alistair23-linux/drivers/staging/comedi/comedilib.h
Ian Abbott 0f3ce1a600 staging: comedi: comedi_bond: handle base channel for insn_bits
If a DIO subdevice has more than 32 channels, its 'insn_bits' handler is
supposed to take account of the base channel from
`CR_CHAN(insn->chanspec)`.  (The comedi core will adjust the base
channel to 0 and shift the mask and data to compensate if the subdevice
has less than or equal to 32 channels.)  The "comedi_bond" driver
currently ignores the base channel and assumes it is 0.

Replace `comedi_dio_bitfield()` in the "kcomedilib" module with
`comedi_dio_bitfield2()` that takes account of the base channel, and
rewrite the "comedi_bond" driver's 'insn_bits' handler
(`bonding_dio_insn_bits()`) to take account of the base channel and use
the new function.

No other modules use `comedi_dio_bitfield()` so it is safe to replace it
with `comedi_dio_bitfield2()`.  The name follows that of the equivalent
function in the user-space comedilib.  If the base channel is non-zero
and the subdevice has less than or equal to 32 channels it needs to
adjust things in the same way as the comedi core (same as `parse_insn()`
in "comedi_fops.c") due to most drivers ignoring the base channel.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-26 06:41:56 -07:00

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C

/*
linux/include/comedilib.h
header file for kcomedilib
COMEDI - Linux Control and Measurement Device Interface
Copyright (C) 1998-2001 David A. Schleef <ds@schleef.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*/
#ifndef _LINUX_COMEDILIB_H
#define _LINUX_COMEDILIB_H
struct comedi_device *comedi_open(const char *path);
int comedi_close(struct comedi_device *dev);
int comedi_dio_get_config(struct comedi_device *dev, unsigned int subdev,
unsigned int chan, unsigned int *io);
int comedi_dio_config(struct comedi_device *dev, unsigned int subdev,
unsigned int chan, unsigned int io);
int comedi_dio_bitfield2(struct comedi_device *dev, unsigned int subdev,
unsigned int mask, unsigned int *bits,
unsigned int base_channel);
int comedi_find_subdevice_by_type(struct comedi_device *dev, int type,
unsigned int subd);
int comedi_get_n_channels(struct comedi_device *dev, unsigned int subdevice);
#endif