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>

diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 7f4d7e5f20b34c9d6ffa3d00de46c8dd5ce16a39..cf732b4e938a9aa830fe05258fccbb9eabc7cd1d 100644 (file)
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -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);

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index c4ed8fd686884d3a00e0555f5ffc44dfd7463831..891c092697c56103c4687f8633c7d50f88437efe 100644 (file)
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -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)

diff --git a/drivers/staging/comedi/drivers/comedi_fc.c b/drivers/staging/comedi/drivers/comedi_fc.c
index c33c3e5680a64ebd94394e21b8cf1cf15a2b6686..407ec70798ebe6c3e012c1cb56244429cc5df9cf 100644 (file)
--- a/drivers/staging/comedi/drivers/comedi_fc.c
+++ b/drivers/staging/comedi/drivers/comedi_fc.c
@@ -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;

diff --git a/drivers/staging/comedi/drivers/comedi_fc.h b/drivers/staging/comedi/drivers/comedi_fc.h
index 541b9371d3da1b6c8ab495272b74b38c6b3f7203..90acb8f29912af6ae96fbf3d2151246e2191966b 100644 (file)
--- a/drivers/staging/comedi/drivers/comedi_fc.h
+++ b/drivers/staging/comedi/drivers/comedi_fc.h
@@ -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 */