdevice */
s = &dev->subdevices[2];