Convert the legacy raw protocol driver to a bundle driver.
This also fixes a potential crash should a (malicious) module have sent
an early request before the private data had been initialised.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
If an incoming request comes on the connection, before the driver has
allocated its raw->device in gb_raw_connection_init(), then it might
result in a crash while printing error messages.
Fix that by using bundle->dev for printing error messages.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Some of the labels are named based on what they are going to undo, while
others are based on where we failed in connection_init().
Follow only the first type of naming.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The build is broken if you try to build the arche platform driver
without the usb3163 driver enabled at the same time, so specify that
dependency in the greybus Makefile.
Testing done: built inside and outside of the build system against
many different kernel versions.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
USB3613 hub driver exports control function, which allows caller
to switch the mode of operation of hub device.
As we know that, we have dependency between HUB3613 and APB's where,
HUB supposed to enter into HUB only after APB's brought out of reset.
Until now, we had all userspace driver sequences to control this,
but now since we are moving all resource management strictly to the
driver, it makes sense (even though it looks hacky) to enable control
of hub3613 from arche-platform driver.
Note that, there is another discussion where, the hub.connect IO pin may
get interfaced with MSM gpio, at that time, we can get rid of this hack
and replace it with gpio control.
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
With addition of operational state in driver, user/developer
can switch to FW flashing state through sysfs. So no need to
export any gpios to userspace now.
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
With addition of operational state in driver, user/developer
can switch to FW flashing state through sysfs. So no need to
export any gpios to userspace now.
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Now SVC driver has an access to APBs operational functions
(coldboot, standby_boot, fw_flashing and poweroff), SVC driver
can control APB's as per below rules,
- If SVC goes down (poweroff state), it will also power off APBs
and vice a versa for all operational states.
- On boot, SVC will probe/populate APB device, but will not coldboot
it. APBs will coldboot only after handshaking with SVC over
wake/detect line.
Note that, both APBs share same wake/detect line.
So from user/developer perspective, it is highly recommended that
they should use arche-platform interfaces, instead of individual
apb interface,
# echo [off/active/standby/fw_flashing] > /sys/devices/arche_platform.*/state
Note: 'standby' mode is not supported as of now.
Testing Done: Testd on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
In order to use single wake/detect line for both APB's we need to have
access to APB operational functions to parent/SVC driver.
So export coldboot, standby_boot, fw_flashing and poweroff operation
functions from the driver.
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This is preparation for enabling export set of operational fns
to parent driver.
So it is important to differentiate internal ops function against
externally accessed (from parent).
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
New DT property "ara,init-disable" will allow user to disable
APB1 or APB2 during boot and enable it only when needed through
command prompt via sysfs interface.
- To disable APB2 during boot, specify "ara,init-disable" property in
respective APB node.
- How to check the state
# cat /sys/devices/arche_platform.*/apb*/state
It should be 'off', if 'ara,init-disable' enabled in DT.
- During runtime if user/developer desired to enable APB2 (strictly and
only for development purpose) then respective APB can be enabled
through,
# echo active > /sys/devices/arche_platform.*/apb*/state
Note:
- If APB device is in 'off,disabled' state, then no state transitions
are permitted.
- User/developer must first activate APB device
# echo active > /sys/devices/arche_platform.*/apb*/state
This will clear the 'init-disable' flag and allow state transition
from here onwards.
Note that, 'off,disabled' is only indicative state and is only
applicable during init/boot.
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This patch introduces sysfs interface for the user space to enable
state change of the driver. Driver supports below operational
states,
- off
- active
- standby
- fw_flashing
To see the current state
i # cat /sys/devices/arche_platform.*/apb*/state
And to change the state
# echo [off/active/standby/fw_flashing] > /sys/devices/arche_platform.*/apb*/state
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Pass only pointer to platform_device to _seq fns and fetch handle to
arche_apb_ctrl_drvdata from platform_device.
This is preparation for support for dynamic switching between operational
states for the device, where these functions will be called from parent
driver.
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Explicitly set default apb->state value to ARCHE_PLATFORM_STATE_OFF
in probe() fn.
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
apb_ctrl_coldboot_seq() and apb_ctrl_poweroff_seq()
is appropriate name as per spec and implementation, so rename it.
Also move apb_ctrl_poweroff_seq() fn above, to group it with
other _seq functions.
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
In order to allow APB2 disable by default on boot/init, and also
provide interface to user to enable it later on, re-arrange the init_seq
fn.
The idea here is, the apb_ctrl_init_seq() fn will be renamed to
apb_ctrl_coldboot_seq(), and should not try to claim any resources.
All the resource claim should happen in apb_ctrl_get_devtree_data() fn.
And also uses devm_gpio_request_one() fn wherever possible.
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Introduce FW_FLASHING state to arche-platform driver, to enable
user space to flash/upgrade SVC firmware.
Command to enter into flashing state:
# echo fw_flashing > /sys/devices/arche_platform.*/state
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This patch introduces sysfs interface for the user space to enable
operational state change of the driver.
Currently, driver supports, 'off', 'active' and 'standby'
Note that, driver doesn't do anything for standby state as of today.
To see the current state
# cat /sys/devices/arche_platform.*/state
And to change the state
# echo [off/active/standby] > /sys/devices/arche_platform.*/state
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
When SVC goes down, make sure that wake/detect is also pulled low.
Note that this is not the criteria for SVC poweroff, but it is required
to have right state on wake/detect line before powering off.
And on next boot, the boot-sequence code would take care of
handshaking with SVC.
Tested-on: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This is preparation for operational state support.
So in order to provide operational state transitions, driver needs to
maintain state. So add 'enum arche_platform_state' variable to
'struct arche_platform_drvdata'
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This is a bug fix, where as part of cleanup, delayed work was not
canceled in driver remove function. So fix it.
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This is preparation for support for different operational states
(defined by arche_platform_state) in the driver, to enable
user/developer to dynamically configure the state.
arche_platform_coldboot_seq() fn will be responsible for
rebooting SVC device.
Testing Done: Tested on EVT1.2 and DB3.5 platform
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Make 'enum apb_state' common to both platform drivers, so that
both drivers can make use of same state and user will have
unified control configuration across devices (SVC, APB1 and APB2)
Testing Done: Tested on EVT1.2 and DB3.5 platform.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Make sure the class device is freed as well as deregistered on
disconnect.
Also deregister the class device before character device as the former
depends on the latter.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Remove the private data field from the bundle structure as it is no
longer needed. Bundle drivers can use the driver data field in the
bundle device.
Update the only current user to use the connection private data until it
has been converted to a bundle driver.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Replace all pr_err with dev_err so we can tell what device (and driver)
a message was for.
Testing Done: Compiled
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Add missing pr_fmt so we can at least tell what module the sole
remaining pr_err was from.
Testing Done:
Tested on DB3.5 with the generic bridge firmware on APB2.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Replace all pr_err with dev_err so we can tell what device (and driver)
a message was for.
Testing Done: Compiled
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Use dev_err and dev_warn where appropriate and remove now unused pr_fmt
defines.
Testing Done:
Tested on DB3.5 with the generic bridge firmware on APB2.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Use dev_err and friends so that we can tell which interface (and module)
a manifest-parsing error messages was for.
Testing Done:
Tested on DB3.5 with the generic bridge firmware on APB2.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Current userspace looks through the sysfs interface entries for
matching vendor_id and product_id any time an interface is opened
by module developers. The upper 16-bits of ES3 vendor_id and
product_id contain a reverse mask of the lower 16-bits. This
additional information is never used and should be removed so
that every consumer of these sysfs entries doesn't have to perform
the same bit clearing logic.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
We are seeing failures on DB3.1 board, and Axel root-caused it to this
commit, so revert it as of now.
This reverts commit 942627227684c187b727ba5fb581bc2d886b6708.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Add device_type field in device config operation to get the type of
device and try to expose less the kernel internal over greybus.
This include the spidev, spi-nor will fetch the correct nor id over
jede and a modalias that will have the previous behavior (name will set
the driver to be loaded).
As at it, fix a trivial error path and return immediately.
Tested: using gbsim and confirming that a spidev and mtd device were
created.
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
When inserting and removing a module with a UART protocol defined a
double free of the tty_port would happen and that would generate a lot
of kernel oops in different places related to memory corruption.
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Rework the get property descriptors function to fix a memory handling
error for the response structure. This could corrupt the stack and
throw nonalignment PC or SP error:
Internal error: SP or PC abort: 8a000000 1 PREEMPT SMP
Modules linked in: gb_power_supply(O) gb_arche(O) gb_camera(O) gb_es2(O) gb_vibrator(O) gb_raw(O) g]
CPU: 3 PID: 51 Comm: kworker/u16:2 Tainted: G W O 3.10.73-g8a6af60-00118-g599a5c1 #1
Workqueue: greybus1:svc gb_svc_connection_destroy [greybus]
task: ffffffc0ba249580 ti: ffffffc0ba294000 task.ti: ffffffc0ba294000
PC is at gb_power_supply_connection_init+0x81/0x1dc [gb_power_supply]
LR is at gb_power_supply_connection_init+0x81/0x1dc [gb_power_supply]
pc : [<ffffffbffc03b901>] lr : [<ffffffbffc03b901>] pstate: 80000145
sp : ffffffc0ba297a00
x29: 32002e002a001100 x28: ffffffc042cb2c80
To fix this, allocate firstly the operation and handle request and
response using operation payload.
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Improve the management of unipro power mode changes in response
to a configure_stream operation.
When sending a "test only" request to camera module, do not change power
mode to HS-G2 as no frame will be actually transmitted.
When receiveing an "adjusted" configuration response, reset power
mode to PWM-G1.
Signed-off-by: Jacopo Mondi <jacopo.mondi@linaro.org>
Reviewed-by: Gjorgji Rosikopulos <grosikopulos@mm-sol.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
With synchronization between SVC <=> AP over wake/detect line to
bring APB's out of reset, we do not need any extra delays now.
So remove it.
Testing Done: Tested for 10 iterations on EVT1
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Reviewed-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The cport id field is a le16, so treat it as such when comparing it to
something else.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
There's a definition missing in audio_manager causing the kernel build
to fail:
CC [M] ./greybus/audio_manager.o
./greybus/audio_manager.c:22:8: warning: type defaults to 'int' in declaration of 'DEFINE_IDA' [-Wimplicit-int]
error, forbidden warning: audio_manager.c:22
./kernel/scripts/Makefile.build:308: recipe for target './greybus/audio_manager.o' failed
Including linux/idr.h fixes the issue.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
there is race condition between _disconnect() request &
stop_trigger() in case of abrupt module removal.
And sometimes this can lead to deadlock while acquiring
codec_info->lock.
To avoid such situation, atomic variable is used to maintain
codec connected state.
During dai operations (trigger, shutdown, etc.), 'is_connected'
variable is validated to avoid unnecessary lock acquire in
case module already removed.
Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
audio codec driver is now moved to bundle driver approach.
This resolved many race conditions related to audio mgmt &
data connection init/exit sequence.
Thus, a lot of helper functions can now be safely removed.
Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The callers ensures that connection->lock is taken before calling few
routines, but that isn't enough for sparse as it sees an unexpected
unlock.
greybus/connection.c:380:29: warning: context imbalance in 'gb_connection_cancel_operations' - unexpected unlock
Fix that adding __must_lock() attribute to the function declaration.
This also adds the attribute for
gb_connection_flush_incoming_operations(), which isn't showing any
sparse warnings with the current state of code, but with minor
rearrangements of the code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
gb_control_get_version() is not used outside of the file and must be
marked as static. Following sparse warnings are reported today:
greybus/control.c:20:5: warning: symbol 'gb_control_get_version' was not declared. Should it be static?
Fix it by marking gb_control_get_version() 'static'.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
greybus/audio_apbridgea.c:13:5: warning: symbol 'gb_audio_apbridgea_set_config' was not declared. Should it be static?
greybus/audio_apbridgea.c:30:5: warning: symbol 'gb_audio_apbridgea_register_cport' was not declared. Should it be static?
greybus/audio_apbridgea.c:44:5: warning: symbol 'gb_audio_apbridgea_unregister_cport' was not declared. Should it be static?
greybus/audio_apbridgea.c:58:5: warning: symbol 'gb_audio_apbridgea_set_tx_data_size' was not declared. Should it be static?
greybus/audio_apbridgea.c:72:5: warning: symbol 'gb_audio_apbridgea_get_tx_delay' was not declared. Should it be static?
greybus/audio_apbridgea.c:80:5: warning: symbol 'gb_audio_apbridgea_start_tx' was not declared. Should it be static?
greybus/audio_apbridgea.c:94:5: warning: symbol 'gb_audio_apbridgea_stop_tx' was not declared. Should it be static?
greybus/audio_apbridgea.c:106:5: warning: symbol 'gb_audio_apbridgea_set_rx_data_size' was not declared. Should it be static?
greybus/audio_apbridgea.c:120:5: warning: symbol 'gb_audio_apbridgea_get_rx_delay' was not declared. Should it be static?
greybus/audio_apbridgea.c:128:5: warning: symbol 'gb_audio_apbridgea_start_rx' was not declared. Should it be static?
greybus/audio_apbridgea.c:141:5: warning: symbol 'gb_audio_apbridgea_stop_rx' was not declared. Should it be static?
greybus/audio_gb.c:14:5: warning: symbol 'gb_audio_gb_get_topology' was not declared. Should it be static?
greybus/audio_gb.c:48:5: warning: symbol 'gb_audio_gb_get_control' was not declared. Should it be static?
greybus/audio_gb.c:70:5: warning: symbol 'gb_audio_gb_set_control' was not declared. Should it be static?
greybus/audio_gb.c:85:5: warning: symbol 'gb_audio_gb_enable_widget' was not declared. Should it be static?
greybus/audio_gb.c:97:5: warning: symbol 'gb_audio_gb_disable_widget' was not declared. Should it be static?
greybus/audio_gb.c:109:5: warning: symbol 'gb_audio_gb_get_pcm' was not declared. Should it be static?
greybus/audio_gb.c:133:5: warning: symbol 'gb_audio_gb_set_pcm' was not declared. Should it be static?
greybus/audio_gb.c:150:5: warning: symbol 'gb_audio_gb_set_tx_data_size' was not declared. Should it be static?
greybus/audio_gb.c:163:5: warning: symbol 'gb_audio_gb_get_tx_delay' was not declared. Should it be static?
greybus/audio_gb.c:183:5: warning: symbol 'gb_audio_gb_activate_tx' was not declared. Should it be static?
greybus/audio_gb.c:195:5: warning: symbol 'gb_audio_gb_deactivate_tx' was not declared. Should it be static?
greybus/audio_gb.c:207:5: warning: symbol 'gb_audio_gb_set_rx_data_size' was not declared. Should it be static?
greybus/audio_gb.c:220:5: warning: symbol 'gb_audio_gb_get_rx_delay' was not declared. Should it be static?
greybus/audio_gb.c:240:5: warning: symbol 'gb_audio_gb_activate_rx' was not declared. Should it be static?
greybus/audio_gb.c:252:5: warning: symbol 'gb_audio_gb_deactivate_rx' was not declared. Should it be static?
Fix them by including the header that declares the exported routines.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Every time we hotplug an audio module, we get a new audio module id. We
should recycle them instead of just constantly incrementing the number
so we don't see things like:
[178016.832580] Created audio module #6124
in the kernel logs.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Its unrealistic to expect 50 loopback devices,
and the mask parameter can hold up to "int" anyways
so decrease to max number of devices to sane value.
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Convert the legacy firmware protocol driver to a bundle driver.
This also fixes a potential crash should a (malicious) module have sent
an early request before the private data had been initialised.
Note that the firmware protocol needs to support the version request
indefinitely since it has been burnt into ROM.
In order to avoid having to update current module-loading scripts, keep
this driver internal to greybus core at least until modalias support is
added.
Note that there is no MODULE_DEVICE_TABLE defined for firmware as we
cannot have two greybus tables in one module on ancient 3.10 kernels and
that the legacy driver is currently also internal to core. This needs be
added once the driver can be built as a module.
Testing Done: Tested on DB3.
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>