Add a Memory Descriptor List (MDL) layer to buffer handling to implement
scatter-gather I/O.  Currently there is still only 1 buffer per MDL.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

To avoid sleeps in providing buffers to user space and in handling incoming
buffers from the capture unit, converted the per stream mutex for locking
queues to 3 spin locks.  There is now a spin lock per queue
to increase concurrency when moving buffers around.

Also simplified queue manipulations and buffer handling of incoming buffers
of data from the capture unit.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

When sending an outgoing firmware command, prepare to wait before we raise the
interrupt, so we don't miss the wake_up() on the acknowledgment.  When waiting
for the acknowledgement, there is no need to loop around schedule(), as there
will only be one interrupt, and hence one wake_up(), issued.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Rename the work queue to "in_work_queue" to indicate it is handling
incoming mailbox commands.  This is preparation for adding a work queue
for handling deferrable outgoing mailbox commands.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Normalize the APU state before the second firmware load so that audio
for the first analog capture is correct.

Many thanks to Conexant for supporting me in finding a solution for this
problem.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Added debug display of outgoing mailbox arguments.  Fixed a minor problem
with display of stale incoming mailbox contents, when user was not looking for
debug warnings.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Refine the firmware load and firmware startup process.  Significant changes
are to ensure the SCB and IPC area are correct before starting up the firmware,
and letting the CPU firmware start up the APU firmware for us.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Use a known open task handle when setting stream CX2341x parameters
Sometimes, we might only have VBI or YUV stream open instead of an MPEG stream.
Let's make sure we use a valid task handle to perform the CX2341x control
settings.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Avoid making firmware API calls with the queue lock held.  The source
of MPEG strem corruption when not holding the queue lock was found to be that
the MPEG buffer could be retrieved by the user app before it was sync'ed for
the host cpu.  Incoming buffers are now sync'ed before being put on q_full and
releasing the queue lock.  We can thus avoid the sometimes lengthy call to
the firmware for CPU_DE_SET_MDL while holding the queue lock, so we can get
better performance.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Allow more than 63 capture buffers in rotation per stream.  Implement
q_busy to hold buffers the firmware has for use.  q_free holds truly unused
buffers in a pool.  New buffers are given to the firmware as soon as the
firmware returns one, if there are any to give to the firmware.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Change to per CX23418 device work queues for deferrable work handling.
Needed to support 2.6.22 and earlier kernels that can't selectively cancel
work orders.  Also will provide slightly better performance on SMP systems.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Quiet a sometimes common warning that often has benign consequences.
No one probably cares that the firmware took forever to ack our command, as
they always seem to succeed whether or not the firmware acks it in a reasonable
amount of time.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add copyright attribution for files modified by awalls in 2008
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Adjust outgoing mailbox timeouts and remove statistics logging.
This saves some wasted storage in struct cx18 for each card.  Cutting
the outgoing mailbox timeouts in half from the previous value appears to
be safe with MythTV.  Got rid of interrupted case code path after
a wait uninterruptable returns.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Restore buffers that have fallen out of the transfer rotation, and check
for coherent mailbox data when processing a stale mailbox.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Remove unnecessary MMIO accesses in time critical irq handling path.  Also
ensured that the mailbox ack field is read in last, so we know for sure if we
have a stale mailbox or not on receipt.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Propagate staleness of mailbox and mdl ack data to work handler to let
the work handler know that the data from the encoder may not be coherent.
Allows for smarter handling of buffers in future, to deal with MDLs that fall
out of rotation due to irq handler being late in collecting mailbox and mdl ack
info.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Change to singlethreaded global work queue thread for deferable work,
instead of the kernel default multithreaded work queue.  This ensures
execution of deferable work is always in the proper order, so caputred buffers
don't get reordered.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

A major rewrite of interrupt handling for incoming mailbox processing, to split
the timing critical steps from the the deferrable steps as the sending XPU on
the CX23418 will time out and overwrite our incoming mailboxes rather quickly.
Setup a pool of work "order forms" for the irq handler to send jobs to the new
work handler routine which uses the kernel default work queue to do the
deferrable work.  Started optimizing some of the cx18-io calls as they are now
the low hanging fruit for recoving microseconds back from the timeline.
Future optimizations will get rid of mmio read retries, mmio stats logging, and
combine smaller functions in the irq path into the larger ones to save ~2 us
each.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

All waits for cx18 mailbox API commands are now uninterruptable.  Added
code to collect mailbox ack statistics.  Tweaked timeouts based on collected
stats and video vertical frame and field rates.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Improve handling of outgoing mailboxes detected to be busy.  When
encountering a busy mailbox, sleep instead of polling, and wait for interrupt or
timeout.  If the mailbox is still busy, force it free.  When sending commands,
make sure we never create a situation where we mark the mailbox busy upon
sending, and ensure we always have a method to cleanly recover from a busy
mailbox.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add mutexes to ensure exclusive access for outgoing driver to CX23418 mailboxes.
Also wait on a waitq for mailbox acknowledgement from the CX23418 instead of
polling.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Mark CX18_CPU_DE_RELEASE_MDL as a slow API call.
Give the encoder time to complete the MDL release before destroying the
encoder internal task.  This avoids an encoder lockup on the next digital
capture and error messages about buffers being returned for an inactive
encoder task handle.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Fix write retries for registers that always change - part 2.
Some registers, especially interrupt related ones, will never read
back the value just written.  Modified interrupt register readback
checks to make sure the intended effect was achieved.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Disable write retries for registers that always change - part 1.
Interrupt related registers will likely not read back the value we just wrote.
Disable retries for these registers for now to avoid accidently discarding
interrupts.  More intelligent read back verification criteria are needed for
these and other registers (e.g. GPIO line registers), which will be addressed in
subsequent changes.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Create cx18_ specific wrappers for all pci mmio accessesors.  This is a
first step in instrumenting all CX23418 PCI bus IO, to debug problems with
accessing the CX23418's PCI memory mapped IO.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

cx18: Have CX23418 release buffers at end of capture.  The CX23418 reuses task
handles so we need to have it release the buffers associated with a task handle
at the end of a capture.  If we don't, buffer ids used for one type of stream
in the driver (MPEG, TS, PCM), could be used for another type of stream by the
CX23418, if a previously used handle is assigned to a different type of stream.
The driver would drop valid buffers when this happened.
Signed-off-by: NAndy Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Many thanks to Steve Toth from Hauppauge and Nattu Dakshinamurthy from
Conexant for their support. I am in particular thankful to Hauppauge
since without their help this driver would not exist. It should also
be noted that Steve did the work to get the DVB part up and running.
Thank you!
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NSteven Toth <stoth@hauppauge.com>
Signed-off-by: NMichael Krufky <mkrufky@linuxtv.org>
Signed-off-by: NG. Andrew Walls <awalls@radix.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>