treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: rc: rename RC_TYPE_* to RC_PROTO_* and RC_BIT_* to RC_PROTO_BIT_*

RC_TYPE is confusing and it's just the protocol. So rename it.

Suggested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sean Young <sean@mess.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] rc: img-ir: add philips rc6 decoder module

Add img-ir module for decoding Philips rc6 protocol.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] rc: img-ir: add philips rc5 decoder module

Add img-ir module for decoding Philips rc5 protocol.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] rc: img-ir: biphase enabled with workaround

Biphase decoding in the current img-ir has got a quirk, where multiple
Interrupts are generated when an incomplete IR code is received by the
decoder.

Patch adds a work around for the quirk and enables biphase decoding.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] rc: img-ir: pass toggle bit to the rc driver

Add toggle bit to struct img_ir_scancode_req so that protocols can
provide it to img_ir_handle_data(), and pass that toggle bit up to
rc_keydown instead of 0.

This is needed for the upcoming rc-5 and rc-6 patches.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] rc: img-ir: add scancode requests to a struct

The information being requested of hardware decode callbacks through
the img-ir-hw scancode API is mounting up, so combine it into a struct
which can be passed in with a single pointer rather than multiple
pointer arguments. This allows it to be extended more easily without
touching all the hardware decode callbacks.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] img-ir/hw: Drop [un]register_decoder declarations

The img_ir_register_decoder() and img_ir_unregister_decoder() functions
were dropped prior to the img-ir driver being applied to simplify the
protocol decoder setup. However the declarations of these functions in
img-ir-hw.h were still included. Delete them since they're completely
unused.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] img-ir/hw: Fix potential deadlock stopping timer

The end timer is used for switching back from repeat code timings when
no repeat codes have been received for a certain amount of time. When
the protocol is changed, the end timer is deleted synchronously with
del_timer_sync(), however this takes place while holding the main spin
lock, and the timer handler also needs to acquire the spin lock.

This opens the possibility of a deadlock on an SMP system if the
protocol is changed just as the repeat timer is expiring. One CPU could
end up in img_ir_set_decoder() holding the lock and waiting for the end
timer to complete, while the other CPU is stuck in the timer handler
spinning on the lock held by the first CPU.

Lockdep also spots a possible lock inversion in the same code, since
img_ir_set_decoder() acquires the img-ir lock before the timer lock, but
the timer handler will try and acquire them the other way around:

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.18.0-rc5+ #957 Not tainted
---------------------------------------------------------
swapper/0/0 just changed the state of lock:
(((&hw->end_timer))){+.-...}, at: [<4006ae5c>] _call_timer_fn+0x0/0xfc
but this lock was taken by another, HARDIRQ-safe lock in the past:
(&(&priv->lock)->rlock#2){-.....}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(((&hw->end_timer)));
local_irq_disable();
lock(&(&priv->lock)->rlock#2);
lock(((&hw->end_timer)));
<Interrupt>
lock(&(&priv->lock)->rlock#2);

*** DEADLOCK ***

This is fixed by releasing the main spin lock while performing the
del_timer_sync() call. The timer is prevented from restarting before the
lock is reacquired by a new "stopping" flag which img_ir_handle_data()
checks before updating the timer.

---------------------------------------------------------
swapper/0/0 just changed the state of lock:
(((&hw->end_timer))){+.-...}, at: [<4006ae5c>] _call_timer_fn+0x0/0xfc
but this lock was taken by another, HARDIRQ-safe lock in the past:
(&(&priv->lock)->rlock#2){-.....}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(((&hw->end_timer)));
local_irq_disable();
lock(&(&priv->lock)->rlock#2);
lock(((&hw->end_timer)));
<Interrupt>
lock(&(&priv->lock)->rlock#2);
*** DEADLOCK ***
This is fixed by releasing the main spin lock while performing the
del_timer_sync() call. The timer is prevented from restarting before the
lock is reacquired by a new "stopping" flag which img_ir_handle_data()
checks before updating the timer.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Sifan Naeem <sifan.naeem@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] img-ir: fix sparse warnings

drivers/media/rc/img-ir/img-ir-nec.c:111:23: warning: symbol 'img_ir_nec' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-jvc.c:54:23: warning: symbol 'img_ir_jvc' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-sony.c:120:23: warning: symbol 'img_ir_sony' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-sharp.c:75:23: warning: symbol 'img_ir_sharp' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-sanyo.c:82:23: warning: symbol 'img_ir_sanyo' was not declared. Should it be static?

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] rc-core: document the protocol type

Right now the protocol information is not preserved, rc-core gets handed a
scancode but has no idea which protocol it corresponds to.

This patch (which required reading through the source/keymap for all drivers,
not fun) makes the protocol information explicit which is important
documentation and makes it easier to e.g. support multiple protocols with one
decoder (think rc5 and rc-streamzap). The information isn't used yet so there
should be no functional changes.

[m.chehab@samsung.com: rebased, added cxusb and removed bad whitespacing]
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] rc: img-ir: Expand copyright headers with GPL notices

Add the basic GPLv2+ license notice to the copyright headers at the top
of all the source files in the img-ir driver.

Reported-by: David Härdeman <david@hardeman.nu>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

[media] rc: img-ir: add hardware decoder driver

Add remote control input driver for the ImgTec Infrared block hardware
decoder, which is set up with timings for a specific protocol and
supports mask/value filtering and wake events.

The hardware decoder timing values, raw data to scan code conversion
function and scan code filter to raw data filter conversion function
will be provided in separate files for each protocol which this part of
the driver can use. The new generic scan code filter interface is made
use of to reduce interrupts and control wake events.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>