Note that this also makes sure the id-field is naturally aligned in case
we ever were to remove the __packed attribute.
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Explicitly add pad-bytes to manifest descriptors to match their layout
in greybus specification.
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

We carry this information as part of bundle descriptor now and this can
be removed.
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>

It is not required anymore. Drop it.
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>

These should come from control protocol instead.

For now, initialize this statically with a FIXME to not forget it later.
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>

The kernfs code guarantees we'll get a NUL-terminated buffer.
Use kstrdup() rather than kzalloc() + memcpy() in state_store()
making it slightly clearer what we're doing.  This has the added
benefit of guaranteeing that the stored string has no NUL character
inside it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

A descriptor passed to AP can be bigger than what AP expects, if
manifest's minor version is higher with same major number as the AP. As
it can have some extra data in descriptor.

But, if AP and manifest versions are identical, or if the AP's minor
version is greater than the manifest version, we should at least warn
(if not fail).

Doing this would require some changes to record the manifest version
somewhere reachable by identify_descriptor().

For now, just warn if descriptor is bigger than expected.
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>

String descriptors are padded towards the end to align them to 4 byte
boundaries. Take that into account while calculating expected size.
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

These structures are already marked as __packed, as these are enclosed
within:

	#pragma pack(push, 1)
	#pragma pack(pop)

Lets mark them __packed explicitly.
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

There can be three Endo types: mini, medium and large. And that's what
Endo 'type' should refer to.

But we have named the 16 bit number that uniquely represents a valid
endo, as its type. 'id' seems to be a more suitable name to that instead
of 'type'. Lets rename it.
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>

0x0555 isn't a valid endo id, use a real one.

0x4755 should be the Endo id for the (medium) Spiral 2 prototype. Lets
use that.
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>

These are all GPLv2-only kernel modules, so properly set the correct
MODULE_LICENSE string to make static checkers happy.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

A bundle has a state file, that is managed by the endo userspace
process.  This file can be written to and any process that is polling on
the file will be woken up and can read the new value.  It's a "cheap"
IPC for programs that are not allowed to do anything other than
read/write to kernel sysfs files.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The code uses 64-bit divisions, which should be avoided, and also
prevents the module from loading on 32-bit systems:

	gb_loopback: Unknown symbol __aeabi_uldivmod (err 0)

Fix by using the kernel's 64-bit by 32-bit division implementation
do_div.

Compile tested only. I did not look very closely at the code itself.
Perhaps this could be worked around in some other way, but this silences
the linker warning and allows the module to be loaded.
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

It's up to other files to define this if it's not present, not this
file.
Reported-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Replace #define<TAB> with #define<SPACE>.

Also move the #ifdef block to below the initial comment block, like
other .h files are.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

In order to facilitate re-use of the gpio, i2c, pwm and i2s
structures, split them out of independent files and add
them into a shared gpbridge.h

This will be a prereq to sharing these headers w/ gbsim.

Cc: Alex Elder <alex.elder@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@google.com>
CC: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

This documents the module slot sysfs files "epm", "power_control", and
"present".
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

This documents the endo device, and the SVC specific files that are
present in the sysfs device tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

The kernel is now on the 4.XX numbering scheme, and it's going to be a
while before we merge this code, so pick a date sometime in the future
to be safe.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

This hooks up the endo, and modules, into the device tree.  All modules
for a specific endo are created when the host device is initialized.
When an interface is registered, the correct module for it is found and
that module is used for the sysfs tree.  When the interface is removed,
the reference on the module is dropped.

When the host device goes away, the whole endo and modules are removed
at once.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

This adds endo.c and endo.h and provides functions to create an endo and
the initial 0x0555 set of modules.

But, it doesn't hook this logic up into the running code yet, that comes
next.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

This adds the attributes power_control and present to a module.  It also
removes the unneeded module_id attribute, as that comes from the name of
the module itself.
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

Drop the host-driver buffer headroom that was used to transfer the cport
id on ES1 and ES2.

Rather than transferring additional bytes on the wire and having to deal
with buffer-alignment issues (e.g. requiring the headroom to be a
multiple of 8 bytes) simply drop the headroom functionality.

Host drivers are expected set up their transfer descriptors separately
from the data buffers and any intermediate drivers (e.g. for Greybus
over USB) can (ab)use the operation message pad bytes for now.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Fix transfer-buffer alignment of es2 as well.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Fix transfer-buffer alignment of outgoing transfers which are currently
byte aligned.

Some USB host drivers cannot handle byte-aligned buffers and will
allocate temporary buffers, which the data is copied to or from on every
transfer. This affects for example musb (e.g. Beaglebone Black) and
ehci-tegra (e.g. Jetson).

Instead of transferring pad bytes on the wire, let's (ab)use the pad
bytes of the operation message header to transfer the cport id. This
gives us properly aligned buffers and more efficient transfers in both
directions.

By using both pad bytes, we can also remove the arbitrary limitation of
256 cports.

Note that the protocol between the host driver and the UniPro bridge is
not necessarily Greybus. As long as the firmware clears the pad bytes
before forwarding the data, and the host driver does the same before
passing received data up the stack, this should be considered "legal"
use.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add explicit pad bytes to the message header.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Make sure to allocate the message transfer-buffer separately from the
containing message structure to avoid data corruption on systems without
DMA-coherent caches.

The message structure contains state that is updated while the buffer
may be used for DMA, something which could lead to data corruption due
to cache-line sharing on some architectures.

Use the (renamed) message cache for the message structure itself and
allocate the buffer separately.

If the additional allocation is a concern, the message structures
could eventually be allocated as part of the operation structure.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Pass structured greybus messages rather than buffers to the host
drivers.

This will allow us to separate the transfer buffers from the message
structures.

Rename the related functions to reflect the new interface.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Move operation message-header to operation.h so that it can be used
by host drivers.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Remove unused and unnecessary buffer-alignment define that host driver
were supposed to use.

We can handle unaligned incoming buffers just fine by accessing the
operation-message header via a copy in the receive path, rather than
requiring host drivers to make sure the alignment is correct.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The buffer received from our current host driver is 1-byte aligned and
will therefore cause unaligned memory accesses if simply cast to an
operation-message header.

Fix this by making a properly aligned copy of the header in
gb_connection_recv_response before accessing its fields.

Note that this does not affect protocol drivers as the whole buffer is
copied when creating the corresponding request or response before being
forwarded.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Fix two bugs in es2 and do some minor clean up.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The maximum buffer size does not include the headroom, so subtract the
headroom size from the actual buffer size.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

A stack-allocated buffer is not generally DMA-able and must not be used
for USB control transfers.

Note that the memset and extra buffer byte were redundant as no more
than the bytes actually transferred was ever added to the fifo.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Drop unnecessary explicit casts.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Alex suggested to name it class instead of class type.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

A Greybus driver will bind to a bundle, not an interface. Lets follow
this rule in code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

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

A module can have more than one interfaces and we get hotplug events or
manifests for interfaces, not modules. Details like version, vendor,
product id, etc. can be different for different interfaces within the
same module and so shall be fetched from interface descriptor instead of
module descriptor.

So what we have been doing for module descriptors until now must be done
for interface descriptors. There can only be one interface descriptor in
the manifest. Module descriptor isn't used anymore and probably most of
its fields can be removed now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>