If a gbuf completion indicates an error has occurred, report it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Currently, if a USB urb completes with an error, that error status
is not transferred back to the gbuf that it's associated with.  For
inbound data there's not a lot we can do about an error, but for
outbound data, this means there is no notification to the submitter
that something went wrong.

For outbound data copy the urb status directly back to the gbuf as
its status.  Follow USB's lead and set the status to -EINPROGRESS
while a gbuf is "in flight."  Assign a gbuf an initial status value
of -EBADR to help identify use of never-set status values.

When an inbound urb fails (SVC or CPort), currently the urb is just
leaked, more or less (i.e., we lose an urb posted to receive
incoming data).  Change that so such an error is reported, but
then re-submitted.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

It is expected that i2c writes may fail, and in that case the driver
simply retries some number of times before actually treating it as a
failure.  Define a GB_OP_RETRY status, which is interpreted by the
i2c driver as an indication a retry is in order.  We just translate
that into an EAGAIN error passed back to the i2c core.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

First cut.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

This patch adds the i2c driver, based on the use of Greybus operations
over Greybus connections.  It basically replaces almost all of what
was previously found in "i2c-gb.c".

When gb_connection_device_init(connection) is called, any connection
that talks the GREYBUS_PROTOCOL_I2C is passed to gb_i2c_device_init()
to be initialized.

Initialization involves verifying the code is able to support the
version of the protocol.  For I2C, we then query the functionality
mask, and set the retry count and timeout to default values.

After that, we set up the i2c device and associate it with the
connection.  The i2c_algorithm methods are then implemented
by translating them into Greybus operations.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

The original CPort message handlers are not needed.  All incoming
data is passed to handlers based on the protocol used over the
connection over which the data was transferred.  So get rid of the
old CPort handler code.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

At this point all incoming messages are handled by the operation
code, so this obviates the need for the gbuf workqueue.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Set up the infrastructure for initializing connections based on
their protocol.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Create a work queue to do the bulk of processing of received
operation request or response messages.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Give the operation layer a chance to examine incoming data so that
it can handle it appropriately.

Treat the data as an operation message header.  If it's a response,
look up the operation it's associated with.  If it's not, create a
new operation.  Copy the incoming data into the request or response
buffer.  The next patch adds a work queue to pick up handling
the request or response from there.

Get rid of gb_operation_submit().  Instead, we have two functions,
one for sending an operation's request message, the other for
sending an operation's response message.

Not fully functional yet, still just filling things in...
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Add a red-black tree indexed by operation id to a connection to
allow pending operations (whose requests are in-flight) to be
found when their matching response is recieved.

Assign the id at the time an operation is inserted, and update
the operation's message header(s) to include it.

Rename gb_connection_op_id() to be more consistent with the
naming conventions being used elsewhere.

(Noting now that this may switch to a simple list implementation
based on Greg's assertion that lists are faster than red-black trees
for up to a few hundred entries.)
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

We need to track both request messages and response messages in
operations.  So add another gbuf (and payload pointer) field to
the operation structure, and rename them to indicate which one
is which.  Allow the creator specify the size of the response
buffer; just leave it a null pointer if the size is 0.

Define a new helper function gb_operation_gbuf_create() to
encapsulate creating either a request or a response buffer.

Any buffer associated with a connection will (eventually) have been
created as part of an operation.  So stash the operation pointer in
the gbuf as the context pointer.  Whether a buffer is for the
request or the response can be determined by pointer comparison.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Upcoming patches are going to set up devices based on what is
discovered in the module manifest.  Get rid of the hard-coded
initialization done by gb_init_subdevs(), along with other related
code.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Every gbuf is associated with a connection when it is created.  And
a connection contains a pointer to the host device that will carry
messages.  So there's no need for the submit_gbuf() method to have
the host device pointer passed to it, the function can get it from
the gbuf's connection.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Don't assume the buffer data area will all be overwritten.  Zero all
buffer space, to avoid sending crap over the wire.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Don't assume that input buffers have any particular content.  The
only thing the gbuf layer needs to be concerned with is the presence
of the cport_id byte at the beginning of a transfer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

When free_hd() is called, hd_mutex is held.  It is the
responsibility of free_hd() to drop that mutex.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

To drop a reference on a gbuf, greybus_free_gbuf() is called.  That
uses kref_put_mutex() to drop the refernce under protection of
gbuf_mutex.  However the release routine, free_gbuf(), never
releases the mutex as it should.  Fix that.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Most of the disconnect routines for the "subdevs" of a module
blindly assume that initialization of the subdev was successful.

Fix this by checking for null pointers.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

On a disconnect we can also have a status of -EPROTO. This results in
a flood of error messages due to the -EAGAIN handling of unsupported
status results. Fix this by also returning status when we have -EPROTO.
Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

In order to easily integrate into the Android build, include
an Android.mk.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

We didn't use them, so drop it.

Also some other checkpatch cleanups while I was in there.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We had a lock, but we never used it, so move it to be per-hd, like the
idr structure is.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Even if we successfully parse a manifest we are returning
failure. Instead, we now proudly proclaim success.
Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Without this, null-testing the return value of this function is
broken.
Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

The internal struct manifest_desc needs the data payload, rather
than the entire descriptor with header to be populated into the
data field. Also fix two places where the parser was trying to
extract the entire descriptor with header for the data payload
field.
Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Last time I tried to kill off gbuf->context my efforts were shot
down.  Now that I've got the connection infrastructure in place,
maybe I'll have more luck getting rid of gbuf->hdpriv.

The only place it's used is to stash the es1_ap_dev structure
pointer in the buffer.  But that information is now available
through the buffer's connection, so we don't need to use the
hdpriv field any more.

So get rid of it, and use hd_to_es1(gbuf->connection->hd) to
get at what we need.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

GEt rid of __alloc_gbuf(), now that it's used in only one place.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Change the "direction" flag field of a gbuf to be a Boolean called
"outbound".

Add a Boolean outbound flag to alloc_gbuf_data(), and use it for
allocating the data buffer for gbufs for data being transferred in
either direction.

Update free_gbuf_data() accordingly--letting the host device
driver's gbuf data free function handle all of them.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Switch to using the connection rather than the host device as
the locus for doing Greybus buffer allocation.  A connection
encapsulates both the host device (whose driver is what's required
for allocation) and the *destination* cport id.  Record the
connection a gbuf is associated with rather than the host module and
(unspecified) cport id.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Look up the connection that an incoming message is associated with.
This is the start of making message handling oriented toward the
the connection rather than the cport.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Add a function that looks up a connection given the host device
pointer an the host cport id.  This will be used to determine which
connection an incoming message is associated with.

Replace the list tracking host device connections with a red-black
tree so lookup can scale and be done quickly.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

One data structure and a few fields in another one are no longer
used, and were not removed when they should have been.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

I guess I got a little hd crazy.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

Define a function that prints error information about a Greybus
connection in a standard format.  This adopts the convention that
[M:I:C] represents the "path" the connection represents--specifying
the module id, the interface number on that module, and the
connection id on that interface.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

This will be used for driver-specific data for whatever drives the
other end of the connection.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>