Commit graph

8 commits

Author SHA1 Message Date
Max Staudt
ec5ad33168 tty: Add N_CAN327 line discipline ID for ELM327 based CAN driver
The actual driver will be added via the CAN tree.

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Max Staudt <max@enpas.org>
Link: https://lore.kernel.org/r/20220618180134.9890-1-max@enpas.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27 15:56:10 +02:00
Max Staudt
c2faf737ab tty: Reserve ldisc 29 for development purposes
It's handy to have an ldisc number free for out-of-tree testing. This
way, a new ldisc can be developed on any running system, without having
to recompile the kernel just to define a new number.

This is the highest number (and also the last one) available under the
old numbering scheme, so let's reserve it before it's too late.

From now on, every new ldisc upstreamed will have to increment NR_LDISCS
in lockstep with its addition to the table in tty.h.

Signed-off-by: Max Staudt <max@enpas.org>
Link: https://lore.kernel.org/r/20220211141036.6403-1-max@enpas.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-26 10:03:21 +01:00
Jeremy Kerr
a0c2ccd9b5 mctp: Add MCTP-over-serial transport binding
This change adds a MCTP Serial transport binding, as defined by DMTF
specificiation DSP0253 - "MCTP Serial Transport Binding". This is
implemented as a new serial line discipline, and can be attached to
arbitrary tty devices.

From the Kconfig description:

  This driver provides an MCTP-over-serial interface, through a
  serial line-discipline, as defined by DMTF specification "DSP0253 -
  MCTP Serial Transport Binding". By attaching the ldisc to a serial
  device, we get a new net device to transport MCTP packets.

  This allows communication with external MCTP endpoints which use
  serial as their transport. It can also be used as an easy way to
  provide MCTP connectivity between virtual machines, by forwarding
  data between simple virtual serial devices.

  Say y here if you need to connect to MCTP endpoints over serial. To
  compile as a module, use m; the module will be called mctp-serial.

Once the N_MCTP line discipline is set [using ioctl(TCIOSETD)], we get a
new netdev suitable for MCTP communication.

The 'mctp' utility[1] provides a simple wrapper for this ioctl, using
'link serial <device>':

  # mctp link serial /dev/ttyS0 &
  # mctp link
  dev lo index 1 address 0x00:00:00:00:00:00 net 1 mtu 65536 up
  dev mctpserial0 index 5 address 0x(no-addr) net 1 mtu 68 down

[1]: https://github.com/CodeConstruct/mctp

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-23 11:47:51 +00:00
Greg Kroah-Hartman
6f52b16c5b License cleanup: add SPDX license identifier to uapi header files with no license
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:19:54 +01:00
Alan Cox
8a8dabf2dd tty: handle the case where we cannot restore a line discipline
Historically the N_TTY driver could never fail but this has become broken over
time. Rather than trying to rewrite half the ldisc layer to fix the breakage
introduce a second level of fallback with an N_NULL ldisc which cannot fail,
and thus restore the guarantees required by the ldisc layer.

We still try and fail to N_TTY first. It's much more useful to find yourself
back in your old ldisc (first attempt) or in N_TTY (second attempt), and while
I'm not aware of any code out there that makes those assumptions it's good to
drive(r) defensively.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:43:46 +09:00
Greg Kroah-Hartman
47f58e32a2 tty: reserve N_SPEAKUP number
Over in the staging tree, N_SPEAKUP is added, so to make life easier for
merging and other development, also reserve it in the tty tree.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:42:41 +09:00
Vincent Cuissard
9961127d4b NFC: nci: add generic uart support
Some NFC controller supports UART as host interface.
As with SPI, a lot of code can be shared between vendor
drivers. This patch add the generic support of UART and
provides some extension API for vendor specific needs.

This code is strongly inspired by the Bluetooth HCI ldisc
implementation. NCI UART vendor drivers will have to register
themselves to this layer via nci_uart_register.

Underlying tty will have to be configured from user land
thanks to an ioctl.

Signed-off-by: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2015-06-11 23:37:37 +02:00
David Howells
607ca46e97 UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-13 10:46:48 +01:00