Commit graph

15 commits

Author SHA1 Message Date
Colin Ian King 0fd6e12173 media: cec: set ev rather than v with CEC_PIN_EVENT_FL_DROPPED bit
Setting v with the CEC_PIN_EVENT_FL_DROPPED is incorrect, instead
ev should be set with this bit. Fix this.

Detected by CoverityScan, CID#1467974 ("Extra high-order bits")

Fixes: 6ec1cbf6b1 ("media: cec: improve CEC pin event handling")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-04-20 08:37:35 -04:00
Jasmin Jessich 437fba47f4 media: cec-pin: Fixed ktime_t to ns conversion
Older Kernels use a struct for ktime_t, which requires the conversion
function ktime_to_ns to be used on some places. With this patch it will
compile now also for older Kernel versions.

Signed-off-by: Jasmin Jessich <jasmin@anw.at>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-04-04 06:12:52 -04:00
Hans Verkuil 6ec1cbf6b1 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>
2018-03-22 08:16:52 -04:00
Hans Verkuil 2b76e5392d media: cec-pin: improve status log
Keep track of the number of short or long start bits, the number
of short or long data bits and the number of initiated or detected
low drive conditions.

Show this information in the status debugfs log.

Helpful when debugging, particularly when doing error injection
as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-22 08:16:21 -04:00
Hans Verkuil 865463fc03 media: cec-pin: add error injection support
Implement all the error injection commands.

The state machine gets new states for the various error situations,
helper functions are added to detect whether an error injection is
active and the actual error injections are implemented.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-22 08:01:43 -04:00
Hans Verkuil 22712b389e media: cec-pin-error-inj: parse/show error injection
Add support to the CEC Pin framework to parse error injection commands
and to show them.

The next patch will do the actual implementation of this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-22 08:00:59 -04:00
Hans Verkuil 0ee492ad54 media: cec-pin: create cec_pin_start_timer() function
This function will be needed for injecting a custom pulse.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-03-22 08:00:27 -04:00
Hans Verkuil b4e30a9e05 media: cec: add SPDX license info
Replace the old license information with the corresponding SPDX
license.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-02-14 13:16:03 -05:00
Hans Verkuil 60757ee62b media: cec-pin: use IS_ERR instead of PTR_ERR_OR_ZERO
cec_allocate_adapter never returns NULL, so just use IS_ERR instead of
PTR_ERR_OR_ZERO.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-10-31 07:21:23 -04:00
Hans Verkuil 5bf24e08b6 media: cec-pin.h: move non-kAPI parts into cec-pin-priv.h
The kAPI cec-pin.h header also defined data structures that did
not belong here but were private to the CEC core code.

Split that part off into a cec-pin-priv.h header.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2017-10-27 14:02:19 +02:00
Hans Verkuil 805f23af6f media: cec-pin.c: use proper ktime accessor functions
Use ktime_to_ns/ns_to_ktime. This makes it possible to work with older kernels
and the media_build compatibility system.

For the mainline kernel these functions are NOPs.

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>
2017-09-23 07:34:48 -04:00
Hans Verkuil 28e11b15b6 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>
2017-08-26 08:35:10 -04:00
Hans Verkuil cb74749493 media: cec-pin: fix irq handling
The free_irq() function could be called from interrupt context,
which is invalid. Move this to the thread.

In the interrupt handler we just request that the thread disables
the irq. This is done through an atomic so we don't need to add
any spinlocks.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-08-20 08:15:00 -04:00
Hans Verkuil 9a6b2a8740 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>
2017-08-20 08:14:03 -04:00
Hans Verkuil ea5c8ef296 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>
2017-07-18 12:57:18 -03:00