Handle credits. Do not just ask for maximum credits all the time as this
will stop the download. Also do not let the credits go back to 0 (while
this might work, this is not tested). Getting back the 0 credits stops
the download, and even when it can be restarted, it is less efficient
(and not needed). Notice also that it takes some time before a grant
request is honoured. During testing I saw reception of up to 25 packets
between request and grant. So a lower bound for the request of
32 packets seems resonable.
One aspect the Telit/Stollmann TIO puzzeled me. Sections 4.1 and 4.2
both talk about credits, but my hyphothesis is that there are two
credits counters in play. One for traffic either way. This commit
only deals with credits granted by Subsurface to the OSTC to send
data. Credits granted by the OSTC to allow Subsurface to send new
commands is NOT part of this commit, and is seemingly not needed
in our scenario. As we only send new commands to the OSTC when
a previous one is finished (per HW's interface spec), the OSTC
does not run out of credits to receive commands.
Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
1) As the OSTC sends data to the BLE central role (the SSRF client) over 2
characteristics, we have to filter the administrative credit data from
the actual dive data that it received. The characteristcStateChanged
function is adapted for this.
2) We have to be sure that the Terminal Client I/O is fully defined during
opening the connecton to the OSTC. From 6d505b24f0c15 we can see
that the last step in setting up the terminal interface is the grant
of credits. This is done by writing to the proper (the only one, with
id = 0x2902) descriptor of the credits RX characteristic. The here
added slot is triggered on the completion of write of credits marking
the final stage of the setup.
Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
This initalizes the Terminal I/O client as described in paragraph 3 of
http://www.telit.com/fileadmin/user_upload/products/Downloads/sr-rf/BlueMod/TIO_Implementation_Guide_r04.pdf
This is for all Heinrichs Weikamp computers, that use referenced BT/BLE hardware
module from Telit Wireless Solutions (Formerly Stollmann E+V GmbH). The 16 bit
UUID 0xFEFB (or a derived 128 bit UUID starting with 0x0000FEFB is a
clear indication that the OSTC is equipped with this BT/BLE hardware.
Furthermore, most devices equipped with this BT/BLE hardware have BT addresses
starting with 00:80:25:...
Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>
Right now we have a quirk for Shearwater devices to set the random
address flag, but also to handle the differences at read/write time.
With this, I can finally download from both the Suunto EON Steel and the
Shearwater Perdix AI with the same binary.
It's not *pretty*, but it works.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a device has more than one service the order of service discovery
determined the selection of the service that we intend to interact
with. This assumption is not accurate and is even platform dependent.
Thinking ahead, it is likely that some devices may require us to keep
track and interact with multiple services at the time.
The new logic still suffers from the fact that there is no way
to select the correct service for interaction. This will require
higher level stack changes.
Signed-off-by: Alex Blasche <alexander.blasche@qt.io>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is some very early and hacky code to be able to access BLE-enabled
dive computers that use the GATT protocol to send packets back and forth
(which seems to be pretty much all of them: a vendor-specific GATT
service with a write characteristic and a notification characteristic
for reading).
For testing only. But it does successfully let me download dives from
my EON Steel and my Scubapro G2.
NOTE! There are several very hacky pieces in here, including just
"knowing" that the write characteristic is the first one, and the
notification characteristic is second. The code should actually check
the properties rather than have those kinds of hardcoded assumptions.
It also checks "vendor specific" by looking at the UUID string
representation, and knowing that the standard ones start with zero.
Crazily, there doesn't seem to be any normal way to test for this,
although I guess that maybe the uuid.minimumSize() function could be
used.
There are other nasty corners. Don't complain, send me patches.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
