The only limit for the stop_arg with a stop_src == TRIG_COUNT is that there is at
least 1 scan in order to prevent an empty acquisition. The max test is bogus.

Fix the validation.
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>

When the cmd->stop_src == TRIG_COUNT, the 'ai_sample_count' is the cmd->stop_arg.
For a stop_src == TRIG_NONE the 'ai_sample_count' is currently set to 1 but the
driver never actually uses the value.

Simplify the 'stop_count' initialization by just setting it to the cmd->stop_arg.
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>

The end-of-acquisition only applies when the cmd->stop_src == TRIG_COUNT.

Refactor the code in s626_handle_eos_interrupt() that detects the end-of-
acquisition to clarify this.
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 member of the private data is set based on the cmd->stop_src. Just use the
cmd->stop_src directly and remove the member.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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 function always returns '0' so the comedi_event() is never done by the
callers.

Change the return type to void and remove the comedi_event() dead code.
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>

When the cmd->stop_src == TRIG_COUNT, the 'stop_count' is the cmd->stop_arg.
For any other stop_src the 'stop_count' is 0, which is also the cmd->stop_arg.

Simplify the 'stop_count' initialization.
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 member of the private data is set based on the cmd->stop_src. Just use the
cmd->stop_src directly and remove the member.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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 function always returns '0' so the comedi_event() is never done by the
callers.

Change the return type to void and remove the comedi_event() dead code.
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>

When the cmd->stop_src == TRIG_COUNT, the 'stop_count' is the cmd->stop_arg.
For any other stop_src the 'stop_count' is 0, which is also the cmd->stop_arg.

Simplify the 'stop_count' initialization.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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>

The async command arguments are supposed to be trivially validated in step 3
of the (*do_cmdtest). Fix the validation of the stop_arg.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0 for both the analog input and output async commands. The (*do_cmd) for
both subdevices sets up and starts the command without handling the "empty
acquisition". This results in the interrupt functions trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0 for both the analog input and output async commands. The (*do_cmd) for
both subdevices sets up and starts the command without handling the "empty
acquisition". This results in the interrupt functions trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".
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>

When the cmd->stop_src == TRIG_COUNT, the 'ai_scan_count' is the cmd->stop_arg.
For any other stop_src the 'ai_scan_count' is 0, which is also the cmd->stop_arg.

Simplify the 'ai_scan_count' initialization.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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>

When the cmd->stop_src == TRIG_COUNT, the 'ao_scan_count' is the cmd->stop_arg.
For any other stop_src the 'ao_scan_count' is 0, which is also the cmd->stop_arg.

Simplify the 'ao_scan_count' initialization.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediately generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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 function always returns '0' so the comedi_event() is never done by the
callers.

Change the return type to void and remove the comedi_event() dead code.
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>

When the cmd->stop_src == TRIG_COUNT, the 'stopcount' is the cmd->stop_arg. When
the stop_src == TRIG_NONE the 'stopcount' is 0, which is also the cmd->stop_arg.

Simplify the 'stopcount' initialization.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediatelt generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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 function always returns 'false' so the caller never does the comedi_event().

Absorb the function into the caller and remove the 'do_event' dead code.
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 driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. This causes the (*do_cmd) to immediatelt generate a COMEDI_CB_EOA event
without acquiring any data.

This "empty acquisition" async command is not really useful. Validate that the
cmd->stop_arg is >= 1 in the (*do_cmdtest) and remove the "empty acquisition"
code.
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>

For aesthetics, move this function closer to the (*do_cmd).
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>

Currently the pci9118_ai_docmd_dma() or pci9118_ai_docmd_sampl() helper
is called by the (*do_cmd) to do the final setup for the command. Most
of this invloves setting various bits in 'ai_ctrl' and 'int_ctrl' to
setup the acquisition based on the 'ai_do' mode. Most of this is the
same for the DMA and non-DMA setup. The differences are easily handled
by either checking the cmd trigger sources or if DMA is used.

Absorb the helper functions into the (*do_cmd) to clarify the code.
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>

The async command can start immediately (TRIG_NOW), from an internal
trigger (TRIG_INT), or from an external trigger (TRIG_EXT). Currently
the start of the command is scattered in the DMA and non-DMA helper
functions.

Consolidate the start of the async command at the end of the (*do_cmd)
function. For aesthetics, use the 'cmd->start_src' directly instead
of the 'ai12_startstop' in the private data to determine how to start
the command. This also fixes a minor bug where the external trigger
gets enabled for a start_src == TRIG_INT.
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>

Introduce a helper function to start the async command.
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>

The pci9118_ai_docmd_dma() function enables the DMA bit in the ai control
register for all acquisition modes. For aesthetics, move the enable of
this bit into the (*do_cmd).
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>

The 'ai_cfg' was already set to PCI9118_AI_CFG_PDTRG | PCI9118_AI_CFG_PETRG.
Don't bother setting those bits in pci9118_ai_docmd_dma().
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>

The async command can operation in 4 modes in this driver.

Modes 1 and 4 use timers 1 and 2 as a cascaded timer to trigger each conversion.
Mode 1 begins the acquisitions immediately (scan_begin_src == TRIG_FOLLOW) and
Mode 4 begins after an external trigger (scan_begin_src == TRIG_EXT). Both modes
use a convert_src == TRIG_TIMER.

Mode 2 uses timers 1 and 2 in a double timed action (scan_begin_src == TRIG_TIMER
and convert_src != TRIG_EXT (TRIG_TIMER and TRIG_NOW are valid)).

Mode 3 does not use the timers. Each acquisition is triggered by an external
signal (scan_begin_src == TRIG_FOLLOW and convert_src == TRIG_EXT.

The (*do_cmdtest) validates the scan_begin_src as TRIG_FOLLOW, TRIG_TIMER,
or TRIG_EXT. Remove the invalid check for TRIG_INT in the (*do_cmd).

Clarify the logic used to determine the mode in the (*do_cmd).

Also, simplify pci9118_calc_divisors(). Call i8253_cascade_ns_to_timer() directly
in the (*do_cmd) for the mode 1 and mode 4 cases. Call pci9118_calc_divisors()
only for mode 2 acquisitions.
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>

The (*do_cmdtest) validates the scan_begin_src as TRIG_FOLLOW, TRIG_TIMER,
or TRIG_EXT. Remove the invalid check for TRIG_INT in the (*do_cmd).
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>

The 'tim2' parameter to this function is actually the cmd->convert_arg which
was validated in the (*do_cmdtest) as:

	err |= cfc_check_trigger_arg_min(&cmd->convert_arg,
					 devprivriv->ai_ns_min);

The sanity checks in this function are just repeating that validation. The
'min_pacer' sanity check is simply not needed.

Remove these unnecessary checks.
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>

Define some macros to set the 'chan' and 'range' bits in the chanlist
register. Use them to tidy up this function.
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>