The coresight drivers have absolutely no control over bind and unbind
operations triggered from sysfs. The operations simply can't be
cancelled or denied event when one or several tracing sessions are
under way.  Since the memory associated to individual device is
invariably freed, the end result is a kernel crash when the path from
source to sink is travelled again as demonstrated here[1].

One solution could be to keep track of all the path (i.e tracing
session) that get created and iterate through the elements of those path
looking for the coresight device that is being removed.  This proposition
doesn't scale well since there is no upper bound on the amount of
concurrent trace session that can be created.

With the above in mind, this patch prevent devices from being unbounded
from their driver by using the driver->suppress_bind_attr option.  That way
trace sessions can be managed without fearing to loose devices.

Since device can't be removed anymore the xyz_remove() functions found in
each driver is also removed.

[1]. http://www.spinics.net/lists/arm-kernel/msg474952.htmlReported-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In commit 620cf787 ("coresight: replicator:
Add Qualcomm CoreSight Replicator driver") this driver was added.

It uses module_amba_driver(replicator_driver) to register itself with
the system -- which is just an alias for module_driver.  This currently
works by relying on getting that via init.h but we are planning to move
that code[1] to module.h -- at which time this will fail to compile since
it does not include module.h currently, resulting in:

drivers/hwtracing/coresight/coresight-replicator-qcom.c:214:1: error: type defaults to 'int' in declaration of 'module_init' [-Werror=implicit-int]
drivers/hwtracing/coresight/coresight-replicator-qcom.c:214:1: error: type defaults to 'int' in declaration of 'module_exit' [-Werror=implicit-int]

In the future, the amba support may want to create another alias that
uses builtin_driver[2] for cases like this which are using bool Kconfig
triggers, but for now we just fix the implicit include.

[1] https://lkml.kernel.org/r/1433276168-21550-1-git-send-email-paul.gortmaker@windriver.com
[2] https://lkml.kernel.org/r/1431287385-1526-1-git-send-email-paul.gortmaker@windriver.com

Cc: Pratik Patel <pratikp@codeaurora.org>
Cc: Ivan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver manages Qualcomm CoreSight Replicator device, which
resides on the AMBA bus. Replicator has been made programmable to
allow software to turn of the replicator branch to sink that is not
being used. This avoids trace traffic to the unused/non-current sink
from causing back pressure that results in overflows at the source.
Signed-off-by: NPratik Patel <pratikp@codeaurora.org>
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As can be seen from the datasheet of the CoreSight
Components, DDI0314 table A-4 the funnel has a clock signal
apart from the AHB interconnect ("amba_pclk", that we're
already handling) called ATCLK, ARM Trace Clock, that SoC
implementers may provide from an entirely different clock
source. So to model this correctly create an optional
path for handling ATCLK alongside the PCLK so we don't
break old platforms that only define PCLK ("amba_pclk") but
still makes it possible for SoCs that have both clock signals
(such as the DB8500) to fetch and prepare/enable/disable/
unprepare both clocks.

The ATCLK is enabled and disabled using the runtime PM
callbacks. As the replicator is a platform device, the
code is a bit different from the other CoreSight components
and the bus core does not activate runtime PM by default,
so we need a few extra calls.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Keeping drivers related to HW tracing on ARM, i.e coresight,
under "drivers/coresight" doesn't make sense when other
architectures start rolling out technologies of the same
nature.

As such creating a new "drivers/hwtracing" directory where all
drivers of the same kind can reside, reducing namespace
pollution under "drivers/".
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the classification, the type of replicator
is link, so the subtype should also be link_subtype.
Signed-off-by: NKaixu Xia <xiakaixu@huawei.com>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need of .owner field for driver using
module_platform_driver.
Signed-off-by: NPankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver manages non-configurable CoreSight Replicator that
takes a single input trace data stream and replicates it to
produce two identical trace data output streams. Replicators
are typically used to route single interleaved trace data
stream to two or more sinks.
Signed-off-by: NPratik Patel <pratikp@codeaurora.org>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>