Subject: Re: issues with com and non-PCI platforms.... a proposal
To: None <>
From: Izumi Tsutsui <>
List: tech-kern
Date: 03/07/2006 22:46:00
In article <> wrote:

>     2) use a separate bus space.  I don't know of any existing examples
> outside of my AR5212 com driver.  In this case I had to implement a
> pretty hefty amount of bus space logic *in com_arbus.c".  This seems
> ugly and unwieldy.

Well, how about com_dio.c and com_frodo.c in arch/hp300/dev/ ?

> My proposal is to *change* com so that instead of using fixed offsets,
> it uses a register look up table.  E.g.
> bus_offset_t   sc_regoffs[NCOM_PORTS];
> #define   GETREG(x)   bus_space_read_1(bst, bsh, sc_regoffs[x])
> Then the various attachment points can populate these registers as they
> see fit.

IMHO, if address mapping (sparse address etc.) is bus specific
it should be handled by bus_space. On the other hand, if the
(unusual) mapping is the device specific, it should be handled
by each driver.
Izumi Tsutsui