Commit Graph

33 Commits

Author SHA1 Message Date
Mika Westerberg c4630d6ae6 thunderbolt: Start firmware on Titan Ridge Apple systems
Titan Ridge flow to start the firmware is the same as Alpine Ridge so we
can do the same on Titan Ridge based Apple systems.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-04-18 11:18:54 +03:00
Mika Westerberg 62efe699a7 thunderbolt: Make rest of the logging to happen at debug level
Now that the driver can handle every possible tunnel types there is no
point to log everything as info level so turn these to happen at debug
level instead.

While at it remove duplicated tunnel activation log message
(tb_tunnel_activate() calls tb_tunnel_restart() which print the same
message) and add one missing '\n' termination.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-04-18 11:18:53 +03:00
Mika Westerberg 444ac38448 thunderbolt: Make tb_switch_alloc() return ERR_PTR()
In order to detect possible connections to other domains we need to be
able to find out why tb_switch_alloc() fails so make it return ERR_PTR()
instead. This allows the caller to differentiate between errors such as
-ENOMEM which comes from the kernel and for instance -EIO which comes
from the hardware when trying to access the possible switch.

Convert all the current call sites to handle this properly.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-04-18 11:18:53 +03:00
Mika Westerberg dfe40ca486 thunderbolt: Assign remote for both ports in case of dual link
Currently the driver only assigns remote port for the primary port if in
case of dual link. This makes things such as walking from one port to
another more complex than necessary because the code needs to change
from secondary to primary port if the path that is established is
created using secondary links.

In order to always assign both remote pointers we need to prevent the
scanning code from following the secondary link. Failing to do that
might cause problems as the same switch may be enumerated twice (or
removed in case of unplug). Handle that properly by introducing a new
function tb_port_has_remote() that returns true only for the primary
port. We also update tb_is_upstream_port() to support both dual link
ports, make it take const port pointer and move it below
tb_upstream_port() to keep similar functions close.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-04-18 11:18:52 +03:00
Mika Westerberg f0342e757c thunderbolt: Do not allocate switch if depth is greater than 6
Maximum depth in Thunderbolt topology is 6 so make sure it is not
possible to allocate switches that exceed the depth limit.

While at it update tb_switch_alloc() to use upper/lower_32_bits()
following tb_switch_alloc_safe_mode().

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-04-18 11:18:51 +03:00
Mika Westerberg 8f965efd21 thunderbolt: Drop duplicated get_switch_at_route()
tb_switch_find_by_route() does the same already so use it instead and
remove duplicated get_switch_at_route().

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
2019-04-18 11:18:51 +03:00
Aditya Pakki fd21b79e54 thunderbolt: Fix to check the return value of kmemdup
uuid in add_switch is allocted via kmemdup which can fail. The patch
logs the error and cleans up the allocated memory for switch.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-03-28 11:33:59 +03:00
Greg Kroah-Hartman ba1cb318dc Merge 4.19-rc7 into char-misc-next
We want the fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-08 15:33:21 +02:00
Mika Westerberg fd3b339cbb thunderbolt: Convert rest of the driver files to use SPDX identifier
This gets rid of the licence boilerplate duplicated in each file. While
there fix doubled space in domain.c author line.

No functional changes intended.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkelshb@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02 15:52:08 -07:00
Mika Westerberg 86da809dda thunderbolt: Do not handle ICM events after domain is stopped
If there is a long chain of devices connected when the driver is loaded
ICM sends device connected event for each and those are put to tb->wq
for later processing. Now if the driver gets unloaded in the middle, so
that the work queue is not yet empty it gets flushed by tb_domain_stop().
However, by that time the root switch is already removed so the driver
crashes when it tries to dereference it in ICM event handling callbacks.

Fix this by checking whether the root switch is already removed. If it
is we know that the domain is stopped and we should merely skip handling
the event.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02 10:51:16 -07:00
Mika Westerberg 2d8ff0b586 thunderbolt: Add support for runtime PM
When Thunderbolt host controller is set to RTD3 mode (Runtime D3) it is
present all the time. Because of this it is important to runtime suspend
the controller whenever possible. In case of ICM we have following rules
which all needs to be true before the host controller can be put to D3:

  - The controller firmware reports to support RTD3
  - All the connected devices announce support for RTD3
  - There is no active XDomain connection

Implement this using standard Linux runtime PM APIs so that when all the
children devices are runtime suspended, the Thunderbolt host controller
PCI device is runtime suspended as well. The ICM firmware then starts
powering down power domains towards RTD3 but it can prevent this if it
detects that there is an active Display Port stream (this is not visible
to the software, though).

The Thunderbolt host controller will be runtime resumed either when
there is a remote wake event (device is connected or disconnected), or
when there is access from userspace that requires hardware access.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 10:55:29 +02:00
Colin Ian King fa3af1cb1e thunderbolt: Remove redundant variable 'approved'
Variable 'approved' is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'approved' set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 10:15:46 +02:00
Mika Westerberg d04522fa08 thunderbolt: Use correct ICM commands in system suspend
The correct way to put the ICM into suspend state is to send it
NHI_MAILBOX_DRV_UNLOADS mailbox command. NHI_MAILBOX_SAVE_DEVS is not
needed on Intel Titan Ridge so we can skip it.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 10:15:24 +02:00
Mika Westerberg fdd92e89a4 thunderbolt: Do not unnecessarily call ICM get route
This command is not really fast and can make resume time slower. We only
need to get route again if the link was changed and during initial
device connected message.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-25 10:15:24 +02:00
Mika Westerberg dd010bd7af thunderbolt: Handle NULL boot ACL entries properly
If the boot ACL entry is already NULL we should not fill in the upper
two DWs with 0xfffffffff. Otherwise they are not shown as empty entries
when the sysfs attribute is read.

Fixes: 9aaa3b8b4c ("thunderbolt: Add support for preboot ACL")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkelshb@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-15 18:02:00 +02:00
Mika Westerberg ea9d7bb798 thunderbolt: Prevent crash when ICM firmware is not running
On Lenovo ThinkPad Yoga 370 (and possibly some other Lenovo models as
well) the Thunderbolt host controller sometimes comes up in such way
that the ICM firmware is not running properly. This is most likely an
issue in BIOS/firmware but as side-effect driver crashes the kernel due
to NULL pointer dereference:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000980
  IP: pci_write_config_dword+0x5/0x20
  Call Trace:
   pcie2cio_write+0x3b/0x70 [thunderbolt]
   icm_driver_ready+0x168/0x260 [thunderbolt]
   ? tb_ctl_start+0x50/0x70 [thunderbolt]
   tb_domain_add+0x73/0xf0 [thunderbolt]
   nhi_probe+0x182/0x300 [thunderbolt]
   local_pci_probe+0x42/0xa0
   ? pci_match_device+0xd9/0x100
   pci_device_probe+0x146/0x1b0
   driver_probe_device+0x315/0x480
   ...

Instead of crashing update the driver to bail out gracefully if we
encounter such situation.

Fixes: f67cf49117 ("thunderbolt: Add support for Internal Connection Manager (ICM)")
Reported-by: Jordan Glover <Golden_Miller83@protonmail.ch>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Cc: stable@vger.kernel.org
2018-03-14 14:26:38 +03:00
Radion Mirchevsky 4bac471da0 thunderbolt: Add support for Intel Titan Ridge
Intel Titan Ridge is the next Thunderbolt 3 controller. The ICM firmware
message format in Titan Ridge differs from Falcon Ridge and Alpine Ridge
somewhat because it is using route strings addressing devices. In
addition to that the DMA port of 4-channel (two port) controller is in
different port number than the previous controllers. There are some
other minor differences as well.

This patch add support for Intel Titan Ridge and the new ICM firmware
message format.

Signed-off-by: Radion Mirchevsky <radion.mirchevsky@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2018-03-09 12:54:11 +03:00
Mika Westerberg 9aaa3b8b4c thunderbolt: Add support for preboot ACL
Preboot ACL is a mechanism that allows connecting Thunderbolt devices
boot time in more secure way than the legacy Thunderbolt boot support.
As with the legacy boot option, this also needs to be enabled from the
BIOS before booting is allowed. Difference to the legacy mode is that
the userspace software explicitly adds device UUIDs by sending a special
message to the ICM firmware. Only the devices listed in the boot ACL are
connected automatically during the boot. This works in both "user" and
"secure" security levels.

We implement this in Linux by exposing a new sysfs attribute (boot_acl)
below each Thunderbolt domain. The userspace software can then update
the full list as needed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:11 +03:00
Yehezkel Bernat 14862ee308 thunderbolt: Add 'boot' attribute for devices
In various cases, Thunderbolt device can be connected by ICM on boot
without waiting for approval from user. Most cases are related to
OEM-specific BIOS configurations. This information is interesting for
user-space as if the device isn't in SW ACL, it may create a friction in
the user experience where the device is automatically authorized if it's
connected on boot but requires an explicit user action if connected
after OS is up. User-space can use this information to suggest adding
the device to SW ACL for auto-authorization on later connections.

Signed-off-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:11 +03:00
Mika Westerberg 3080e197e9 thunderbolt: Move driver ready handling to struct icm
Intel Titan Ridge uses slightly different format for ICM driver ready
response, so add a new ->driver_ready() callback to struct icm and move
the existing handling to a separate function which we then use in Falcon
Ridge and Alpine Ridge.

No functional changes intended.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:11 +03:00
Mika Westerberg 0b0a0bd06e thunderbolt: Add constant for approval timeout
We will be using this from Titan Ridge support code as well so make it
constant.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:10 +03:00
Mika Westerberg ee487dd244 thunderbolt: Factor common ICM add and update operations out
The newer ICM will not use link and depth to address devices. Instead it
uses route strings. In order to take advantage of the existing code
factor out common operations so that we can use the same functions with
the new ICM as well.

No functional changes intended.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:10 +03:00
Mika Westerberg cb653eecde thunderbolt: Handle rejected Thunderbolt devices
The ICM firmware rejects devices if the maximum topology limit is
exceeded (more than 6 devices are connected). If that happens just log a
message to the kernel message buffer and bail out.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:10 +03:00
Mika Westerberg e4be8c9b6a thunderbolt: Wait a bit longer for ICM to authenticate the active NVM
Sometimes during cold boot ICM has not yet authenticated the active NVM
image leading to timeout and failing the driver probe. Allow ICM to take
some more time and increase the timeout to 3 seconds before we give up.

While there fix icm_firmware_init() to return the real error code
without overwriting it with -ENODEV.

Fixes: f67cf49117 ("thunderbolt: Add support for Internal Connection Manager (ICM)")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: stable@vger.kernel.org
2018-03-09 12:54:10 +03:00
Mika Westerberg 44b51bbb16 thunderbolt: Wait a bit longer for root switch config space
In some case reading root switch config space takes longer than what we
are currently waiting in the driver resulting timeout and failure.
Increase number of retries to allow some more time for the root switch
config space to become accesssible.

Also log an error if the timeout is exceeded so we know why the driver
probe failed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
2018-03-09 12:54:10 +03:00
Mika Westerberg 79fae98751 thunderbolt: Handle connecting device in place of host properly
If the system is suspended and user disconnects cable to another host
and connects it to a Thunderbolt device instead we get a warning from
driver core about adding duplicate sysfs attribute and adding the new
device fails.

Handle this properly so that we first remove the existing XDomain
connection before adding new devices.

Fixes: d1ff70241a ("thunderbolt: Add support for XDomain discovery protocol")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: stable@vger.kernel.org
2018-03-09 12:54:09 +03:00
Mika Westerberg d1ff70241a thunderbolt: Add support for XDomain discovery protocol
When two hosts are connected over a Thunderbolt cable, there is a
protocol they can use to communicate capabilities supported by the host.
The discovery protocol uses automatically configured control channel
(ring 0) and is build on top of request/response transactions using
special XDomain primitives provided by the Thunderbolt base protocol.

The capabilities consists of a root directory block of basic properties
used for identification of the host, and then there can be zero or more
directories each describing a Thunderbolt service and its capabilities.

Once both sides have discovered what is supported the two hosts can
setup high-speed DMA paths and transfer data to the other side using
whatever protocol was agreed based on the properties. The software
protocol used to communicate which DMA paths to enable is service
specific.

This patch adds support for the XDomain discovery protocol to the
Thunderbolt bus. We model each remote host connection as a Linux XDomain
device. For each Thunderbolt service found supported on the XDomain
device, we create Linux Thunderbolt service device which Thunderbolt
service drivers can then bind to based on the protocol identification
information retrieved from the property directory describing the
service.

This code is based on the work done by Amir Levy and Michael Jamet.

Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-02 11:24:41 -07:00
Mika Westerberg e69b71f845 thunderbolt: Move tb_switch_phy_port_from_link() to thunderbolt.h
A Thunderbolt service might need to find the physical port from a link
the cable is connected to. For instance networking driver uses this
information to generate MAC address according the Apple ThunderboltIP
protocol.

Move this function to thunderbolt.h and rename it to
tb_phy_port_from_link() to reflect the fact that it does not take switch
as parameter.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-02 11:24:41 -07:00
Rafael J. Wysocki 01d2f105a4 Merge branches 'acpi-x86', 'acpi-soc', 'acpi-pmic' and 'acpi-apple'
* acpi-x86:
  ACPI / boot: Add number of legacy IRQs to debug output
  ACPI / boot: Correct address space of __acpi_map_table()
  ACPI / boot: Don't define unused variables

* acpi-soc:
  ACPI / LPSS: Don't abort ACPI scan on missing mem resource

* acpi-pmic:
  ACPI / PMIC: xpower: Do pinswitch magic when reading GPADC

* acpi-apple:
  spi: Use Apple device properties in absence of ACPI resources
  ACPI / scan: Recognize Apple SPI and I2C slaves
  ACPI / property: Support Apple _DSM properties
  ACPI / property: Don't evaluate objects for devices w/o handle
  treewide: Consolidate Apple DMI checks
2017-09-03 23:54:03 +02:00
Lukas Wunner 630b3aff8a treewide: Consolidate Apple DMI checks
We're about to amend ACPI bus scan with DMI checks whether we're running
on a Mac to support Apple device properties in AML.  The DMI checks are
performed for every single device, adding overhead for everything x86
that isn't Apple, which is the majority.  Rafael and Andy therefore
request to perform the DMI match only once and cache the result.

Outside of ACPI various other Apple DMI checks exist and it seems
reasonable to use the cached value there as well.  Rafael, Andy and
Darren suggest performing the DMI check in arch code and making it
available with a header in include/linux/platform_data/x86/.

To this end, add early_platform_quirks() to arch/x86/kernel/quirks.c
to perform the DMI check and invoke it from setup_arch().  Switch over
all existing Apple DMI checks, thereby fixing two deficiencies:

* They are now #defined to false on non-x86 arches and can thus be
  optimized away if they're located in cross-arch code.

* Some of them only match "Apple Inc." but not "Apple Computer, Inc.",
  which is used by BIOSes released between January 2006 (when the first
  x86 Macs started shipping) and January 2007 (when the company name
  changed upon introduction of the iPhone).

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Suggested-by: Darren Hart <dvhart@infradead.org>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-08-03 23:26:22 +02:00
Rafael J. Wysocki a684c5b188 thunderbolt: icm: Ignore mailbox errors in icm_suspend()
On one of my test machines nhi_mailbox_cmd() called from icm_suspend()
times out and returnes an error which then is propagated to the
caller and causes the entire system suspend to be aborted which isn't
very useful.

Instead of aborting system suspend, print the error into the log
and continue.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Michael Jamet <michael.jamet@intel.com>
2017-07-31 13:24:29 +02:00
Mika Westerberg e6b245ccd5 thunderbolt: Add support for host and device NVM firmware upgrade
Starting from Intel Falcon Ridge the NVM firmware can be upgraded by
using DMA configuration based mailbox commands. If we detect that the
host or device (device support starts from Intel Alpine Ridge) has the
DMA configuration based mailbox we expose NVM information to the
userspace as two separate Linux NVMem devices: nvm_active and
nvm_non_active. The former is read-only portion of the active NVM which
firmware upgrade tools can be use to find out suitable NVM image if the
device identification strings are not enough.

The latter is write-only portion where the new NVM image is to be
written by the userspace. It is up to the userspace to find out right
NVM image (the kernel does very minimal validation). The ICM firmware
itself authenticates the new NVM firmware and fails the operation if it
is not what is expected.

We also expose two new sysfs files per each switch: nvm_version and
nvm_authenticate which can be used to read the active NVM version and
start the upgrade process.

We also introduce safe mode which is the mode a switch goes when it does
not have properly authenticated firmware. In this mode the switch only
accepts a couple of commands including flashing a new NVM firmware image
and triggering power cycle.

This code is based on the work done by Amir Levy and Michael Jamet.

Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:42:43 +02:00
Mika Westerberg f67cf49117 thunderbolt: Add support for Internal Connection Manager (ICM)
Starting from Intel Falcon Ridge the internal connection manager running
on the Thunderbolt host controller has been supporting 4 security
levels. One reason for this is to prevent DMA attacks and only allow
connecting devices the user trusts.

The internal connection manager (ICM) is the preferred way of connecting
Thunderbolt devices over software only implementation typically used on
Macs. The driver communicates with ICM using special Thunderbolt ring 0
(control channel) messages. In order to handle these messages we add
support for the ICM messages to the control channel.

The security levels are as follows:

  none - No security, all tunnels are created automatically
  user - User needs to approve the device before tunnels are created
  secure - User need to approve the device before tunnels are created.
	   The device is sent a challenge on future connects to be able
	   to verify it is actually the approved device.
  dponly - Only Display Port and USB tunnels can be created and those
           are created automatically.

The security levels are typically configurable from the system BIOS and
by default it is set to "user" on many systems.

In this patch each Thunderbolt device will have either one or two new
sysfs attributes: authorized and key. The latter appears for devices
that support secure connect.

In order to identify the device the user can read identication
information, including UUID and name of the device from sysfs and based
on that make a decision to authorize the device. The device is
authorized by simply writing 1 to the "authorized" sysfs attribute. This
is following the USB bus device authorization mechanism. The secure
connect requires an additional challenge step (writing 2 to the
"authorized" attribute) in future connects when the key has already been
stored to the NVM of the device.

Non-ICM systems (before Alpine Ridge) continue to use the existing
functionality and the security level is set to none. For systems with
Alpine Ridge, even on Apple hardware, we will use ICM.

This code is based on the work done by Amir Levy and Michael Jamet.

Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 11:42:43 +02:00