V3 of the early platform driver implementation.
Platform drivers are great for embedded platforms because we can separate
driver configuration from the actual driver. So base addresses,
interrupts and other configuration can be kept with the processor or board
code, and the platform driver can be reused by many different platforms.
For early devices we have nothing today. For instance, to configure early
timers and early serial ports we cannot use platform devices. This
because the setup order during boot. Timers are needed before the
platform driver core code is available. The same goes for early printk
support. Early in this case means before initcalls.
These early drivers today have their configuration either hard coded or
they receive it using some special configuration method. This is working
quite well, but if we want to support both regular kernel modules and
early devices then we need to have two ways of configuring the same
driver. A single way would be better.
The early platform driver patch is basically a set of functions that allow
drivers to register themselves and architecture code to locate them and
probe. Registration happens through early_param(). The time for the
probe is decided by the architecture code.
See Documentation/driver-model/platform.txt for more details.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make note of the legacy "probe-the-hardware" drivers, and some APIs that
are mostly unused except by such drivers. We probably can't escape having
legacy drivers for a while (e.g. old ISA drivers), but we can at least
discourage this style code for new drivers, and unless it's unavoidable.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Andres Salomon <dilinger@debian.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix various typos in kernel docs and Kconfigs, 2.6.21-rc4.
Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Found a couple of typos in the Documentation/driver-model/platform.txt
file. This patch fixes both of them.
Signed-off-by: Erik Hovland <erik@hovland.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
This is almost a rewrite of the driver-model/platform.txt documentation;
the previous text was obsolete (for several years), evidently it never
got updated to match the change from being a PC "legacy_bus" to the more
widely used core bus for most embedded systems.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Magnus Damm