The interrupt support available on this board is pretty limited but its
simple enough to give basic async command support.

This allows reading a single channel continuously using either the internal
or an external clock to trigger each conversion. The command can also use
the external trigger input to start the command if the external clock is
being used for conversions.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed following checkpatch.pl warnings
WARNING: Prefer WRITE_ONCE(<FOO>, <BAR>) over ACCESS_ONCE(<FOO>) = <BAR>

WARNING: Prefer READ_ONCE(<FOO>) over ACCESS_ONCE(<FOO>)
Signed-off-by: NShyam Saini <mayhs11saini@gmail.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Change the MODULE_DESCRIPTION to something more useful than the generic
"Comedi low-level driver".
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename this array so it has namespace associated with the driver.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This define is not used by the driver. Remove it.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add some whitespace to the analog output subdevice initialization
and rename the (*insn_read) function.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The A/D ranges are not programmable but the gain is. Currently this driver
uses a configuration option to select the comedi_lrange that will be used
for the analog input subdevice. This requires that the user makes sure the
correct option value is used.

The user space library uses the range information to convert between raw
values and physical units. If the user passed an incorrect option when
attaching the driver the conversion will be incorrect.

A previous patch allowed the gain to be set based on the chanspec range.
Prior to that the gain was always set to 1 so any conversion with a gain
that is not 1 would be incorrect anyway.

Simplify the analog input ranges by providing a range_table for the pgh and
pgl boards that contain all the possible range/gain options. The user can
then select the correct range (and gain) when converting values or reading
the analog inputs.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The remaining members of the private data are not used by the driver.
Remove it and the allocation.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The analog inputs are confgured with jumpers on the board to be:
  * 16 single-ended inputs
  * 8 differential inputs
  * 16 pseudo-differential inputs (common ground)

Simplify the handling of this configuration option and properly set
the subdev_flags based on the selected input mode.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add some whitespace to the analog output subdevice initialization.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The D/A ranges are not programmable. Currently this driver uses some
configuration options to select the comedi_lrange for each channel.
This is a bit messy and it requires the user to make sure the correct
option value is used.

The range information isn't used by the driver. The user space library
uses it to convert between raw data values and physical units. If the
user passed an incorrect option when attaching the driver the conversion
will be incorrect.

Simplify the analog output ranges by providing a range_table that
contains all the possible output ranges. The user can then select the
correct range when converting values.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add some whitespace to the digital input and output subdevice
initialization. Reorder the initialization a bit.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This register currently is not being used. For aesthetics, cleanup the
define and the comment about the frequency control.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The digital input and outputs are separate ports even though they share the
same register offset. For aesthetics, define then separately and remove the
redundant information in the comment.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cleanup the defines for these registers and and remove the redundant
information in the comment.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cleanup the defines for these registers and and remove the redundant
information in the comment.

Tidy up the reading of the data registers in the (*insn_read).
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cleanup the defines for this register and its bits and remove the
redundant information in the comment.

Make the (*insn_read) use the range to set the gain bits correctly.
Currently the gain is always set to 1.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cleanup the defines for this register and its bits and remove the
redundant information in the comment.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no reason the (*attach) should be trying to read an analog
input sample. Remove this disabled code.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The configuration options are listed in the comedi comment block.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the checkpatch.pl issue:
WARNING: Block comments use * on subsequent lines
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixed the checkpatch.pl warning:

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
Signed-off-by: NNikita Eshkeev <kastolom@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Change the MODULE_DESCRIPTION to something more usefull than the generic
"Comedi low-level driver".
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For aesthetics, remove the redundant '_struct' suffix.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For aesthetics, convert this function into a subdevice (*munge) function and let
the comedi core handle the munging.

Add a comment about why the data needs to be munged.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The (*insn_read) functions return the number of data values read. The 'n'
value is correct but for clarity change the return to 'insn->n'.

For aesthetics, change the 'n' loop variable name to 'i'. That's more common
in comedi drivers.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For aesthetics, init the comedi_subdevice, comedi_async, and comedi_cmd
pointers when the local variables are declared.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The configuration options are listed in the comedi comment block.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For aesthetics, move these after the register map defines and rename
the FIFO_SIZE define.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For aesthetics, rename these defines.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add some whitespace to the subdevice init and rename the support
function.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The (*insn_bits) for a digital input subdevice only needs to return the
state of the inputs in data[1]. Remove the cruft.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add some whitespace to the subdevice init and rename the support
function.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add some whitespace to the subdevice init and rename the support
functions.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce a helper function to handle writing the channel/gain data to
the queue for single channel reads, (*insn_read), and multi-channel
scans, (*do_cmd).
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename these defines.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename these defines and use the BIT macro to define the bits. Define
some macros for the multi-bit fields in the register.

Rename the private data 'control_state' member to better match the
register name.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The comedi core will only call the (*insn_read) and (*do_cmd) functions
if the subdevice is not "busy". All async commands are terminated by
a (*cancel) operation which clears the INTE and PACER_MASK bits in the
interrupt control register. These bits are also cleared when the driver
first attaches. There is no need for the (*insn_read) or (*do_cmd) to
duplicate the cancel.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename this define and use a consistent comment throughout the code.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The digtial inputs and outputs are read/written using the same register
offset but they are different logical registers. Physically they are the
same register with the hi 4 bits returning the inputs and the lo 4 bits
driving the outputs.

For aesthetics, use two different defines for the registers.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>