All the comedi drivers that use memory mapped io currently have a
void __iomem * member in their private data for the driver. For
some of the drivers this is actually the only member in that data.

For convienence, add a new member to the comedi_device for this
void __iomem *.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This parameter is never used by any of the comedi drivers that provide a
(*buf_change) callback. If the 'new_size' is needed in the callback it can
be found from the 's->async->prealloc_bufsz' as done in the ni_pcidio driver.

Remove the unused parameter.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the checkpatch.pl --strict issues:

CHECK: DEFINE_MUTEX definition without comment
CHECK: braces {} should be used on all arms of this statement

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The comedi_error() function is just a wrapper around dev_err() that adds
the dev->driver->driver_name prefix to the message and a terminating
new-line character.

All of the users of this function have been converted to use dev_err()
directly. Remove the now unused function.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The `async` member of `struct comedi_subdevice` may point to a `struct
comedi_async` or may be NULL.  The `subdevice` member of `struct
comedi_async` points back to the `struct comedi_subdevice` associated
with it in a one-to-one relationship.

All uses of the `subdevice` member of `struct comedi_async` apart from
its initialization have now been removed (by passing around a pointer to
the subdevice instead of to the "async" structure), so get rid of it.

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>

Signed-off-by: Yves Deweerdt <yves.deweerdt.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce a comedi core helper function to handle the boilerplate
needed by the drivers to busy- wait for a condition to occur.
Typically this condition is the analog input/output end-of-conversion
used with the comedi (*insn_read) and (*insn_write) operations.

To use this function, the drivers just need to provide a callback
that checks for the desired condition. The callback should return
0 if the condition is met or -EBUSY if it is still waiting. Any
other errno will be returned to the caller. If the timeout occurs
before the condition is met -ETIMEDOUT will be returned.

The parameters to the callback function are the comedi_device,
comedi_subdevice, and comedi_insn pointers that were passed to the
(*insn_read) or (*insn_write) as well as an unsigned long, driver
specific, 'context' that can be used to pass any other information
that might be needed in the callback. This 'context' could be anything
such as the register offset to read the status or the bits needed
to check the status. The comedi_timeout() function itself does not
use any of these parameters.

This will help remove all the crazy "wait this many loops" used by
some of the drivers. It also creates a common errno for comedi to
detect when a timeout occurs.

ADC/DAC conversion times are typically pretty fast, usually around
100K samples/sec (10 usec). A conservative timeout of 1 second is used
in comedi_timeout().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

`comedi_auto_config()` is usually called from the probe routine of a
low-level comedi driver to allocate and auto-configure a comedi device.
Part of this involves calling the low-level driver's `auto_attach()`
handler, and if that is successful, `comedi_device_postconfig()` tries
to complete the configuration of the comedi device.  If either of those
fail, `comedi_device_detach()` is called to clean up, and
`comedi_release_hardware_device()` is called to remove the dynamically
allocated comedi device.

Unfortunately, `comedi_device_detach()` clears the `hw_dev` member of
the `struct comedi_device` (indirectly via `comedi_clear_hw_dev()`), and
that stops `comedi_release_hardware_device()` finding the comedi device
associated with the hardware device, so the comedi device won't be
removed properly.

Since `comedi_release_hardware_device()` also calls
`comedi_device_detach()` (assuming it finds the comedi device associated
with the hardware device), the fix is to remove the direct call to
`comedi_device_detach()` from `comedi_auto_config()` and let the call to
`comedi_release_hardware_device()` take care of it.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Added success message to the driver autoconfig and error
message in case it fails. A success message is required
so that the user can find out which comedi driver has been
associated with which udev device. This also makes troubleshooting
much easier when more than one card is in the computer or
there is a mix of USB and PCI devices.
As Ian suggested we should report both the driver and the board
which might have different names, especially if one driver covers a
range of different boards.

Signed-off-by: Bernd Porr <mail@berndporr.me.uk>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This resolves a merge issue with drivers/staging/imx-drm/imx-drm-core.c

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>