[PATCH 7/9] staging: comedi: das1800: don't pass struct comedi_cmd by value
Ian Abbott
abbotti at mev.co.uk
Wed Sep 19 18:37:41 UTC 2012
Various functions in das1800.c take a `struct comedi_cmd` parameter by
value. Change them to pass the parameter by reference instead.
Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
---
drivers/staging/comedi/drivers/das1800.c | 77 +++++++++++++++++---------------
1 file changed, 41 insertions(+), 36 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index 9972c5a..99aad86 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -959,14 +959,14 @@ static int das1800_ai_do_cmdtest(struct comedi_device *dev,
}
/* returns appropriate bits for control register a, depending on command */
-static int control_a_bits(struct comedi_cmd cmd)
+static int control_a_bits(const struct comedi_cmd *cmd)
{
int control_a;
control_a = FFEN; /* enable fifo */
- if (cmd.stop_src == TRIG_EXT)
+ if (cmd->stop_src == TRIG_EXT)
control_a |= ATEN;
- switch (cmd.start_src) {
+ switch (cmd->start_src) {
case TRIG_EXT:
control_a |= TGEN | CGSL;
break;
@@ -981,7 +981,7 @@ static int control_a_bits(struct comedi_cmd cmd)
}
/* returns appropriate bits for control register c, depending on command */
-static int control_c_bits(struct comedi_cmd cmd)
+static int control_c_bits(const struct comedi_cmd *cmd)
{
int control_c;
int aref;
@@ -989,18 +989,18 @@ static int control_c_bits(struct comedi_cmd cmd)
/* set clock source to internal or external, select analog reference,
* select unipolar / bipolar
*/
- aref = CR_AREF(cmd.chanlist[0]);
+ aref = CR_AREF(cmd->chanlist[0]);
control_c = UQEN; /* enable upper qram addresses */
if (aref != AREF_DIFF)
control_c |= SD;
if (aref == AREF_COMMON)
control_c |= CMEN;
/* if a unipolar range was selected */
- if (CR_RANGE(cmd.chanlist[0]) & UNIPOLAR)
+ if (CR_RANGE(cmd->chanlist[0]) & UNIPOLAR)
control_c |= UB;
- switch (cmd.scan_begin_src) {
+ switch (cmd->scan_begin_src) {
case TRIG_FOLLOW: /* not in burst mode */
- switch (cmd.convert_src) {
+ switch (cmd->convert_src) {
case TRIG_TIMER:
/* trig on cascaded counters */
control_c |= IPCLK;
@@ -1048,29 +1048,33 @@ static int das1800_set_frequency(struct comedi_device *dev)
}
/* sets up counters */
-static int setup_counters(struct comedi_device *dev, struct comedi_cmd cmd)
+static int setup_counters(struct comedi_device *dev,
+ const struct comedi_cmd *cmd)
{
+ unsigned int period;
+
/* setup cascaded counters for conversion/scan frequency */
- switch (cmd.scan_begin_src) {
+ switch (cmd->scan_begin_src) {
case TRIG_FOLLOW: /* not in burst mode */
- if (cmd.convert_src == TRIG_TIMER) {
+ if (cmd->convert_src == TRIG_TIMER) {
/* set conversion frequency */
+ period = cmd->convert_arg;
i8253_cascade_ns_to_timer_2div(TIMER_BASE,
- &(devpriv->divisor1),
- &(devpriv->divisor2),
- &(cmd.convert_arg),
- cmd.
- flags & TRIG_ROUND_MASK);
+ &devpriv->divisor1,
+ &devpriv->divisor2,
+ &period,
+ cmd->flags &
+ TRIG_ROUND_MASK);
if (das1800_set_frequency(dev) < 0)
return -1;
}
break;
case TRIG_TIMER: /* in burst mode */
/* set scan frequency */
- i8253_cascade_ns_to_timer_2div(TIMER_BASE, &(devpriv->divisor1),
- &(devpriv->divisor2),
- &(cmd.scan_begin_arg),
- cmd.flags & TRIG_ROUND_MASK);
+ period = cmd->scan_begin_arg;
+ i8253_cascade_ns_to_timer_2div(TIMER_BASE, &devpriv->divisor1,
+ &devpriv->divisor2, &period,
+ cmd->flags & TRIG_ROUND_MASK);
if (das1800_set_frequency(dev) < 0)
return -1;
break;
@@ -1079,7 +1083,7 @@ static int setup_counters(struct comedi_device *dev, struct comedi_cmd cmd)
}
/* setup counter 0 for 'about triggering' */
- if (cmd.stop_src == TRIG_EXT) {
+ if (cmd->stop_src == TRIG_EXT) {
/* load counter 0 in mode 0 */
i8254_load(dev->iobase + DAS1800_COUNTER, 0, 0, 1, 0);
}
@@ -1088,7 +1092,7 @@ static int setup_counters(struct comedi_device *dev, struct comedi_cmd cmd)
}
/* utility function that suggests a dma transfer size based on the conversion period 'ns' */
-static unsigned int suggest_transfer_size(struct comedi_cmd *cmd)
+static unsigned int suggest_transfer_size(const struct comedi_cmd *cmd)
{
unsigned int size = DMA_BUF_SIZE;
static const int sample_size = 2; /* size in bytes of one sample from board */
@@ -1126,7 +1130,7 @@ static unsigned int suggest_transfer_size(struct comedi_cmd *cmd)
}
/* sets up dma */
-static void setup_dma(struct comedi_device *dev, struct comedi_cmd cmd)
+static void setup_dma(struct comedi_device *dev, const struct comedi_cmd *cmd)
{
unsigned long lock_flags;
const int dual_dma = devpriv->irq_dma_bits & DMA_DUAL;
@@ -1135,7 +1139,7 @@ static void setup_dma(struct comedi_device *dev, struct comedi_cmd cmd)
return;
/* determine a reasonable dma transfer size */
- devpriv->dma_transfer_size = suggest_transfer_size(&cmd);
+ devpriv->dma_transfer_size = suggest_transfer_size(cmd);
lock_flags = claim_dma_lock();
disable_dma(devpriv->dma0);
/* clear flip-flop to make sure 2-byte registers for
@@ -1164,14 +1168,15 @@ static void setup_dma(struct comedi_device *dev, struct comedi_cmd cmd)
}
/* programs channel/gain list into card */
-static void program_chanlist(struct comedi_device *dev, struct comedi_cmd cmd)
+static void program_chanlist(struct comedi_device *dev,
+ const struct comedi_cmd *cmd)
{
int i, n, chan_range;
unsigned long irq_flags;
const int range_mask = 0x3; /* masks unipolar/bipolar bit off range */
const int range_bitshift = 8;
- n = cmd.chanlist_len;
+ n = cmd->chanlist_len;
/* spinlock protects indirect addressing */
spin_lock_irqsave(&dev->spinlock, irq_flags);
outb(QRAM, dev->iobase + DAS1800_SELECT); /* select QRAM for baseAddress + 0x0 */
@@ -1179,9 +1184,9 @@ static void program_chanlist(struct comedi_device *dev, struct comedi_cmd cmd)
/* make channel / gain list */
for (i = 0; i < n; i++) {
chan_range =
- CR_CHAN(cmd.
- chanlist[i]) | ((CR_RANGE(cmd.chanlist[i]) &
- range_mask) << range_bitshift);
+ CR_CHAN(cmd->chanlist[i]) |
+ ((CR_RANGE(cmd->chanlist[i]) & range_mask) <<
+ range_bitshift);
outw(chan_range, dev->iobase + DAS1800_QRAM);
}
outb(n - 1, dev->iobase + DAS1800_QRAM_ADDRESS); /*finish write to QRAM */
@@ -1197,7 +1202,7 @@ static int das1800_ai_do_cmd(struct comedi_device *dev,
int ret;
int control_a, control_c;
struct comedi_async *async = s->async;
- struct comedi_cmd cmd = async->cmd;
+ const struct comedi_cmd *cmd = &async->cmd;
if (!dev->irq) {
comedi_error(dev,
@@ -1207,12 +1212,12 @@ static int das1800_ai_do_cmd(struct comedi_device *dev,
/* disable dma on TRIG_WAKE_EOS, or TRIG_RT
* (because dma in handler is unsafe at hard real-time priority) */
- if (cmd.flags & (TRIG_WAKE_EOS | TRIG_RT))
+ if (cmd->flags & (TRIG_WAKE_EOS | TRIG_RT))
devpriv->irq_dma_bits &= ~DMA_ENABLED;
else
devpriv->irq_dma_bits |= devpriv->dma_bits;
/* interrupt on end of conversion for TRIG_WAKE_EOS */
- if (cmd.flags & TRIG_WAKE_EOS) {
+ if (cmd->flags & TRIG_WAKE_EOS) {
/* interrupt fifo not empty */
devpriv->irq_dma_bits &= ~FIMD;
} else {
@@ -1220,8 +1225,8 @@ static int das1800_ai_do_cmd(struct comedi_device *dev,
devpriv->irq_dma_bits |= FIMD;
}
/* determine how many conversions we need */
- if (cmd.stop_src == TRIG_COUNT)
- devpriv->count = cmd.stop_arg * cmd.chanlist_len;
+ if (cmd->stop_src == TRIG_COUNT)
+ devpriv->count = cmd->stop_arg * cmd->chanlist_len;
das1800_cancel(dev, s);
@@ -1241,9 +1246,9 @@ static int das1800_ai_do_cmd(struct comedi_device *dev,
/* set conversion rate and length for burst mode */
if (control_c & BMDE) {
/* program conversion period with number of microseconds minus 1 */
- outb(cmd.convert_arg / 1000 - 1,
+ outb(cmd->convert_arg / 1000 - 1,
dev->iobase + DAS1800_BURST_RATE);
- outb(cmd.chanlist_len - 1, dev->iobase + DAS1800_BURST_LENGTH);
+ outb(cmd->chanlist_len - 1, dev->iobase + DAS1800_BURST_LENGTH);
}
outb(devpriv->irq_dma_bits, dev->iobase + DAS1800_CONTROL_B); /* enable irq/dma */
outb(control_a, dev->iobase + DAS1800_CONTROL_A); /* enable fifo and triggering */
--
1.7.12
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