media: cec.h: Fix kerneldoc

The fields are gone, remove their documentation.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: cec: core: count low-drive, error and arb-lost conditions

Count how many Low Drive, Error and Arbitration Lost transmit
status errors occurred, and expose that in debugfs.

Also log the first 8 transmits that result in Low Drive or Error
conditions. That really should not happen with well-behaved CEC devices
and good HDMI cables.

This is useful to detect and debug HDMI cable issues.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec.h: increase input_phys buffer

Fixes this compiler warning:

drivers/media/cec/core/cec-core.c: In function 'cec_allocate_adapter':
drivers/media/cec/core/cec-core.c:317:21: warning: '/input0' directive output may be truncated writing 7 bytes into a region of size between 1 and 32 [-Wformat-truncation=]
317 | "%s/input0", adap->name);
| ^~~~~~~
drivers/media/cec/core/cec-core.c:316:9: note: 'snprintf' output between 8 and 39 bytes into a destination of size 32
316 | snprintf(adap->input_phys, sizeof(adap->input_phys),
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
317 | "%s/input0", adap->name);
| ~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

media: cec: core: add adap_unconfigured() callback

The adap_configured() callback was called with the adap->lock mutex
held if the 'configured' argument was false, and without the adap->lock
mutex held if that argument was true.

That was very confusing, and so split this up in a adap_unconfigured()
callback and a high-level configured() callback.

This also makes it easier to understand when the mutex is held: all
low-level adap_* callbacks are called with the mutex held. All other
callbacks are called without that mutex held.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: f1b57164305d ("media: cec: add optional adap_configured callback")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec: core: add adap_nb_transmit_canceled() callback

A potential deadlock was found by Zheng Zhang with a local syzkaller
instance.

The problem is that when a non-blocking CEC transmit is canceled by calling
cec_data_cancel, that in turn can call the high-level received() driver
callback, which can call cec_transmit_msg() to transmit a new message.

The cec_data_cancel() function is called with the adap->lock mutex held,
and cec_transmit_msg() tries to take that same lock.

The root cause is that the received() callback can either be used to pass
on a received message (and then adap->lock is not held), or to report a
canceled transmit (and then adap->lock is held).

This is confusing, so create a new low-level adap_nb_transmit_canceled
callback that reports back that a non-blocking transmit was canceled.

And the received() callback is only called when a message is received,
as was the case before commit f9d0ecbf56f4 ("media: cec: correctly pass
on reply results") complicated matters.

Reported-by: Zheng Zhang <zheng.zhang@email.ucr.edu>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: f9d0ecbf56f4 ("media: cec: correctly pass on reply results")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec-adap.c: drop activate_cnt, use state info instead

Using an activation counter to decide when the enable or disable the
cec adapter is not the best approach and can lead to race conditions.

Change this to determining the current status of the adapter, and
enable or disable the adapter accordingly.

It now only needs to be called whenever there is a chance that the
state changes, and it can handle enabling/disabling monitoring as
well if needed.

This simplifies the code and it should be a more robust approach as well.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec-adap.c: reconfigure if the PA changes during configuration

If the physical address changes (i.e. becomes invalid, then valid again)
while the adapter is still claiming free logical addresses, then trigger
a reconfiguration since any claimed LAs may now be stale.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec: add optional adap_configured callback

This new optional callback is called when the adapter is fully configured
or fully unconfigured. Some drivers may have to take action when this
happens.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec: add xfer_timeout_ms field

Allow drivers to change the transmit timeout value, i.e. after how
long should a transmit be considered 'lost', i.e. the corresponding
cec_transmit_done_ts was never called.

Some CEC devices have their own timeout, and so this timeout value must be
longer than that hardware timeout value. If it is shorter then the
framework would consider the transmit lost, even though it is effectively
still in progress at the hardware level.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec: abort if the current transmit was canceled

If a transmit-in-progress was canceled, then, once the transmit
is done, mark it as aborted and refrain from retrying the transmit.

To signal this situation the new transmit_in_progress_aborted field is
set to true.

The old implementation would just set adap->transmitting to NULL and
set adap->transmit_in_progress to false, but on the hardware level
the transmit was still ongoing. However, the framework would think
the transmit was aborted, and if a new transmit was issued, then
it could overwrite the HW buffer containing the old transmit with the
new transmit, leading to garbled data on the CEC bus.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec: call enable_adap on s_log_addrs

Don't enable/disable the adapter if the first fh is opened or the
last fh is closed, instead do this when the adapter is configured
or unconfigured, and also when we enter Monitor All or Monitor Pin
mode for the first time or we exit the Monitor All/Pin mode for the
last time.

However, if needs_hpd is true, then do this when the physical
address is set or cleared: in that case the adapter typically is
powered by the HPD, so it really is disabled when the HPD is low.
This case (needs_hpd is true) was already handled in this way, so
this wasn't changed.

The problem with the old behavior was that if the HPD goes low when
no fh is open, and a transmit was in progress, then the adapter would
be disabled, typically stopping the transmit immediately which
leaves a partial message on the bus, which isn't nice and can confuse
some adapters.

It makes much more sense to disable it only when the adapter is
unconfigured and we're not monitoring the bus, since then you really
won't be using it anymore.

To keep track of this store a CEC activation count and call adap_enable
only when it goes from 0 to 1 or back to 0.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: cec: fix a deadlock situation

The cec_devnode struct has a lock meant to serialize access
to the fields of this struct. This lock is taken during
device node (un)registration and when opening or releasing a
filehandle to the device node. When the last open filehandle
is closed the cec adapter might be disabled by calling the
adap_enable driver callback with the devnode.lock held.

However, if during that callback a message or event arrives
then the driver will call one of the cec_queue_event()
variants in cec-adap.c, and those will take the same devnode.lock
to walk the open filehandle list.

This obviously causes a deadlock.

This is quite easy to reproduce with the cec-gpio driver since that
uses the cec-pin framework which generated lots of events and uses
a kernel thread for the processing, so when adap_enable is called
the thread is still running and can generate events.

But I suspect that it might also happen with other drivers if an
interrupt arrives signaling e.g. a received message before adap_enable
had a chance to disable the interrupts.

This patch adds a new mutex to serialize access to the fhs list.
When adap_enable() is called the devnode.lock mutex is held, but
not devnode.lock_fhs. The event functions in cec-adap.c will now
use devnode.lock_fhs instead of devnode.lock, ensuring that it is
safe to call those functions from the adap_enable callback.

This specific issue only happens if the last open filehandle is closed
and the physical address is invalid. This is not something that
happens during normal operation, but it does happen when monitoring
CEC traffic (e.g. cec-ctl --monitor) with an unconfigured CEC adapter.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org> # for v5.13 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: core headers: fix kernel-doc warnings

This patch fixes the following kernel-doc warnings:

include/uapi/linux/videodev2.h:996: warning: Function parameter or member 'm' not described in 'v4l2_plane'
include/uapi/linux/videodev2.h:996: warning: Function parameter or member 'reserved' not described in 'v4l2_plane'
include/uapi/linux/videodev2.h:1057: warning: Function parameter or member 'm' not described in 'v4l2_buffer'
include/uapi/linux/videodev2.h:1057: warning: Function parameter or member 'reserved2' not described in 'v4l2_buffer'
include/uapi/linux/videodev2.h:1057: warning: Function parameter or member 'reserved' not described in 'v4l2_buffer'
include/uapi/linux/videodev2.h:1068: warning: Function parameter or member 'tv' not described in 'v4l2_timeval_to_ns'
include/uapi/linux/videodev2.h:1068: warning: Excess function parameter 'ts' description in 'v4l2_timeval_to_ns'
include/uapi/linux/videodev2.h:1138: warning: Function parameter or member 'reserved' not described in 'v4l2_exportbuffer'
include/uapi/linux/videodev2.h:2237: warning: Function parameter or member 'reserved' not described in 'v4l2_plane_pix_format'
include/uapi/linux/videodev2.h:2270: warning: Function parameter or member 'hsv_enc' not described in 'v4l2_pix_format_mplane'
include/uapi/linux/videodev2.h:2270: warning: Function parameter or member 'reserved' not described in 'v4l2_pix_format_mplane'
include/uapi/linux/videodev2.h:2281: warning: Function parameter or member 'reserved' not described in 'v4l2_sdr_format'
include/uapi/linux/videodev2.h:2315: warning: Function parameter or member 'fmt' not described in 'v4l2_format'

include/uapi/linux/v4l2-subdev.h:53: warning: Function parameter or member 'reserved' not described in 'v4l2_subdev_format'
include/uapi/linux/v4l2-subdev.h:66: warning: Function parameter or member 'reserved' not described in 'v4l2_subdev_crop'
include/uapi/linux/v4l2-subdev.h:89: warning: Function parameter or member 'reserved' not described in 'v4l2_subdev_mbus_code_enum'
include/uapi/linux/v4l2-subdev.h:108: warning: Function parameter or member 'min_width' not described in 'v4l2_subdev_frame_size_enum'
include/uapi/linux/v4l2-subdev.h:108: warning: Function parameter or member 'max_width' not described in 'v4l2_subdev_frame_size_enum'
include/uapi/linux/v4l2-subdev.h:108: warning: Function parameter or member 'min_height' not described in 'v4l2_subdev_frame_size_enum'
include/uapi/linux/v4l2-subdev.h:108: warning: Function parameter or member 'max_height' not described in 'v4l2_subdev_frame_size_enum'
include/uapi/linux/v4l2-subdev.h:108: warning: Function parameter or member 'reserved' not described in 'v4l2_subdev_frame_size_enum'
include/uapi/linux/v4l2-subdev.h:119: warning: Function parameter or member 'reserved' not described in 'v4l2_subdev_frame_interval'
include/uapi/linux/v4l2-subdev.h:140: warning: Function parameter or member 'reserved' not described in 'v4l2_subdev_frame_interval_enum'

include/uapi/linux/cec.h:406: warning: Function parameter or member 'raw' not described in 'cec_connector_info'
include/uapi/linux/cec.h:470: warning: Function parameter or member 'flags' not described in 'cec_event'

include/media/v4l2-h264.h:82: warning: Function parameter or member 'reflist' not described in 'v4l2_h264_build_p_ref_list'
include/media/v4l2-h264.h:82: warning: expecting prototype for v4l2_h264_build_b_ref_lists(). Prototype was for v4l2_h264_build_p_ref_list()
instead

include/media/cec.h:50: warning: Function parameter or member 'lock' not described in 'cec_devnode'

include/media/v4l2-jpeg.h:122: warning: Function parameter or member 'num_dht' not described in 'v4l2_jpeg_header'
include/media/v4l2-jpeg.h:122: warning: Function parameter or member 'num_dqt' not described in 'v4l2_jpeg_header'

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: cec: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: cec: add adap_controls_phys_addr option

Use of the cec notifier framework is required to support
CEC_CAP_CONNECTOR_INFO but some devices do not want physical address
updates from the notifier. This adds an option to allow registering
with a cec notifier without getting address updates.

[hans: document the new adap_controls_phys_addr bool]

Signed-off-by: Jeff Chase <jnchase@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: media/cec.h: document cec_adapter fields

Document this core CEC structure.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: cec: remove unused waitq and phys_addrs fields

The cec_adapter struct contained a waitq field that isn't used
anywhere, so drop this.

It also contained a phys_addrs array to store any reported physical
addresses. However, this was never actually used, so this field is
removed as well. The original idea was to let the core keep track of
this information, but nothing was ever done with this. Should this
be needed in the future then it is easy enough to resurrect this.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: cec: remove unused functions

Remove several functions that are no longer used now that the
conversion of cec drivers to cec_notifier_conn_(un)register() and
cec_notifier_cec_adap_(un)register() is complete.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: cec: expose the new connector info API

Until now the connector info API was a kernel-internal API only.
This moves it to the public API and adds the new ioctl to retrieve
this information.

Signed-off-by: Dariusz Marcinkiewicz <darekm@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: add struct cec_connector_info support

Define struct cec_connector_info in media/cec.h and define
CEC_CAP_CONNECTOR_INFO. In a later patch this will be moved to
uapi/linux/cec.h.

The CEC_CAP_CONNECTOR_INFO capability can be set by drivers, but
cec_allocate_adapter() will remove it again until the public API
for this can be enabled once all drm drivers wire this up correctly.

Also add the cec_fill_conn_info_from_drm and cec_s_conn_info functions,
which are needed by drm drivers to fill in the cec_connector info
based on a drm_connector.

The cec_notifier_(un)register and cec_register_cec_notifier
prototypes were moved from cec-notifier.h to cec.h since cec.h no longer
includes cec-notifier.h. These headers included each other before,
which caused various problems.

Due to these changes the seco-cec driver was changed as well: it
should include cec-notifier.h, not cec.h.

Signed-off-by: Dariusz Marcinkiewicz <darekm@google.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: keep track of outstanding transmits

I noticed that repeatedly running 'cec-ctl --playback' would occasionally
select 'Playback Device 2' instead of 'Playback Device 1', even though there
were no other Playback devices in the HDMI topology. This happened both with
'real' hardware and with the vivid CEC emulation, suggesting that this was an
issue in the core code that claims a logical address.

What 'cec-ctl --playback' does is to first clear all existing logical addresses,
and immediately after that configure the new desired device type.

The core code will poll the logical addresses trying to find a free address.
When found it will issue a few standard messages as per the CEC spec and return.
Those messages are queued up and will be transmitted asynchronously.

What happens is that if you run two 'cec-ctl --playback' commands in quick
succession, there is still a message of the first cec-ctl command being transmitted
when you reconfigure the adapter again in the second cec-ctl command.

When the logical addresses are cleared, then all information about outstanding
transmits inside the CEC core is also cleared, and the core is no longer aware
that there is still a transmit in flight.

When the hardware finishes the transmit it calls transmit_done and the CEC core
thinks it is actually in response of a POLL messages that is trying to find a
free logical address. The result of all this is that the core thinks that the
logical address for Playback Device 1 is in use, when it is really an earlier
transmit that ended.

The main transmit thread looks at adap->transmitting to check if a transmit
is in progress, but that is set to NULL when the adapter is unconfigured.
adap->transmitting represents the view of userspace, not that of the hardware.
So when unconfiguring the adapter the message is marked aborted from the point
of view of userspace, but seen from the PoV of the hardware it is still ongoing.

So introduce a new bool transmit_in_progress that represents the hardware state
and use that instead of adap->transmitting. Now the CEC core waits until the
hardware finishes the transmit before starting a new transmit.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org> # for v4.18 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: name for RC passthrough device does not need 'RC for'

An RC device is does not need to be called 'RC for'. Simply the name
will suffice.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: fix the Signal Free Time calculation

The calculation of the Signal Free Time in the framework was not
correct. If a message was received, then the next transmit should be
considered a New Initiator and use a shorter SFT value.

This was not done with the result that if both sides where continually
sending messages, they both could use the same SFT value and one side
could deny the other side access to the bus.

Note that this fix does not take the corner case into account where
a receive is in progress when you call adap_transmit.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org> # for v4.18 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec/v4l2: move V4L2 specific CEC functions to V4L2

Several CEC functions are actually specific for use with receivers,
i.e. they should be part of the V4L2 subsystem, not CEC.

These functions deal with validating and modifying EDIDs for (HDMI)
receivers, and they do not actually have anything to do with the CEC
subsystem and whether or not CEC is enabled. The problem was that if
the CEC_CORE config option was not set, then these functions would
become stubs, but that's not right: they should always be valid.

So replace the cec_ prefix by v4l2_ and move them to v4l2-dv-timings.c.
Update all drivers that call these accordingly.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <stable@vger.kernel.org> # for v4.17 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: make cec_get_edid_spa_location() an inline function

This function is needed by both V4L2 and CEC, so move this to
cec.h as a static inline since there are no obvious shared
modules between the two subsystems.

This patch, together with the following ones, fixes a
dependency bug: if CEC_CORE is disabled, then building adv7604
(and other HDMI receivers) will fail because an essential
function is now stubbed out.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org> # for v4.17 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: add support for 5V signal testing

Add support for the new 5V CEC events

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: cec: improve CEC pin event handling

It turns out that the struct cec_fh event buffer size of 64 events
(64 for CEC_EVENT_PIN_CEC_LOW and 64 for _HIGH) is too small. It's
about 160 ms worth of events and if the Raspberry Pi is busy, then it
might take too long for the application to be scheduled so that it can
drain the pending events. Increase these buffers to 800 events which
is at least 2 seconds worth of events.

There is also a FIFO in between the interrupt and the cec-pin thread.
The thread passes the events on to the CEC core. It is important that
should this FIFO fill up the cec core will be informed that events
have been lost so this can be communicated to the user by setting
CEC_EVENT_FL_DROPPED_EVENTS.

It is very hard to debug CEC problems if events were lost without
informing the user of that fact.

If events were dropped due to the FIFO filling up, then the debugfs
status file will let you know how many events were dropped.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: add core error injection support

Add two new ops (error_inj_show and error_inj_parse_line) to support
error injection functionality for CEC adapters. If both are present,
then the core will add a new error-inj debugfs file that can be used
to see the current error injection commands and to set error injection
commands.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: include/(uapi/)media: add SPDX license info

Replace the old license information with the corresponding SPDX
license for those headers that I authored.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: move cec autorepeat handling to rc-core

CEC autorepeat is different than other protocols. Autorepeat is triggered
by the first repeated user control pressed CEC message, rather than a
fixed REP_DELAY.

This change also does away with the KEY_UP event directly after the first
KEY_DOWN event, which was used to stop autorepeat from starting.

See commit a9a249a2c997 ("media: cec: fix remote control passthrough")
for the original change.

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

media: cec: disable the hardware when unregistered

When the device is being unregistered disable the hardware, don't wait
until cec_delete_adapter is called as the hardware may have disappeared by
then. This would be the case for hotplugable devices.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Bård Eirik Winther <bwinther@cisco.com>
Tested-by: Bård Eirik Winther <bwinther@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: add the adap_monitor_pin_enable op

Some devices can monitor the CEC pin using an interrupt, but you
only want to enable the interrupt if you actually switch to pin
monitoring mode.

So add a new op that is called when pin monitoring needs to be
switched on or off.

Also fix a small bug where the initial CEC pin event was sent
again when calling S_MODE twice with the same CEC_MODE_MONITOR_PIN
mode.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec.h: initialize *parent and *port in cec_phys_addr_validate

Make sure these values are set to avoid 'uninitialized variable'
warnings. Hasn't happened yet, but better safe than sorry.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: add CEC_EVENT_PIN_HPD_LOW/HIGH events

Add support for two new low-level events: PIN_HPD_LOW and PIN_HPD_HIGH.

This is specifically meant for use with the upcoming cec-gpio driver
and makes it possible to trace when the HPD pin changes. Some HDMI
sinks do strange things with the HPD and this makes it easy to debug
this.

Note that this also moves the initialization of a devnode mutex and
list to the allocate_adapter function: if the HPD is high, then as
soon as the HPD interrupt is created an interrupt occurs and
cec_queue_pin_hpd_event() is called which requires that the devnode
mutex and list are initialized.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: replace pin->cur_value by adap->cec_pin_is_high

The current CEC pin value (0 or 1) was part of the cec_pin struct,
but that assumes that CEC pin monitoring can only be used with
a driver that uses the low-level CEC pin framework.

But hardware that has both a high-level API and can monitor the
CEC pin at low-level at the same time does not need to depend on
the cec pin framework.

To support such devices remove the cur_value field from struct cec_pin
and add a cec_pin_is_high field to cec_adapter. This also makes it
possible to drop the '#ifdef CONFIG_CEC_PIN' in cec-api.c.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: fix remote control passthrough

The 'Press and Hold' operation was not correctly implemented, in
particular the requirement that the repeat doesn't start until
the second identical keypress arrives. The REP_DELAY value also
had to be adjusted (see the comment in the code) to achieve the
desired behavior.

The 'enabled_protocols' field was also never set, fix that too. Since
CEC is a fixed protocol the driver has to set this field.

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

media: rc-core: rename input_name to device_name

When an ir-spi is registered, you get this message.

rc rc0: Unspecified device as /devices/platform/soc/3f215080.spi/spi_master/spi32766/spi32766.128/rc/rc0

"Unspecified device" refers to input_name, which makes no sense for IR
TX only devices. So, rename to device_name.

Also make driver_name const char* so that no casts are needed anywhere.

Now ir-spi reports:

rc rc0: IR SPI as /devices/platform/soc/3f215080.spi/spi_master/spi32766/spi32766.128/rc/rc0

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: rename pin events/function

The CEC_EVENT_PIN_LOW/HIGH defines and the cec_queue_pin_event() function
did not specify that these were about CEC pin events.

Since in the future there will also be HPD pin events it is wise to rename
the event defines and function to CEC_EVENT_PIN_CEC_LOW/HIGH and
cec_queue_pin_cec_event() now before these become part of the ABI.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: media/cec.h: add CEC_CAP_DEFAULTS

The CEC_CAP_LOG_ADDRS, CEC_CAP_TRANSMIT, CEC_CAP_PASSTHROUGH and
CEC_CAP_RC capabilities are normally always present.

Add a CEC_CAP_DEFAULTS define that ORs these four caps to simplify
drivers.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: move cec_register_cec_notifier to cec-notifier.h

The cec_register_cec_notifier function was in media/cec.h, but it
has to be in cec-notifier.h.

While we are at it, also document it and add a stub function for when
the notifier is disabled or the CEC core code is unreachable.

Based on an earlier patch from Jose Abreu <Jose.Abreu@synopsys.com>.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec-pin: add low-level pin hardware support

Add support for CEC hardware that relies on low-level pin polling or
GPIO interrupts.

One example is the Allwinner SoC. But any GPIO-based CEC implementation can
use this as well.

A GPIO implementation is very suitable as well for debugging: it can use
interrupts to detect state changes and report it. Userspace can then verify
if the bus traffic is correct. This also makes error injection possible.

The disadvantage is that it is hard to get the timings right since linux
isn't a hard realtime system.

In general on an idle system it works quite well, but under load the timer
will miss its mark every so often.

The debugfs file /sys/kernel/debug/cec/cecX/status gives some statistics
with respect to the timer overruns.

When the adapter is unconfigured and the low-level driver supports
interrupts, then the interrupt will be used to detect changes. This should
be quite accurate. But when the adapter is configured a hrtimer has to be
used.

The hrtimer implements a state machine where for each state the code will
read the bus or drive the bus and go on to the next state. It will re-arm
the timer with a delay based on the next state.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: add core support for low-level CEC pin monitoring

Add support for the new MONITOR_PIN mode.

Add the cec_pin_event function that the CEC pin code will call to queue pin
change events.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: rework the cec event handling

Event handling was always fairly simplistic since there were only
two events. With the addition of pin events this needed to be redesigned.

The state_change and lost_msgs events are now core events with the
guarantee that the last state is always available. The new pin events
are a queue of events (up to 64 for each event) and the oldest event
will be dropped if the application cannot keep up. Lost events are
marked with a new event flag.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: add adap_free op

This is needed for CEC adapters that allocate resources that have
to be freed before the cec_adapter is deleted.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: add *_ts variants for transmit_done/received_msg

Currently the transmit_(attempt_)done and received_msg functions set
the timestamp themselves. For the upcoming low-level pin API we need
to pass this as an argument instead. So make _ts variants that allow
the caller to specify the timestamp.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

media: cec: improve transmit timeout logging

Kernel logging messes up the upcoming low-level CEC monitoring support
which is very time-sensitive. So change the debug level of this message
but keep a counter that is shown in the debugfs status log.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: add CEC_CAP_NEEDS_HPD

Add a new capability CEC_CAP_NEEDS_HPD. If this capability is set
then the hardware can only use CEC if the HDMI Hotplug Detect pin
is high. Such hardware cannot handle the corner case in the CEC specification
where it is possible to transmit messages even if no hotplug signal is
present (needed for some displays that turn off the HPD when in standby,
but still have CEC enabled).

Typically hardware that needs this capability have the HPD wired to the CEC
block, often to a 'power' or 'active' pin.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: add cec_transmit_attempt_done helper function

A simpler variant of cec_transmit_done to be used where the HW does
just a single attempt at a transmit. So if the status indicates an
error, then the corresponding error count will always be 1 and this
function figures that out based on the status argument.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: add cec_phys_addr_invalidate() helper function

Simplifies setting the physical address to CEC_PHYS_ADDR_INVALID.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: add cec_s_phys_addr_from_edid helper function

This function simplifies the integration of CEC in DRM drivers.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media/cec.h: use IS_REACHABLE instead of IS_ENABLED

Fix messages like this:

adv7842.c:(.text+0x2edadd): undefined reference to `cec_unregister_adapter'

when CEC_CORE=m but the driver including media/cec.h is built-in. In that case
the static inlines provided in media/cec.h should be used by that driver.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: rename MEDIA_CEC_NOTIFIER to CEC_NOTIFIER

This config option is strictly speaking independent of the
media subsystem since it can be used by drm as well.

Besides, it looks odd when drivers select CEC_CORE and
MEDIA_CEC_NOTIFIER, that's inconsistent naming.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec.h: merge cec-edid.h into cec.h

Drop the separate cec-edid.h header and merge it into cec.h.

There was really no need to have a separate header for this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: Kconfig cleanup

The Kconfig options for the CEC subsystem were a bit messy. In
addition there were two cec sources (cec-edid.c and cec-notifier.c)
that were outside of the media/cec directory, which was weird.

Move those sources to media/cec as well.

The cec-edid and cec-notifier functionality is now part of the cec
module and these are no longer separate modules.

Also remove the MEDIA_CEC_EDID config option and include it with the
main CEC config option (which defined CEC_EDID anyway).

Added static inlines to cec-edid.h for dummy functions when CEC_CORE
isn't defined.

CEC drivers should now depend on CEC_CORE.

CEC drivers that need the cec-notifier functionality must explicitly
select CEC_NOTIFIER.

The s5p-cec and stih-cec drivers depended on VIDEO_DEV instead of
CEC_CORE, fix that as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: integrate CEC notifier support

Support the CEC notifier framework, simplifying drivers that
depend on this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: Add cec_get_drvdata()

Add a helper function to get driver private data from CEC
adapter. This helps the readability a little bit and allows
to change the 'priv' field name to something else without
needing to touch all drivers.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: pass parent device in register(), not allocate()

The cec_allocate_adapter function doesn't need the parent device, only the
cec_register_adapter function needs it.

Drop the cec_devnode parent field, since devnode.dev.parent can be used
instead.

This change makes the framework consistent with other frameworks where the
parent device is not used until the device is registered.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: move the CEC framework out of staging and to media

The last open issues have been addressed, so it is time to move
this out of staging and into the mainline and to move the public
cec headers to include/uapi/linux.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: rename cec_devnode fhs_lock to just lock

This lock will be used to protect more than just the fhs list.
So rename it to just 'lock'.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: limit the size of the transmit queue

The size of the transmit queue was unlimited, which meant that
in non-blocking mode you could flood the CEC adapter with messages
to be transmitted.

Limit this to 18 messages.

Also print the number of pending transmits and the timeout value
in the status debugfs file.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] cec: add HDMI CEC framework (core)

The added HDMI CEC framework provides a generic kernel interface for
HDMI CEC devices.

Note that the CEC framework is added to staging/media and that the
cec.h and cec-funcs.h headers are not exported yet. While the kABI
is mature, I would prefer to allow the uABI some more time before
it is mainlined in case it needs more tweaks.

This adds the cec-core.c, media/cec.h and cec-priv.h sources.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[k.debski@samsung.com: Merged CEC Updates commit by Hans Verkuil]
[k.debski@samsung.com: Merged Update author commit by Hans Verkuil]
[k.debski@samsung.com: code cleanup and fixes]
[k.debski@samsung.com: add missing CEC commands to match spec]
[k.debski@samsung.com: add RC framework support]
[k.debski@samsung.com: move and edit documentation]
[k.debski@samsung.com: add vendor id reporting]
[k.debski@samsung.com: reorder of API structs and add reserved fields]
[k.debski@samsung.com: fix handling of events and fix 32/64bit timespec problem]
[k.debski@samsung.com: add sequence number handling]
[k.debski@samsung.com: add passthrough mode]
[k.debski@samsung.com: fix CEC defines, add missing CEC 2.0 commands]
Signed-off-by: Kamil Debski <kamil@wypas.org>

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>