We now limit the maximum value for both host and module CPort ids,
and we know they can always be represented in a single byte.

Make use of this by using only one of the two pad bytes for encoding
the CPort id in a message header.

(Note that we have never used a CPort higher than 255.  Encoding
such a small CPort id in little endian 2-byte format has the same
result as what is done here.)
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

For ES1 and ES2, we use pad bytes in an operation message header to
encode the CPort ID used for transferring the message.  The pad
bytes should otherwise be zero, and we ensure this as the message
is passed to or from the upper layer.

If host-side CPort ID 0 is used, we have no way of knowing whether
the CPort field has been "packed" into the header.

To allow detection of this, reserve host CPort id 0.  Update
cport_id_valid() to treat 0 as invalid.

(CPort ID 0 is reserved by one of the UniPro standards.  We'll
assume for now that we never use it for Greybus.)
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

We limit the number of host-side CPorts to a fixed maximum (which
is less than the 4096 that UniPro allows).  This patch imposes a
similar limit on the CPort IDs defined by modules (signaling an
error if one too large is found in a manifest).

It seems reasonable to use the same value for both limits.  Change
the name of the constant that defines the host limit and use it for
both.  Update cport_id_valid() to enforce the maximum.

(Ultimately we should impose a limit like this; this change is being
made in preparation for supporting multiple connections over a
single CPort.)
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

For the ES1 and ES2 host interfaces we encode the CPort ID over
which the message should be sent within the message itself.  The
CPort ID is recorded in unused pad bytes found in the operation
message header in order to avoid introducing misaligned messages.

This patch defines some helper routines to abstract this activity.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Define a public predicate that defines whether a CPort ID is valid.

Use it in the message_send() routine, and make the message reported
more accurately reflect the error.  Also use it to check whether the
CPort ID in a received message is valid; if it is not, just drop the
message.

Get rid of local variable "buffer" in message_send(); it adds no
value.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Currently, if an error occurs creating a bundle, we simply
return an error without cleaning up any of the bundles that
had already been successfully set up.

Add code to destroy bundles that have been created in the event
an error occurs.  Add a check to ensure the interface's list of
bundles was empty before parsing for bundles begins.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Currently gb_bundle_destroy() takes an interface as an argument,
and really doesn't do what a function by that name should do.

What it now does is delete all bundles associated with a given
interface.  What it should do is destroy a single bundle.

Move the looping logic out of gb_bundle_destroy() and into its
caller, gb_interface_destroy().  Pass each bundle in an interface to
gb_bundle_destroy(), which will do what's required to destroy a
single bundle (including removing it from its interface's bundle
list under protection of the lock).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rearrange gb_bundle_find() so it follows the pattern used by
gb_connection_find().
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Currently, if an error occurs creating a connection, we simply
return an error without cleaning up any of the connections that
had already been successfully set up.

Add code to destroy connections that have been created in the event
an error occurs.  Add a check to ensure the bundle's list of
connections was empty before parsing for CPorts begins.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

I did this recently for the endo id allocation code.

It's clearer now that the allocation of a CPort ID to use for
the AP side of a connection is not very complicated, and it
happens in a pretty controlled environment.  The functions that
abstract getting and releasing those ids don't really add that
much value.

This patch removes gb_connection_hd_cport_id_alloc() and
gb_connection_hd_cport_id_free(), and just open-codes their
activity in the few places they are called.

It is obvious now that the CPort ID allocation isn't done in
atomic context, so we can change the ida_simple_get() call to
use GFP_KERNEL.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Although a connection records its protocol id when it gets
created, its protocol handler doesn't actually get assigned
until gb_connection_bind_protocol() is called.

In gb_connection_create() there are some error paths in
which a reference to the connection's protocol is released
before the protocol handler has been associated with the
connection.

Get rid of those calls.

As a result, we will never pass a null protocol pointer to
gb_protocol_put().  Add a precautionary warning in that
function in the event that ever occurs.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

When an error occurs in the device_add() call for a connection, the
device reference is dropped as required.  Because that's the device's
only reference, that will also lead to gb_connection_release() being
called, which frees the connection structure.

Right now we're then making an extra request to free the connection,
which is wrong.  Fix that.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

There is lack of unregister and free the tty driver.
This patch fixes it.
Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

__init does not belong in a .h file, as it does not do anything there,
so remove all instances of it.
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

WARNING: /home/viresh/work/repos/ara/greybus/greybus.o(.init.text+0xb8):
Section mismatch in reference from the function init_module() to the
function .exit.text:gb_endo_exit()

The function __init init_module() references
a function __exit gb_endo_exit().

Fix it by removing __exit from endo_exit().

Fixes: cf64356c5151 ("endo: define endo_init() and endo_exit()")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Check at connection creation time for an attempt to create a
connection with an interface CPort ID that's the same as one that's
already been created.

Define a new helper function to look for such a duplicate.  The
check for a duplicate is only performed at initialization time,
and CPorts are initialized serially for each bundle, so there's
no need to acquire the list lock for this search.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Check at bundle creation time to ensure we're not creating a bundle
with an id that's the same as one that's already been created.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rework the the code that parses the manifest for bundles so it only
touches each manifest descriptor once.  (Previously the list was
scanned from the beginning repeatedly until all bundles were found.)
Shorten the name of the descriptor variable, to avoid line wrap.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rework the the code that parses the manifest for CPorts associated
with a bundle so it only touches each manifest descriptor once.
(Previously the list was scanned from the beginning repeatedly
until all bundle CPorts were found.)  Shorten the name of the
descriptor variable, to avoid line wrap.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

An initialized bundle structure contains a pointer to its
interface.  Because of this there's no need to provide
the interface pointer to gb_manifest_parse_cports().  This
also precludes the possibility of passing a bad interface
pointer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

This patch incorporates some very small cleanups to "manifest.c":
    - Rearrange code a bit in gb_manifest_parse() that ensures a
      manifest is big enough to hold a header.  If the manifest is
      exactly the size of a header, the error reported will now be
      "...must have 1 interface..." rather than "short manifest".
    - Fix the function comment for gb_manifest_parse_cports().
    - Use "an interface," not "a interface," and don't capitalize.
    - Delete some braces when getting interface product string.
    - A few other minor changes to comments and white space.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Recently code was added (back) to assign a unique id to each
endo, so satisfy uniqueness requirements of the Linux device
subsystem.  An ID allocator is used to manage the space of IDs.

Now that we have gb_endo_init(), we can initialize the map there,
and fully hide the ID map within "endo.c".

The original functions gb_endo_id_alloc() and gb_endo_id_free()
provided a nice abstract interface, but the direct ID allocation
calls are quite simple, so just call them directly.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Define init and exit functions to do one-time setup and teardown
of endo-related functionality.  Currently they're place holders;
the next patch will populate them.

Note that we now call gb_operation_exit() from gb_init(), so
we can no longer mark that function with __exit.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The top-level functions gb_init() and gb_exit() are tagged with
__init and __exit, respectively.  These functions call a few
other functions that are similarly used only at initialization
and termination time.  So mark those functions accordingly.

Note that, because gb_ap_exit() and gb_debugfs_cleanup()
are called by gb_init() in error paths, these functions
cannot be declared with the __exit attribute.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

There's no need to include anything other than "greybus.h" in
"connection.c".  Same thing in "core.c" and "manifest.c" and
"svc.c".  Some files need headers included, but most come along
with "greybus.h".
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The sample count placed in Greybus I2S audio messages should be
reset every time a new audio stream is set up.  However, the
current code does not do the reset so make it so it does.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The firmware is having a hard time with 4k buffers and memory
allocation, so decrease the size on the host side to 2k.  Also move away
from using PAGE_SIZE to denote 4k as that's not the case on all
architectures, and someone, someday, might get a rude surprise.
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The unregister_chrdev_region() does twice here.
The chrdev region was unregistered
inside tty_unregister_driver().
Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

There is a sparse warning. The endo id map is also
used in endo.c. Should define in endo.h
Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Normally, its a good practice to free resources in the reverse order in
which they are allocated, so that all the dependencies can be sorted out
properly.

This is true while creating/destroying devices as well. For example
consider this scenario (I faced a crash with control protocol due to
this). For a new module, we will first create a bundle+connection for
the control cport and then create other bundles/connections after
parsing manifest.

And while destroying interface on module hot unplug, we are removing the
devices in the order they are added. And so the bundle/connection for
the control cport are destroyed first. But, control cport was still
required while destroying other bundles/connections.

To solve this problem, lets destroy the resources in the reverse order
in which they are added.
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>

Provide a little more information in two pr_err() calls.
Also enclose a reported condition in parentheses, to match
the style used everywhere else in the file.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rename greybus_deregister() to be greybus_deregister_driver(), so
its name mirrors the greybus_register_driver() function it matches.
Define greybus_deregister() to be a trivial macro.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

In gb_uart_request_recv(), the receive data size is in little-endian
format.  Do the proper byte swapping of that value before using it.
Found by "make check".
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Give gb_connection_hd_find() static scope; it's never used
outside "connection.c".
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The SVC protocol driver should have been defined as a basic
Greybus protocol driver, not a GP Bridge protocol driver.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Prefix module-id with endo-id to uniquely identify it for the entire
kernel.
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Currently we name the endo device as "endo". And it shows up with the
same name in sysfs directory: /sys/bus/greybus/devices/.

But each device in kernel should be represented by a unique id in
kernel, and "endo" isn't unique.

Lets generate unique ids for endo devices. The ida mechanism for
allocating ids may be overkill but it works.
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

This isn't unique just for the bundle but the complete interface. Its
wrong to call it bundle_cport_id. Lets name it intf_cport_id to make
things clear.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

'buffer' isn't used in this function, remove it.
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Use defines for the data format command.
Tidy up naming of gb_tty variables.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>