linux-toradex.git/Documentation/devices.txt, branch imx-android-r10.4

driver core: add devname module aliases to allow module on-demand auto-loading

2010-05-25T22:08:26+00:00

This adds:
  alias: devname:
to some common kernel modules, which will allow the on-demand loading
of the kernel module when the device node is accessed.

Ideally all these modules would be compiled-in, but distros seems too
much in love with their modularization that we need to cover the common
cases with this new facility. It will allow us to remove a bunch of pretty
useless init scripts and modprobes from init scripts.

The static device node aliases will be carried in the module itself. The
program depmod will extract this information to a file in the module directory:
  $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname
  # Device nodes to trigger on-demand module loading.
  microcode cpu/microcode c10:184
  fuse fuse c10:229
  ppp_generic ppp c108:0
  tun net/tun c10:200
  dm_mod mapper/control c10:235

Udev will pick up the depmod created file on startup and create all the
static device nodes which the kernel modules specify, so that these modules
get automatically loaded when the device node is accessed:
  $ /sbin/udevd --debug
  ...
  static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184
  static_dev_create_from_modules: mknod '/dev/fuse' c10:229
  static_dev_create_from_modules: mknod '/dev/ppp' c108:0
  static_dev_create_from_modules: mknod '/dev/net/tun' c10:200
  static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235
  udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666
  udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666

A few device nodes are switched to statically allocated numbers, to allow
the static nodes to work. This might also useful for systems which still run
a plain static /dev, which is completely unsafe to use with any dynamic minor
numbers.

Note:
The devname aliases must be limited to the *common* and *single*instance*
device nodes, like the misc devices, and never be used for conceptually limited
systems like the loop devices, which should rather get fixed properly and get a
control node for losetup to talk to, instead of creating a random number of
device nodes in advance, regardless if they are ever used.

This facility is to hide the mess distros are creating with too modualized
kernels, and just to hide that these modules are not compiled-in, and not to
paper-over broken concepts. Thanks! :)

Cc: Greg Kroah-Hartman 
Cc: David S. Miller 
Cc: Miklos Szeredi 
Cc: Chris Mason 
Cc: Alasdair G Kergon 
Cc: Tigran Aivazian 
Cc: Ian Kent 
Signed-Off-By: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

lanana: assign a device name and numbering for MAX3100

2009-04-07T15:44:05+00:00

This is a low density serial port so needs a real major/minor

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

LANANA: Fix dates

2009-04-06T21:54:17+00:00

As noted by Janne Grunau it would be good if the date was also right.

(Web site also resynched)

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

LANANA: Change of management and resync

2009-04-03T22:27:19+00:00

Bring the devices.txt back into some relationship with reality. Update the
documentation a bit.

Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

[SCSI] major.h: char-major number for OSD device driver

2009-03-12T17:58:05+00:00

Allocate major 260 for osd.

Signed-off-by: Boaz Harrosh 
CC: Torben Mathiasen 
Signed-off-by: James Bottomley

USB: add USB test and measurement class driver

2008-10-17T21:40:51+00:00

This driver was originaly written by Stefan Kopp, but massively
reworked by Greg for submission.

Thanks to Felipe Balbi  for lots of work in cleaning
up this driver.

Thanks to Oliver Neukum  for reviewing previous
versions and pointing out problems.


Cc: Stefan Kopp 
Cc: Marcel Janssen 
Cc: Felipe Balbi 
Cc: Oliver Neukum 
Signed-off-by: Greg Kroah-Hartman

usb: auerswald: remove driver (obsolete)

2008-08-14T00:32:47+00:00

This patch removes the auerswald USB driver from the linux kernel
2.6.26.

This driver was included into the kernel mainly to connect to the ISDN
framework. This was done in linux 2.4.x. For 2.6.x, due to the fragile
and moving ISDN support, this connection was never realized, and the
only use of this driver was for device configuration. In the age of DSL,
the demand of ISDN support is getting very low.

Meanwhile, with the advent of libusb, an userspace driver was done for
the device configuration which works fine for linux and mac. (Thanks to
the libusb developers!). The userspace driver is downloadable from the
auerswald web site.

So this driver is obsolete now and has to be removed. Many thanks to all
developers which helped me to bring this driver up and working.

Signed-off-by: Wolfgang Muees 
Signed-off-by: Greg Kroah-Hartman

typo fixes

2007-10-19T23:34:40+00:00

Most of these fixes were already submitted for old kernel versions, and were
approved, but for some reason they never made it into the releases.

Because this is a consolidation of a couple old missed patches, it touches both
Kconfigs and documentation texts.

Signed-off-by: Matt LaPlante 
Acked-by: Randy Dunlap 
Signed-off-by: Adrian Bunk

Add /dev/oldmem to devices.txt documentation

2007-10-01T14:52:23+00:00

Signed-off-by: Dave Jones 
Cc: "H. Peter Anvin" 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] New updated devices.txt - LANANA

2006-12-07T16:39:45+00:00

[jengelh@linux01.gwdg.de: cleanups]
Signed-off-by: Jan Engelhardt 
Acked-by: Torben Mathiasen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds