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2020-07-10intel_th: Fix a NULL dereference when hub driver is not loadedAlexander Shishkin1-3/+18
Connecting master to an output port when GTH driver module is not loaded triggers a NULL dereference: > RIP: 0010:intel_th_set_output+0x35/0x70 [intel_th] > Call Trace: > ? sth_stm_link+0x12/0x20 [intel_th_sth] > stm_source_link_store+0x164/0x270 [stm_core] > dev_attr_store+0x17/0x30 > sysfs_kf_write+0x3e/0x50 > kernfs_fop_write+0xda/0x1b0 > __vfs_write+0x1b/0x40 > vfs_write+0xb9/0x1a0 > ksys_write+0x67/0xe0 > __x64_sys_write+0x1a/0x20 > do_syscall_64+0x57/0x1d0 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 Make sure the module in question is loaded and return an error if not. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Fixes: 39f4034693b7c ("intel_th: Add driver infrastructure for Intel(R) Trace Hub devices") Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reported-by: Ammy Yi <ammy.yi@intel.com> Tested-by: Ammy Yi <ammy.yi@intel.com> Cc: stable@vger.kernel.org # v4.4 Link: https://lore.kernel.org/r/20200706161339.55468-5-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17intel_th: Fix freeing IRQsAlexander Shishkin1-3/+4
Commit aac8da65174a ("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: aac8da65174a ("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>
2019-11-20intel_th: Fix a double put_device() in error pathAlexander Shishkin1-6/+2
Commit a753bfcfdb1f ("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: a753bfcfdb1f ("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>
2019-07-30drivers: Introduce device lookup variants by device typeSuzuki K Poulose1-9/+1
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>
2019-06-24bus_find_device: Unify the match callback with class_find_deviceSuzuki K Poulose1-3/+2
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>
2019-05-03intel_th: Add switch triggering supportAlexander Shishkin1-2/+23
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>
2019-05-03intel_th: Only report useful IRQs to subdevicesAlexander Shishkin1-1/+6
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>
2019-05-03intel_th: msu: Start handling IRQsAlexander Shishkin1-0/+32
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>
2019-05-03intel_th: Communicate IRQ via resourceAlexander Shishkin1-5/+18
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>
2019-05-03intel_th: Add "rtit" source deviceAlexander Shishkin1-0/+18
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>
2019-05-03intel_th: Skip subdevices if their MMIO is missingAlexander Shishkin1-4/+9
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>
2019-05-03intel_th: Rework resource passing between glue layers and coreAlexander Shishkin1-20/+7
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>
2019-02-21intel_th: Only create useful device nodesAlexander Shishkin1-1/+5
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>
2018-09-18intel_th: Fix resource handling for ACPI glue layerAlexander Shishkin1-2/+11
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: ebc57e399b8e ("intel_th: Add ACPI glue layer") CC: stable@vger.kernel.org # v4.17+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18intel_th: Fix device removal logicAlexander Shishkin1-1/+2
Commit a753bfcfdb1f ("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: a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices") CC: stable@vger.kernel.org # v4.14+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28intel_th: Allow forcing host mode through drvdataAlexander Shishkin1-2/+4
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>
2018-03-28intel_th: Pick up irq number from resourcesAlexander Shishkin1-1/+8
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>
2018-03-28intel_th: Don't touch switch routing in host modeAlexander Shishkin1-0/+4
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>
2018-03-28intel_th: Use correct method of finding hubAlexander Shishkin1-1/+1
Since commit 8edc514b01e9 ("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: 8edc514b01e9 ("intel_th: Make SOURCE devices children of the root device") Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2018-03-28intel_th: Add SPDX GPL-2.0 header to replace GPLv2 boilerplateAlexander Shishkin1-9/+1
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>
2017-08-25intel_th: Perform time resync on capture startAlexander Shishkin1-1/+2
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>
2017-08-25intel_th: Add global activate/deactivate callbacks for the glue layersAlexander Shishkin1-4/+22
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>
2017-08-25intel_th: pci: Use drvdata for quirksAlexander Shishkin1-2/+4
Allow attaching miscellaneous quirk information to devices as drvdata. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2017-08-25intel_th: Enumerate Low Power Path output port typeAlexander Shishkin1-0/+15
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>
2017-08-25intel_th: Make the switch allocate its subdevicesAlexander Shishkin1-82/+206
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>
2017-08-25intel_th: Make SOURCE devices children of the root deviceAlexander Shishkin1-3/+3
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>
2017-08-25intel_th: Streamline the subdevice tree accessorsAlexander Shishkin1-15/+0
Make to_intel_th*() accessors available from the main header file. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2017-06-09hwtracing: intel_th: use dev_groups and not dev_attrs for bus_typeGreg Kroah-Hartman1-1/+0
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>
2017-03-15intel_th: Don't leak module refcount on failure to activateAlexander Shishkin1-1/+3
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+
2016-11-18intel_th: Support Host Debugger mode of operationAlexander Shishkin1-8/+18
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>
2016-11-18intel_th: Constify subdevicesAlexander Shishkin1-1/+1
The subdevice array consists of immutable objects, make them const. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
2016-07-15Merge tag 'stm-for-greg-20160714' of ↵Greg Kroah-Hartman1-1/+34
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
2016-07-14intel_th: Fix a deadlock in modprobingAlexander Shishkin1-1/+34
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-
2016-07-01intel_th: Add runtime power management handlingAlexander Shishkin1-9/+45
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>
2016-04-08intel_th: Hold output driver module reference while capture is activeAlexander Shishkin1-0/+5
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>
2016-04-08intel_th: Fix activating a subdevice without a driverAlexander Shishkin1-2/+10
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>
2016-04-08intel_th: Allow subdevice drivers to bring in own attribute groupsAlexander Shishkin1-0/+12
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>
2016-02-20intel_th: Use real device index in the node namesAlexander Shishkin1-3/+20
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>
2016-02-20intel_th: Set root device's drvdata earlyAlexander Shishkin1-0/+2
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>
2016-02-20intel_th: Update scratchpad bits according to enabled output activityAlexander Shishkin1-0/+5
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>
2015-10-04intel_th: Add driver infrastructure for Intel(R) Trace Hub devicesAlexander Shishkin1-0/+692
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>