The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.
This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.
With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.
Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some devices don't drain their pipelines if we don't make sure that
the corresponding output port is in reset before programming it for
a new trace capture, resulting in bits of old trace appearing in the
new trace capture. Fix that by explicitly making sure the reset is
asserted before programming new trace capture.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210621151246.31891-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As described in the added comment device_for_each_child() never returns
a non-zero value. So remove the corresponding error check.
This simplifies the quest to make struct bus_type::remove() return void.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210621151246.31891-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Anything that deals with drvdata structures should leave them intact.
Reflect this in function signatures.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210414171251.14672-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit aac8da6517 ("intel_th: msu: Start handling IRQs") implicitly
relies on the use of devm_request_irq() to subsequently free the irqs on
device removal, but in case of the pci_free_irq_vectors() API, the
handlers need to be freed before it is called. Therefore, at the moment
the driver's remove path trips a BUG_ON(irq_has_action()):
> kernel BUG at drivers/pci/msi.c:375!
> invalid opcode: 0000 1 SMP
> CPU: 2 PID: 818 Comm: rmmod Not tainted 5.5.0-rc1+ #1
> RIP: 0010:free_msi_irqs+0x67/0x1c0
> pci_disable_msi+0x116/0x150
> pci_free_irq_vectors+0x1b/0x20
> intel_th_pci_remove+0x22/0x30 [intel_th_pci]
> pci_device_remove+0x3e/0xb0
> device_release_driver_internal+0xf0/0x1c0
> driver_detach+0x4c/0x8f
> bus_remove_driver+0x5c/0xd0
> driver_unregister+0x31/0x50
> pci_unregister_driver+0x40/0x90
> intel_th_pci_driver_exit+0x10/0xad6 [intel_th_pci]
> __x64_sys_delete_module+0x147/0x290
> ? exit_to_usermode_loop+0xd7/0x120
> do_syscall_64+0x57/0x1b0
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by explicitly freeing irqs before freeing the vectors. We keep
using the devm_* variants because they are still useful in early error
paths.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: aac8da6517 ("intel_th: msu: Start handling IRQs")
Reported-by: Ammy Yi <ammy.yi@intel.com>
Tested-by: Ammy Yi <ammy.yi@intel.com>
Cc: stable@vger.kernel.org # v5.2+
Link: https://lore.kernel.org/r/20191217115527.74383-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a753bfcfdb ("intel_th: Make the switch allocate its subdevices")
factored out intel_th_subdevice_alloc() from intel_th_populate(), but got
the error path wrong, resulting in two instances of a double put_device()
on a freshly initialized, but not 'added' device.
Fix this by only doing one put_device() in the error path.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: a753bfcfdb ("intel_th: Make the switch allocate its subdevices")
Reported-by: Wen Yang <wenyang@linux.alibaba.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable@vger.kernel.org # v4.14+
Link: https://lore.kernel.org/r/20191120130806.44028-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a helper to match a device by its type and provide wrappers
for {bus/class/driver}_find_device() APIs.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-usb@vger.kernel.org
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20190723221838.12024-5-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is an arbitrary difference between the prototypes of
bus_find_device() and class_find_device() preventing their callers
from passing the same pair of data and match() arguments to both of
them, which is the const qualifier used in the prototype of
class_find_device(). If that qualifier is also used in the
bus_find_device() prototype, it will be possible to pass the same
match() callback function to both bus_find_device() and
class_find_device(), which will allow some optimizations to be made in
order to avoid code duplication going forward. Also with that, constify
the "data" parameter as it is passed as a const to the match function.
For this reason, change the prototype of bus_find_device() to match
the prototype of class_find_device() and adjust its callers to use the
const qualifier in accordance with the new prototype of it.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Kershner <david.kershner@unisys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Sebastian Ott <sebott@linux.ibm.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: rafael@kernel.org
Acked-by: Corey Minyard <minyard@acm.org>
Acked-by: David Kershner <david.kershner@unisys.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for asserting window switch trigger when tracing to MSU output
ports. This allows for software controlled switching between windows of
the MSU buffer, which can be used for double buffering while exporting the
trace data further from the MSU.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The only type of IRQ triggering event that is useful to us at the moment
is the "last block" interrupt of the MSU. This interrupt can only be
enabled via "MINTCTL" register that doesn't exist in earlier version of
the Intel TH.
Enumerate the presence of MINTCTL via per-device driver data structure
and only instantiate the IRQ resource for subdevices if this capability
is present.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We intend to use the interrupt to detect Last Block condition in the MSU
driver, which we can use for double-buffering software-managed data
transfers.
Add an interrupt handler to the MSU driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, the IRQ is passed between the glue layers and the core as a
separate argument, while the MMIO resources are passed as resources.
This also limits the number of IRQs thus used to one, while the current
versions of Intel TH use a different MSI vector for each interrupt
triggering event, of which there are 7.
Change this to pass IRQ in the resources array.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In some versions of Intel TH, the Software Trace Hub (STH) has a second
MMIO BAR dedicated to the input from Intel PT. This calls for a new
subdevice that will be enumerated if the corresponding BAR is present.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a subdevice requires an MMIO region that wasn't in the resources passed
down from the glue layer, don't instantiate it, but don't error out. This
means that that particular subdevice doesn't exist for this instance of
Intel TH, which is a perfectly normal situation. This applies, for example,
to the "rtit" source device.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, MMIO resource numbers in the TH driver core correspond to
PCI BAR numbers, because in the beginning there was only the PCI glue
layer. This created some confusion when the ACPI glue layer was added.
To avoid confusion and remove glue-specific code from the driver core,
split the resource indices between core and glue layers and change the
API so that the driver core receives the MMIO resources in the same
fixed order. At the same time, make the IRQ always be a parameter to
intel_th_alloc() instead of sometimes passing it as a resource.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Right now, the driver will create a device node for each output port,
with the intent to provide read access to that port's data. However,
only the memory ports are readable this way (msc0, msc1). Other output
ports don't need device nodes, so remove them.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
The core of the driver expects the resource array from the glue layer
to be indexed by even numbers, as is the case for 64-bit PCI resources.
This doesn't hold true for others, ACPI in this instance, which leads
to an out-of-bounds access and an ioremap() on whatever address that
access fetches.
This patch fixes the problem by reading resource array differently based
on whether the 64-bit flag is set, which would indicate PCI glue layer.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: ebc57e399b ("intel_th: Add ACPI glue layer")
CC: stable@vger.kernel.org # v4.17+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a753bfcfdb ("intel_th: Make the switch allocate its subdevices")
brings in new subdevice addition/removal logic that's broken for "host
mode": the SWITCH device has no children to begin with, which is not
handled in the code. This results in a null dereference bug later down
the path.
This patch fixes the subdevice removal code to handle host mode correctly.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: a753bfcfdb ("intel_th: Make the switch allocate its subdevices")
CC: stable@vger.kernel.org # v4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some devices can only operate in host mode, so we need means of
communicating this to the core driver on per-device basis. This
adds a flag to drvdata to signal host-only capability to the core.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Platform devices pass their IRQs around as resources, so as a convenience
for the glue layer code, allow them pass the IRQ to the core driver in
the resources array.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
When the Trace Hub is operating in Host Debugger mode, it is up to the
debugger to configure master routing even for the software sources. Do
not do this in the driver in this case.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Since commit 8edc514b01 ("intel_th: Make SOURCE devices children of the
root device") the hub is not the parent of SOURCE devices any more, so the
new helper function should be used for that instead of always using the
parent. The intel_th_set_output() path, however, still uses the old
logic, leading to the hub driver structure being aliased with something
else, like struct pci_driver or struct acpi_driver, and an incorrect call
to an address inferred from that, potentially resulting in a crash.
Fixes: 8edc514b01 ("intel_th: Make SOURCE devices children of the root device")
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
This adds SPDX GPL-2.0 header to the Trace Hub driver and removes the
GPLv2 boilerplate text.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
On some devices (TH 2.x devices at the moment), the internal time counter
is initially not synchronized to the global crystal clock, so the time
stamps it produces will not be useful. In this case, the driver needs
to force the time counter resync.
This applies the workaround to relevant devices.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
A glue layer may want to install its own hooks into trace capture start
and stop paths to apply workarounds. This adds optional callbacks.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Trace Hub 2.x adds Low Power Path (LPP) output port type, which provides
a low power mode trace path from sources to PTI or BSSB.
This adds an output subdevice for the LPP port.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Instead of allocating devices for every possible output subdevice,
allow the switch to allocate only the ones that it knows about.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
The switch (GTH) does not directly interact with SOURCE type devices and
may not even be present (in host mode). To reflect this and avoid
inconsistencies between target and host mode, make SOURCE devices
descendant directly from the root (i.e. PCI) device. Their symlinks
will no longer appear under the switch device, but they can still
be found under intel_th bus.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
The dev_attrs field has long been "depreciated" and is finally being
removed, and as this driver isn't even using it, just drop the NULL
setting, it is pointless.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Output 'activation' may fail for the reasons of the output driver,
for example, if msc's buffer is not allocated. We forget, however,
to drop the module reference in this case. So each attempt at
activation in this case leaks a reference, preventing the module
from ever unloading.
This patch adds the missing module_put() in the activation error
path.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: stable@vger.kernel.org # v4.8+
This patch adds a 'host_mode' module option to enable host-driven
operational mode in the driver. In this mode, the driver does not
perform trace configuration or enable trace capture, but still
provides all the means necessary for software trace sources to
write their data to the Trace Hub. This means that the debug host
takes care of all the configuration and enabling and we do not
interfere.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
These are:
* a fix for a modprobe time deadlock
* a new PCI ID for Kaby Lake PCH-H
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Merge tag 'stm-for-greg-20160714' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-next
Alexander writes:
intel_th: Fixes -t://git.kernel.org/pub/scm/linux/kernel/git/ash/stm.git
tags/stm-for-greg-20160714
stable
These are:
* a fix for a modprobe time deadlock
* a new PCI ID for Kaby Lake PCH-H
Driver initialization tries to request a hub (GTH) driver module from
its probe callback, resulting in a deadlock.
This patch solves the problem by adding a deferred work for requesting
the hub module.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: <stable@vger.kernel.org> # 4.4.x-
Currently, an Intel TH (pci) device will be always active, because the
devices on the 'intel_th' bus don't implement runtime pm to track their
usage.
To address this, this patch adds runtime pm support to the 'intel_th'
bus and some additional bits for the hub. The 'output' type device is
in use while a capture is active; the 'source' type device (STH) relies
on its child stm class device for runtime pm tracking.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Right now it's possible to unload the output subdevice's driver while
the capture to this output is active. Prevent this by holding the
output driver's module reference.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
If output subdevice driver is not loaded, activating it will try to
call its ->activate method and crash. Fix this by explicitly checking
for the driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Some subdevices (MSU, PTI) need to register their own driver-specific
attribute groups. Provide a way for those to pass their attribute
groups to the core driver in their driver structure so that the
core can take care of creating and removing them.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Laurent Fert <laurent.fert@intel.com>
Most of the intel_th core supports multiple co-existing TH devices,
except for output device nodes, where intel_th device id is hardcoded
to be zero.
Fix this by fetching the actual intel_th device id from the parent
device's drvdata.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Already during the subdevice initialization time, devices will need
to reference Intel TH controller descriptor structure.
This patch moves setting the drvdata from the pci glue to intel_th
core, before subdevices are populated.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel TH implements a scratchpad register to indicate to the firmware
and external debuggers what trace configuration is enabled so that
everybody plays nicely together. The register is a bit field and the
bit assignment convention is described in the developer's manual.
This patch enables the driver to automatically set scratchpad register
bits according to the output configuration that's enabled.
Based on work by Yann Fouassier.
Signed-off-by: Yann Fouassier <yann.fouassier@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel(R) Trace Hub (TH) is a set of hardware blocks (subdevices) that
produce, switch and output trace data from multiple hardware and
software sources over several types of trace output ports encoded
in System Trace Protocol (MIPI STPv2) and is intended to perform
full system debugging.
For these subdevices, we create a bus, where they can be discovered
and configured by userspace software.
This patch creates this bus infrastructure, three types of devices
(source, output, switch), resource allocation, some callback mechanisms
to facilitate communication between the subdevices' drivers and some
common sysfs attributes.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Uwe Kleine-König