Re: [RFC PATCH 0/3] introduce: Multistate Switch Class

From: MyungJoo Ham
Date: Wed Nov 30 2011 - 23:46:15 EST


On Thu, Dec 1, 2011 at 7:56 AM, NeilBrown <neilb@xxxxxxx> wrote:
> On Wed, 30 Nov 2011 15:40:48 +0900 MyungJoo Ham <myungjoo.ham@xxxxxxxxx>
> wrote:
>
>> I'm focusing on an external connector or port that each physical port
>> may inhabit multiple cables at a time although it should support a
>> port that may inhabit a single cable only at a time. However, the
>> class could be used for other general "multistate mux" that connects
>> different device drivers.
>
> Hi,
>  maybe I'm just slow, but I'm having a lot of trouble imagining a single port
>  that could have multiple cables plugged in at the same time.  And this
>  blockage is stopping me from reflecting usefully on your other points.
>
>  Are you able to show me a picture or a diagram or something so I can
>  visualise what you are talking about?
>  To me: once you plug one cable into a port, it is full and there is no room
>  for any more cables.

Hello,

I can't take/send picture at work, so, I'll write some examples.

1. Dock with multiple ports as Mark suggested.
2. a 30-pin cable with multiple cable sockets (basically, this is a
light-weight dock, too). A cable that connects to multiple other
devics from a computer (including any ARM midgets and full PCs). Plus,
there can be multiple different types of such cables for a single
model of port. For example, in Samsung Galaxy Tab series, there is a
30-pin port, which can be connected to Serial(UART), Dedicated
charger, USB (either as a host or client), Audio I/O, HDMI, Video I/O,
and others. And the cable does not need to be 1-to-1 (Tab-to-USB,
Tab-to-HDMI). There are cables that may connect Tab-to-USB-and-HDMI or
Tab-to-Charger-and-A/V. In fact, among these 30 pins, there are
independent pins for HDMI, pins for Audio, pins for charging, pins for
USB, and others sharing ground/power pins, and a "multi-socket" 30-pin
cable may simply open them up to other "standard" cables.

Cheers!
MyungJoo


--
MyungJoo Ham, Ph.D.
Mobile Software Platform Lab, DMC Business, Samsung Electronics
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