Device information for PDAs

[Andrei Yurkevich]

Hi,

this issue has once been discussed on the HAL list some time ago [1] but
no final decision has been made about what information about PDA devices
(if any) should go to HAL device list. However the project that I am
currently busy with is connecting to PDA devices with help of HAL and I
would really would like a part about pda namespace appear in the HAL
specs.

I've seen a fdi file that comes with HAL for Palm PDAs, but I would
rather treat that as an example of what properties a PDA device can
have, not an example of how it should appear in HAL. So here's what I
propose for the PDAs in HAL:

1) A "pda" capability and category. This should be set for the usb
interface of pda devices [2].
2) A "pda.*" namespace with the following possible proprerties:
     pda.platform (string, mandatory) - this can be 'PalmOS',
'PocketPC', 'Linux' or 'Symbian' or whatever else existing in this
world, indicating to the 3rd-party applications how the device should be
treated. Acquiring this information is a matter of knowing what driver
is used for the interface [2] under linux (at least that's 'ipaq' for
Pocket PCs and 'visor' for Palms and that's about 90%  PDAs in the
world) or matching the usb vendor/product id's of the usb-device.
     pda.platform.version (string, optional) - even more details about
the platform. Examples: '5.0' or '4.1' or whatever else for PalmOS;
'WM2003', 'PocketPC2002', etc. for WindowsMobile devices; 'Series60' or
whatever else for Symbian OS; etc.
     pda.serial_device  (strlist, optional) - the serial device(s) that
can be used to talk to the pda. All of the PDAs I know of are usb-serial
devices, however some of them (PalmOS devices for instance) have 2
serial ports, however only one is used for the connection, the other is
exported for some different use [2]. The one used for serial link could
be listed as such so that the application that establishes a connection
knows what serial port to talk thru.

All the other information I can imagine about PDAs only makes sense on
certain PDA platforms, so I propose to store it as pda.platform_name.* -
that is 'pda.palm.*' or 'pda.pocket_pc.*'. This can be facts that make
sense to only that kind of PDAs, like the 'pda.serial.use_net' property
from the usb-pda-devices.fdi that comes with HAL-0.5 that should really
be 'pda.palm.serial_use_net' instead.

I think it only makes sense to include a device information file that
would match the info.linux.driver property of the usb interface to mark
it as a pda device of some platform (see the attachment) and a fdi that
would match usb vendor/device id's to set a sane info.product value for
the USB interface of the PDA [3]. All the platform-dependant stuff
should not be included into HAL itself but installed by the 3rdparty
applications.

Comments? Objections?

[1] http://lists.freedesktop.org/pipermail/hal/2004-November/001252.html
    http://lists.freedesktop.org/archives/hal/2004-December/001489.html

[2] The following screenshots show how a pda device appears in HAL
device manager:
    http://people.redhat.com/dmalcolm/Screenshot-PDA-HAL.png (PalmOS
PDA)
    http://people.softspb.com/andrei/hal-pocketpc.png (PocketPC PDAs)

    in general, a PDA appears as a usb-device that has a usb-interface
as its child, which represents the PDA device itself. The interface may
have one or two serial ports that are used to talk to the PDA itself.

[3] Since the USB interface is the device entry that represents the PDA
hardware, I think that it should be named as e.g. 'Palm Tungsten T' or
'Compaq iPAQ 3600-series' for user's convenience. In most cases HAL
picks up the name of the usb device, but that is not always available
and appears as 'USB vendor-specific interface' in that case. The
following fdi files can be used as a base for PDA descriptions in HAL:

    http://people.softspb.com/andrei/usb-pda-devices.fdi
    http://people.softspb.com/andrei/pda-palm.fdi
    http://people.softspb.com/andrei/pda-pocketpc.fdi

cheers,
Andrei

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