staging: comedi: add comedi_bytes_per_scan()

The "comedi_fc" module contains a few functions useful to Comedi
drivers.  Their functionality is being migrated to the core "comedi"
module and renamed to start with the prefix `comedi_`.  As part of this
migration, move `cfc_bytes_per_scan()` into the core comedi module and
rename it to `comedi_bytes_per_scan()`.  Change the external declaration
of `cfc_bytes_per_scan()` into an inline function that calls
`comedi_bytes_per_scan()`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ian Abbott 2014-09-15 13:45:57 +01:00 committed by Greg Kroah-Hartman
parent 062fdcada9
commit f146fe6341
4 changed files with 43 additions and 23 deletions

View File

@ -442,6 +442,7 @@ int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
unsigned int mask);
unsigned int comedi_dio_update_state(struct comedi_subdevice *,
unsigned int *data);
unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
void *comedi_alloc_devpriv(struct comedi_device *, size_t);
int comedi_alloc_subdevices(struct comedi_device *, int);

View File

@ -290,6 +290,43 @@ unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
}
EXPORT_SYMBOL_GPL(comedi_dio_update_state);
/**
* comedi_bytes_per_scan - get length of asynchronous command "scan" in bytes
* @s: comedi_subdevice struct
*
* Determines the overall scan length according to the subdevice type and the
* number of channels in the scan.
*
* For digital input, output or input/output subdevices, samples for multiple
* channels are assumed to be packed into one or more unsigned short or
* unsigned int values according to the subdevice's SDF_LSAMPL flag. For other
* types of subdevice, samples are assumed to occupy a whole unsigned short or
* unsigned int according to the SDF_LSAMPL flag.
*
* Returns the overall scan length in bytes.
*/
unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
{
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int num_samples;
unsigned int bits_per_sample;
switch (s->type) {
case COMEDI_SUBD_DI:
case COMEDI_SUBD_DO:
case COMEDI_SUBD_DIO:
bits_per_sample = 8 * bytes_per_sample(s);
num_samples = (cmd->chanlist_len + bits_per_sample - 1) /
bits_per_sample;
break;
default:
num_samples = cmd->chanlist_len;
break;
}
return num_samples * bytes_per_sample(s);
}
EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);
static int insn_rw_emulate_bits(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)

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@ -22,28 +22,6 @@
#include "comedi_fc.h"
unsigned int cfc_bytes_per_scan(struct comedi_subdevice *s)
{
struct comedi_cmd *cmd = &s->async->cmd;
unsigned int num_samples;
unsigned int bits_per_sample;
switch (s->type) {
case COMEDI_SUBD_DI:
case COMEDI_SUBD_DO:
case COMEDI_SUBD_DIO:
bits_per_sample = 8 * bytes_per_sample(s);
num_samples = (cmd->chanlist_len + bits_per_sample - 1) /
bits_per_sample;
break;
default:
num_samples = cmd->chanlist_len;
break;
}
return num_samples * bytes_per_sample(s);
}
EXPORT_SYMBOL_GPL(cfc_bytes_per_scan);
void cfc_inc_scan_progress(struct comedi_subdevice *s, unsigned int num_bytes)
{
struct comedi_async *async = s->async;

View File

@ -23,7 +23,11 @@
#include "../comedidev.h"
unsigned int cfc_bytes_per_scan(struct comedi_subdevice *);
static inline unsigned int cfc_bytes_per_scan(struct comedi_subdevice *s)
{
return comedi_bytes_per_scan(s);
}
void cfc_inc_scan_progress(struct comedi_subdevice *, unsigned int num_bytes);
/* Writes an array of data points to comedi's buffer */