This patch adds a tracepoint to the TimeSync ISR, the purpose of which is
to indicate a TimeSync event has happened. This tracepoint can be enabled
by issuing the following command:

echo 1 > /sys/kernel/debug/tracing/events/greybus/gb_timesync_irq/enable

Synchronization looks like this:

 TIMESTAMP  FUNCTION
    |         |
147.865788: gb_timesync_irq: strobe 1/4 frame-time 2910076529
147.866781: gb_timesync_irq: strobe 2/4 frame-time 2910095689
147.867777: gb_timesync_irq: strobe 3/4 frame-time 2910114820
147.868791: gb_timesync_irq: strobe 4/4 frame-time 2910134038

A ping can be triggered like this:

cat /sys/kernel/debug/greybus/frame-time

And that ping looks like this:

 TIMESTAMP  FUNCTION
    |         |
147.934678: gb_timesync_irq: ping 4/4 frame-time 2911380356
169.280551: gb_timesync_irq: ping 4/4 frame-time 3321221069
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Acked-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

TimeSync needs to bind into Greybus in a few places.

- core.c
  To initialize its internal state and tear-down its internal state.
  To schedule a timesync to a newly added Bundle after probe() completes.

- svc.c
  To get access to the SVC and enable/disable timesync as well as
  extracting the authoritative time from the SVC to subsequently
  disseminate to other entities in the system.

- interface.c
  To get access to an Interface in order to inform APBx of timesync
  enable/disable and authoritative operations.

This patch adds those bindings into Greybus core.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Acked-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

This patch adds the core timesync functionality.

0. arche-platform.c/arche-apb-ctrl.c
   Modifies the platform layer to hook the incoming TIME_SYNC signal up to
   the timesync strobe IRQ handler. If the arche-platform driver can't
   satisfy the request for the wake-detect line, it will return -EAGAIN and
   the calling work-queue must reschedule the attempt to get exclusive
   access to the wake-detect pin logic. A private data field is added to
   the arche-platform driver to enable passing of a timesync pointer to the
   ISR responsible for synchronizing time.

1. timesync.c
   A new file added which contains all of the logic associated with sending
   greybus commands to SVC, APBx or Interfaces to enable, disable and
   disseminate timing information.

2. timesync_platform.c
   Any platform/arch specific code goes into timesync_platform.c.
   Originally the idea was to keep the x86 and ARM arch dependencies in a
   timesync_platform_arch.c file - however with further refinement that's
   currently not necessary however just-in-case it becomes necessary to
   resuscitate arch or platform specific methods for accessing timer
   resources that access shouldn't be part of the core timesync.c logic and
   so for the moment we access these timer resources through a thin access
   layer in timesync_platform.c. Expect this to go away long term ideally.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Acked-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Reporting DISCONNECT event immediately on module removal causes
race condition while re-populating mixer controls by above HAL. The
original intent was to avoid any (invalid) mixer control modification
request from above layer.

Ideally, it should report 'MODULE_NOT_READY' on module plug-out and
DISCONNECT after resource cleanup. This would involve changes in GB
Audio manager and HAL layer.

Since we already have a plan to remove GB Audio manager, I'm making this
change in GB codec driver to avoid any race condition. Also, codec
driver already ensures mixer control modifcations for disconnected
modules are not triggered to AP Bridge audio FW & reported invalid.
Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Added warning message in find_gb_module(). This will help to identify
invalid mixer control/widget modification triggered from above layer.
Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The original message trace events were defined long before the
recent tracing updates.  It records information that's not
really directly related to a message.  Change the information
recorded and reported for message events to just be the content
of the message header.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Bryan reports he used certain message traces to determine when time
sync messages transit the boundary between the Greybus core and the
host device.  This patch adds two trace events--one a message event
for outbound messages (because it indicates its operation and its
destination), and one host device event for incoming messages
(because message information isn't available as early as desired).
These events are being created to allow the same sort of analysis
of messages without having to store extra information for every
message trace.  (The next patch changes the information a message
trace records.)
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Define a new gb_connection trace point event class, used to trace
events associated with the connection abstraction.  Define four basic
trace events for this--creation, drop of last reference, and when
adding or dropping any other reference.  There are certainly
more events that we might want to add, but aim is to just get the
basic framework in place.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Define a new gb_bundle trace point event class, used to trace events
associated with the bundle abstraction.  Define four basic trace
points for this--creation time, drop of last reference, before
adding it to its interface and when removed when its interface
is destroyed.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add the value of an interface's mode_switch field to the information
tracked and reported for tracing.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Most abstractions to be traced will have a sort of "parent" object
it is associated with, and an identifier for that parent is stored
with the as trace event data.  For example, the parent of a message
is the operation it's a part of, and the parent of an operation is
the connection it uses.

We'll arrange to define that parent id first in all events.  Most
abstractions already do this.  Move an interface's module id so it's
defined and assigned first.  The message traces are going to be
changed soon, so leave that one alone.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

A module's num_interfaces field is included in the data to be
recorded for tracing, but it's never assigned or reported.  Fix
its type to be size_t, to match its definition in the gb_module
structure.

Also correct a format length modifier used for a host device's
num_cports field.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Move the definition of the module trace events below those for the
interface.  We'll define them in an order that represents a sort of
layering of the abstractions (note not all of these are defined yet):
    message
    operation
    connection
    bundle
    interface
    module
    host device
Other tracepoints (like perhaps some tied to timesync) will go at the
beginning or end.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The type of the gb_host_device num_cports field is size_t.  Correct
the num_cports data recorded with a host device event so its type
matches that; fix the format length modifier used for it as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Define a bundle ID that means "no bundle".  This will be used for
tracing connection events during the portion of a connection's
lifetime when it has no bundle associated with it.  Don't allow
any bundle to be created using that ID.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Some of the trace buffer fields were defined as Booleans.  This
leads to two problems reported by "make check":
    - the __field() macro (or some descendent macro) performs
      a sizeof(bool) operation, which results in a warning
    - The TP_printk() macro, which specifies a printf() style
      format string, produces a warning when one attempts to
      format a Boolean as an integer.
Fix both problems implicitly converting Boolean values from the data
structures into integers in the trace buffer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

In explanation:

The main idea for implementing reference counting is to not block exit
until any other modules are in use. Camera responsibility is to handle
properly any additional calls after camera exit and that what this
patch is doing:

1. Free camera module when reference count is zero.
2. After camera cleanup handle properly any additional ongoing
   transaction. Return error if connection is destroyed.
Signed-off-by: Evgeniy Borisov <eborisov@mm-sol.com>
Reviewed-by: Gjorgji Rosikopulos <grosikopulos@mm-sol.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add additional information in gb camera module.
 - interface ID
 - reference count
 - release handle
Signed-off-by: Evgeniy Borisov <eborisov@mm-sol.com>
Reviewed-by: Gjorgji Rosikopulos <grosikopulos@mm-sol.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add description for all interface structures in
gb-camera.h.
Signed-off-by: Evgeniy Borisov <eborisov@mm-sol.com>
Reviewed-by: Gjorgji Rosikopulos <grosikopulos@mm-sol.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add a comment to describe the purpose of the flag.
Suggested-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Mode switch takes just over a second to complete and the current timeout
of one second isn't sufficient.

Mode-switch logs from EVT 1.5:

[   56.709082] gb-firmware 1-3.3.1: Requested firmware package 'ara_00000126_00001002_fffe0001_ff980067_03.tftf'
[   57.003968] gb_control_mode_switch_operation: 176
[   58.041616] greybus 1-3.3: mode switch detected

Increase the timeout to two seconds.

Tested with EVT 1.5 with gpbridge-test module.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Karthik Ravi Shankar <karthikrs@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The operation layer allows only the 'core' operations on a connection,
which is in its 'disconnecting' state.

Mode switch is sent at the very end of interface-disable sequence, and
the control connection is already in its 'disconnecting' state at that
time. And so gb_operation_get_active() always fail with error -ENOTCONN.

The operation core already has support for such 'core' operations, just
that we were missing the needed flag while creating the mode switch
operation.

Fix that.

Tested on EVT 1.5 with gpbridge-test module.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Karthik Ravi Shankar <karthikrs@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

This is the last step to required to finish the mode switch story.  That
is, call the hook provided by Interface layer to accomplish mode switch.

Tested on EVT 1.5 with gpbridge-test module.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Karthik Ravi Shankar <karthikrs@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

We should be using the generic version handling at bundle level, instead
of at protocol level for bridged PHY devices as well.

The bundle version handling is already in place, though it is *not* used
today as we haven't bumped the version of control protocol yet.

Remove protocol specific handling for bridged PHY devices.

Tested on EVT 1.5 with gpbridge-test module. No nuttx changes are
required with this.
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>

We don't use these anymore. Drop them.

Note that some macro's specific to bridged PHY devices aren't removed in
the patch, as gbsim will break otherwise. They will be removed
separately.

Compile tested.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

We should try to wait until all credits are accounted
for before returning from shutdown.

For this purpose add a helper function that will
wait on completion, and call it form the shutdown.
This helper will also be useful when "wait until sent" is
implemented.
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Data may be held pening in the hardware because of flow
control mechanisms. When the port is closed, we need to flush
all data that was not sent.

For this, use the greybus message GB_UART_TYPE_FLUSH_FIFOS
which will flush all data queued on the module but not
yet sent on the data line.
Suggested-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

To avoid polling the firmware for space, a credit based system
is implemented.

The host will keep track of how many credits (bytes) it has
sent to the firmware, and stop sending data when the quota
is filled.

The host will be informed that the firmware has more
room for data when it handles the receive_credits request
message from the firmware, and will continue to write data
as credits become available.

The firmware and the host may implement an algorithm to aggregate
credits, and avoid extra greybus traffic.
Suggested-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The firmware now buffers data instead of blocking while the transfer
is sent, and the write operation cannot sleep.

Instead of using gb_transfer_sync (which sleeps) in the write callback,
buffer data in a fifo and send it from from a work queue.

The write_room callback will will report 1 byte less that what is really
available in the fifo, to leave space for extra characters that may
be added by the tty layer.
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Dtr_dts allows the tty layer to set the flow control lines
to the correct state during open and close.

Note that locking for newctrl is missing throughout the
driver and will be addressed on a separate patch.
Suggested-and-reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Handle the CRTSCTS flag in set_termios, so that auto
flow control can be turned off. For this, add a new flag
in the line coding request specifically for this purpose.
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The recently added gb_hd_release tracepoint was added to the wrong
function.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Fix some whitespace issues introduced by the recent tracepoint changes.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Now that firmware has made the switch to the new interface boot
sequence, we can remove support for the deprecated hotplug and
hot-unplug operations.
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>

Add a generic interface for bundle drivers to use to request that a
mode switch is carried out on its behalf.

Mode switching involves tearing down all connections to an interface,
sending a unidirectional mode-switch request, and waiting for a mailbox
event that triggers deferred control connection reset and re-enumeration
of the interface. In case of a timeout waiting for the interface mailbox
event, or on other errors, the interface is powered off.

All of this needs to be done by core from work-queue context in order
not to block incoming SVC requests and bundle-device tear down. Care
must also be taken to serialise against concurrent module removal events
and eject requests.

Special handling of legacy mode-switching is also added in order to
continue to support the ES3 bootrom.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Print an informative error message in case sending the mode-switch
request fails.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Backport upstream reinit_completion() to pre-3.13 kernels.
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>

Add a new host-device callback to flush any host-device queues,
including any ongoing transfers, as part of connection tear down.

The host-device buffers are flushed after the disconnecting operation
have completed and the AP queues have been emptied.

This can be used to flush already queued messages which upon reception
would have been discarded by the remote end anyway.

Note that this does not remove the need to flush any host-device queues
as part of CPort disable which needs to make the CPort ready for reuse
after deallocating all associated state and resetting the port.
Suggested-by: Mitchell Tasman <tasman@leaflabs.com>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Implement proper connection closure, which includes sending ping
requests on the connection being tore down while coordinating with the
remote interface as well as the SVC.

This specifically implements the new ping operation, which in case of
offloaded connections is handled by the host-device driver in an
implementation-defined manner through a new callback.

Note that the normal connection tear-down procedure is executed in case
of failed connection establishment due to failed connected operation.
Specifically, the disconnecting request is sent also in case the
connected operation never succeeded. This is needed since the interface
may have enabled FCT flow upon receiving the connected request.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add a new core operation flag and a helper that core can use to create
core operations.

This will be used to implement the ping operations that core sends as
part of connection tear down.

Note that a new trace point is also added.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>