RE: [PATCH v3] i2c-hid: introduce HID over i2c specification implementation

Hi,

-----Original Message-----
From: Benjamin Tissoires [mailto:benjamin.tissoires@gmail.com]
Sent: Friday, November 16, 2012 8:26 PM
To: Jiri Kosina; Ramalingam C
Cc: Dmitry Torokhov; Stephane Chatty; fabien.andre@gmail.com;
scott.liu@emc.com.tw; Jean Delvare; JJ Ding; Jiri Slaby; Shubhrajyoti Datta;
linux-i2c@vger.kernel.org; linux-input@vger.kernel.org; linux-
kernel@vger.kernel.org
Subject: Re: [PATCH v3] i2c-hid: introduce HID over i2c specification
implementation

On Thu, Nov 15, 2012 at 3:04 PM, Benjamin Tissoires
[off-list ref] wrote:

quoted

On Thu, Nov 15, 2012 at 2:51 PM, Jiri Kosina [off-list ref] wrote:

quoted

On Mon, 12 Nov 2012, Benjamin Tissoires wrote:

quoted

Microsoft published the protocol specification of HID over i2c:
http://msdn.microsoft.com/en-

us/library/windows/hardware/hh852380.as

quoted

quoted

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px

This patch introduces an implementation of this protocol.

This implementation does not includes the ACPI part of the specification.
This will come when ACPI 5.0 devices enumeration will be available.

Once the ACPI part is done, OEM will not have to declare HID over
I2C devices in their platform specific driver.

Signed-off-by: Benjamin Tissoires <redacted>

Out of curiosity -- has this been tested on a real device (is there
any such device available anyway?), or is that just the
implementation of the defined protocol?

It has been tested on an ELAN microelectronics device (a prototype),
on an odroid-x board. That's how we figure out the bug in the
set_report command.
I think we manage to test all main features of the protocol
(get_report, irqs, hid descriptor, report descriptors, set_report).

I'm currently waiting for a Synaptics touchpad to check if it's also
working with their devices.

The thing is that HID over i2c for x86 platform will presumably
require the Haswell platform from Intel (we need ACPI 5 for
enumeration), but it would be very nice to get this in the kernel just
before hardware arrive on the market :) However, I won't be surprise
if android OEMs also start using this specification because it won't
force them to write kernel drivers...

And as a complement, Ramalingam tested it for Nvidia on an early NVIDIA's
Tegra reference board for PISMO which is registered at
http://www.arm.linux.org.uk/developer/machines/list.php?id=4439 , with a
HID over i2c keyboard.
He is up to test also his Synaptics touchpad.

I have tested with Synaptics trackpad. It is working fine. Thank you Benjamin.

Thanks and Regards,
Ramalingam C

Cheers,
Benjamin

quoted

Cheers,
Benjamin

quoted

Thanks,

--
Jiri Kosina
SUSE Labs