Re: [PATCH] powerpc/qe_lib: Share the qe_lib for the others architecture

[Kumar Gala <galak@kernel.crashing.org>]

On Oct 15, 2013, at 8:16 AM, Gerhard Sittig wrote:

> On Mon, Oct 14, 2013 at 13:09 -0700, Greg Kroah-Hartman wrote:
>> 
>> On Mon, Oct 14, 2013 at 02:40:44PM -0500, Kumar Gala wrote:
>>> 
>>> Greg,
>>> 
>>> Wondering your thoughts on drivers/qe vs something like
>>> drivers/soc/fsl/qe.  The QuiccEngine (qe) is a communication core on
>>> some of the Freescale networking SoCs that provides the ability to do
>>> various networking/communication functionality.  "Channels" on the QE
>>> can be used for various different things from ethernet, ATM, UART, or
>>> other functions.
>> 
>> What makes the code "QE" specific?  Are these devices that live on the
>> QE "bus", or are they controlling the QE controller?
> 
> You may think of the QUICC as a "programmable bitbang machine" if
> you like.  The very same component runs arbitrary and rather
> different protocols depending on how you setup its parameters.
> 
> There have been serial controllers capable of different protocols
> like UART or SPI or I2S, but all of them are "serial
> communication".  There have been memory controllers which could
> bitbang different protocols (NAND, NOR/SRAM, DRAM), but all of
> them are "memory".
> 
> The QUICC is just a little more versatile, and appears to cover
> cases which reside in different Linux kernel subsystems (like:
> it's neither serial nor network exclusively, but can be either
> and potentially more).
> 
> IIUC the question which Kumar Gala was asking is where to put
> code for the component which is neither a strict subset of any
> subsystem.  Please correct me if I'm wrong.

Thanks for the description.

Yeah, the actual ethernet, usb, serial drivers that exist with QE live today in proper drivers/ dirs.  This is the infrastructure that those drivers utilize that isn't quite related to an existing subsystem.  Mostly set up of channel state/cfg/etc.

- k