The support for asynchronous commands in this driver is currently
broken.  If interrupts are enabled, the interrupt handler is called at
the end of every A/D conversion.  A/D conversions could be due to
software-triggered conversions resulting from Comedi `INSN_READ`
instruction handling, or due to timer-trigger conversions enabled when
a Comedi asynchronous command is set up.  We only want the interrupt
handler to read a sample from the A/D Data register for timer-triggered
conversions, but currently it always reads the A/D Data register.  Since
the A/D Data register is read twice (to read a 12-bit value from an
8-bit register), that probably interferes with the reading for
software-triggered conversions.

The interrupt handler does not currently do anything with the data, it
just ignores it.  It should be written to the Comedi buffer if handling
an asynchronous command.

Other problems are that the driver has no Comedi `cancel` handler to
call when the asynchronous command is being stopped manually, and it
does not handle "infinite" acquisitions (when the command's `stop_src ==
TRIG_NONE`) properly.

Change the interrupt handler to check the timer enable (ENB) bit to
check the asynchronous command is active and return early if not
enabled.  Also check the error (ERR) and "conversion complete" (FINISH)
bits, and return early if neither is set.  Then the sample can be read
from the A/D Data register to clear the ERR and FINISH bits.  If the ERR
bit was set, terminate the acquisition with an error, otherwise write
the data to the Comedi buffer and check for end of acquisition.  Replace
the current check for end of acquisition, using the count of completed
scans in `scans_done` (updated by calls to `comedi_buf_write_samples()`)
when `stop_src == TRIG_COUNT`) and allowing "infinite" acquisitions when
`stop_src == TRIG_NONE`.

Add a `cancel` handler function `dt2814_ai_cancel()` that will be called
when the end of acquisition event is processed and when the acquisition
is stopped manually.  It turns off the timer enable (ENB) bit in the
Control register, leaving the current channel selected.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210301165757.243065-5-abbotti@mev.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The Comedi "attach" handler `dt2814_attach()` writes to the Control
register to turn off the timer enable 'ENB' bit, which triggers a
conversion.  It then sleeps awhile and checks the Status register,
returning an error if the ERR bit is set.  However, the ERR bit could
have been set due to the conversion being triggered while the A/D
converter was busy (unlikely) or due to the conversion being triggered
before some previous sample had been read from the A/D Data register.

Replace the existing code with a call to `dt2814_ai_clear()` which waits
for any conversion to finish and then clears any unread data or error
condition.  A non-zero return value from `dt2814_ai_clear()` indicates a
time-out while waiting for the A/D converter to become non-busy.  Return
an error in that case.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210301165757.243065-4-abbotti@mev.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When the interrupt handler decides the final sample has been acquired,
it turns off the timer enable (ENB) bit in the Command register.  That
triggers another A/D conversion.  The interrupt handler currently waits
for that to finish and then reads the resulting, unwanted sample.  Since
the functions for handling Comedi read instructions and for setting up
asynchronous commands now call `dt2814_ai_clear()` to wait for and
discard any spurious A/D conversion, let's remove that code from the
interrupt handler.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210301165757.243065-3-abbotti@mev.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When performing a Comedi read instruction or setting up an asynchronous
command on the AI subdevice, clear any stale data on the A/D registers
by waiting for the Status register's BUSY bit to clear (if set) and then
if the FINISH or ERR bit is set, reading the A/D Data register twice to
clear the stale data.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210301165757.243065-2-abbotti@mev.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The number of output clocks are configurable in the hardware.
Currently the driver registers the maximum number of outputs.
Fix the same by registering only the outputs that are there.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-8-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently the set rate granularity is to integral divisors.
Add support for the fractional divisors.
Only the first output0 is fractional in the hardware.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-7-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The patch adds support for dynamic reconfiguration of clock output rate.
Output clocks are registered as dividers and set rate callback function
is used for dynamic reconfiguration.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Co-developed-by: Chirag Parekh <chirag.parekh@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-6-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If there is only one output then allow changing of the parent rate.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-5-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Update the fixed factor clock registration to register the divisors.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-4-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename speed-grade to xlnx,speed-grade
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-3-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the clocking wizard main structure kernel documentation.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1614172241-17326-2-git-send-email-shubhrajyoti.datta@xilinx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This change uses a space instead of tabs between the type and name of
each member of the struct.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-14-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdHT1R to bd_ht_1r to silence a checkpatch warning about
CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-13-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename RT2RT_HT_Mode to rt2rt_ht_mode to silence a checkpatch warning
about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-12-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdRT2RTLongSlotTime to bd_rt2rt_long_slot_time to silence a
checkpatch warning about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-11-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdRT2RTAggregation to bd_rt2rt_aggregation to silence a
checkpatch warning about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-10-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdBandWidth to bd_bandwidth to silence a checkpatch warning about
CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-9-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdHTSpecVer to bd_ht_spec_ver to silence a checkpatch warning
about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-8-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdHTInfoLen to bd_ht_info_len to silence a checkpatch warning
about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-7-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdHTInfoBuf to bd_ht_info_buf to silence a checkpatch warning
about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-6-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdHTCapLen to bd_ht_cap_len to silence a checkpatch warning about
CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-5-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdHTCapBuf to bd_ht_cap_buf to silence a checkpatch warning about
CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-4-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename bdSupportHT to bd_support_ht to silence a checkpatch warning
about CamelCase.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-3-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix a checkpatch warning about a blank line after an open curly brace.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210220172909.15812-2-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes 'WARNING: Missing a blank line after declarations' generated by
checkpatch.pl script.
Signed-off-by: Hassan Shahbazi <h.shahbazi.git@gmail.com>
Link: https://lore.kernel.org/r/20210223064227.62631-1-h.shahbazi.git@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix checkpatch.pl warning regarding space indents and replace it with
tabs to comply with kernel coding style.
Signed-off-by: Bastien Maureille <bastien.maureille@gmail.com>
Link: https://lore.kernel.org/r/20210222181812.268909-1-bastien.maureille@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes checkpatch warning:

WARNING: Comparisons should place the constant on the right side of the test
Signed-off-by: Simone Serra <serrazimone@gmail.com>
Link: https://lore.kernel.org/r/20210223234102.15784-1-serrazimone@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This change fixes a checkpatch warning for "Block comments use
* on subsequent lines". It removes the unnecessary block comment.
Signed-off-by: Amrit Khera <amritkhera98@gmail.com>
Link: https://lore.kernel.org/r/20210222101541.2571-1-amritkhera98@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This commit fixes a checkpatch warning that references the filename in
the the file comments.
Signed-off-by: George Xanthakis <kompiouterakias@gmail.com>
Link: https://lore.kernel.org/r/20210221170542.45309-1-kompiouterakias@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Removed unused variables.
Acked-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Fatih Yildirim <yildirim.fatih@gmail.com>
Link: https://lore.kernel.org/r/20210221202855.12442-1-yildirim.fatih@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fixing ERROR: space required before the open parenthesis '('
Signed-off-by: Rajesh Kumbhakar <sssraj.sssraj@gmail.com>
Link: https://lore.kernel.org/r/20210221133951.21234-1-sssraj.sssraj@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the following checkpatch.pl warning:

WARNING: line length of 124 exceeds 100 columns

in file kpc2000_i2c.c
Signed-off-by: Nikolay Kyx <knv418@gmail.com>
Link: https://lore.kernel.org/r/20210221132246.1154-2-knv418@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the following checkpatch.pl check:

CHECK: Alignment should match open parenthesis

in files kpc2000_i2c.c kpc2000_spi.c
Signed-off-by: Nikolay Kyx <knv418@gmail.com>
Link: https://lore.kernel.org/r/20210221132246.1154-1-knv418@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes "Alignment should match open parenthesis" issues reported by
checkpatch.pl in the `rtllib_wx.c` file.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219233352.2298-1-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This change uses a space instead of tabs between the type and name of
each member of the struct.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219231128.27119-8-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes a checkpatch CHECK issue.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219231128.27119-7-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes a checkpatch CHECK issue.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219231128.27119-6-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes a checkpatch CHECK issue.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219231128.27119-5-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes a checkpatch CHECK issue.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219231128.27119-4-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes a checkpatch CHECK issue.
Signed-off-by: William Durand <will+git@drnd.me>
Link: https://lore.kernel.org/r/20210219231128.27119-3-will+git@drnd.meSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>